WO2003032058A1 - Visual display unit illumination - Google Patents

Visual display unit illumination Download PDF

Info

Publication number
WO2003032058A1
WO2003032058A1 PCT/NZ2002/000213 NZ0200213W WO03032058A1 WO 2003032058 A1 WO2003032058 A1 WO 2003032058A1 NZ 0200213 W NZ0200213 W NZ 0200213W WO 03032058 A1 WO03032058 A1 WO 03032058A1
Authority
WO
WIPO (PCT)
Prior art keywords
light
display unit
screen
visual display
toled
Prior art date
Application number
PCT/NZ2002/000213
Other languages
French (fr)
Inventor
Gareth Paul Bell
Gabriel Damon Engel
Original Assignee
Deep Video Imaging Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Deep Video Imaging Limited filed Critical Deep Video Imaging Limited
Priority to US10/492,624 priority Critical patent/US8149353B2/en
Publication of WO2003032058A1 publication Critical patent/WO2003032058A1/en
Priority to US13/438,833 priority patent/US8687149B2/en
Priority to US14/192,619 priority patent/US9721378B2/en

Links

Classifications

    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • G02F1/1335Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336Illuminating devices
    • G02F1/133602Direct backlight
    • G02F1/133603Direct backlight with LEDs
    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • G02F1/1347Arrangement of liquid crystal layers or cells in which the final condition of one light beam is achieved by the addition of the effects of two or more layers or cells
    • G02F1/13471Arrangement of liquid crystal layers or cells in which the final condition of one light beam is achieved by the addition of the effects of two or more layers or cells in which all the liquid crystal cells or layers remain transparent, e.g. FLC, ECB, DAP, HAN, TN, STN, SBE-LC cells
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F3/00Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
    • G06F3/14Digital output to display device ; Cooperation and interconnection of the display device with other functional units
    • G06F3/1423Digital output to display device ; Cooperation and interconnection of the display device with other functional units controlling a plurality of local displays, e.g. CRT and flat panel display
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06TIMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T11/002D [Two Dimensional] image generation
    • G06T11/60Editing figures and text; Combining figures or text
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06TIMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T15/003D [Three Dimensional] image rendering
    • G06T15/08Volume rendering
    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • G02F1/1335Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/133553Reflecting elements
    • G02F1/133555Transflectors
    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/137Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering
    • G02F1/13718Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering based on a change of the texture state of a cholesteric liquid crystal

Definitions

  • the present invention relates to a means for illuminating visual display units, particularly portable computing means including the genre known as Personal Digital Assistants (PDA).
  • portable computing means including the genre known as Personal Digital Assistants (PDA).
  • PDA Personal Digital Assistants
  • PDA Personal Digital Assistant
  • a transflective liquid crystal display is overlaid with a transparent touch sensitive screen capable of detecting the position of a stylus point impressed upon it.
  • the stylus may be used to select various icons and/or menus in order to issue instructions to the operating system and to input hand written data.
  • Streamlined versions of popular spreadsheet, word processing and organisational programs are available for PDAs in addition to other specific applications designed for use within the constraints of the PDA hardware.
  • Typical PDA transflective displays consist of a birefringent liquid with a chiral additive trapped between conductive layers rubbed with a cloth or similar to align the liquid crystal molecules in a suitable manner.
  • the birefringence of the liquid crystal may be switched to zero by applying an electric field perpendicular to the alignment layers.
  • To achieve this one of the conductive layers is broken up into small, square or rectangular, addressable, electrodes tessellated to form a matrix while the other forms a voltage reference plane. Colour filters can be added over the electrodes to improve the effect.
  • This arrangement is then placed between sheets of polarising film with either aligned or perpendicular polarisation axes, located in front of a half-silvered mirror and provided with illumination.
  • the half-silvered mirror transmits 50% and reflects 50% of the incident light
  • the display can be illuminated from either side, i.e., front or back lit.
  • LCD liquid crystal displays
  • Backlighting is provided by cold cathode fluorescent tubes in combination with a light-guide, also known as a light pipe, and diffuser.
  • a light-guide also known as a light pipe, and diffuser.
  • Prior art light pipe backlight assemblies are constructed from a light guiding panel with boundaries substantially coterminous with the LCD panel edges (normally rectangular), typically fabricated from an acrylic plastic with similar optical properties to those of borosilicate.
  • a pair of miniature fluorescent light tubes are mounted within suitably designed light reflective mounts (i.e. , located at the foci of parabolic reflectors) along the opposite side edges of the acrylic sheet.
  • the function of the fluorescent light tubes is to produce and direct incoherent light into the interior of the light guiding panel within which the light is typically bounded by the well known principle of "total internal reflection". Under ideal conditions, light will not leak out of the surfaces of the acrylic plastic sheet. However, light can be extracted or caused to 'leak' out from the light guide surface by forming therein scratches, undulations, or any other means of locally altering the critical angle for total internal reflection. The extracted light can be used for illumination purposes such as the above described LCD panel backlighting. A reflector is placed behind the rear surface of the light pipe to reflect rearward emitted light through the LCD, adding to the display illumination.
  • a light extracting pattern is permanently formed on one or both surfaces of the light guiding panel.
  • the light extracting pattern is realised as a dot pattern permanently embossed or sandblasted upon the front surface of the acrylic light guiding panel.
  • the density of the dot pattern may be configured to increase quadratically with distance from the fluorescent light tubes. This construction provides a constant backlighting luminance across the light guiding panel.
  • Alternative means of maintaining a uniform light emission intensity across the light guide surface is to form the panel with a tapering cross-sectional profile.
  • a light diffusing sheet is placed on top of the light guiding panel.
  • the diffuser is generally a thin sheet of transparent plastic or glass material which has one surface imprinted with small ( ⁇ 10 "6 m) humps and hollows, is placed over the face of the guide resulting in a thin, bright, uniformly lit lambertian surface.
  • Prismatic films may be also placed between the display and the back-light to increase its efficiency.
  • a second light diffusing sheet is placed over the rear surface of the light guiding panel in most commercial "light pipe” backlight designs, to diffuse the spotted distribution of light emanating from the permanently formed diffusion dot pattern on the rearward surface facing towards the reflective surface disposed behind the light guiding panel.
  • the combination of the light guiding panel, fluorescent light tubes, diffusing sheets and the reflective layer together produce a plane of backlight having a uniform spatial intensity for illumination of the LCD panel affixed to the backlighting panel.
  • Transflective display constructions are employed in most PDA devices due to their reduced power storage capabilities and their need to function in outdoor and/or bright ambient light conditions.
  • PDA devices may be generally characterised therefore as having a shortage of display/input interface area and a limited ability to operate power intensive devices such as high luminance emissive displays.
  • an at least partially transparent emissive layer is provided between said first screen and at least one said additional display screen.
  • the term 'emissive layer' includes any optical component capable of emitting light when stimulated by an external input, whether electrical, optical, mechanical, magnetic or other.
  • the term 'visual display unit' includes, but is not limited to personnel digital assistants (PDA), computing means - including portable and/or hand held, devices, mobile phones, watches, calculators, data loggers, cameras, instrument displays, televisions, and any other electronic display means.
  • PDA personnel digital assistants
  • computing means including portable and/or hand held, devices, mobile phones, watches, calculators, data loggers, cameras, instrument displays, televisions, and any other electronic display means.
  • visual display unit having two or more at least partially overlapping display screen located in distinct focal planes, at least one said screen being at least partially transparent; characterised in that an at least partially transparent emissive layer is provided between said screens.
  • a visual display unit such as a PDA may be adapted to incorporate multi focal plane displays and an emissive layer either at the initial manufacturing stage, or retro-fitted as a separate accessory.
  • said emissive layer is a sheet with substantially planar opposed upper and a lower surfaces and a peripheral boundary of a prescribed thickness, said sheet formed from a material such that light rays incident from said peripheral boundary are retained between the said planar surface through total internal refraction at angles less than a critical angle.
  • At least one said sheet planar surface has a plurality of defined features located thereupon capable of refracting a said retained light ray incident on a said feature through an angle greater than the said critical angle of total internal reflection sufficient to exit said sheet via one of said planar surfaces.
  • said features include diffusion dots, predetermined scratches, indentations grooves, protrusions, regular or irregular undulations and the like.
  • At least one light source such as cold cathode fluorescent tube is located along said peripheral edge.
  • said light source is an array of light emitting diodes.
  • said emissive layer is configured to refract the ray axis of light at the said peripheral border such that the peripheral border between adjacent screens is not visible along said viewer's sightline.
  • the said features are distributed with an increasing density as a function of distance (e.g. a quadratic function) from said light source.
  • the said prescribed thickness of the emissive sheet is reduced as a function of distance from a said light source.
  • said emissive layer is formed from a light guide.
  • said emissive layer is formed from a transparent organic light emitting diode (TOLED) assembly.
  • TOLED transparent organic light emitting diode
  • a TOLED emits light uniformly from both sides and does not necessarily require the above-described means of controlling the light intensity distribution via said defined features and the like.
  • black regions e.g. text
  • the light emitted from the TOLED has no means of being directly varied according to whether it is aligned or overlays a portion of black text on the rear screen.
  • said emissive layer is a polarised TOLED emissive layer located between a front screen and a rear screen,
  • the front and rear screens are defined with respect to the physical proximity of a user viewing the displays in a conventional manner, i.e the front screen is nearer to the user than the rear screen.
  • One or more additional screens may be located between the said front and rear screens.
  • Polarised light is emitted from both surfaces of the TOLED, with the upward/outward emissions potentially degrading the clarity, contrast and/or effectiveness or the composite image formed by all the overlapping display screens.
  • Wire grid polarisers are defined herein to include any polariser capable of transmitting P polarised light whilst reflecting S polarised light or vice versa.
  • Polarization is defined relative to the plane of incidence, i.e. the plane that contains the incoming and reflected rays as well as the normal to the sample surface.
  • S polarization is where the electric field is perpendicular to the plane of incidence, while for P polarization, the electric field is parallel to the plane of incidence.
  • Wire grid polarisers may be formed from a variety of materials and manufacturing techniques , though they generally include a regular formation of spaced lines formed on a transparent substrate or film.
  • the strips may be an array of extremely fine metal wires deposited on a face of an optically transparent window such as KRS-5 or ZnSe. Since the electric field of the light oriented along the direction of wires can induce electrical currents along the wires, the wire grid acts as a metal surface reflecting virtually all the radiation polarized along the direction of the wires. The electric field perpendicular to the direction of wires is unable to induce electrical current in the wire grid. Thus, the light transmits through the polariser with only the reflectance losses from the substrate window.
  • precisely spaced groves are ruled directly into a highly polished CaF 2 or ZnSe substrate which is then aluminised.
  • Holographic methods may also be employed to produce grooves for holographic wire grids.
  • wire grids have the property that incident light of a given polarisation may pass through the polariser, whilst light of orthogonal polarisation to said given polarisation is reflected reciprocally. It follows therefore, that if a wire grid polariser is illuminated by light polarised in the same direction as the polarisation axis of the grid, all the light will be reflected. Conversely, polarised light orientated orthogonally to the polarisation axis of the wire grid will be transmitted through the grid. However, polarised light incident on the wire grid polariser.
  • the polarisation axis of the wire grid is arranged to reflect polarised light emitted from the TOLED back through the TOLED towards the rear screen.
  • said rear screen is a cholesteric LCD display.
  • the reflected light passes through a quarter wave retarder before being reflected by said rear screen. This produces a quarter wavelength shift in the light, which is then reflected and circularly polarised by the rear display.
  • retarders producing other degrees of retardation may be utilised, depending on the characteristics of the incident light and the display screens.
  • the light reflected by the rear display passes through the quarter wave retarder a second time before passing through the TOLED a second time to the wire grid polariser.
  • the retarder applies a further quarter wave shift resulting in linearly polarise light. Regions denoting text or graphics on the rear display, i.e. those regions preventing the transmission of light, remain un-illuminated regions in the light reflected from the rear screen to the viewer.
  • the linearly polarised light then passes through the wire grid polariser and front screen polariser.
  • the above configuration thus effectively re-cycles the light emitted from the upper surface of the TOLED which would otherwise degrade the contrast and luminance of the image seen by viewer.
  • the retarder may be omitted altogether.
  • the light emitted from TOLED directly towards the rear screen (10) plus the light reflected from the wire grid polariser is directly reflected by the rear screen (10) before being transmitted trough the wire grid polariser and front screen.
  • the degree to which the reflected light from the rear display is transmitted through the wire grid polariser depends on its polarisation, which in turn depends on the polarisation of the light incident on the rear screen.
  • a cholesteric rear LCD rear screen behaves essentially as a circular polariser. Consequently, for the three possible polarisations of light incident on the rear screen, the reflected light polarisation is as follows:
  • the incident light is randomly polarized in which case that which is reflected will be circularly polarized;
  • the incident light is linearly polarized in which case it will emerge circularly polarized;
  • the incident light is elliptically polarized in which case it will emerge as elliptically polarized.
  • the reflected light is able to pass through the wire grid unaffected if its polarisation orientation corresponds with the transmission axis of the wire grid, i.e. linearly polarised.
  • the reflected light is circularly polarised, it is advantageous to use an appropriate retarder to correct the polarisation alignment to match that of the wire grid polariser.
  • said screens are liquid crystal displays.
  • LCDs liquid crystal displays
  • the main criteria for the rear display is that it reflect the incident light to at least some degree.
  • Alternatives to LCD displays suitable for this purpose include the recently developed 'electronic paper' . This is an area of considerable interest in display research circles, with the aim of producing a product forming an electronic alternative to conventional paper with a very thin, inexpensive, low power consumption display for text and static images. This electronic paper is intended to provide a product that is addressable in the manner of a desktop display but without the same bulk.
  • interferometric modulators which are formed by a switchable array of optically resonant cavities
  • micro-encapsulated electrophoretic displays which use electrically controllable pigments as well as well established reflective and transflective liquid crystal technologies.
  • a practical multi-focal plane visual display unit such as a PDA may be realised.
  • the transparent properties of the emissive layer permit transflective display constructions to be retained and thus dispensing with the need for additional powered display illumination in conditions of high ambient light.
  • the emissive layer provides a low-power means of providing the necessary illumination.
  • the above-described configuration using a TOLED as the emissive layer need not necessarily be applied between two display screens. Instead, the configuration may be used as a front illumination means in other single or multi layer displays, either individually, or in combination with other backlight and/or emissive layers located between the displays.
  • a visual display unit illumination assembly including;
  • TOLED polarised transparent organic light emitting diode
  • wire grid polariser located between the TOLED and an observer viewing the visual display unit.
  • said illumination assembly incorporates an optical retarder located between the TOLED and a rear of the display.
  • the degree of retardation e.g. a quarter wave retarder
  • the degree of retardation may be defined according to variation between the polarisation of the light emitted from the TOLED and reflected from the rear display screen(s) and polarisation transmission axis of the wire grid polariser. It will be appreciated that the degree of retardation provided by optical retarder need be half the total phase shift required, as the light passes through the retarder twice.
  • Said illumination assembly may be used in front of a visual display unit comprised of one or more screens, though attenuation of light by successive screens places a limit on the number of screen layers.
  • the illumination assembly may also be located between two screens in a multi-layered display, as described in the above embodiments.
  • the visual display unit illumination assembly may thus be fitted to the front of a multi- layered display, such as a two screen LCD display unit as a replacement for a conventional backlight.
  • the illumination assembly may also be used in applications where a user needs to view an object/scene from substantially the same direction as an illumination source directed at the scene/object, e.g. a dentists or jewellers light with a central transparent magnifying section.
  • Figure 1 shows a schematic cross sectional side elevation through a light pipe backlighting assembly of prior art displays
  • Figure 2 shows a plan view of the diffusion dot dispersion pattern distributed on the surface of a light pipe
  • Figure 3 shows a schematic composite view of a first preferred embodiment of the present invention
  • Figure 4 shows a schematic cross section through a known PDA display
  • Figure 5 shows a schematic cross sectional view through a further preferred embodiment of the present invention.
  • FIG. 6 shows a schematic cross sectional view through an TOLED in accordance with a further preferred embodiment of the present invention.
  • Figure 7 shows a schematic cross sectional view through the embodiment of the present invention shown in figures 3, 5 and 6;
  • FIG. 8 shows a schematic cross sectional view through a TOLED in accordance with a further preferred embodiment of the present invention.
  • FIG. 9 shows a schematic cross sectional view through a TOLED in accordance with a further preferred embodiment of the present invention.
  • FIGS 1-7 illustrate preferred embodiments of the present invention in the form of a personal digital assistant (PDA), or parts thereof.
  • PDA personal digital assistant
  • the present invention is equally applicable to a variety of visual display units including portable and/or hand held computing means such as mobile phones, watches, calculators, data loggers, and such like and these are defined for the purposes of the specification as being encompassed by the invention.
  • FIG. 1 shows a typical back light assembly (1) used in notebook type computers incorporating a light guide (2) in the form of a rectangular clear acrylic sheet with a substantially planar upper and lower surface with a diffuser (3) and a reflector (4) affixed thereto or located adjacent to respectively.
  • the light guide has along one peripheral edge, a cold cathode florescent tube (5) housed within a parabolic reflector (6) which reflects the illumination through the peripheral boundary wall of the light pipe (2), it there being retained by virtue of total internal reflection.
  • a parabolic reflector (6) which reflects the illumination through the peripheral boundary wall of the light pipe (2), it there being retained by virtue of total internal reflection.
  • Either or both of the planar surfaces of the light guide (2) may be provided with a plurality of diffusion dots (7).
  • the light guide (2) provides an illumination source and is not part of the optical portion ' of the display.
  • the diffusion dots (7) are localised regions whereby the light constrained within the light guide striking the diffusion dots (7) exceed the critical angle for total internal refraction and are emitted from the planar surface.
  • the cross sectional profile of the light guide (2) tapers with respect to distance from the florescent tube (5).
  • the opposing peripheral edge to the florescent tube (5) is provided with an end reflector (8).
  • the back lighting assembly shown in figure 1 is located at the rear most portion of typical notebook-type computer display screens.
  • FIG. 3 shows a cross sectional diagram through an existing PDA (1) configuration fitted with a supplementary display (20), which is parallel to and spaced apart from the original display (10).
  • a polarised back light source (11) located at the rear of the display (10) is placed behind a composite series of layers comprised, in sequence, of a half silvered mirror (12), a glass substrate (13), a rubbed conductive ITO ground layer (14), a liquid crystal (15), an ITO layer with an electrode pattern and subsequent rubbed polyimide layer (16), glass substrate (17) and an analyser (18).
  • This construction is typical of transflective LCDs as is well known to those in the art and is not discussed in further detail.
  • the original display (10) may be augmented by attaching a second display (20) which is attached over the planar face of the original display (10) and is substantially co-terminus with same.
  • the second display (20) is also comprised of a plurality of layers which in sequence from the front of the original display (10) consists of, an emissive transparent refractor (21), a rear analyser/polariser (22), a glass substrate (23), a rubbed ITO conductive ground layer and subsequent polyimide alignment layer (24), a second liquid crystal (25), a rubbed polyimide alignment layer and subsequent ITO electrode pattern (26), a front glass substrate (27), front analyser (28), and a diffuser (29).
  • the diffuser (17) may be applied to the surface of a touch screen layer (30).
  • Figure 3 shows an embodiment whereby the two display assemblies (10, 20) are combined at the manufacturing stage as a homogenous unit.
  • the second display (20) may be retro-fitted as a distinct unit to the front of a PDA display (10) as illustrated in figures 4 and 5 where identical elements to that shown in figure 3 are like numbered.
  • Figure 4 shows an existing PDA display (10) with the additional layer (to that illustrated in figure 3) of a touch screen layer (19) to which the diffuser (18) layer may be affixed.
  • Figure 5 shows the secondary display screen (20) which is connected to the original screen (10) via appropriate mounting clips (not shown) and coupled to the PDA processor via appropriate drive electronics and power supply interfaced via an expansion slot as commonly found in known PDAs. Such interconnections are well known to those in the art and are consequently not discussed further herein.
  • the emissive layer, or emissive transparent refractor (21) is formed in one embodiment from a sheet of acrylic plastic known as a light guide (2) or light pipe as described with reference to figure 1.
  • a light guide generally consists of a sheet with two substantially planar opposing surfaces on which a number of defined features such as diffusion dots (7) are located.
  • the light guide is illuminated by one or more light sources, eg cold cathode florescent tubes (5) located about the peripheral edge of the light guide (21) in a corresponding manner to that shown in figure 1.
  • the configuration of the emissive layer (21) corresponds almost directly to the light guide (2) shown in figure 1 with exception that a lower reflector (4) is omitted.
  • Light may be emitted from both planar surfaces from the emissive transparent light guide (21) to directly illuminate both LCD displays, (10, 20).
  • only the lower planar surface of the light guide (2) is provided with a plurality of diffusion dots (7) to restrict the emitted illumination to the rearward display (10) only.
  • the light is then reflected from the cholesteric liquid crystal in the rearward display (10) and is transmitted through the emissive layer (21) and front display screen (20).
  • Restricting the light emission in this manner ensures regions of text or graphics on the rearward screen (10) do not align directly with light emitted directly from the emissive display (21) through the front display (20) to a viewer with a corresponding reduction in contrast and greying/fading of tones.
  • the light guide (21) may be replaced by a transparent organic light emitting diode (TOLED) light source (30).
  • TOLED transparent organic light emitting diode
  • Figure 6 shows an existing TOLED backlight (30) composed of a further plurality of layers in the form of a transparent anode (31), a glass plate (32), a hole injection layer (33), a hole transport layer (34), an electron transport layer (35), a light generating layer (36) and a cathode (37).
  • Organic light omitting diodes are a recent entry in the field of display technology and provide numerous beneficial characteristics for use in lighting applications. However, large area TOLEDs are not currently available, thus lending TOLEDs backlights to small area LCD displays and the like.
  • the operating principle of a TOLED (30), as illustrated in figure 6 is based on electron-whole recombination.
  • a glass plate (32) containing transparent anode (31) (usually an ITO) is employed as a substrate for depositing small molecules in a series of organic layers (33-36). Electrons are injected in the organic layers (33-36) by the cathode upon application of a DC voltage beyond a critical threshold voltage. Holes are correspondingly injected into the organic layers (33-36) by the anode (31).
  • the light-generating layer (36) may be doped with traces of specific organic molecules (dopants) in order to improve the efficiency of the generated light.
  • the light generating layer (36) utilising dopants is generally called the "host" layer. Appropriate choice of dopants and hosts can lead to the generation of different colour light; white light may be created by two layers of hosts and dopants.
  • the cathode (37) is transparent in order that the emitted light may illuminate both the LCD screens (10, 20) .
  • Possible configurations of embodiments using TOLED (30) in place of a light guide (2) as the emissive layer (21) correspond to that shown in figures 3-5, with the substitution of the TOLED (30) for the emissive transparent refractor (21).
  • the refractive properties of the emissive transparent reflector (21) prevent the sightline access of the viewer from detecting the actual edge boundaries of the rearward display (10) at shallow angles of incidence. This may be seen in figure 7 whereby emitted light rays (38 and 39) originating from object points (42, 43) respectively appeal- to originate from image points (40, 41) respectively. This prevents the peripheral edge of the portion of the combined display located between the separate LCD units (10, 20) being visible to the viewer. This also enhances the three-dimensional quality of the whole display (10, 20).
  • FIG 8 shows a yet further embodiment of the present invention, addressing a shortcoming of the above-described TOLED - based embodiment.
  • areas of the TOLED overlapping regions of text or graphics on the rearward screen (10) will appear grey (in the case of a display using monochrome LCD screens) instead of black, due to the extra luminance emitted towards the viewer by TOLED.
  • the light transmitted from the TOLED through front screen (20) has no interaction with the rearward display (20), it is impossible to overcome this drawback without intervening in the optical path of the light.
  • Unlike a light guide (2) it is difficult to restrict the emission of light to only one surface without affecting the transparency of the TOLED (30).
  • the TOLED (30) is configured to emit polarised light. Initially, light is emitted (stage 46) from both sides of the TOLED (30) towards the front (20) and rearward (10 ) displays, each represented by the Jones Vector (46) of
  • the light (47) emitted towards the front display (20) is reflected from the wire grid polariser (44) and passes back through the TOLED (30), summing with the light (48) originally emitted towards the rear screen (10) (of the same polarisation) with the resultant light (49) having a Jones Vector of
  • the resultant linearly polarised illumination (49) passes through the optical retarder (45) which applies a corresponding phase shift.
  • the retarder (45) produces a quarter wavelength phase shift, as denoted by its corresponding Jones matrix " 1 0 ' 0 -z
  • the resultant retarded light (50) is reflected by the liquid crystal of the rear cholesteric display (10), which behaves essentially as a circular polariser.
  • the resultant reflected light (51) is described by the equation;
  • the reflected light (51) is then re-transmitted through the retarder (45) with a further quarter wave retardation wit a resultant linearly polarised output given by the equation;
  • the light (51) transmitted through the retarder (45) passes again through the TOLED
  • the light (53) re-transmitted through the TOLED (30) then passes through the wire grid ro oi polariser (44) described by a Jones matrix of o 1 with the resultant transmitted light (54) given by the equation;
  • the resultant light (54) transmitted through the wire grid polariser (44) preserves all the polarising attributes of each portion of the any image generated on the rear screen (10), maintaining the relative luminosity between the darkened and light areas. In the embodiment shown in figure 8, this light (54) then passes through the front screen (20).
  • the combination of the TOLED (30), wire grid polariser (44) and (optionally) the optical retarder (45), collectively forming an illumination assembly (55) may be located in front of a multi-screen display or even used as a transparent illumination means enabling a user to illuminate a scene whilst viewing the scene from the same axis as the illumination source.
  • the inclusion of the retarder (45) is optional depending on the reflective properties of the rear display (10).
  • the retarder (45) is thus used to correct the oscillation plane of the electric field (i.e. the polarisation) to ensure the eventual transmission through the wire grid polariser (44) is achieved with the minimum of absorption losses.
  • the rear display (10) is a cholesteric transflective liquid crystal, which acts as a circular polariser.
  • the light reflected from the rear screen (10) may be one of the following: i. the incident light is randomly polarized in which case that which is reflected will be circularly polarized;
  • the incident light is linearly polarized in which case it will emerge circularly polarized;
  • the incident light is elliptically polarized in which case it will emerge as elliptically polarized.
  • the retarder (45) is thus incorporated only if required to alter the polarization orientation of the light reflected from the rear screen (10) before it being transmitted or reflected by the wire grid polariser (44).
  • Figure 9 shows an embodiment of the present invention identical to that shown in figure 8, with the exception that the optical retarder (45) is omitted.
  • Like components (10, 20,44, 47) are like numbered.
  • the transformation of the light (46, 47, 48, 49) emitted from the TOLED (30), reflected from the wire grid (44), transmitted through the TOLED (30), and that incident on the rear screen (10) is identical to that shown in figure 8 with like reference numbering.
  • the Jones vectors associated with the light (46, 47, 48, 49) and the Jones matrices characterizing the front screen (20), rear screen (10), TOLED (30) and wire grid polariser (44) are also identical to the previous embodiment.
  • the reflected light (56) then passes through the TOLED (30) again.
  • the Jones matrix As the Jones matrix
  • the light (57) transmitted through the TOLED (30) is then transmitted through the wire
  • the imaginary component is only considered as a mathematical aid in expressing the polarisation orientation.
  • the retarder (45) when using a cholesteric liquid crystal rear display (10), or other display with the same reflective properties, the retarder (45) may be omitted without detriment. If, however, the rear display (10) and/or any additional optical components that may be placed in the light path from the TOLED (30) to the front screen (20) results in a misalignment between the polarisation axis of the wire grid (44) and the light incident on it, the retarder (45) may be used to correct for misalignment. As visual display unit back lights and other such illumination sources generate heat which may can be difficult to dissipate without constraints on casing design and/or the need for active cooling such as fans. Placing the illumination source forward of the front screen may alleviate such heating issues. Thus, an illumination assembly may, for example, be used with single screen displays to replace backlights in applications such as notebook computers and the like.
  • the wire grid polariser (44) is formed on the inner surface of a substrate, or between substrate layers in a sandwich construction, to protect the delicate wire grid.

