|Publication number||US20050285985 A1|
|Application number||US 11/137,753|
|Publication date||Dec 29, 2005|
|Filing date||May 25, 2005|
|Priority date||Feb 20, 2002|
|Also published as||US6947102, US6995743, US7280102, US7408598, US7872641, US20030156087, US20030156230, US20030179323, US20040046900, US20070279346, US20080055295, US20080055499, US20080055507, US20080062343, US20080066972, US20080129909, US20080129913, US20080129914, US20100013794, US20100020044, US20100059296, WO2003073159A1|
|Publication number||11137753, 137753, US 2005/0285985 A1, US 2005/285985 A1, US 20050285985 A1, US 20050285985A1, US 2005285985 A1, US 2005285985A1, US-A1-20050285985, US-A1-2005285985, US2005/0285985A1, US2005/285985A1, US20050285985 A1, US20050285985A1, US2005285985 A1, US2005285985A1|
|Inventors||Willem Boer, Adiel Abileah|
|Original Assignee||Planar Systems, Inc.|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (99), Referenced by (14), Classifications (40), Legal Events (2)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This application claims the benefit of U.S. Patent Application Ser. No. 60/359,263, filed Feb. 20, 2002.
The present invention relates to touch sensitive displays.
Touch sensitive screens (“touch screens”) are devices that typically mount over a display such as a cathode ray tube. With a touch screen, a user can select from options displayed on the display's viewing surface by touching the surface adjacent to the desired option, or, in some designs, touching the option directly. Common techniques employed in these devices for detecting the location of a touch include mechanical buttons, crossed beams of infrared light, acoustic surface waves, capacitance sensing, and resistive membranes.
For example, Kasday, U.S. Pat. No. 4,484,179 discloses an optically-based touch screen comprising a flexible clear membrane supported above a glass screen whose edges are fitted with photodiodes. When the membrane is flexed into contact with the screen by a touch, light which previously would have passed through the membrane and glass screen is trapped between the screen surfaces by total internal reflection. This trapped light travels to the edge of the glass screen where it is detected by the photodiodes which produce a corresponding output signal. The touch position is determined by coordinating the position of the CRT raster beam with the timing of the output signals from the several photodiodes. The optically-based touch screen increases the expense of the display, and increases the complexity of the display.
Denlinger, U.S. Pat. No. 4,782,328 on the other hand, relies on reflection of ambient light from the actual touch source, such as a finger or pointer, into a pair of photosensors mounted at comers of the touch screen. By measuring the intensity of the reflected light received by each photosensor, a computer calculates the location of the touch source with reference to the screen. The inclusion of the photosensors and associated computer increases the expense of the display, and increases the complexity of the display.
May, U.S. Pat. No. 5,105,186, discloses a liquid crystal touch screen that includes an upper glass sheet and a lower glass sheet separated by spacers. Sandwiched between the glass sheets is a thin layer of liquid crystal material. The inner surface of each piece of glass is coated with a transparent, conductive layer of metal oxide. Affixed to the outer surface of the upper glass sheet is an upper polarizer which comprises the display's viewing surface. Affixed to the outer surface of glass sheet is a lower polarizer. Forming the back surface of the liquid crystal display is a transflector adjacent to the lower polarizer. A transflector transmits some of the light striking its surface and reflects some light. Adjacent to transflector is a light detecting array of light dependent resistors whose resistance varies with the intensity of light detected. The resistance increases as the light intensity decreases, such as occurs when a shadow is cast on the viewing surface. The light detecting array detect a change in the light transmitted through the transflector caused by a touching of viewing surface. Similar to touch sensitive structures affixed to the front of the liquid crystal stack, the light sensitive material affixed to the rear of the liquid crystal stack similarly pose potential problems limiting contrast of the display, increasing the expense of the display, and increasing the complexity of the display.
Touch screens that have a transparent surface which mounts between the user and the display's viewing surface have several drawbacks. For example, the transparent surface, and other layers between the liquid crystal material and the transparent surface may result in multiple reflections which decreases the display's contrast and produces glare. Moreover, adding an additional touch panel to the display increases the manufacturing expense of the display and increases the complexity of the display. Also, the incorporation of the touch screen reduces the overall manufacturing yield of the display.
Accordingly, what is desired is a touch screen that does not significantly decrease the contrast ratio, does not significantly increase the glare, does not significantly increase the expense of the display, and does not significantly increase the complexity of the display.