Abstract

A method of adapting a visual unit having a first screen (10) in a first focal plane by the addition of one or more at least partially transparent display screens (20) at least partially overlapping said first screen (10) and located in focal planes distinct from said first focal plane, characterised in that an at least partially transparent emissive layer (21) is provided between said first screen (10) and at least one said additional display screen (20).

Description

VISUAL DISPLAY UNIT ILLUMINATION
TECHNICAL FIELD
The present invention relates to a means for illuminating visual display units, particularly portable computing means including the genre known as Personal Digital Assistants (PDA).
BACKGROUND ART
The relentless tide of technological improvements in computing has inexorably led to ever more powerful computers, of ever-smaller volumes. This has given rise in recent times, to successively smaller incarnations of the Personnel Computer (PC), i.e., the desktop, laptop and notebook computer. Although of reduced physical dimensions in comparison to its predecessor, each has retained a conventional keyboard as its primary means of data input.
However, the advent of yet smaller personnel computing devices, i.e., the palmtop or Personal Digital Assistant (PDA) has precluded the use of a full-size keyboard. Furthermore, the display areas of such devices are equally restricted by their diminutive size. PDAs are typically the size of a user's hand, requiring the user interface to be designed so that input operations are not too intricate and sufficient space is available for data display. These factors are often applicable to a host of other mobile computing means such as mobile telephones, watches, calculators, data loggers, and so forth and as such these devices are included by reference herein.
These space constraints have lead to the incorporation of touchscreens as a means of combining the functions of both data entry and data display. A transflective liquid crystal display is overlaid with a transparent touch sensitive screen capable of detecting the position of a stylus point impressed upon it. The stylus may be used to select various icons and/or menus in order to issue instructions to the operating system and to input hand written data. Streamlined versions of popular spreadsheet, word processing and organisational programs are available for PDAs in addition to other specific applications designed for use within the constraints of the PDA hardware.
Most of the systems present in a conventional PC are present in a PDA. These include volatile/dynamic and permanent information storage devices or memory and a logic processor. In contrast to PCs, the operating system of a PDA is usually proprietary and stored on an on-board ROM. Subsequent user-loaded applications are stored in solid state "flash memory" rather than the rotating storage media (magnetic or optical) typically employed in PCs.
Typical PDA transflective displays consist of a birefringent liquid with a chiral additive trapped between conductive layers rubbed with a cloth or similar to align the liquid crystal molecules in a suitable manner. The birefringence of the liquid crystal may be switched to zero by applying an electric field perpendicular to the alignment layers. To achieve this one of the conductive layers is broken up into small, square or rectangular, addressable, electrodes tessellated to form a matrix while the other forms a voltage reference plane. Colour filters can be added over the electrodes to improve the effect.
This arrangement is then placed between sheets of polarising film with either aligned or perpendicular polarisation axes, located in front of a half-silvered mirror and provided with illumination. As the half-silvered mirror transmits 50% and reflects 50% of the incident light, the display can be illuminated from either side, i.e., front or back lit.
Larger, transparent liquid crystal displays (LCD) are fabricated in a similar fashion as the transflective displays with the omission of the half-silvered mirror. Backlighting is provided by cold cathode fluorescent tubes in combination with a light-guide, also known as a light pipe, and diffuser. Prior art light pipe backlight assemblies are constructed from a light guiding panel with boundaries substantially coterminous with the LCD panel edges (normally rectangular), typically fabricated from an acrylic plastic with similar optical properties to those of borosilicate. A pair of miniature fluorescent light tubes are mounted within suitably designed light reflective mounts (i.e. , located at the foci of parabolic reflectors) along the opposite side edges of the acrylic sheet.
The function of the fluorescent light tubes is to produce and direct incoherent light into the interior of the light guiding panel within which the light is typically bounded by the well known principle of "total internal reflection". Under ideal conditions, light will not leak out of the surfaces of the acrylic plastic sheet. However, light can be extracted or caused to 'leak' out from the light guide surface by forming therein scratches, undulations, or any other means of locally altering the critical angle for total internal reflection. The extracted light can be used for illumination purposes such as the above described LCD panel backlighting. A reflector is placed behind the rear surface of the light pipe to reflect rearward emitted light through the LCD, adding to the display illumination.
In order to compensate for the decrease in light guide light intensity as a function of distance from the fluorescent tubes, a light extracting pattern is permanently formed on one or both surfaces of the light guiding panel. Typically, the light extracting pattern is realised as a dot pattern permanently embossed or sandblasted upon the front surface of the acrylic light guiding panel.
In order to achieve light intensity compensation along the light guiding panel, the density of the dot pattern may be configured to increase quadratically with distance from the fluorescent light tubes. This construction provides a constant backlighting luminance across the light guiding panel. Alternative means of maintaining a uniform light emission intensity across the light guide surface is to form the panel with a tapering cross-sectional profile.
In order to integrate (ie diffuse) the spotted distribution of light emanating from the light extracting pattern towards the LCD panel, a light diffusing sheet is placed on top of the light guiding panel. The diffuser is generally a thin sheet of transparent plastic or glass material which has one surface imprinted with small (~10"6m) humps and hollows, is placed over the face of the guide resulting in a thin, bright, uniformly lit lambertian surface. Prismatic films may be also placed between the display and the back-light to increase its efficiency.
A second light diffusing sheet is placed over the rear surface of the light guiding panel in most commercial "light pipe" backlight designs, to diffuse the spotted distribution of light emanating from the permanently formed diffusion dot pattern on the rearward surface facing towards the reflective surface disposed behind the light guiding panel.
The combination of the light guiding panel, fluorescent light tubes, diffusing sheets and the reflective layer together produce a plane of backlight having a uniform spatial intensity for illumination of the LCD panel affixed to the backlighting panel.
Transflective display constructions are employed in most PDA devices due to their reduced power storage capabilities and their need to function in outdoor and/or bright ambient light conditions.
PDA devices may be generally characterised therefore as having a shortage of display/input interface area and a limited ability to operate power intensive devices such as high luminance emissive displays.
One means of addressing the shortage of display/input interface area is by overlaying a further transparent display pane over the existing PDA display. This type of technology (as described in the applicants co-pending applications PCT/NZ98/00098 and PCT/NZ99/00021, incorporated herein by reference) enables, by various means, the stacking of image planes at set distances. These configurations provide intrinsic motion parallax, where the x and y distance changes between objects displayed on different planes depending on viewing angle, binocular depth cues and separate focal planes that may be brought in and out of focus depending on where the viewer fixes his or her attention..
However, the addition of a further display screen overlaying the existing screen of a PDA type device results in a significantly darkened combined display. This is due in part to the intrinsic attenuation of light passing through the additional layers of the additional display and to the unpracticality of increasing the bacldighting luminance due to the power constraints discussed above.
There is therefore a need to provide an enlarged display area of PDA type devices (as hereinbefore defined) without incurring a detrimental loss in display brightness.
All references, including any patents or patent applications, cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the reference states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications may be referred to herein, this reference does not constitute an admission that any of these documents forms parts of the common general knowledge in the art in any country.
It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.
DISCLOSURE OF INVENTION
According to one aspect of the present invention there is provided a method of adapting a visual display unit having a first screen in a first focal plane by the addition of one or more at least partially transparent display screens at least partially overlapping said first screen and located in focal planes distinct from said first focal plane, characterised in that
an at least partially transparent emissive layer is provided between said first screen and at least one said additional display screen.
As used herein, the term 'emissive layer' includes any optical component capable of emitting light when stimulated by an external input, whether electrical, optical, mechanical, magnetic or other.
As used herein, the term 'visual display unit' includes, but is not limited to personnel digital assistants (PDA), computing means - including portable and/or hand held, devices, mobile phones, watches, calculators, data loggers, cameras, instrument displays, televisions, and any other electronic display means.
According to a further embodiment, there is provided visual display unit produced by the above-described method.
According to a still further aspect of the present invention there is visual display unit having two or more at least partially overlapping display screen located in distinct focal planes, at least one said screen being at least partially transparent; characterised in that an at least partially transparent emissive layer is provided between said screens.
It may be seen therefore, that a visual display unit such as a PDA may be adapted to incorporate multi focal plane displays and an emissive layer either at the initial manufacturing stage, or retro-fitted as a separate accessory.
According to one aspect of the present invention, said emissive layer is a sheet with substantially planar opposed upper and a lower surfaces and a peripheral boundary of a prescribed thickness, said sheet formed from a material such that light rays incident from said peripheral boundary are retained between the said planar surface through total internal refraction at angles less than a critical angle.
Preferably, at least one said sheet planar surface has a plurality of defined features located thereupon capable of refracting a said retained light ray incident on a said feature through an angle greater than the said critical angle of total internal reflection sufficient to exit said sheet via one of said planar surfaces.
Preferably, said features include diffusion dots, predetermined scratches, indentations grooves, protrusions, regular or irregular undulations and the like.
Preferably, at least one light source such as cold cathode fluorescent tube is located along said peripheral edge.
In an alternative embodiment, said light source is an array of light emitting diodes.
Preferably, said emissive layer is configured to refract the ray axis of light at the said peripheral border such that the peripheral border between adjacent screens is not visible along said viewer's sightline.
According to one aspect of the present invention, the said features are distributed with an increasing density as a function of distance (e.g. a quadratic function) from said light source.
According to an alternative embodiment of the present invention, the said prescribed thickness of the emissive sheet is reduced as a function of distance from a said light source.
The above configurations of the said feature distribution and emissive sheet thickness both provide a means of outputting a uniform light intensity, avoiding decreasing intensity with distance from the light source. According to one embodiment of the present invention, said emissive layer is formed from a light guide.
According to an alternative embodiment of the present invention, said emissive layer is formed from a transparent organic light emitting diode (TOLED) assembly.
A TOLED emits light uniformly from both sides and does not necessarily require the above-described means of controlling the light intensity distribution via said defined features and the like.
However, the fact that light emits from both sides of a TOLED can in-itself cause degradation of the image seen by the viewer. This is due to the fact that light emitted upwards through transparent portions of the front LCD panel towards the viewer will be transmitted with equal intensity, irrespective of whether the rear LCD panel is displaying a clear or black region at any given point on the rear screen.
Whilst this causes no drawback for the transparent portions of the rear screen, black regions (e.g. text) appear grey, with reduced contrast to an adjacent transparent region. The light emitted from the TOLED has no means of being directly varied according to whether it is aligned or overlays a portion of black text on the rear screen.
This drawback is addressed by the use of a wire grid polariser and a polarised TOLED, i.e. a TOLED emitting polarised light. Optionally, an optical retarder may also be incorporated. This combination (described below) effectively re-cycles the light radiating directly upwards from the TOLED and re-orientates the polarisation of the light to maximise the illumination of the displays without degrading the display contrast
Thus in a preferred embodiment of the present invention, said emissive layer is a polarised TOLED emissive layer located between a front screen and a rear screen,
wherein a wire grid polariser and is interposed between the TOLED and the front screen. As used herein, the front and rear screens are defined with respect to the physical proximity of a user viewing the displays in a conventional manner, i.e the front screen is nearer to the user than the rear screen. One or more additional screens may be located between the said front and rear screens.
Polarised light is emitted from both surfaces of the TOLED, with the upward/outward emissions potentially degrading the clarity, contrast and/or effectiveness or the composite image formed by all the overlapping display screens.
Wire grid polarisers are defined herein to include any polariser capable of transmitting P polarised light whilst reflecting S polarised light or vice versa.
Polarization is defined relative to the plane of incidence, i.e. the plane that contains the incoming and reflected rays as well as the normal to the sample surface.
S polarization is where the electric field is perpendicular to the plane of incidence, while for P polarization, the electric field is parallel to the plane of incidence.
Wire grid polarisers may be formed from a variety of materials and manufacturing techniques , though they generally include a regular formation of spaced lines formed on a transparent substrate or film.
The strips may be an array of extremely fine metal wires deposited on a face of an optically transparent window such as KRS-5 or ZnSe. Since the electric field of the light oriented along the direction of wires can induce electrical currents along the wires, the wire grid acts as a metal surface reflecting virtually all the radiation polarized along the direction of the wires. The electric field perpendicular to the direction of wires is unable to induce electrical current in the wire grid. Thus, the light transmits through the polariser with only the reflectance losses from the substrate window.
In alternative constructions, precisely spaced groves are ruled directly into a highly polished CaF2 or ZnSe substrate which is then aluminised. Holographic methods may also be employed to produce grooves for holographic wire grids.
Thus, wire grids have the property that incident light of a given polarisation may pass through the polariser, whilst light of orthogonal polarisation to said given polarisation is reflected reciprocally. It follows therefore, that if a wire grid polariser is illuminated by light polarised in the same direction as the polarisation axis of the grid, all the light will be reflected. Conversely, polarised light orientated orthogonally to the polarisation axis of the wire grid will be transmitted through the grid. However, polarised light incident on the wire grid polariser.
In one embodiment therefore, the polarisation axis of the wire grid is arranged to reflect polarised light emitted from the TOLED back through the TOLED towards the rear screen.
Preferably, said rear screen is a cholesteric LCD display.
In one embodiment, the reflected light passes through a quarter wave retarder before being reflected by said rear screen. This produces a quarter wavelength shift in the light, which is then reflected and circularly polarised by the rear display. However, it will be appreciated that retarders producing other degrees of retardation may be utilised, depending on the characteristics of the incident light and the display screens.
The light reflected by the rear display passes through the quarter wave retarder a second time before passing through the TOLED a second time to the wire grid polariser. The retarder applies a further quarter wave shift resulting in linearly polarise light. Regions denoting text or graphics on the rear display, i.e. those regions preventing the transmission of light, remain un-illuminated regions in the light reflected from the rear screen to the viewer.
The linearly polarised light then passes through the wire grid polariser and front screen polariser.
The above configuration thus effectively re-cycles the light emitted from the upper surface of the TOLED which would otherwise degrade the contrast and luminance of the image seen by viewer.
In an alternative embodiment, the retarder may be omitted altogether. In such embodiments, the light emitted from TOLED directly towards the rear screen (10) plus the light reflected from the wire grid polariser is directly reflected by the rear screen (10) before being transmitted trough the wire grid polariser and front screen.
The degree to which the reflected light from the rear display is transmitted through the wire grid polariser depends on its polarisation, which in turn depends on the polarisation of the light incident on the rear screen. A cholesteric rear LCD rear screen behaves essentially as a circular polariser. Consequently, for the three possible polarisations of light incident on the rear screen, the reflected light polarisation is as follows:
i. the incident light is randomly polarized in which case that which is reflected will be circularly polarized;
ii. the incident light is linearly polarized in which case it will emerge circularly polarized;
iii. the incident light is elliptically polarized in which case it will emerge as elliptically polarized.
The reflected light is able to pass through the wire grid unaffected if its polarisation orientation corresponds with the transmission axis of the wire grid, i.e. linearly polarised.
If the reflected light is circularly polarised, it is advantageous to use an appropriate retarder to correct the polarisation alignment to match that of the wire grid polariser. Preferably, said screens are liquid crystal displays. However, it will be understood alternative constructions are possible and the invention is not necessarily limited to the use of LCDs.
The main criteria for the rear display is that it reflect the incident light to at least some degree. Alternatives to LCD displays suitable for this purpose include the recently developed 'electronic paper' . This is an area of considerable interest in display research circles, with the aim of producing a product forming an electronic alternative to conventional paper with a very thin, inexpensive, low power consumption display for text and static images. This electronic paper is intended to provide a product that is addressable in the manner of a desktop display but without the same bulk.
Technologies involved include interferometric modulators which are formed by a switchable array of optically resonant cavities, micro-encapsulated electrophoretic displays which use electrically controllable pigments as well as well established reflective and transflective liquid crystal technologies.
These and any other type of display that reflects between 10% and 100% of the incident light would be suitable for use as the rear display in the present invention.
Consequently, by virtue of incorporating an at least partially transparent emissive layer, a practical multi-focal plane visual display unit such as a PDA may be realised. The transparent properties of the emissive layer permit transflective display constructions to be retained and thus dispensing with the need for additional powered display illumination in conditions of high ambient light. When additional illumination is required indoors, or in low-light environments, the emissive layer provides a low-power means of providing the necessary illumination.