The transmittance of light from the backlight 52 to the eye of a viewer 58, observing an image displayed on the front of the panel, is controlled by the light valve 54. The light valve 54 normally includes a pair of polarizers 60 and 62 separated by a layer of liquid crystals 64 contained in a cell gap between the polarizers. Light from the backlight 52 impinging on the first polarizer 62 comprises electromagnetic waves vibrating in a plurality of planes. Only that portion of the light vibrating in the plane of the optical axis of a polarizer passes through the polarizer. In an LCD light valve, the optical axes of the first 62 and second 60 polarizer are typically arranged at an angle so that light passing through the first polarizer would normally be blocked from passing through the second polarizer in the series. However, the orientation of the translucent crystals in the layer of liquid crystals 64 can be locally controlled to either “twist” the vibratory plane of the light into alignment with the optical axes of the polarizer, permitting light to pass through the light valve creating a bright picture element or pixel, or out of alignment with the optical axis of one of the polarizes, attenuating the light and creating a darker area of the screen or pixel.
The surfaces of the a first glass substrate 61 and a second glass substrate 63 form the walls of the cell gap are buffed to produce microscopic grooves to physically align the molecules of liquid crystal 64 immediately adjacent to the walls. Molecular forces cause adjacent liquid crystal molecules to attempt to align with their neighbors with the result that the orientation of the molecules in the column of molecules spanning the cell gap twist over the length of the column. Likewise, the plane of vibration of light transiting the column of molecules will be “twisted” from the optical axis of the first polarizer 62 to a plane determined by the orientation of the liquid crystals at the opposite wall of the cell gap. If the wall of the cell gap is buffed to align adjacent crystals with the optical axis of the second polarizer, light from the backlight 52 can pass through the series of polarizers 60 and 62 to produce a lighted area of the display when viewed from the front of the panel (a “normally white” LCD).
To darken a pixel and create an image, a voltage, typically controlled by a thin film transistor, is applied to an electrode in an array of transparent electrodes deposited on the walls of the cell gap. The liquid crystal molecules adjacent to the electrode are attracted by the field produced by the voltage and rotate to align with the field. As the molecules of liquid crystal are rotated by the electric field, the column of crystals is “untwisted,” and the optical axes of the crystals adjacent to the cell wall are rotated progressively out of alignment with the optical axis of the corresponding polarizer progressively reducing the local transmittance of the light valve 54 and attenuating the luminance of the corresponding pixel. Conversely, the polarizers and buffing of the light valve can be arranged to produce a “normally black” LCD having pixels that are dark (light is blocked) when the electrodes are not energized and light when the electrodes are energized. Color LCD displays are created by varying the intensity of transmitted light for each of a plurality of primary color (typically, red, green, and blue) sub-pixels that make up a displayed pixel.
The aforementioned example was described with respect to a twisted nematic device. However, this description is only an example and other devices may likewise be used, including but not limited to, multi-domain vertical alignment, patterned vertical alignment, in-plane switching, and super-twisted nematic type LCDs. In addition other devices, such as for example, plasma displays, electroluminescent displays, liquid crystal on silicon displays, reflective liquid crystal devices may likewise be used. For such displays the light emitting portion of the display, or portion of the display that permits the display of selected portions of light may be considered to selectively cause the pixels to provide light.
For an active matrix LCD (AMLCD) the inner surface of the second glass substrate 63 is normally coated with a continuous electrode while the first glass substrate 61 is patterned into individual pixel electrodes. The continuous electrode may be constructed using a transparent electrode, such as indium tin oxide. The first glass substrate 61 may include thin film transistors (TFTs) which act as individual switches for each pixel electrode (or group of pixel electrodes) corresponding to a pixel (or group of pixels). The TFTs are addressed by a set of multiplexed electrodes running along the gaps between the pixel electrodes. Alternatively the pixel electrodes may be on a different layer from the TFTs. A pixel is addressed by applying voltage (or current) to a select line which switches the TFT on and allows charge from the data line to flow onto the rear pixel electrodes. The combination of voltages between the front electrode and the pixel electrodes sets up a voltage across the pixels and turns the respective pixels on. The thin-film transistors are typically constructed from amorphous silicon, while other types of switching devices may likewise be used, such as for example, metal-insulator-metal diode and polysilicon thin-film transistors. The TFT array and pixel electrodes may alternatively be on the top of the liquid crystal material. Also the light sensitive elements may likewise be located on the top of the liquid crystal material, if desired.
The present inventors considered different potential architectural touch panel schemes to incorporate additional optical layers between the polarizer on the front of the liquid crystal display and the front of the display. These additional layers include, for example, glass plates, wire grids, transparent electrodes, plastic plates, spacers, and other materials. In addition, the present inventors considered the additional layers with different optical characteristics, such as for example, birefringence, non-birefringence, narrow range of wavelengths, wide range of wavelengths, etc. After an extensive analysis of different potential configurations of the touch screen portion added to the display together with materials having different optical properties and further being applied to the different types of technologies (e.g., mechanical switches, crossed beams of infrared light, acoustic surface waves, capacitance sensing, and resistive membranes), the present inventors determined that an optimized touch screen is merely a tradeoff between different undesirable properties. Accordingly, the design of an optimized touch screen is an ultimately unsolvable task. In contrast to designing an improved touch screen, the present inventors came to the realization that modification of the structure of the active matrix liquid crystal device itself could provide an improved touch screen capability without all of the attendant drawbacks to the touch screen configuration located on the front of the display.
As an example, the common line may be set at a negative voltage potential, such as −10 volts. During the previous readout cycle, a voltage is imposed on the select line which causes the voltage on the readout line to be coupled to the drain of the photo TFT and the drain of the readout TFT, which results in a voltage potential across Cst2. The voltage coupled to the drain of the photo TFT and the drain of the readout TFT is approximately ground (e.g., zero volts) with the non-inverting input of the operational amplifier connected to ground. The voltage imposed on the select line is removed so that the readout TFT will turn “off”.
Under normal operational conditions ambient light from the front of the display passes through the black matrix and strikes the amorphous silicon of the photo TFT. However, if a person touches the front of the display in a region over the opening in the black matrix or otherwise inhibits the passage of light through the front of the display in a region over the opening in the black matrix, then the photo TFT transistor will be in an “off” state. If the photo TFT is “off” then the voltage across the capacitor Cst2 will not significantly discharge through the photo TFT. Accordingly, the charge imposed across Cst2 will be substantially unchanged. In essence, the voltage imposed across Cst2 will remain substantially unchanged if the ambient light is inhibited from striking the photo TFT.
To determine the voltage across the capacitor Cst2, a voltage is imposed on the select line which causes the gate of the readout TFT to interconnect the imposed voltage on Cst2 to the readout line. If the voltage imposed on the readout line as a result of activating the readout TFT is substantially unchanged, then the output of the operational amplifier will be substantially unchanged (e.g., zero). In this manner, the system is able to determine whether the light to the device has been inhibited, in which case the system will determine that the screen has been touched at the corresponding portion of the display with the photo TFT.
During the readout cycle, the voltage imposed on the select line causes the voltage on the respective drain of the photo TFT and the drain of the readout TFT to be coupled to the respective readout line, which results in resetting the voltage potential across Cst2. The voltage coupled to the drain of the photo TFT and the drain of the readout TFT is approximately ground (e.g., zero volts) with the non-inverting input of the operational amplifier connected to ground. The voltage imposed on the select line is removed so that the readout TFT will turn “off”. In this manner, the act of reading the voltage simultaneously acts to reset the voltage potential for the next cycle.
Under normal operational conditions ambient light from the front of the display passes through the black matrix and strikes the amorphous silicon of the photo TFT. If a person does not touch the front of the display in a region over the opening in the black matrix or otherwise inhibits the passage of light through the front of the display in a region over the opening in the black matrix, then the photo TFT transistor will be in an “on” state. If the photo TFT is “on” then the voltage across the capacitor Cst2 will significantly discharge through the photo TFT, which is coupled to the common line. In essence the voltage imposed across Cst2 will decrease toward the common voltage. Accordingly, the charge imposed across Cst2 will be substantially changed in the presence of ambient light. Moreover, there is a substantial difference in the voltage potential across the hold capacitor when the light is not inhibited verus when the light is inhibited.
Similarly, to determine the voltage across the capacitor Cst2, a voltage is imposed on the select line which causes the gate of the readout TFT to interconnect the imposed voltage to the readout line. If the voltage imposed on the readout line as a result of activating the readout TFT is substantially changed or otherwise results in an injection of current, then the output of the operational amplifier will be substantially non-zero. The output voltage of the operational amplifier is proportional or otherwise associated with the charge on the capacitor Cst2. In this manner, the system is able to determine whether the light to the device has been uninhibited, in which case the system will determine that the screen has not been touched at the corresponding portion of the display with the photo TFT.