It will furthermore be appreciated that the above-described configuration using a TOLED as the emissive layer need not necessarily be applied between two display screens. Instead, the configuration may be used as a front illumination means in other single or multi layer displays, either individually, or in combination with other backlight and/or emissive layers located between the displays.
Thus, according to a further aspect of the present invention there is provided a visual display unit illumination assembly including;
a polarised transparent organic light emitting diode (TOLED) and a wire grid polariser located between the TOLED and an observer viewing the visual display unit.
Optionally, said illumination assembly incorporates an optical retarder located between the TOLED and a rear of the display. The degree of retardation (e.g. a quarter wave retarder) may be defined according to variation between the polarisation of the light emitted from the TOLED and reflected from the rear display screen(s) and polarisation transmission axis of the wire grid polariser. It will be appreciated that the degree of retardation provided by optical retarder need be half the total phase shift required, as the light passes through the retarder twice.
Said illumination assembly may be used in front of a visual display unit comprised of one or more screens, though attenuation of light by successive screens places a limit on the number of screen layers. The illumination assembly may also be located between two screens in a multi-layered display, as described in the above embodiments.
The visual display unit illumination assembly may thus be fitted to the front of a multi- layered display, such as a two screen LCD display unit as a replacement for a conventional backlight. The illumination assembly may also be used in applications where a user needs to view an object/scene from substantially the same direction as an illumination source directed at the scene/object, e.g. a dentists or jewellers light with a central transparent magnifying section. Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.
BRIEF DESCRIPTION OF DRAWINGS
Further aspects of the present invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings in which:
Figure 1 shows a schematic cross sectional side elevation through a light pipe backlighting assembly of prior art displays;
Figure 2 shows a plan view of the diffusion dot dispersion pattern distributed on the surface of a light pipe;
Figure 3 shows a schematic composite view of a first preferred embodiment of the present invention;
Figure 4 shows a schematic cross section through a known PDA display;
Figure 5 shows a schematic cross sectional view through a further preferred embodiment of the present invention;
Figure 6 shows a schematic cross sectional view through an TOLED in accordance with a further preferred embodiment of the present invention;
Figure 7 shows a schematic cross sectional view through the embodiment of the present invention shown in figures 3, 5 and 6;
Figure 8 shows a schematic cross sectional view through a TOLED in accordance with a further preferred embodiment of the present invention; and
Figure 9 shows a schematic cross sectional view through a TOLED in accordance with a further preferred embodiment of the present invention.
BEST MODES FOR CARRYING OUT THE INVENTION
Figures 1-7 illustrate preferred embodiments of the present invention in the form of a personal digital assistant (PDA), or parts thereof. However, it should be appreciated that the present invention is equally applicable to a variety of visual display units including portable and/or hand held computing means such as mobile phones, watches, calculators, data loggers, and such like and these are defined for the purposes of the specification as being encompassed by the invention.
Existing devices incorporating portable visual display units such as PDAs are severely restricted in their power consumption requirements of their components due to the limited battery storage capacities. Consequently, there is widespread adoption of transflective displays and the use of light pipes or light guides as part of the back lighting assembly. Figure 1 shows a typical back light assembly (1) used in notebook type computers incorporating a light guide (2) in the form of a rectangular clear acrylic sheet with a substantially planar upper and lower surface with a diffuser (3) and a reflector (4) affixed thereto or located adjacent to respectively.
The light guide has along one peripheral edge, a cold cathode florescent tube (5) housed within a parabolic reflector (6) which reflects the illumination through the peripheral boundary wall of the light pipe (2), it there being retained by virtue of total internal reflection. Either or both of the planar surfaces of the light guide (2) may be provided with a plurality of diffusion dots (7). Essentially, the light guide (2) provides an illumination source and is not part of the optical portion' of the display.
As shown in plan view in figure 2 the diffusion dots (7) are localised regions whereby the light constrained within the light guide striking the diffusion dots (7) exceed the critical angle for total internal refraction and are emitted from the planar surface. To maintain an even distribution of luminosity, the cross sectional profile of the light guide (2) tapers with respect to distance from the florescent tube (5). The opposing peripheral edge to the florescent tube (5) is provided with an end reflector (8).
The back lighting assembly shown in figure 1 is located at the rear most portion of typical notebook-type computer display screens.
Display area and/or user input interface area is at a premium in PDAs due to their size. Figure 3 shows a cross sectional diagram through an existing PDA (1) configuration fitted with a supplementary display (20), which is parallel to and spaced apart from the original display (10).
Referring specifically to figure 3, a polarised back light source (11) (of known type) located at the rear of the display (10) is placed behind a composite series of layers comprised, in sequence, of a half silvered mirror (12), a glass substrate (13), a rubbed conductive ITO ground layer (14), a liquid crystal (15), an ITO layer with an electrode pattern and subsequent rubbed polyimide layer (16), glass substrate (17) and an analyser (18). This construction is typical of transflective LCDs as is well known to those in the art and is not discussed in further detail.
The original display (10) may be augmented by attaching a second display (20) which is attached over the planar face of the original display (10) and is substantially co-terminus with same.
The second display (20) is also comprised of a plurality of layers which in sequence from the front of the original display (10) consists of, an emissive transparent refractor (21), a rear analyser/polariser (22), a glass substrate (23), a rubbed ITO conductive ground layer and subsequent polyimide alignment layer (24), a second liquid crystal (25), a rubbed polyimide alignment layer and subsequent ITO electrode pattern (26), a front glass substrate (27), front analyser (28), and a diffuser (29). The diffuser (17) may be applied to the surface of a touch screen layer (30). Figure 3 shows an embodiment whereby the two display assemblies (10, 20) are combined at the manufacturing stage as a homogenous unit.
Alternatively, the second display (20) may be retro-fitted as a distinct unit to the front of a PDA display (10) as illustrated in figures 4 and 5 where identical elements to that shown in figure 3 are like numbered.
Figure 4 shows an existing PDA display (10) with the additional layer (to that illustrated in figure 3) of a touch screen layer (19) to which the diffuser (18) layer may be affixed. Figure 5 shows the secondary display screen (20) which is connected to the original screen (10) via appropriate mounting clips (not shown) and coupled to the PDA processor via appropriate drive electronics and power supply interfaced via an expansion slot as commonly found in known PDAs. Such interconnections are well known to those in the art and are consequently not discussed further herein.
The emissive layer, or emissive transparent refractor (21) is formed in one embodiment from a sheet of acrylic plastic known as a light guide (2) or light pipe as described with reference to figure 1. A light guide generally consists of a sheet with two substantially planar opposing surfaces on which a number of defined features such as diffusion dots (7) are located. The light guide is illuminated by one or more light sources, eg cold cathode florescent tubes (5) located about the peripheral edge of the light guide (21) in a corresponding manner to that shown in figure 1.
The configuration of the emissive layer (21) corresponds almost directly to the light guide (2) shown in figure 1 with exception that a lower reflector (4) is omitted. Light may be emitted from both planar surfaces from the emissive transparent light guide (21) to directly illuminate both LCD displays, (10, 20). However, preferably, only the lower planar surface of the light guide (2) is provided with a plurality of diffusion dots (7) to restrict the emitted illumination to the rearward display (10) only. The light is then reflected from the cholesteric liquid crystal in the rearward display (10) and is transmitted through the emissive layer (21) and front display screen (20).
Restricting the light emission in this manner ensures regions of text or graphics on the rearward screen (10) do not align directly with light emitted directly from the emissive display (21) through the front display (20) to a viewer with a corresponding reduction in contrast and greying/fading of tones.
In an alternative embodiment, the light guide (21) may be replaced by a transparent organic light emitting diode (TOLED) light source (30). Figure 6 shows an existing TOLED backlight (30) composed of a further plurality of layers in the form of a transparent anode (31), a glass plate (32), a hole injection layer (33), a hole transport layer (34), an electron transport layer (35), a light generating layer (36) and a cathode (37).
Organic light omitting diodes are a recent entry in the field of display technology and provide numerous beneficial characteristics for use in lighting applications. However, large area TOLEDs are not currently available, thus lending TOLEDs backlights to small area LCD displays and the like. The operating principle of a TOLED (30), as illustrated in figure 6 is based on electron-whole recombination. A glass plate (32) containing transparent anode (31) (usually an ITO) is employed as a substrate for depositing small molecules in a series of organic layers (33-36). Electrons are injected in the organic layers (33-36) by the cathode upon application of a DC voltage beyond a critical threshold voltage. Holes are correspondingly injected into the organic layers (33-36) by the anode (31). Electrons travelling through the electron transport layer (35) meet the holes from the anode (31) through the hole injection layer (33) and hole transport layer (34). The recombination of the electrons with the holes at the light-generating layer (36) creates "excitons" (excited neutral molecule) which subsequently fall back to ground state thereby releasing the recombination energy in the form of visible radiation.
The light-generating layer (36) may be doped with traces of specific organic molecules (dopants) in order to improve the efficiency of the generated light. The light generating layer (36) utilising dopants is generally called the "host" layer. Appropriate choice of dopants and hosts can lead to the generation of different colour light; white light may be created by two layers of hosts and dopants.
In order to utilise the TOLED (30) illustrated in figure 6 as an emissive transparent refractor (21), (as opposed to its role as a back light), it is necessary to specify that the cathode (37) is transparent in order that the emitted light may illuminate both the LCD screens (10, 20) . Possible configurations of embodiments using TOLED (30) in place of a light guide (2) as the emissive layer (21) correspond to that shown in figures 3-5, with the substitution of the TOLED (30) for the emissive transparent refractor (21).
By forming the rearward screen (10) to be enlarged with respect to the front screen (20), the refractive properties of the emissive transparent reflector (21) prevent the sightline access of the viewer from detecting the actual edge boundaries of the rearward display (10) at shallow angles of incidence. This may be seen in figure 7 whereby emitted light rays (38 and 39) originating from object points (42, 43) respectively appeal- to originate from image points (40, 41) respectively. This prevents the peripheral edge of the portion of the combined display located between the separate LCD units (10, 20) being visible to the viewer. This also enhances the three-dimensional quality of the whole display (10, 20).
It will be appreciated that various alterations and permutations may be made to the display assemblies shown without departing from the scope of the invention. For example, two or more further displays (20) may be added to an existing display (10) to provide yet further available display area, each display with or without an associated emissive transparent refractor (21).
Although the above embodiments refer to the use of a liquid crystal displays, it will be understood that these are not essential and that any alternative displays technologies may be employed, whether non-emissive or self-emissive, provided the or each front display is at least partially transparent.
Figure 8 shows a yet further embodiment of the present invention, addressing a shortcoming of the above-described TOLED - based embodiment. As light is emitted equally from both surfaces of the TOLED, areas of the TOLED overlapping regions of text or graphics on the rearward screen (10) will appear grey (in the case of a display using monochrome LCD screens) instead of black, due to the extra luminance emitted towards the viewer by TOLED. As the light transmitted from the TOLED through front screen (20) has no interaction with the rearward display (20), it is impossible to overcome this drawback without intervening in the optical path of the light. Unlike a light guide (2), it is difficult to restrict the emission of light to only one surface without affecting the transparency of the TOLED (30).
This difficulty is overcome in the embodiment shown in figure 8 by incorporation of a wire grid polariser (44) between the TOLED (30) and the front (20) screen and an optical retarder (45) located between the TOLED (30) and rearward screen (10).
The passage of light emitted from the TOLED (30) layer is described with reference to stages 46-53 with reference to the associated Jones vectors and matrices.
In this embodiment, the TOLED (30) is configured to emit polarised light. Initially, light is emitted (stage 46) from both sides of the TOLED (30) towards the front (20) and rearward (10 ) displays, each represented by the Jones Vector (46) of
Figure imgf000022_0001
The light (47) emitted towards the front display (20) is reflected from the wire grid polariser (44) and passes back through the TOLED (30), summing with the light (48) originally emitted towards the rear screen (10) (of the same polarisation) with the resultant light (49) having a Jones Vector of
The resultant linearly polarised illumination (49) passes through the optical retarder (45) which applies a corresponding phase shift. In the embodiment shown the retarder (45) produces a quarter wavelength phase shift, as denoted by its corresponding Jones matrix "1 0 ' 0 -z
The resultant transmission is given by the equation;
Figure imgf000023_0003
-i).
The resultant retarded light (50) is reflected by the liquid crystal of the rear cholesteric display (10), which behaves essentially as a circular polariser. Given that the Jones iπ_ ej [ l ~ matrix of the rear display is 2 L~ 'J , the resultant reflected light (51) is described by the equation;
Figure imgf000023_0001
The reflected light (51) is then re-transmitted through the retarder (45) with a further quarter wave retardation wit a resultant linearly polarised output given by the equation;
Figure imgf000023_0002
The light (51) transmitted through the retarder (45) passes again through the TOLED
"1 ol layer (30). As the Jones matrix of the TOLED (30) is the identity matrix 0 1 the resultant effect of the transmission, as given by the equation;
Figure imgf000024_0001
leaves the resultant light (53) unchanged.
The light (53) re-transmitted through the TOLED (30) then passes through the wire grid ro oi polariser (44) described by a Jones matrix of o 1 with the resultant transmitted light (54) given by the equation;
Figure imgf000024_0002
v).
The resultant light (54) transmitted through the wire grid polariser (44) preserves all the polarising attributes of each portion of the any image generated on the rear screen (10), maintaining the relative luminosity between the darkened and light areas. In the embodiment shown in figure 8, this light (54) then passes through the front screen (20).
However, in alternative embodiments, the combination of the TOLED (30), wire grid polariser (44) and (optionally) the optical retarder (45), collectively forming an illumination assembly (55) may be located in front of a multi-screen display or even used as a transparent illumination means enabling a user to illuminate a scene whilst viewing the scene from the same axis as the illumination source.
The inclusion of the retarder (45) is optional depending on the reflective properties of the rear display (10). The retarder (45) is thus used to correct the oscillation plane of the electric field (i.e. the polarisation) to ensure the eventual transmission through the wire grid polariser (44) is achieved with the minimum of absorption losses.
In the above example, the rear display (10) is a cholesteric transflective liquid crystal, which acts as a circular polariser. Dependent on the polarisation of the incident light (49), the light reflected from the rear screen (10) may be one of the following: i. the incident light is randomly polarized in which case that which is reflected will be circularly polarized;
i. the incident light is linearly polarized in which case it will emerge circularly polarized;
the incident light is elliptically polarized in which case it will emerge as elliptically polarized.
The retarder (45) is thus incorporated only if required to alter the polarization orientation of the light reflected from the rear screen (10) before it being transmitted or reflected by the wire grid polariser (44).
Figure 9 shows an embodiment of the present invention identical to that shown in figure 8, with the exception that the optical retarder (45) is omitted. Like components (10, 20,44, 47) are like numbered. Similarly, the transformation of the light (46, 47, 48, 49) emitted from the TOLED (30), reflected from the wire grid (44), transmitted through the TOLED (30), and that incident on the rear screen (10) is identical to that shown in figure 8 with like reference numbering. The Jones vectors associated with the light (46, 47, 48, 49) and the Jones matrices characterizing the front screen (20), rear screen (10), TOLED (30) and wire grid polariser (44) are also identical to the previous embodiment.
Thus, considering the situation following the incidence of light (49) on to the rear screen
(10) that has not passed through a retarder (45), the subsequent transitions are as follows;
"ι " The incident light (49) characterized by the Jones vector L ° J is reflected by rear screen
(10) with a resultant transformation given by the equation;
Figure imgf000025_0001
The reflected light (56) then passes through the TOLED (30) again. As the Jones matrix
"1 0] of the TOLED (30) is the identity matrix L 01 1 , the resultant effect of the transmission as given by the equation;
Figure imgf000026_0001
leaves the resultant light (57) unchanged.
The light (57) transmitted through the TOLED (30) is then transmitted through the wire
"0 0" grid (44) characterized by the Jones matrix L 0 1 to the extent given by the equation;
0 0 1 0 0 1 — i viii).
In accordance with recognised convention, the imaginary component is only considered as a mathematical aid in expressing the polarisation orientation. The resultant output
(58) gives a Jones vector of in comparison with a Jones vector of ' for the corresponding light output (54) produced in the embodiment incorporating a retarder (45). This difference is just a phase shift of 180 degrees with respect to the other. Since the eye integrates over time it cannot distinguish this difference, and the resultant luminance of the both embodiments appears the same.
Thus, when using a cholesteric liquid crystal rear display (10), or other display with the same reflective properties, the retarder (45) may be omitted without detriment. If, however, the rear display (10) and/or any additional optical components that may be placed in the light path from the TOLED (30) to the front screen (20) results in a misalignment between the polarisation axis of the wire grid (44) and the light incident on it, the retarder (45) may be used to correct for misalignment. As visual display unit back lights and other such illumination sources generate heat which may can be difficult to dissipate without constraints on casing design and/or the need for active cooling such as fans. Placing the illumination source forward of the front screen may alleviate such heating issues. Thus, an illumination assembly may, for example, be used with single screen displays to replace backlights in applications such as notebook computers and the like.
In such instances, the wire grid polariser (44) is formed on the inner surface of a substrate, or between substrate layers in a sandwich construction, to protect the delicate wire grid.
Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof.