In the circuit topology illustrated, the value of the capacitor Cst2 may be selected such that it is suitable for high ambient lighting conditions or low ambient lighting conditions. For low ambient lighting conditions, a smaller capacitance may be selected so that the device is more sensitive to changes in light. For high ambient lighting conditions, a larger capacitance may be selected so that the device is less sensitive to changes in light. In addition, the dimensions of the photo transistor may be selected to change the photo-leakage current. Also, one set of light sensitive elements (e.g., the photo TFT and the capacitance) within the display may be optimized for low ambient lighting conditions while another set of light sensitive elements (e.g., the photo TFT and the capacitance) within the display may be optimized for high ambient lighting conditions. Typically, the data from light sensitive elements for low ambient conditions and the data from light sensitive elements for high ambient conditions are separately processed, and the suitable set of data is selected. In this manner, the same display device may be used for high and low ambient lighting conditions. In addition, multiple levels of sensitivity may be provided. It is to be understood that a single architecture may be provided with a wide range of sensitivity from low to high ambient lighting conditions.
Another structure that may be included is selecting the value of the capacitance so that under normal ambient lighting conditions the charge on the capacitor only partially discharges. With a structure where the capacitive charge only partially discharges, the present inventors determined that an optical pointing device, such as a light wand or laser pointer, may be used to point at the display to further discharge particular regions of the display. In this manner, the region of the display that the optical pointing device remains pointed at may be detected as local maximums (or otherwise). In addition, those regions of the display where light is inhibited will appear as local minimums (or otherwise). This provides the capability of detecting not only the absence of light (e.g., touching the panel) but likewise those regions of the display that have increased light incident thereon. Referring to
A switch associated with the display may be provided to select among a plurality of different sets of light sensitive elements. For example, one of the switches may select between low, medium, and high ambient lighting conditions. For example, another switch may select between a touch sensitive operation (absence of light) and a optical pointing device (addition of light). In addition, the optical pointing device may communicate to the display, such as through a wire or wireless connection, to automatically change to the optical sensing mode.
It is noted that the teachings herein are likewise applicable to transmissive active matrix liquid crystal devices, reflective active matrix liquid crystal devices, transflective active matrix liquid crystal devices, etc. In addition, the light sensitive elements may likewise be provided within a passive liquid crystal display. The sensing devices may be, for example, photo resistors and photo diodes.
Alternatively, light sensitive elements may be provided between the rear polarizing element and active matrix layer. In this arrangement, the light sensitive elements are preferably fabricated on the polarizer, or otherwise a film attached to the polarizer. In addition, the light sensitive elements may be provided on a thin glass plate between the polarizer and the liquid crystal material. In addition, the black matrix or otherwise light inhibiting material is preferably arranged so as to inhibit ambient light from striking the readout TFT while free from inhibiting light from striking the photo TFT. Moreover, preferably a light blocking material is provided between the photo TFT and/or the readout TFT and the backlight, such as gate metal, if provided, to inhibit the light from the backlight from reaching the photo TFT and/or the readout TFT.
Alternatively, light sensitive elements may be provided between the front polarizing element and the liquid crystal material. In this arrangement, the light sensitive elements are preferably fabricated on the polarizer, or otherwise a film attached to the polarizer. In addition, the light sensitive elements may be provided on a thin glass plate between the polarizer and the liquid crystal material. The light sensitive elements may likewise be fabricated within the front electrode layer by patterning the front electrode layer and including suitable fabrication techniques. In addition, a black matrix or otherwise light inhibiting material is preferably arranged so as to inhibit ambient light from striking the readout TFT while free from inhibiting light from striking the photo TFT. Moreover, preferably a light blocking material is provided between the photo TFT and/or the readout TFT and the backlight, if provided, to inhibit the light from the backlight from reaching the photo TFT and/or the readout TFT.
Alternatively, light sensitive elements may be provided between the front of the display and the rear of the display, normally fabricated on one of the layers therein or fabricated on a separate layer provided within the stack of layers within the display. In the case of a liquid crystal device with a backlight the light sensitive elements are preferably provided between the front of the display and the backlight material. The position of the light sensitive elements are preferably between (or at least partially) the pixel electrodes, when viewed from a plan view of the display. This may be particularly useful for reflective displays where the pixel electrodes are opaque. In this arrangement, the light sensitive elements are preferably fabricated on one or more of the layers, or otherwise a plate attached to one or more of the layers. In addition, a black matrix or otherwise light inhibiting material is preferably arranged so as to inhibit ambient light from striking the readout TFT while free from inhibiting light from striking the photo TFT. Moreover, preferably a light blocking material is provided between the photo TFT and/or the readout TFT and the backlight, if provided, to inhibit the light from the backlight from reaching the photo TFT and/or the readout TFT.