Claims

CLAIMS;
1. A method of adapting a visual display unit having a first screen in a first focal plane by the addition of one or more at least partially transparent display screens at least partially overlapping said first screen and located in focal planes distinct from said first focal plane, characterised in that;
• an at least partially transparent emissive layer is provided between said first screen and at least one said additional display screen.
2. The method claimed in claim 1, wherein said visual display unit is a personnel digital assistant (PDA).
3. The method claimed in claim 1, wherein said emissive layer is a sheet with substantially planar opposed upper and a lower surfaces and a peripheral boundary of a prescribed thickness, said sheet formed from a material such that light rays incident from said peripheral boundary are retained between the said planar surface through total internal refraction at angles less than a critical angle.
4. The method claimed in claim 3 , wherein at least one said sheet planar surface has a plurality of defined features located thereupon capable of refracting a said retained light ray incident on a said feature through an angle greater than the said critical angle of total internal reflection sufficient to exit said sheet via one of said planar surfaces.
5. The method claimed in claim 4, wherein said features include diffusion dots, predetermined scratches, indentations, grooves, protrusions, regular or irregular undulations and the like.
6. The method claimed in any one of claims 3-5, wherein at least one light source is located along said peripheral edge.
7. The method claimed in claim 6, wherein said light source is a cold cathode fluorescent tube.
8. The method claimed in claim 6, wherein said light source is an array of light emitting diodes.
9. The method claimed in any one of claims 3-8, wherein said emissive layer is configured to refract the ray axis of light at the said peripheral border such that the peripheral border between adjacent screens is not visible along said viewer's sightline.
10. The method claimed in any one of claims 4-9, wherein the said features are distributed with an increasing density as a function of distance from said light source.
11. The method claimed in claim 10, wherein said function is quadratic.
12. The method claimed in any one of claims 3-11, wherein the said prescribed thickness of the emissive sheet is reduced as a function of distance from a said light source.
13. The method claimed in any one of claims 1-12, wherein said emissive layer is formed from a light guide.
14. The method claimed in claim 1 or claim 2, wherein said emissive layer is formed from a transparent organic light emitting diode (TOLED) assembly.
15. The method as claimed in claim 1 or claim 2, wherein said emissive layer is a polarised transparent organic light emitting diode TOLED emissive layer located between a front screen and a rear screen, wherein said visual display unit further includes;
• a wire grid polariser interposed between the TOLED and the front and screen.
16. The method as claimed in claim 15 , further including an optical retarder interposed between the TOLED and the rear screen.
17. The method as claimed in claim 16, wherein the optical retarder is a quarter wave retarder.
18. The method claimed in any one of the preceding claims, wherein said screens are liquid crystal displays.
19. The method as claimed in any one of the preceding claims, wherein said first screen is a cholesteric LCD display.
20. The method as claimed in any one of the preceding claims, wherein said first screen reflects between 10-100% of incident illumination.
21. A visual display unit produced by the method claimed in any one of claims 1-20.
22. A visual display unit having two or more at least partially overlapping display screen(s) located in distinct focal planes, at least one said screen being at least partially transparent;
characterised in that an at least partially transparent emissive layer is provided between said screens.
23. The visual display unit claimed in claim 21 or claim 22, wherein said emissive layer is a sheet with substantially planar opposed upper and a lower surfaces and a peripheral boundary of a prescribed thickness, said sheet formed from a material such that light rays incident from said peripheral boundary are retained between the said planar surface through total internal refraction at angles less than a critical angle.
24. The visual display unit claimed in claim 23, wherein at least one said sheet planar surface has a plurality of defined features located thereupon capable of refracting a said retained light ray incident on a said feature through an angle greater than the said critical angle of total internal reflection sufficient to exit said sheet via one of said planar surfaces.
25. The visual display unit claimed in claim 24, wherein said features include diffusion dots, predetermined scratches, indentations, grooves, protrusions, regular or irregular undulations and the like.
26. The visual display unit claimed in any one of claims 23-25, wherein at least one light source is located along said peripheral edge.
27. The visual display unit claimed in claim 26, wherein said light source is a cold cathode fluorescent tube.
28. The visual display unit claimed in claim 26, wherein said light source is an array of light emitting diodes
29. The visual display unit claimed in any one of claims 23-28, wherein said emissive layer is configured to refract the ray axis of light at the said peripheral border such that the peripheral border between adjacent screens is not visible along said viewer's sightline.
30. The visual display unit claimed in any one of claims 24-29, wherein the said features are distributed with an increasing density as a function of distance from said light source.
31. The visual display unit claimed in claim 30, wherein said function is quadratic.
32. The visual display unit claimed in any one of claims 23-31, wherein the said prescribed thickness of the emissive sheet is reduced as a function of distance from a said light source.
33. The visual display unit as claimed in any one of claims 21-33 wherein said emissive layer is formed from a light guide.
34. The visual display unit as claimed in claim 21 or claim 22, wherein said emissive layer is formed from a transparent organic light emitting diode (TOLED) assembly.
35. The visual display unit as claimed in claim 21 or claim 22, wherein said emissive layer is a polarised TOLED emissive layer located between a front screen and a rear screen, wherein said visual display unit further includes;
• a wire grid polariser interposed between the TOLED and the front screen.
36. The visual display unit as claimed in claim 35, further including an optical retarder interposed between the TOLED and the rear screen.
37. The visual display unit as claimed in claim 36, wherein the optical retarder is a quarter wave retarder.
38. The visual display unit as claimed in any one of claims 35-37, wherein a polarisation axis of the wire grid is arranged to reflect polarised light emitted from the TOLED back through the TOLED towards the rear screen.
39. The visual display unit as claimed in claim 35, wherein light reflected from said wire grid polariser passes through an optical retarder before being reflected by said rear screen.
40. The visual display unit as claimed in claim 36 or claim 37, wherein light reflected by the rear screen passes a second time through the optical retarder, and the TOLED, before passing through the wire grid polariser and the front screen.
41. The visual display unit as claimed in claim 39, wherein light reflected from said wire grid polariser is then reflected by said rear screen.
42. The visual display unit as claimed in claim 41, wherein light reflected by the rear screen passes through the TOLED, before passing through the wire grid polariser and the front screen.
43. The visual display unit as claimed in any one of claims 22-42, wherein said screens are liquid crystal displays.
44. The visual display unit as claimed in any one of claims 22-43, wherein said rear screen is a cholesteric LCD display.
45. The visual display unit as claimed in any one of claims 22-44, wherein said first screen reflects between 10-100% of incident illumination.
46. The visual display unit as claimed in any one of claims 21-45, wherein one or more additional screens may be located between the said front and rear screens.
47. An illumination assembly including;
• a polarised transparent organic light emitting diode (TOLED) and a wire grid polariser located between the TOLED and an observer viewing the visual display unit.
48. The illumination assembly as claimed in claim 47 wherein said assembly further includes an optical retarder between the TOLED and a rear of the display.
49. A method of re-cycling light for display illumination in a visual display unit including;
• two or more at least partially overlapping display screen(s) located in distinct focal planes, at least one said screen being at least partially transparent;
• a polarised transparent organic light emitting diode (TOLED) located between said screens;
• a wire grid polariser interposed between the TOLED and a front screen,
wherein a polarisation axis of the wire grid is arranged to reflect polarised light emitted from the TOLED back through the TOLED towards the rear screen;
said method including the steps of:
• emitting polarised light from both sides of the TOLED;
• reflecting from the wire grid polariser the light emitted towards the front screen, and then
• reflecting the light from said rear screen before being passed through said TOLED and said front screen;
50. The method claimed in claim 49, wherein said screen further includes an optical retarder interposed between the TOLED and a rear screen, said method including the step of:
• passing the light reflected from said wire grid polariser through an optical retarder before being reflected by said rear screen;
passing the light reflected from rear screen through said optical retarder for a second time before being reflected by said rear screen;
51. A method as claimed in any one of claims 1-20 and substantially as hereinbefore described with reference to, and as shown in figures 2-9.
52. A visual display unit as claimed in any one of claims 21-46 and substantially as hereinbefore described with reference to, and as shown in figures 2-9.
53. An illumination assembly as claimed in any one of claims 47-48 and substantially as hereinbefore described with reference to, and as shown in figures 8-9.
54. A method as claimed in any one of claims 49-50 and substantially as hereinbefore described with reference to, and as shown in figures 8-9.
PCT/NZ2002/000213 2001-10-11 2002-10-11 Visual display unit illumination WO2003032058A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US10/492,624 US8149353B2 (en) 2001-10-11 2002-10-11 Visual display unit illumination
US13/438,833 US8687149B2 (en) 2001-10-11 2012-04-03 Visual display unit illumination
US14/192,619 US9721378B2 (en) 2001-10-11 2014-02-27 Display interposing a physical object within a three-dimensional volumetric space

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
NZ514500A NZ514500A (en) 2001-10-11 2001-10-11 A multiplane visual display unit with a transparent emissive layer disposed between two display planes
NZ514500 2001-10-11

Related Child Applications (3)

Application Number Title Priority Date Filing Date
US10/492,624 A-371-Of-International US8149353B2 (en) 2001-10-11 2002-10-11 Visual display unit illumination
US10492624 A-371-Of-International 2002-10-11
US13/438,833 Continuation US8687149B2 (en) 2001-10-11 2012-04-03 Visual display unit illumination

Publications (1)

Publication Number Publication Date
WO2003032058A1 true WO2003032058A1 (en) 2003-04-17

Family

ID=19928765

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/NZ2002/000213 WO2003032058A1 (en) 2001-10-11 2002-10-11 Visual display unit illumination

Country Status (5)

Country Link
US (6) US8149353B2 (en)
JP (1) JP2017513044A (en)
NZ (1) NZ514500A (en)
RU (1) RU2678658C2 (en)
WO (1) WO2003032058A1 (en)

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005081038A1 (en) * 2004-02-21 2005-09-01 Koninklijke Philips Electronics N.V. Optical path length adjuster
EP1544657A3 (en) * 2003-12-19 2006-07-12 Barco N.V. Broadband full white reflective display structure
WO2006112740A1 (en) * 2005-04-22 2006-10-26 Puredepth Limited Multilayer display with active and passive matrix display layers
US7347556B2 (en) 2005-06-07 2008-03-25 The Boeing Company Systems and methods for generating stereo images
CN102722021A (en) * 2004-09-27 2012-10-10 高通Mems科技公司 Touchscreens for displays
US8848294B2 (en) 2010-05-20 2014-09-30 Qualcomm Mems Technologies, Inc. Method and structure capable of changing color saturation
US8861071B2 (en) 2004-09-27 2014-10-14 Qualcomm Mems Technologies, Inc. Method and device for compensating for color shift as a function of angle of view
US8872085B2 (en) 2006-10-06 2014-10-28 Qualcomm Mems Technologies, Inc. Display device having front illuminator with turning features
US8902484B2 (en) 2010-12-15 2014-12-02 Qualcomm Mems Technologies, Inc. Holographic brightness enhancement film
US8928682B2 (en) 2009-07-07 2015-01-06 Pure Depth Limited Method and system of processing images for improved display
US8979349B2 (en) 2009-05-29 2015-03-17 Qualcomm Mems Technologies, Inc. Illumination devices and methods of fabrication thereof
US9019183B2 (en) 2006-10-06 2015-04-28 Qualcomm Mems Technologies, Inc. Optical loss structure integrated in an illumination apparatus
US9019590B2 (en) 2004-02-03 2015-04-28 Qualcomm Mems Technologies, Inc. Spatial light modulator with integrated optical compensation structure
US9025235B2 (en) 2002-12-25 2015-05-05 Qualcomm Mems Technologies, Inc. Optical interference type of color display having optical diffusion layer between substrate and electrode
US9244212B2 (en) 2008-01-30 2016-01-26 Qualcomm Mems Technologies, Inc. Illumination device having a tapered light guide
US9292150B2 (en) 2003-05-16 2016-03-22 Pure Depth Limited Display control system
US9524700B2 (en) 2009-05-14 2016-12-20 Pure Depth Limited Method and system for displaying images of various formats on a single display
CN107991783A (en) * 2018-01-30 2018-05-04 京东方科技集团股份有限公司 3d display device
CN109696770A (en) * 2019-02-28 2019-04-30 上海天马微电子有限公司 Display module and display device

Families Citing this family (111)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070072665A1 (en) * 2001-09-28 2007-03-29 Igt, A Nevada Corporation Methods, Apparatuses And Systems for Multilayer Gaming
NZ514500A (en) 2001-10-11 2004-06-25 Deep Video Imaging Ltd A multiplane visual display unit with a transparent emissive layer disposed between two display planes
US20090124383A1 (en) * 2007-11-09 2009-05-14 Igt Apparatus for use with interactive table games and methods of use
US8715058B2 (en) 2002-08-06 2014-05-06 Igt Reel and video combination machine
US20050153775A1 (en) * 2004-01-12 2005-07-14 Griswold Chauncey W. Multiple-state display for a gaming apparatus
US20070004513A1 (en) * 2002-08-06 2007-01-04 Igt Gaming machine with layered displays
US7841944B2 (en) * 2002-08-06 2010-11-30 Igt Gaming device having a three dimensional display device
TW583466B (en) * 2002-12-09 2004-04-11 Hannstar Display Corp Structure of liquid crystal display
KR100509763B1 (en) * 2003-03-11 2005-08-25 엘지전자 주식회사 Front filter of plasma display panel
US7111782B2 (en) * 2003-04-01 2006-09-26 John Paul Homewood Systems and methods for providing security in a voting machine
US7205959B2 (en) * 2003-09-09 2007-04-17 Sony Ericsson Mobile Communications Ab Multi-layered displays providing different focal lengths with optically shiftable viewing formats and terminals incorporating the same
US7857700B2 (en) * 2003-09-12 2010-12-28 Igt Three-dimensional autostereoscopic image display for a gaming apparatus
US9564004B2 (en) 2003-10-20 2017-02-07 Igt Closed-loop system for providing additional event participation to electronic video game customers
US20070155469A1 (en) * 2003-10-20 2007-07-05 Sam Johnson Automatic funding of paragames on electronic gaming platform
US7309284B2 (en) * 2004-01-12 2007-12-18 Igt Method for using a light valve to reduce the visibility of an object within a gaming apparatus
US7488252B2 (en) * 2004-11-05 2009-02-10 Igt Single source visual image display distribution on a gaming machine
US9613491B2 (en) 2004-12-16 2017-04-04 Igt Video gaming device having a system and method for completing wagers and purchases during the cash out process
US7914368B2 (en) 2005-08-05 2011-03-29 Jay Chun Methods and systems for playing baccarat jackpot with an option for insurance betting
US7922587B2 (en) 2005-01-24 2011-04-12 Jay Chun Betting terminal and system
US8210920B2 (en) 2005-01-24 2012-07-03 Jay Chun Methods and systems for playing baccarat jackpot
US8920238B2 (en) 2005-01-24 2014-12-30 Jay Chun Gaming center allowing switching between games based upon historical results
US20060166726A1 (en) 2005-01-24 2006-07-27 Jay Chun Methods and systems for playing baccarat jackpot
US9940778B2 (en) 2005-01-24 2018-04-10 Igt System for monitoring and playing a plurality of live casino table games
US8308559B2 (en) 2007-05-07 2012-11-13 Jay Chun Paradise box gaming system
JP5144006B2 (en) * 2005-07-25 2013-02-13 ペンタックスリコーイメージング株式会社 Camera with display screen
US7878910B2 (en) * 2005-09-13 2011-02-01 Igt Gaming machine with scanning 3-D display system
US8784196B2 (en) 2006-04-13 2014-07-22 Igt Remote content management and resource sharing on a gaming machine and method of implementing same
US8777737B2 (en) 2006-04-13 2014-07-15 Igt Method and apparatus for integrating remotely-hosted and locally rendered content on a gaming device
US10026255B2 (en) 2006-04-13 2018-07-17 Igt Presentation of remotely-hosted and locally rendered content for gaming systems
US9028329B2 (en) 2006-04-13 2015-05-12 Igt Integrating remotely-hosted and locally rendered content on a gaming device
US8992304B2 (en) 2006-04-13 2015-03-31 Igt Methods and systems for tracking an event of an externally controlled interface
US8968077B2 (en) * 2006-04-13 2015-03-03 Idt Methods and systems for interfacing with a third-party application
US8512139B2 (en) * 2006-04-13 2013-08-20 Igt Multi-layer display 3D server based portals
US20070243928A1 (en) * 2006-04-13 2007-10-18 Igt Casino gaming incentives using game themes, game types, paytables, denominations
IL176673A0 (en) * 2006-07-03 2007-07-04 Fermon Israel A variably displayable mobile device keyboard
KR20090094241A (en) * 2006-10-06 2009-09-04 퀄컴 엠이엠스 테크놀로지스, 인크. Thin light bar and method of manufacturing
US8107155B2 (en) 2006-10-06 2012-01-31 Qualcomm Mems Technologies, Inc. System and method for reducing visual artifacts in displays
WO2008045311A2 (en) 2006-10-06 2008-04-17 Qualcomm Mems Technologies, Inc. Illumination device with built-in light coupler
US20090156303A1 (en) * 2006-11-10 2009-06-18 Igt Bonusing Architectures in a Gaming Environment
US9311774B2 (en) * 2006-11-10 2016-04-12 Igt Gaming machine with externally controlled content display
US8360847B2 (en) 2006-11-13 2013-01-29 Igt Multimedia emulation of physical reel hardware in processor-based gaming machines
US8142273B2 (en) * 2006-11-13 2012-03-27 Igt Presentation of wheels on gaming machines having multi-layer displays
US8727855B2 (en) * 2006-11-13 2014-05-20 Igt Three-dimensional paylines for gaming machines
US8199068B2 (en) * 2006-11-13 2012-06-12 Igt Single plane spanning mode across independently driven displays
US8192281B2 (en) * 2006-11-13 2012-06-05 Igt Simulated reel imperfections
US20080113747A1 (en) * 2006-11-13 2008-05-15 Igt Mechanical reel hardware simulation using multiple layer displays
US8357033B2 (en) * 2006-11-13 2013-01-22 Igt Realistic video reels
US8210922B2 (en) * 2006-11-13 2012-07-03 Igt Separable game graphics on a gaming machine
US20080122865A1 (en) * 2006-11-29 2008-05-29 Arthur Vanmoor Method of Showing Images at Different Depths and Display Showing Images at Different Depths
US9292996B2 (en) 2006-12-19 2016-03-22 Igt Distributed side wagering methods and systems
US8616953B2 (en) * 2007-08-31 2013-12-31 Igt Reel symbol resizing for reel based gaming machines
US8115700B2 (en) * 2007-09-20 2012-02-14 Igt Auto-blanking screen for devices having multi-layer displays
US8012010B2 (en) * 2007-09-21 2011-09-06 Igt Reel blur for gaming machines having simulated rotating reels
US8758144B2 (en) * 2007-10-23 2014-06-24 Igt Separable backlighting system
US8210944B2 (en) 2007-10-29 2012-07-03 Igt Gaming system having display device with changeable wheel
US7949213B2 (en) * 2007-12-07 2011-05-24 Qualcomm Mems Technologies, Inc. Light illumination of displays with front light guide and coupling elements
US8654061B2 (en) * 2008-02-12 2014-02-18 Qualcomm Mems Technologies, Inc. Integrated front light solution
US8118468B2 (en) * 2008-05-16 2012-02-21 Qualcomm Mems Technologies, Inc. Illumination apparatus and methods
JP2011526053A (en) * 2008-06-04 2011-09-29 クォルコム・メムズ・テクノロジーズ・インコーポレーテッド Reduction method of edge shadow for prism front light
KR101045264B1 (en) * 2008-09-09 2011-06-29 네오뷰코오롱 주식회사 Display apparatus, mobile device having the same and display control method
KR101097453B1 (en) * 2008-09-09 2011-12-23 네오뷰코오롱 주식회사 Keypad apparatus, mobile device having the same and keypad control method
US20100083430A1 (en) * 2008-10-06 2010-04-08 David Chen Touch Control Toilet Seat Device
US8810758B2 (en) * 2009-03-24 2014-08-19 Jay Ahling Dual-function alignment layer for liquid crystal devices to improve degradation resistance to radiation
CN102365864B (en) * 2009-03-27 2015-08-26 皇家飞利浦电子股份有限公司 For being placed in the device in display unit front
KR101654055B1 (en) * 2009-04-17 2016-09-05 엘지전자 주식회사 Mobile terminal
DE102009022222A1 (en) * 2009-05-20 2010-11-25 Giesecke & Devrient Gmbh Arrangement for the display of information, methods for displaying information and electronic terminal equipment
KR101045265B1 (en) * 2009-05-29 2011-06-29 네오뷰코오롱 주식회사 Display apparatus
GB2475026A (en) * 2009-08-07 2011-05-11 Alessandro Artusi Display for displaying digital images having improved contrast ratio
US8425316B2 (en) 2010-08-03 2013-04-23 Igt Methods and systems for improving play of a bonus game on a gaming machine and improving security within a gaming establishment
WO2012075056A2 (en) * 2010-11-29 2012-06-07 Saint-Gobain Performance Plastics Corporation Articles including surface microfeatures and methods for forming same
KR101244823B1 (en) * 2010-11-30 2013-03-25 (주)코텍 Display Apparatus For Slot Machine
US8298081B1 (en) 2011-06-16 2012-10-30 Igt Gaming system, gaming device and method for providing multiple display event indicators
US9466173B2 (en) 2011-09-30 2016-10-11 Igt System and method for remote rendering of content on an electronic gaming machine
US9524609B2 (en) 2011-09-30 2016-12-20 Igt Gaming system, gaming device and method for utilizing mobile devices at a gaming establishment
DE102011114702A1 (en) * 2011-09-30 2013-04-04 Blexton Management Ltd. Multi-layer image display device i.e. two-layer image display device, for performing three dimensional multi-level imaging in arcade game machine, has reflection unit for reflecting foreground image at image central line
US8605114B2 (en) 2012-02-17 2013-12-10 Igt Gaming system having reduced appearance of parallax artifacts on display devices including multiple display screens
US9129469B2 (en) 2012-09-11 2015-09-08 Igt Player driven game download to a gaming machine
AU2013327323B2 (en) 2012-10-02 2017-03-30 Igt System and method for providing remote wagering games in live table game system
US20140204039A1 (en) * 2013-01-22 2014-07-24 Adobe Systems Incorporated Compositing display
US8872420B2 (en) 2013-03-15 2014-10-28 Thomas J. Brindisi Volumetric three-dimensional display with evenly-spaced elements
US9423891B2 (en) * 2013-07-16 2016-08-23 Lenovo (Singapore) Pte. Ltd. Shared digitizer
US8821239B1 (en) 2013-07-22 2014-09-02 Novel Tech International Limited Gaming table system allowing player choices and multiple outcomes thereby for a single game
US8684830B1 (en) 2013-09-03 2014-04-01 Novel Tech International Limited Individually paced table game tournaments
US9595159B2 (en) 2013-10-01 2017-03-14 Igt System and method for multi-game, multi-play of live dealer games
CN104391406B (en) * 2014-12-01 2017-10-20 昆山龙腾光电有限公司 Organic LED display device
WO2016138313A1 (en) * 2015-02-26 2016-09-01 Puredepth Inc. A display interposing a physical object within a three-dimensional volumetric space
EP3303241A1 (en) * 2015-06-02 2018-04-11 Corning Incorporated Multi-functional material system for surface display unit
US9916735B2 (en) 2015-07-22 2018-03-13 Igt Remote gaming cash voucher printing system
US10055930B2 (en) 2015-08-11 2018-08-21 Igt Gaming system and method for placing and redeeming sports bets
CN108474943B (en) 2015-10-02 2021-04-27 安波福技术有限公司 Method and system for performing sub-pixel compression to reduce moire interference in a display system including multiple displays
CN108431885B (en) 2015-10-02 2022-03-25 安波福技术有限公司 Method and system for performing color filter shifting to reduce moire interference in a display system comprising multiple displays
CN108770384B (en) 2015-10-02 2021-09-07 安波福技术有限公司 Method and system for reducing Moire interference in a display system including multiple displays using a refractive beam mapper
US10684491B2 (en) 2015-10-02 2020-06-16 Pure Depth Limited Method and system using refractive beam mapper having square element profiles to reduce moire interference in a display system including multiple displays
JP2019510996A (en) 2016-01-20 2019-04-18 アプティブ・テクノロジーズ・リミテッド Method and system for using a refractive beam mapper having a rectangular element profile to reduce Moire interference in a display system comprising a plurality of displays
CN106024844B (en) * 2016-07-27 2019-01-22 京东方科技集团股份有限公司 Organic luminescent device and preparation method thereof, display device
CN109922984A (en) * 2016-09-06 2019-06-21 纯深度有限公司 Multi-layer display for vehicular meter
US10621898B2 (en) 2016-11-23 2020-04-14 Pure Depth Limited Multi-layer display system for vehicle dash or the like
WO2018111939A1 (en) * 2016-12-13 2018-06-21 Mirraviz, Inc. Display screen configured to display viewing position-dependent images
US11150488B2 (en) * 2016-12-14 2021-10-19 Pure Depth Limited Fixed depth display for vehicle instrument panel
US10592188B2 (en) 2016-12-28 2020-03-17 Pure Death Limited Content bumping in multi-layer display systems
US10083640B2 (en) 2016-12-29 2018-09-25 Pure Depth Limited Multi-layer display including proximity sensor and depth-changing interface elements, and/or associated methods
US10500957B2 (en) * 2017-01-27 2019-12-10 Denso International America, Inc. Meter cluster and meter cluster system
WO2018191550A1 (en) 2017-04-13 2018-10-18 Mirraviz, Inc. Retroreflective display systems configured to display images using shaped light profile
WO2018213407A1 (en) * 2017-05-17 2018-11-22 Pure Depth, Inc. Method and system for reducing fresnel depolarization to improve image contrast in display system including multiple displays
DE102017212912B4 (en) * 2017-07-27 2022-08-18 Audi Ag Display device for a motor vehicle, method for operating a display device, control device, and motor vehicle
US20190213961A1 (en) * 2018-01-05 2019-07-11 Visteon Global Technologies, Inc. Display assembly with unbalanced backlight to manage windowing effect
TWI650581B (en) * 2018-08-08 2019-02-11 國立中央大學 High contrast double transparent display
WO2021118223A1 (en) * 2019-12-10 2021-06-17 Samsung Electronics Co., Ltd. Display apparatus and method of controlling thereof
RU202859U1 (en) * 2020-08-03 2021-03-11 Общество с ограниченной ответственностью "Эй Ви Эй Системс" Mobile display
US20220198420A1 (en) * 2020-12-17 2022-06-23 Toshiba Global Commerce Solutions Holdings Corporation Self-checkout systems using overlapping display devices
CN113035054B (en) * 2021-04-13 2022-10-25 深圳市传光显示技术有限公司 Outdoor low-power consumption display screen with intelligent lighting system

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5537233A (en) * 1993-11-25 1996-07-16 Sanyo Electric Co., Ltd. Direct-vision/projection type liquid-crystal display having light source at the edge of a gap between two liquid crystal panels
JP2000113988A (en) * 1998-10-08 2000-04-21 Stanley Electric Co Ltd Organic el display device and its lighting method
WO2000049453A1 (en) * 1999-02-17 2000-08-24 Central Research Laboratories Limited Liquid crystal display
EP1046944A2 (en) * 1999-04-13 2000-10-25 Mannesmann VDO Aktiengesellschaft Self illuminating LCD device
EP1081774A2 (en) * 1999-09-01 2001-03-07 Lucent Technologies Inc. Process for fabricating polarized organic photonics devices
EP1093008A1 (en) * 1999-10-14 2001-04-18 Elop Electro-Optics Industries Ltd. Multi-layer three-dimensional display
US20020064037A1 (en) * 2000-11-25 2002-05-30 Lee Pyung Yong Backlight unit of bi-directional irradiation for liquid crystal display device
US20020105516A1 (en) * 2000-11-06 2002-08-08 Tracy Thomas M. Method and apparatus for displaying an image in three dimensions
EP1231757A2 (en) * 2001-02-07 2002-08-14 Hyundai Curitel, Inc. Folder-type mobile communication terminal having double-sided LCD