In many applications it is desirable to modify the intensity of the backlight for different lighting conditions. For example, in dark ambient lighting conditions it may be beneficial to have a dim backlight. In contrast, in bright ambient lighting conditions it may be beneficial to have a bright backlight. The integrated light sensitive elements within the display stack may be used as a measure of the ambient lighting conditions to control the intensity of the backlight without the need for an additional external photo-sensor. One light sensitive element may be used, or a plurality of light sensitive element may be used together with additional processing, such as averaging.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US4220815 *||Dec 4, 1978||Sep 2, 1980||Elographics, Inc.||Nonplanar transparent electrographic sensor|
|US4320292 *||Dec 1, 1978||Mar 16, 1982||Nippon Telegraph And Telephone Public Corporation||Coordinate input apparatus|
|US4345248 *||Dec 12, 1980||Aug 17, 1982||Citizen Watch Company Limited||Liquid crystal display device with write-in capability|
|US4496981 *||Jul 5, 1984||Jan 29, 1985||Matsushita Electric Industrial Co., Ltd.||Video camera with a monitor|
|US4603356 *||Mar 19, 1984||Jul 29, 1986||Energy Conversion Devices, Inc.||Imaging system with light valve and photodetector|
|US4644338 *||Jul 1, 1983||Feb 17, 1987||Hosiden Electronics Co., Ltd.||Dot-matrix liquid crystal display|
|US4655552 *||Mar 18, 1985||Apr 7, 1987||Citizen Watch Co., Ltd.||Flat panel display device having on-screen data input function|
|US4662718 *||Oct 19, 1984||May 5, 1987||Citizen Watch Co., Ltd.||Expansion system for a liquid crystal display|
|US4679909 *||Jun 17, 1985||Jul 14, 1987||Sharp Kabushiki Kaisha||Liquid crystal input/output matrix panel|
|US4684939 *||May 23, 1983||Aug 4, 1987||U.S. Philips Corporation||Liquid crystal display device|
|US4720869 *||Feb 18, 1986||Jan 19, 1988||International Business Machines Corporation||Hand dimension verification|
|US4736203 *||Jul 17, 1985||Apr 5, 1988||Recognition Systems, Inc.||3D hand profile identification apparatus|
|US4740782 *||Sep 3, 1986||Apr 26, 1988||Hosiden Electronics Co., Ltd.||Dot-matrix liquid crystal display|
|US4759610 *||Sep 29, 1986||Jul 26, 1988||Kabushiki Kaisha Toshiba||Active matrix display with capacitive light shield|
|US4767192 *||Oct 31, 1986||Aug 30, 1988||International Business Machines Corporation||Light activated light valve with a silicon control element|
|US4772101 *||Nov 7, 1986||Sep 20, 1988||The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration||Remotely controllable real-time optical processor|
|US4814760 *||Apr 30, 1987||Mar 21, 1989||Wang Laboratories, Inc.||Information display and entry device|
|US4838655 *||Jan 6, 1988||Jun 13, 1989||Hitachi, Ltd.||Projector using guest-host liquid crystal cells for improved color purity|
|US4904056 *||Jul 25, 1989||Feb 27, 1990||General Electric Company||Light blocking and cell spacing for liquid crystal matrix displays|
|US4917474 *||May 23, 1988||Apr 17, 1990||Semiconductor Energy Laboratory Co., Ltd.||Optoelectronic panel and method of making the same|
|US5003356 *||Apr 2, 1990||Mar 26, 1991||Casio Computer Co., Ltd.||Thin film transistor array|
|US5105186 *||May 25, 1990||Apr 14, 1992||Hewlett-Packard Company||Lcd touch screen|
|US5140153 *||Oct 30, 1990||Aug 18, 1992||Heikki Marttila Oy||Circuitry for compensating for the effect of light on the operation of infrared-sensitive phototransistors in a contact display panel|
|US5204661 *||Dec 13, 1990||Apr 20, 1993||Xerox Corporation||Input/output pixel circuit and array of such circuits|
|US5236850 *||Sep 18, 1991||Aug 17, 1993||Semiconductor Energy Laboratory Co., Ltd.||Method of manufacturing a semiconductor film and a semiconductor device by sputtering in a hydrogen atmosphere and crystallizing|
|US5237314 *||Oct 21, 1991||Aug 17, 1993||U.S. Philips Corporation||Addressing a matrix device using electro-optical switching|
|US5276538 *||Apr 2, 1991||Jan 4, 1994||Matsushita Electric Industrial Co., Ltd.||Display device with micro lens array|
|US5301048 *||Oct 28, 1992||Apr 5, 1994||U.S. Philips Corporation||Active matrix display device with Schottky contact switching elements|
|US5339090 *||Sep 10, 1992||Aug 16, 1994||Northern Telecom Limited||Spatial light modulators|
|US5339091 *||Oct 14, 1992||Aug 16, 1994||Semiconductor Energy Laboratory Co., Ltd.||Paperless portable book|
|US5381251 *||Apr 7, 1993||Jan 10, 1995||Sharp Kabushiki Kaisha||Optical switch element and a liquid crystal light directional coupler used in the optical switch element|
|US5386543 *||Jul 21, 1993||Jan 31, 1995||U.S. Philips Corporation||Matrix display device with light sensing function and time-shared amplifier|
|US5387445 *||Mar 9, 1992||Feb 7, 1995||Zeneca Limited||Liquid crystal display device|
|US5414283 *||Nov 19, 1993||May 9, 1995||Ois Optical Imaging Systems, Inc.||TFT with reduced parasitic capacitance|
|US5445871 *||Jul 22, 1994||Aug 29, 1995||Kansai Paint Co., Ltd.||Surface-modified plastic plate|
|US5483263 *||May 11, 1994||Jan 9, 1996||U.S. Philips Corporation||Electro-optic device|
|US5485177 *||Nov 26, 1991||Jan 16, 1996||U.S. Philips Corporation||Matrix display device with write-in facility|
|US5510916 *||Nov 1, 1993||Apr 23, 1996||Nec Corporation||Active matrix liquid crystal device with opposite substrate having black matrix with larger aperture than active substrate|
|US5515186 *||Jul 9, 1993||May 7, 1996||Osd Envizion Company||Eye protection device for welding helmets which reduces obliquely incident light|
|US5525813 *||Jan 26, 1995||Jun 11, 1996||Fuji Xerox Co., Ltd.||Image sensor having TFT gate electrode surrounding the photoelectric conversion element|
|US5532743 *||Nov 17, 1994||Jul 2, 1996||Matsushita Electric Industrial Co., Ltd.||Solid-state image pickup device|
|US5598004 *||Jul 19, 1995||Jan 28, 1997||U.S. Philips Corporation||Image detector|
|US5610629 *||Jul 14, 1994||Mar 11, 1997||Ncr Corporation||Pen input to liquid crystal display|
|US5635982 *||Jun 27, 1994||Jun 3, 1997||Zhang; Hong J.||System for automatic video segmentation and key frame extraction for video sequences having both sharp and gradual transitions|
|US5637187 *||Jun 5, 1995||Jun 10, 1997||Seiko Instruments Inc.||Light valve device making|
|US5652600 *||Nov 17, 1994||Jul 29, 1997||Planar Systems, Inc.||Time multiplexed gray scale approach|
|US5712528 *||Oct 5, 1995||Jan 27, 1998||Planar Systems, Inc.||Dual substrate full color TFEL panel with insulator bridge structure|
|US5751453 *||Oct 23, 1995||May 12, 1998||Ncr Corporation||Liquid crystal display with pen-input capability|
|US5757522 *||Dec 2, 1996||May 26, 1998||Univeristy Of Alabama In Huntsville||Method for electro-optically rendering a holographic image|
|US5767623 *||Sep 11, 1995||Jun 16, 1998||Planar Systems, Inc.||Interconnection between an active matrix electroluminescent display and an electrical cable|
|US5777713 *||Jun 17, 1996||Jul 7, 1998||International Business Machines Corporation||Liquid crystal display unit with spacers form in the light shielding regions|
|US5778108 *||Jun 7, 1996||Jul 7, 1998||Electronic Data Systems Corporation||Method and system for detecting transitional markers such as uniform fields in a video signal|
|US5793342 *||Oct 3, 1995||Aug 11, 1998||Planar Systems, Inc.||Resonant mode active matrix TFEL display excitation driver with sinusoidal low power illumination input|
|US5796121 *||Mar 25, 1997||Aug 18, 1998||International Business Machines Corporation||Thin film transistors fabricated on plastic substrates|
|US5877735 *||Jun 23, 1995||Mar 2, 1999||Planar Systems, Inc.||Substrate carriers for electroluminescent displays|
|US5890799 *||Nov 10, 1997||Apr 6, 1999||Motorola Inc.||Method for reducing power consumption in a portable electronic device with a liquid crystal display screen|
|US5917464 *||Oct 18, 1994||Jun 29, 1999||Xerox Corporation||Combination of 2-D detector array with display for image processing|