Family Cites Families (239)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2543793A (en) * 1946-11-16 1951-03-06 Alvin M Marks Three-dimensional intercommunicating system
US2961486A (en) * 1951-03-05 1960-11-22 Alvin M Marks Three-dimensional display system
US3536921A (en) * 1967-03-31 1970-10-27 Texas Instruments Inc Passive control of focal distances
US3605594A (en) * 1968-08-22 1971-09-20 Hendrik Jurjen Gerritsen Three dimensional optical photography projection system
US3622224A (en) * 1969-08-20 1971-11-23 Xerox Corp Liquid crystal alpha-numeric electro-optic imaging device
US3918796A (en) * 1971-02-09 1975-11-11 Hoffmann La Roche Liquid-crystal non-linear light modulators using electric and magnetic fields
JPS4996628U (en) 1972-12-15 1974-08-21
JPS589634B2 (en) * 1973-01-16 1983-02-22 ミノルタ株式会社 Color TV Ni Okeru Iromura Boushisouchi
US3891305A (en) * 1973-05-08 1975-06-24 Lester Fader Apparatus for simulating a three-dimensional image by use of plural image producing surfaces
DE2329014C2 (en) * 1973-06-07 1983-04-28 Agfa-Gevaert Ag, 5090 Leverkusen Screen arrangement with at least one liquid crystal element
DE2329618A1 (en) * 1973-06-09 1975-01-02 Fraunhofer Ges Forschung ARRANGEMENT FOR MULTICOLORED DISPLAY, CONSISTING OF LIGHT SOURCE AND LINEAR POLARIZATION FILTER
US3863246A (en) * 1973-07-09 1975-01-28 Collins Radio Co Backlighted display apparatus for preventing direct viewing of light sources
JPS5636523B2 (en) 1973-12-26 1981-08-25
DE2404127C3 (en) * 1974-01-29 1979-05-17 Siemens Ag, 1000 Berlin Und 8000 Muenchen Liquid crystal display
GB1448520A (en) 1974-10-25 1976-09-08 Standard Telephones Cables Ltd Stereoscopic display device
GB1543599A (en) * 1976-05-04 1979-04-04 Standard Telephones Cables Ltd Liquid crystal cell
US4114983A (en) * 1977-02-18 1978-09-19 Minnesota Mining And Manufacturing Company Polymeric optical element having antireflecting surface
DE2730785C2 (en) 1977-07-07 1986-01-30 Bruce A. Greenwich Conn. Rosenthal Optical system with lenticular lens
US4190856A (en) * 1977-11-21 1980-02-26 Ricks Dennis E Three dimensional television system
US4333715A (en) * 1978-09-11 1982-06-08 Brooks Philip A Moving picture apparatus
US4294516A (en) * 1978-09-11 1981-10-13 Brooks Philip A Moving picture apparatus
GB2040134A (en) * 1978-11-09 1980-08-20 Marconi Co Ltd Stereoscopic television systems
JPS567916A (en) 1979-07-02 1981-01-27 Mitsubishi Heavy Ind Ltd Air regulator for burner combustion device
JPS5694386A (en) * 1979-12-27 1981-07-30 Suwa Seikosha Kk Liquiddcrystal display unit
JPS57119389A (en) 1981-01-17 1982-07-24 Omron Tateisi Electronics Co Liquid crystal display device
JPS57191674A (en) * 1981-05-22 1982-11-25 Hitachi Ltd Liquid crystal display element
US4523848A (en) * 1981-10-01 1985-06-18 National Research Development Corporation Polariscope
US4447141A (en) * 1982-05-07 1984-05-08 Arthur Eisenkraft Vision testing system
US4472737A (en) * 1982-08-31 1984-09-18 Tokyo Shibaura Denki Kabushiki Kaisha Stereographic tomogram observing apparatus
US4541692A (en) * 1983-05-31 1985-09-17 General Electric Company Transflective liquid crystal display with enhanced contrast ratio
JPS6024502A (en) 1983-07-21 1985-02-07 Mitsui Toatsu Chem Inc Phase difference plate
US4649425A (en) * 1983-07-25 1987-03-10 Pund Marvin L Stereoscopic display
JPS60103895A (en) 1983-11-11 1985-06-08 Matsushita Electric Ind Co Ltd Stereoscopic television device
US4736214A (en) * 1984-01-09 1988-04-05 Rogers Robert E Apparatus and method for producing three-dimensional images from two-dimensional sources
US4613896A (en) * 1984-03-30 1986-09-23 Dainippon Screen Mfg. Co., Ltd. Methods and apparatus for avoiding moire in color scanners for graphic art
JPS60233684A (en) 1984-05-07 1985-11-20 スタンレー電気株式会社 Laminate type lcd device
JPS60244924A (en) 1984-05-21 1985-12-04 Citizen Watch Co Ltd Multi-layered liquid crystal panel
US4734295A (en) * 1985-01-07 1988-03-29 Liu P Dong Guang Glare control
JPS61166524A (en) 1985-01-18 1986-07-28 Canon Inc Liquid crystal display device
US5107352A (en) * 1985-03-01 1992-04-21 Manchester R & D Partnership Multiple containment mediums of operationally nematic liquid crystal responsive to a prescribed input
JPS61200783A (en) 1985-03-01 1986-09-05 Riken Ii M C Kk Light transmitting plate for display device
US4670744A (en) * 1985-03-14 1987-06-02 Tektronix, Inc. Light reflecting three-dimensional display system
JPS6267094A (en) 1985-09-18 1987-03-26 Mitsubishi Chem Ind Ltd Crystalline oxytitanium phthalocyanine and photosensitive material for electrophotography
JPS62122494A (en) 1985-11-22 1987-06-03 Ricoh Co Ltd Stereoscopic vision device
JPS62161294A (en) 1986-01-11 1987-07-17 Pioneer Electronic Corp Stereoscopic tv adapter
JPH0629914B2 (en) 1986-02-18 1994-04-20 シャープ株式会社 Pseudo stereoscopic display system
JPS62191819A (en) 1986-02-18 1987-08-22 Toshiba Corp Stereoscopic image display device
US4768300A (en) * 1986-03-28 1988-09-06 Stewart Warner Corporation Illuminated information display
JPS62235929A (en) 1986-04-07 1987-10-16 Stanley Electric Co Ltd Displaying method for stereoscopic image using liquid crystal display element
JPS6339299A (en) 1986-08-04 1988-02-19 Sony Corp Display device
JPS63100898A (en) 1986-10-17 1988-05-02 Hitachi Ltd Stereoscopic television set
JPS63203088A (en) 1987-02-18 1988-08-22 Victor Co Of Japan Ltd Stereoscopic view reproducing device for television receiver
JPS63274918A (en) 1987-05-06 1988-11-11 Jeco Co Ltd Liquid crystal stereoscopic display device
JPH0742101Y2 (en) * 1987-05-29 1995-09-27 矢崎総業株式会社 Instrument
GB8716369D0 (en) * 1987-07-10 1987-08-19 Travis A R L Three-dimensional display device
US5046826A (en) * 1987-09-19 1991-09-10 Canon Kabushiki Kaisha Illuminator and display panel employing the illuminator
AU610249B2 (en) * 1987-09-29 1991-05-16 Microelectronics And Computer Technology Corporation Customizable circuitry
US4792850A (en) * 1987-11-25 1988-12-20 Sterographics Corporation Method and system employing a push-pull liquid crystal modulator
US5032007A (en) 1988-04-07 1991-07-16 Honeywell, Inc. Apparatus and method for an electronically controlled color filter for use in information display applications
US5086354A (en) * 1989-02-27 1992-02-04 Bass Robert E Three dimensional optical viewing system
US5112121A (en) * 1989-03-21 1992-05-12 Chang David B Display system for multiviewer training simulators
JPH02262119A (en) 1989-03-31 1990-10-24 Nec Corp Three-dimentional display system by laminated liquid crystal display device
US5046827C1 (en) * 1989-07-20 2001-08-07 Honeywell Inc Optical reconstruction filter for color mosaic displays
JPH03101581A (en) 1989-09-14 1991-04-26 Toshiba Corp Stereoscopic picture display device
US5695346A (en) * 1989-12-07 1997-12-09 Yoshi Sekiguchi Process and display with moveable images
JPH03233548A (en) 1990-02-09 1991-10-17 Toshiba Corp Projection type liquid crystal display device
US5113272A (en) 1990-02-12 1992-05-12 Raychem Corporation Three dimensional semiconductor display using liquid crystal
WO1991015930A2 (en) 1990-04-05 1991-10-17 Raychem Corporation Three dimensional display
GB2245092A (en) 1990-04-23 1991-12-18 Tfe Hong Kong Limited Multilayer liquid crystal display.
JPH0434595A (en) 1990-05-31 1992-02-05 Fujitsu General Ltd Picture composing method
JPH0434521A (en) 1990-05-31 1992-02-05 Sanyo Electric Co Ltd Stereoscopic liquid crystal display
US5990990A (en) 1990-08-03 1999-11-23 Crabtree; Allen F. Three-dimensional display techniques, device, systems and method of presenting data in a volumetric format
JPH04107540A (en) 1990-08-28 1992-04-09 Mitsubishi Electric Corp Back projection type television
WO1992009003A1 (en) 1990-11-14 1992-05-29 Chisso Corporation Liquid crystal shuttering device
JP3112485B2 (en) 1991-01-22 2000-11-27 オリンパス光学工業株式会社 3D electronic still camera
US5124803A (en) * 1991-02-25 1992-06-23 Ecrm Method and apparatus for generating digital, angled halftone screens using pixel candidate lists and screen angle correction to prevent moire patterns
GB9108226D0 (en) * 1991-04-17 1991-06-05 Philips Electronic Associated Optical touch input device
US5261404A (en) * 1991-07-08 1993-11-16 Mick Peter R Three-dimensional mammal anatomy imaging system and method
JPH0591545A (en) 1991-09-30 1993-04-09 Toshiba Corp Stereoscopic image recording/reproducing system
JP3091000B2 (en) 1991-11-18 2000-09-25 株式会社リコー Liquid crystal display
DE4300246A1 (en) * 1992-01-08 1993-07-15 Terumo Corp Depth scanner for displaying three=dimensional pictures without lenses - projects collimated light through object to be scanned and condenses light and filters to remove direct flow component
JP3021902B2 (en) 1992-01-17 2000-03-15 エヌティエヌ株式会社 Rolling bearings for semiconductor manufacturing equipment
JP3205373B2 (en) * 1992-03-12 2001-09-04 株式会社日立製作所 Liquid crystal display
US5337181A (en) * 1992-08-27 1994-08-09 Kelly Shawn L Optical spatial filter
JP3006306B2 (en) * 1992-09-16 2000-02-07 インターナショナル・ビジネス・マシーンズ・コーポレイション Optical film and liquid crystal display device using the optical film
US5528259A (en) 1992-10-29 1996-06-18 International Business Machines Corporation Method and system for multi-dimensional scrolling of displayed data collections in a data processing system
US5367801A (en) * 1993-01-25 1994-11-29 Ahn; Young Multi-layer three-dimensional display
JP3034396B2 (en) 1993-02-03 2000-04-17 ローム株式会社 3D display panel
JP3679426B2 (en) * 1993-03-15 2005-08-03 マサチューセッツ・インスティチュート・オブ・テクノロジー A system that encodes image data into multiple layers, each representing a coherent region of motion, and motion parameters associated with the layers.
JPH06274305A (en) * 1993-03-18 1994-09-30 Hitachi Ltd Screen display device and its control method
US5338226A (en) 1993-05-14 1994-08-16 Molex Incorporated Panel mounting system for electrical connectors
GB9316961D0 (en) * 1993-08-14 1994-01-26 Marconi Gec Ltd Display arrangements
US5606165A (en) 1993-11-19 1997-02-25 Ail Systems Inc. Square anti-symmetric uniformly redundant array coded aperture imaging system
US5747152A (en) 1993-12-02 1998-05-05 Dai Nippon Printing Co., Ltd. Transparent functional membrane containing functional ultrafine particles, transparent functional film, and process for producing the same
US5473344A (en) * 1994-01-06 1995-12-05 Microsoft Corporation 3-D cursor positioning device
JPH07209573A (en) 1994-01-24 1995-08-11 Rohm Co Ltd 3-d vision camera
JPH07222202A (en) 1994-02-02 1995-08-18 Rohm Co Ltd Stereoscopic vision camera
US5751385A (en) 1994-06-07 1998-05-12 Honeywell, Inc. Subtractive color LCD utilizing circular notch polarizers and including a triband or broadband filter tuned light source or dichroic sheet color polarizers
US6573961B2 (en) 1994-06-27 2003-06-03 Reveo, Inc. High-brightness color liquid crystal display panel employing light recycling therein
JPH0876139A (en) 1994-07-07 1996-03-22 Sanyo Electric Co Ltd Liquid crystal display device
US6061110A (en) * 1994-10-18 2000-05-09 Kabushiki Kaisha Toshiba Reflection type liquid crystal display device and method of manufacturing the same
JPH0836375A (en) 1995-01-30 1996-02-06 Seiko Epson Corp Display control circuit
CN1126377C (en) 1995-03-08 2003-10-29 皇家菲利浦电子有限公司 Three-dimensional image display system
JP3673007B2 (en) 1995-03-14 2005-07-20 松下電器産業株式会社 Liquid crystal display
EP0733927B1 (en) 1995-03-22 2001-11-07 Canon Kabushiki Kaisha Display apparatus providing a uniform temperature distribution over the display unit
JP3233548B2 (en) 1995-03-31 2001-11-26 株式会社山本製作所 Grain and debris sorting equipment
US5822021A (en) 1996-05-14 1998-10-13 Colorlink, Inc. Color shutter liquid crystal display system
JP2951264B2 (en) 1995-05-24 1999-09-20 三洋電機株式会社 2D / 3D video compatible video display
JPH08335043A (en) 1995-06-09 1996-12-17 Omron Corp Dot matrix image display module and its manufacture
JP2768313B2 (en) * 1995-06-13 1998-06-25 日本電気株式会社 Reflective liquid crystal display
US5764317A (en) * 1995-06-26 1998-06-09 Physical Optics Corporation 3-D volume visualization display
JP2778543B2 (en) 1995-07-27 1998-07-23 日本電気株式会社 3D display device
US6067137A (en) * 1995-08-25 2000-05-23 Kuraray Co., Ltd. Image display apparatus with hydrophobic diffraction grating for an enlarged viewing angle
GB2304921A (en) 1995-09-06 1997-03-26 Thomson Multimedia Sa Stereoscopic display having lenticular lensheet and diffuser
US5706139A (en) 1995-10-17 1998-01-06 Kelly; Shawn L. High fidelity optical system for electronic imaging
US5745197A (en) * 1995-10-20 1998-04-28 The Aerospace Corporation Three-dimensional real-image volumetric display system and method
GB9601049D0 (en) 1996-01-18 1996-03-20 Xaar Ltd Methods of and apparatus for forming nozzles
JP3148622B2 (en) 1996-01-31 2001-03-19 アネスト岩田株式会社 Channel switching mechanism for manifold type automatic gun
GB9608175D0 (en) 1996-04-19 1996-06-26 Ncr Int Inc Method of controlling veiwability of a display screen and a device therefor