|US5920360 *||Jun 7, 1996||Jul 6, 1999||Electronic Data Systems Corporation||Method and system for detecting fade transitions in a video signal|
|US5930591 *||Apr 23, 1997||Jul 27, 1999||Litton Systems Canada Limited||High resolution, low voltage flat-panel radiation imaging sensors|
|US5940049 *||Aug 15, 1996||Aug 17, 1999||Polycom, Inc.||Remote interactive projector with image enhancement|
|US6020590 *||Jan 22, 1998||Feb 1, 2000||Ois Optical Imaging Systems, Inc.||Large area imager with UV blocking layer|
|US6020945 *||Nov 10, 1997||Feb 1, 2000||Dowa Mining Co., Ltd.||Display device with a transparent optical filter|
|US6023307 *||Nov 17, 1997||Feb 8, 2000||Samsung Display Devices Co., Ltd.||Liquid crystal display with photo conversion elements on a black matrix between color filter plates|
|US6028581 *||Oct 21, 1997||Feb 22, 2000||Sony Corporation||Method and apparatus for a liquid crystal display (LCD) having an input function|
|US6049428 *||Nov 17, 1995||Apr 11, 2000||Optiva, Inc.||Dichroic light polarizers|
|US6067062 *||Aug 23, 1991||May 23, 2000||Seiko Instruments Inc.||Light valve device|
|US6067140 *||Nov 13, 1997||May 23, 2000||Lg Electronics Inc.||Liquid crystal display device and method of manufacturing same|
|US6078378 *||Nov 24, 1997||Jun 20, 2000||Industrial Technology Research Institute||Liquid crystal display with pixels having an opening formed from a photosensitive resin with spacers attached|
|US6087599 *||Nov 24, 1997||Jul 11, 2000||The Whitaker Corporation||Touch panels having plastic substrates|
|US6177302 *||Sep 22, 1994||Jan 23, 2001||Semiconductor Energy Laboratory Co., Ltd.||Method of manufacturing a thin film transistor using multiple sputtering chambers|
|US6181394 *||Jan 22, 1999||Jan 30, 2001||White Electronic Designs, Corp.||Super bright low reflection liquid crystal display|
|US6184863 *||Oct 13, 1998||Feb 6, 2001||The George Washington University||Direct pointing apparatus and method therefor|
|US6236063 *||May 11, 1999||May 22, 2001||Semiconductor Energy Laboratory Co., Ltd.||Semiconductor device|
|US6278423 *||Nov 24, 1998||Aug 21, 2001||Planar Systems, Inc||Active matrix electroluminescent grey scale display|
|US6278444 *||Aug 21, 1998||Aug 21, 2001||Geoffrey D. Wilson||Low current four-wire interface for five-wire resistive touch-screen|
|US6351076 *||Oct 6, 2000||Feb 26, 2002||Tohoku Pioneer Corporation||Luminescent display panel drive unit and drive method thereof|
|US6380995 *||Aug 5, 1999||Apr 30, 2002||Lg.Philips Lcd Co., Ltd.||Transflective liquid crystal display device with asymmetry reflective electrode having a transparent portion facing a main viewing angle|
|US6392254 *||Dec 22, 1999||May 21, 2002||General Electric Company||Corrosion resistant imager|
|US6399166 *||Apr 15, 1997||Jun 4, 2002||Optiva, Inc.||Liquid crystal display and method|
|US6441362 *||Oct 28, 1999||Aug 27, 2002||Kabushikikaisha Wacom||Stylus for optical digitizer|
|US6603867 *||Aug 30, 1999||Aug 5, 2003||Fuji Xerox Co., Ltd.||Three-dimensional object identifying system|
|US6681034 *||Jul 15, 1999||Jan 20, 2004||Precise Biometrics||Method and system for fingerprint template matching|
|US6862022 *||Jul 20, 2001||Mar 1, 2005||Hewlett-Packard Development Company, L.P.||Method and system for automatically selecting a vertical refresh rate for a video display monitor|
|US6888528 *||Jun 25, 1999||May 3, 2005||Sanyo Electric Co., Ltd.||Liquid crystal display apparatus having light collecting mechanism|
|US6995743 *||Nov 27, 2002||Feb 7, 2006||Planar Systems, Inc.||Light sensitive display|
|US7009663 *||Dec 17, 2003||Mar 7, 2006||Planar Systems, Inc.||Integrated optical light sensitive active matrix liquid crystal display|
|US20010000676 *||Dec 29, 2000||May 3, 2001||Hongyong Zhang||Integral-type liquid crystal panel with image sensor function|
|US20020027164 *||Sep 7, 2001||Mar 7, 2002||Mault James R.||Portable computing apparatus particularly useful in a weight management program|