US5813742A (en) 1996-04-22 1998-09-29 Hughes Electronics Layered display system and method for volumetric presentation
JPH103355A (en) 1996-06-18 1998-01-06 Fuji Xerox Co Ltd Input display device for oa equipment
GB9613802D0 (en) 1996-07-01 1996-09-04 Nashua Corp Improvements in or relating to light diffusers
US6445833B1 (en) 1996-07-18 2002-09-03 Sanyo Electric Co., Ltd Device and method for converting two-dimensional video into three-dimensional video
US5796509A (en) * 1996-08-21 1998-08-18 International Business Machines Corporation Thin film frontlighting and backlighting for spatial light modulators
SE510642C2 (en) 1996-09-23 1999-06-14 Haakan Lennerstad sign face
JPH10105829A (en) 1996-09-30 1998-04-24 Hitachi Ltd Merchandise information displaying method in electronic mall system on internet
IT1287962B1 (en) 1996-10-14 1998-09-10 S P S Spa LIQUID CRYSTAL DISPLAY DEVICE
US7372447B1 (en) * 1996-10-31 2008-05-13 Kopin Corporation Microdisplay for portable communication systems
JP3339334B2 (en) * 1996-12-05 2002-10-28 松下電器産業株式会社 Reflective liquid crystal display
US5924870A (en) 1996-12-09 1999-07-20 Digillax Systems Lenticular image and method
FR2757461B1 (en) * 1996-12-24 1999-03-19 Magneti Marelli France INDICATOR DEVICE, ESPECIALLY DASHBOARD FOR MOTOR VEHICLE
JPH10186102A (en) 1996-12-26 1998-07-14 Yazaki Corp Anti-reflection film
US5956180A (en) 1996-12-31 1999-09-21 Bass; Robert Optical viewing system for asynchronous overlaid images
US6175399B1 (en) * 1997-02-10 2001-01-16 Sharp Kabushiki Kaisha Reflective type liquid crystal display device having a diffusion layer of phase separated liquid crystal and polymer
JP4011145B2 (en) 1997-02-14 2007-11-21 三菱電機株式会社 Remote control method and apparatus
JP3826474B2 (en) 1997-02-19 2006-09-27 カシオ計算機株式会社 Optical film and manufacturing method thereof
US6147741A (en) 1997-02-25 2000-11-14 Motorola, Inc. Digital scanner employing recorded phase information and method of fabrication
JP3101581B2 (en) 1997-02-27 2000-10-23 富士ゼロックスオフィスサプライ株式会社 Package
US6344272B1 (en) * 1997-03-12 2002-02-05 Wm. Marsh Rice University Metal nanoshells
US5920256A (en) * 1997-04-08 1999-07-06 Ut Automotive Dearborn, Inc. Gauge with mechanical indicator and reconfigurable gauge display
GB9707704D0 (en) 1997-04-16 1997-06-04 British Telecomm Display terminal
EP0872759B1 (en) * 1997-04-17 2001-12-12 Asulab S.A. Liquid crystal display device for a color display panel
JPH10312033A (en) 1997-05-13 1998-11-24 Mitsubishi Electric Corp Display device
JP3056133B2 (en) * 1997-06-26 2000-06-26 静岡日本電気株式会社 Display device
JPH1166306A (en) 1997-08-14 1999-03-09 Ricoh Co Ltd Method and device for evaluating image quality and record medium
JP3147156B2 (en) * 1997-11-18 2001-03-19 富士ゼロックス株式会社 Display storage medium, image writing method, and image writing device
DE19757564A1 (en) * 1997-12-23 1999-07-01 Mannesmann Vdo Ag Display device
JP4191276B2 (en) 1998-01-09 2008-12-03 富士通株式会社 Display device
JPH11205822A (en) 1998-01-13 1999-07-30 Ricoh Co Ltd Image display device
US6204902B1 (en) * 1998-01-14 2001-03-20 Samsung Display Devices Co., Ltd. Flexible plate liquid crystal display device
US6897855B1 (en) 1998-02-17 2005-05-24 Sarnoff Corporation Tiled electronic display structure
TW574106B (en) 1998-02-18 2004-02-01 Dainippon Printing Co Ltd Hard coat film
IL137628A (en) 1998-02-20 2005-09-25 Deep Video Imaging Ltd Multi-layer display and a method for displaying images on such a display
CN1302389A (en) 1998-02-24 2001-07-04 深视频图像有限公司 Improved display
DE19808982A1 (en) 1998-03-03 1999-09-09 Siemens Ag Active matrix liquid crystal display
US6287712B1 (en) * 1998-04-10 2001-09-11 The Trustees Of Princeton University Color-tunable organic light emitting devices
US6100862A (en) 1998-04-20 2000-08-08 Dimensional Media Associates, Inc. Multi-planar volumetric display system and method of operation
US6227669B1 (en) * 1998-05-26 2001-05-08 Industrial Technology Research Institute Illumination device and image projection apparatus comprising the device
US6504587B1 (en) * 1998-06-17 2003-01-07 Hitachi, Ltd. Liquid crystal display device in which the inner frame having sidewall
JP2000019500A (en) * 1998-06-29 2000-01-21 Toshiba Corp Liquid crystal display device
JP2000075135A (en) 1998-09-01 2000-03-14 Nitto Denko Corp Light diffusion polarizing plate
US6310650B1 (en) 1998-09-23 2001-10-30 Honeywell International Inc. Method and apparatus for calibrating a tiled display
US6377306B1 (en) 1998-09-23 2002-04-23 Honeywell International Inc. Method and apparatus for providing a seamless tiled display
JP3858477B2 (en) 1998-10-01 2006-12-13 セイコーエプソン株式会社 Liquid crystal display device and electronic apparatus including the same
JP3226095B2 (en) 1998-10-14 2001-11-05 セイコーエプソン株式会社 Network printer
US6590605B1 (en) 1998-10-14 2003-07-08 Dimension Technologies, Inc. Autostereoscopic display
EP0999088B1 (en) 1998-11-02 2003-03-05 Siemens Aktiengesellschaft Display device for motor vehicle
DE19920789A1 (en) 1998-11-02 2000-05-04 Mannesmann Vdo Ag Display unit intended for use in a motor vehicle
JP4111363B2 (en) * 1998-12-10 2008-07-02 株式会社エンプラス Light guide plate, side light type surface light source device, and liquid crystal display device
US6114814A (en) * 1998-12-11 2000-09-05 Monolithic Power Systems, Inc. Apparatus for controlling a discharge lamp in a backlighted display
AU2480600A (en) 1998-12-15 2000-07-03 Qualcomm Incorporated Dual view lcd assembly
GB2347003A (en) 1999-02-11 2000-08-23 Designaware Trading Ltd Prismatic display device
US6522468B2 (en) 1999-03-18 2003-02-18 Sumitomo Chemical Company, Limited Light-polarizing film
DE19924429A1 (en) 1999-05-28 2000-11-30 Mannesmann Vdo Ag Display instrument
DE60005775D1 (en) * 1999-06-07 2003-11-13 Citizen Watch Co Ltd LIQUID CRYSTAL DISPLAY
US6122103A (en) * 1999-06-22 2000-09-19 Moxtech Broadband wire grid polarizer for the visible spectrum
DE29912074U1 (en) 1999-07-10 1999-11-25 Franz Heinz Georg Three-dimensional color television picture transmission
JP3746403B2 (en) 1999-07-29 2006-02-15 シャープ株式会社 Liquid crystal display
JP2001056410A (en) 1999-08-18 2001-02-27 Nitto Denko Corp Diffusion polarizing member and liquid crystal display device
WO2001015128A1 (en) 1999-08-19 2001-03-01 Deep Video Imaging Limited Data display for multiple layered screens
JP2001125143A (en) * 1999-10-28 2001-05-11 Sharp Corp Reflection type liquid crystal display device
US7342721B2 (en) 1999-12-08 2008-03-11 Iz3D Llc Composite dual LCD panel display suitable for three dimensional imaging
JP4790890B2 (en) 2000-02-03 2011-10-12 日東電工株式会社 Retardation film and continuous production method thereof
WO2001095019A2 (en) 2000-06-07 2001-12-13 Three-Five Systems, Inc. Display system with secondary viewing image capabilities
US6639349B1 (en) * 2000-06-16 2003-10-28 Rockwell Collins, Inc. Dual-mode LCD backlight
JP2002014772A (en) 2000-06-30 2002-01-18 Minolta Co Ltd Touch panel, display panel, and display device
JP2002097269A (en) 2000-07-14 2002-04-02 Mitsui Chemicals Inc Polymer, cosmetic composition for hair, cosmetic composition and foamy aerosol cosmetic composition
US6326738B1 (en) * 2000-08-21 2001-12-04 Innova Electronics, Inc. Two wire light for electronic displays
TW521248B (en) 2000-09-05 2003-02-21 Toshiba Corp Display apparatus and its driving method
US6771327B2 (en) * 2000-09-18 2004-08-03 Citizen Watch Co., Ltd. Liquid crystal display device with an input panel
JP2002099223A (en) 2000-09-21 2002-04-05 Sharp Corp Display device
JP3670949B2 (en) * 2000-09-27 2005-07-13 三洋電機株式会社 Surface light source device
JP2004512564A (en) 2000-10-24 2004-04-22 ディメンション テクノロジーズ インコーポレイテッド Autostereoscopic display
US6557999B1 (en) 2000-11-16 2003-05-06 Koninklijke Philips Electronics N.V. System and method for contrast enhancement in projection imaging system
JP2004514165A (en) 2000-11-17 2004-05-13 ディープ ヴィデオ イメージング リミテッド How to change a display screen mat from an optically smooth surface
JP2002156608A (en) 2000-11-21 2002-05-31 Kureha Chem Ind Co Ltd Optical low-pass filter, optical system, and image pickup device
US7262752B2 (en) * 2001-01-16 2007-08-28 Visteon Global Technologies, Inc. Series led backlight control circuit
US20020154102A1 (en) 2001-02-21 2002-10-24 Huston James R. System and method for a programmable color rich display controller
JP4034521B2 (en) 2001-02-22 2008-01-16 富士通株式会社 Information management method, information management program, and recording medium
GB2372618A (en) 2001-02-23 2002-08-28 Eastman Kodak Co Display device
US6443579B1 (en) 2001-05-02 2002-09-03 Kenneth Myers Field-of-view controlling arrangements
JP2002350772A (en) 2001-05-30 2002-12-04 Kenwood Corp Display device and display control method
US6515881B2 (en) * 2001-06-04 2003-02-04 O2Micro International Limited Inverter operably controlled to reduce electromagnetic interference
US7205355B2 (en) 2001-06-04 2007-04-17 Sipix Imaging, Inc. Composition and process for the manufacture of an improved electrophoretic display
KR100725684B1 (en) * 2001-06-22 2007-06-07 엘지전자 주식회사 Apparatus and method for controlling a back light in LCD
JP2003015555A (en) 2001-06-28 2003-01-17 Minolta Co Ltd Display panel and display device provided with the panel
US6578985B1 (en) * 2001-07-18 2003-06-17 Rainbow Displays, Inc. Back light assembly for use with back-to-back flat-panel displays
US6845578B1 (en) 2001-08-03 2005-01-25 Stephen J. Lucas Illuminated multi-image display system and method therefor
KR100685098B1 (en) * 2001-08-30 2007-02-22 엘지전자 주식회사 Method for driving the lamp in a note-book computer
NZ514119A (en) 2001-09-11 2004-06-25 Deep Video Imaging Ltd Improvement to instrumentation
NZ514500A (en) * 2001-10-11 2004-06-25 Deep Video Imaging Ltd A multiplane visual display unit with a transparent emissive layer disposed between two display planes
US6784856B2 (en) * 2001-12-13 2004-08-31 International Business Machines Corp. System and method for anti-moire display
KR100840933B1 (en) * 2002-01-31 2008-06-24 삼성전자주식회사 Apparatus for driving lamp and liquid crystal display with the same
US7742239B2 (en) 2002-03-17 2010-06-22 Puredepth Limited Method to control point spread function of an image
US6873338B2 (en) * 2002-03-21 2005-03-29 International Business Machines Corporation Anti-moire pixel array having multiple pixel types
JP4034595B2 (en) 2002-05-27 2008-01-16 住友ゴム工業株式会社 Rubber roll
US20040012708A1 (en) * 2002-07-18 2004-01-22 Matherson Kevin James Optical prefilter system that provides variable blur
TWI229230B (en) 2002-10-31 2005-03-11 Sipix Imaging Inc An improved electrophoretic display and novel process for its manufacture
JP2004271259A (en) * 2003-03-06 2004-09-30 Casio Comput Co Ltd Clock module
NZ525956A (en) 2003-05-16 2005-10-28 Deep Video Imaging Ltd Display control system for use with multi-layer displays
JP3101581U (en) 2003-11-10 2004-06-17 維徳生物科技股▲ふん▼有限公司 Electrophoresis module for vertical electrophoresis device
JP2006285112A (en) * 2005-04-05 2006-10-19 Nippon Telegr & Teleph Corp <Ntt> Three-dimensional display method and three-dimensional display device
US7515143B2 (en) 2006-02-28 2009-04-07 Microsoft Corporation Uniform illumination of interactive display panel
JP4191755B2 (en) 2006-08-21 2008-12-03 日本電産コパル株式会社 Focal plane shutter for camera
JP5011968B2 (en) 2006-11-10 2012-08-29 アイシン精機株式会社 Water pump
US20080117231A1 (en) 2006-11-19 2008-05-22 Tom Kimpe Display assemblies and computer programs and methods for defect compensation
JP5142515B2 (en) 2006-12-19 2013-02-13 三洋電機株式会社 Nonaqueous electrolyte secondary battery
JP5091545B2 (en) 2007-06-01 2012-12-05 株式会社日立製作所 MRI phantom and MRI system
WO2009013916A1 (en) * 2007-07-23 2009-01-29 Sharp Kabushiki Kaisha Liquid crystal display unit, game device and display method employed in liquid crystal display unit
DE102007043207A1 (en) * 2007-09-11 2009-03-26 Continental Automotive Gmbh Combination instrument for displaying operating states
JP5406007B2 (en) * 2009-12-24 2014-02-05 矢崎総業株式会社 Instrument device
JP5497424B2 (en) * 2009-12-25 2014-05-21 新生電子株式会社 Liquid crystal display device and device with display function
US8831273B2 (en) * 2010-09-10 2014-09-09 Reald Inc. Methods and systems for pre-processing two-dimensional image files to be converted to three-dimensional image files
US8629886B2 (en) 2010-12-07 2014-01-14 Microsoft Corporation Layer combination in a surface composition system
US8935989B2 (en) * 2011-03-31 2015-01-20 Denso International America, Inc. Backlit reflective pointer
US9002237B2 (en) * 2011-07-13 2015-04-07 Xerox Corporation Electrostatic imaging member and methods for using the same
US9096131B2 (en) * 2012-01-06 2015-08-04 Visteon Global Technologies, Inc. Interactive display and gauge
JP5007373B1 (en) 2012-03-14 2012-08-22 アルプス電気株式会社 Lens drive device
RU127697U1 (en) * 2012-04-26 2013-05-10 Общество с ограниченной ответственностью "Производственная компания "АТПП" UNIVERSAL COMBINATION OF VEHICLE INSTRUMENTS

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5537233A (en) * 1993-11-25 1996-07-16 Sanyo Electric Co., Ltd. Direct-vision/projection type liquid-crystal display having light source at the edge of a gap between two liquid crystal panels
JP2000113988A (en) * 1998-10-08 2000-04-21 Stanley Electric Co Ltd Organic el display device and its lighting method
WO2000049453A1 (en) * 1999-02-17 2000-08-24 Central Research Laboratories Limited Liquid crystal display
EP1046944A2 (en) * 1999-04-13 2000-10-25 Mannesmann VDO Aktiengesellschaft Self illuminating LCD device
EP1081774A2 (en) * 1999-09-01 2001-03-07 Lucent Technologies Inc. Process for fabricating polarized organic photonics devices
EP1093008A1 (en) * 1999-10-14 2001-04-18 Elop Electro-Optics Industries Ltd. Multi-layer three-dimensional display
US20020105516A1 (en) * 2000-11-06 2002-08-08 Tracy Thomas M. Method and apparatus for displaying an image in three dimensions
US20020064037A1 (en) * 2000-11-25 2002-05-30 Lee Pyung Yong Backlight unit of bi-directional irradiation for liquid crystal display device
EP1231757A2 (en) * 2001-02-07 2002-08-14 Hyundai Curitel, Inc. Folder-type mobile communication terminal having double-sided LCD

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
DATABASE WPI Derwent World Patents Index; AN 2000-355751/31 *

Cited By (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9025235B2 (en) 2002-12-25 2015-05-05 Qualcomm Mems Technologies, Inc. Optical interference type of color display having optical diffusion layer between substrate and electrode
US9292150B2 (en) 2003-05-16 2016-03-22 Pure Depth Limited Display control system
EP1544657A3 (en) * 2003-12-19 2006-07-12 Barco N.V. Broadband full white reflective display structure
US9019590B2 (en) 2004-02-03 2015-04-28 Qualcomm Mems Technologies, Inc. Spatial light modulator with integrated optical compensation structure
WO2005081038A1 (en) * 2004-02-21 2005-09-01 Koninklijke Philips Electronics N.V. Optical path length adjuster
US8861071B2 (en) 2004-09-27 2014-10-14 Qualcomm Mems Technologies, Inc. Method and device for compensating for color shift as a function of angle of view
CN102722021A (en) * 2004-09-27 2012-10-10 高通Mems科技公司 Touchscreens for displays
WO2006112740A1 (en) * 2005-04-22 2006-10-26 Puredepth Limited Multilayer display with active and passive matrix display layers
US7347556B2 (en) 2005-06-07 2008-03-25 The Boeing Company Systems and methods for generating stereo images
US8872085B2 (en) 2006-10-06 2014-10-28 Qualcomm Mems Technologies, Inc. Display device having front illuminator with turning features
US9019183B2 (en) 2006-10-06 2015-04-28 Qualcomm Mems Technologies, Inc. Optical loss structure integrated in an illumination apparatus
US9244212B2 (en) 2008-01-30 2016-01-26 Qualcomm Mems Technologies, Inc. Illumination device having a tapered light guide
US9448353B2 (en) 2008-01-30 2016-09-20 Qualcomm Mems Technologies, Inc. Illumination device having a tapered light guide
US9395479B2 (en) 2008-01-30 2016-07-19 Qualcomm Mems Technologies, Inc. Illumination device having a tapered light guide
US9524700B2 (en) 2009-05-14 2016-12-20 Pure Depth Limited Method and system for displaying images of various formats on a single display
US8979349B2 (en) 2009-05-29 2015-03-17 Qualcomm Mems Technologies, Inc. Illumination devices and methods of fabrication thereof
US9121979B2 (en) 2009-05-29 2015-09-01 Qualcomm Mems Technologies, Inc. Illumination devices and methods of fabrication thereof
US8928682B2 (en) 2009-07-07 2015-01-06 Pure Depth Limited Method and system of processing images for improved display
US8848294B2 (en) 2010-05-20 2014-09-30 Qualcomm Mems Technologies, Inc. Method and structure capable of changing color saturation
US8902484B2 (en) 2010-12-15 2014-12-02 Qualcomm Mems Technologies, Inc. Holographic brightness enhancement film
CN107991783A (en) * 2018-01-30 2018-05-04 京东方科技集团股份有限公司 3d display device
US10747016B2 (en) 2018-01-30 2020-08-18 Boe Technology Group Co., Ltd. 3D display device
CN109696770A (en) * 2019-02-28 2019-04-30 上海天马微电子有限公司 Display module and display device
CN109696770B (en) * 2019-02-28 2021-08-24 上海天马微电子有限公司 Display module and display device

Also Published As

Publication number Publication date
US9721378B2 (en) 2017-08-01
US20170287204A9 (en) 2017-10-05
US20120307182A1 (en) 2012-12-06
US8149353B2 (en) 2012-04-03
JP2017513044A (en) 2017-05-25
US20160012630A1 (en) 2016-01-14
RU2016137684A3 (en) 2018-08-07
RU2678658C2 (en) 2019-01-30
US20140362076A1 (en) 2014-12-11
RU2016137684A (en) 2018-03-29
US8687149B2 (en) 2014-04-01
NZ514500A (en) 2004-06-25
US20050062410A1 (en) 2005-03-24
US9922445B2 (en) 2018-03-20
US10262450B2 (en) 2019-04-16
US20170330368A1 (en) 2017-11-16
US20170365088A1 (en) 2017-12-21
US10410402B2 (en) 2019-09-10

Similar Documents

Publication Publication Date Title
US8687149B2 (en) Visual display unit illumination
EP3111424B1 (en) A display interposing a physical object within a three-dimensional volumetric space
CN100385309C (en) Liquid crystal display device using dual light units
US7534026B2 (en) Light source device, display device, and terminal device
JP4152912B2 (en) Dual LCD using a dual front light unit
JPWO2006104160A1 (en) Display device
US6433846B1 (en) Apparatus for maintaining and converting a localized polarization shift into a localized intensity variation in a LCD display assembly
CN101128770A (en) Direct lit backlight source with light recycling and source polarizers
JP3741011B2 (en) Liquid crystal display device and electronic device
US7084941B2 (en) Liquid crystal display device
US7268844B2 (en) Liquid crystal display device
WO2016138313A1 (en) A display interposing a physical object within a three-dimensional volumetric space
JP2000122046A (en) Liquid crystal display device
US20090310071A1 (en) Transreflective display panel and display apparatus including the same
US20170045673A1 (en) Backlight unit and display apparatus
NZ532447A (en) Visual display unit illumination
US20110134367A1 (en) Polarization sheet and liquid crystal display device having the same
KR100885845B1 (en) Transflective liquid crystal display device
JP2002014338A (en) Liquid crystal display device and illumination device of the same

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BY BZ CA CH CN CO CR CU CZ DE DM DZ EC EE ES FI GB GD GE GH HR HU ID IL IN IS JP KE KG KP KR LC LK LR LS LT LU LV MA MD MG MN MW MX MZ NO NZ OM PH PL PT RU SD SE SG SI SK SL TJ TM TN TR TZ UA UG US UZ VC VN YU ZA ZM

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW MZ SD SL SZ UG ZM ZW AM AZ BY KG KZ RU TJ TM AT BE BG CH CY CZ DK EE ES FI FR GB GR IE IT LU MC PT SE SK TR BF BJ CF CG CI GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
32PN Ep: public notification in the ep bulletin as address of the adressee cannot be established

Free format text: NOTING OF LOSS OF RIGHTS PURSUANT TO RULE 69(1) EPC

WWE Wipo information: entry into national phase

Ref document number: 10492624

Country of ref document: US

122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: JP

WWW Wipo information: withdrawn in national office

Country of ref document: JP