|US20020030581 *||Apr 12, 2001||Mar 14, 2002||Janiak Martin J.||Optical and smart card identification reader|
|US20020030768 *||Nov 14, 2001||Mar 14, 2002||I-Wei Wu||Integrated high resolution image sensor and display on an active matrix array with micro-lens|
|US20020052192 *||May 9, 2001||May 2, 2002||Shunpei Yamazaki||User identity authentication system and user identity authenication method and mobile telephonic device|
|US20020071074 *||Nov 23, 1999||Jun 13, 2002||Kazuto Noritake||Liquid crystal display device|
|US20020074549 *||Feb 15, 2002||Jun 20, 2002||Woon-Yong Park||Method for fabricating thin film transistor array substrate for liquid crystal display|
|US20030103020 *||Nov 30, 2001||Jun 5, 2003||Dj Plush Toys (Hk) Ltd.||Doll figure with user initiated audio and electro-luminescent (EL) display|
|US20030137494 *||May 1, 2000||Jul 24, 2003||Tulbert David J.||Human-machine interface|
|US20030156087 *||Nov 27, 2002||Aug 21, 2003||Boer Willem Den||Light sensitive display|
|US20030156230 *||Aug 12, 2002||Aug 21, 2003||Boer Willem Den||Light sensitive display|
|US20040046900 *||Dec 23, 2002||Mar 11, 2004||Boer Willem Den||Light sensitive display|
|US20040125430 *||Jul 3, 2003||Jul 1, 2004||Yasushi Kasajima||Display device and electronic equipment having the same|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US7692734 *||Sep 15, 2006||Apr 6, 2010||Epson Imaging Devices Corporation||Liquid crystal device and electronic apparatus|
|US7773139||Apr 16, 2004||Aug 10, 2010||Apple Inc.||Image sensor with photosensitive thin film transistors|
|US7830461||Apr 19, 2006||Nov 9, 2010||Apple Inc.||Light sensitive display|
|US7852417||Oct 26, 2007||Dec 14, 2010||Apple Inc.||Light sensitive display|
|US7872641||Oct 25, 2007||Jan 18, 2011||Apple Inc.||Light sensitive display|
|US7872695 *||Mar 20, 2007||Jan 18, 2011||Fujifilm Corporation||Process of producing optical compensation sheet, polarizing plate comprising an optical compensation sheet produced by said process, and liquid crystal display device|
|US7880733||Oct 26, 2007||Feb 1, 2011||Apple Inc.||Light sensitive display|
|US7880819||Oct 26, 2007||Feb 1, 2011||Apple Inc.||Light sensitive display|
|US8076741||Apr 22, 2009||Dec 13, 2011||Industrial Technology Research Institute||Photo sensing element array substrate|
|US8446392||Nov 16, 2009||May 21, 2013||Smart Technologies Ulc||Method for determining the location of a pointer in a pointer input region, and interactive input system executing the method|
|US8587511 *||Oct 30, 2003||Nov 19, 2013||Samsung Display Co., Ltd.||Liquid crystal display panel, liquid crystal display device having the same, and method of manufacturing the same|
|US8749476 *||May 31, 2005||Jun 10, 2014||Samsung Display Co., Ltd.||Electrophoretic display device|
|US20040169625 *||Oct 30, 2003||Sep 2, 2004||Won-Sang Park||Liquid crystal display panel, liquid crystal display device having the same,and method of manufacturing the same|
|US20050266590 *||May 31, 2005||Dec 1, 2005||Nam-Seok Roh||Electrophoretic display device|
|International Classification||G06F3/048, G06F3/042, G09G3/36, G06F3/033, G02F1/1335, G02F1/133, G09G3/34, H01L29/04, G06F3/041, G06F1/16, F16M13/02, G02F1/136|
|Cooperative Classification||G06K9/0004, G06F3/0412, G09G2300/0809, G06F3/03545, G06F1/1611, G06F2203/04109, G09G2320/029, G06F3/042, G09G3/3648, G06F3/0488, G02F2001/13312, G06F3/0418, G09G2320/0626, G09G2360/144, G09G2300/0439, G09G2300/0842, G02F1/13338, G06F3/03542|
|European Classification||G06F3/042, G09G3/36C8, G06F3/0354L, G06F3/041T2, G06F3/041D, G02F1/1333U, G06F3/0354N, G06F3/0488, G06K9/00A1E|
|May 25, 2005||AS||Assignment|
Owner name: PLANAR SYSTEMS, INC., OREGON
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:DEN BOER, WILLEM;ABILEAH, ADIEL;REEL/FRAME:016609/0414
Effective date: 20030702
|Sep 28, 2007||AS||Assignment|
Owner name: BANK OF AMERICA, N.A., CALIFORNIA
Free format text: SECURITY AGREEMENT;ASSIGNOR:PLANAR SYSTEMS, INC.;REEL/FRAME:019892/0957
Effective date: 20070629