|Publication number||US3855499 A|
|Publication date||Dec 17, 1974|
|Filing date||Feb 26, 1973|
|Priority date||Feb 25, 1972|
|Publication number||US 3855499 A, US 3855499A, US-A-3855499, US3855499 A, US3855499A|
|Inventors||Okano H, Yamada Y, Yamane M|
|Original Assignee||Hitachi Ltd|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (2), Referenced by (76), Classifications (8)|
|External Links: USPTO, USPTO Assignment, Espacenet|
[111 3,855,499 Dec. 117, 1974 United States Patent [1 1 Yamada et a1.
[ COLOR DISPLAY DEVICE Primary Examiner-James B. Mullins d n 0 t n A & g T .1 C m M w m B W. A F r 0 t m. g A w r m H A H e mm mm ra i Y ;w mm a n dMa -nl Kuwh f d..w n" m .1 Y U mmm an aku YOK s r 0 t n e V n 1  Assignee: Hitachi Ltd-,Tokyc Japan A color display device includes a substrate which  Filed; forms a partition wall for defining a vacuum space, a  plurality of cathode protrusions effecting field emis- Feb. 26, 1973 Appl. No.: 335,755
sion are formed on the substrate, and a transparent insulator which forms the vacuum space along with the substrate. A plurality of phosphor dots are formed on  Foreign Application Priority Data Feb. 25, 1972 the surface of the transparent insulator on the side of the vacuum space, are arranged in opposition to the electron sources and have mutually different colors of light emission. Anodes are arranged between the electron sources and the phosphor dots which cause elec-  US. Cl...... 315/169 R, 313/108 A, 313/108 B, 313/109, 313/1095, 313/336, 313/351  Int. Cl. H05b 37/02 trons to be generated from the electron sources by field emission, and a transparent electrode is disposed K9 9m 6 5 7 ,1 2 B @8 10 ll 5 5 3 .9 0 A moo 0 mH an 9 M3 M3 .n
between the phosphor dots and the transparent insulator. Apertures are provided in the anodes through which the electrons pass, whereby the electrons are  References Cited UNITED STATES PATENTS released from the cathode projections by selectively applying voltages to the anodes, so as to impinge on the phosphor dots of desired color.
3.500.102 3/1970 Crust et a1. 313/109 3.621828 11/1971 313/108 B X 4 Claims, 3 Drawing Figures COLOR DISPLAY DEVICE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color display device for providing a color display of letters, numerals, etc., and more particularly to a device which adequately selects for each letter, numeral, etc., a desired color from a plurality of colors to produce selected color display letters, numerals, etc.
2. Description of the Prior Art As means for effecting letter display, there has heretofore been provided a device, such as the Nixie tube, which produces light emission attendant on gaseous discharge, a device which produces light emission of a fluorescent material based on the impingement of an electron beam with the material, a device which produces electroluminescence, a device which produces changes in the intensity of reflected light due to electric fields applied to a liquid crystal, and a device which produces light emission of a luminescent diode attendant on current injection. In all of these devices, however, the light emission has been in a single color. There has not yet been realized a device capable of altering the color of letters. This has resulted from the fact that gas within a closed envelope cannot be simply exchanged and that multicolored elements for the light emission cannot be arranged in a minute area. It is apparent that, since the prior-art various display devices cannot arbitrarily select a plurality of display colors in this manner, the indicating function cannot help but be insufficient.
If a plurality of colors are selected for the display, the indicating function will be enhanced. For example, if the display color is changed in accordance with the transfer of codes or with the relation in magnitude to a suitably set threshold value in the indication of numerals, or with the contents of words such as caution by red and preparation by green, then the meaning of the display can be more sufficiently impressed on an observer.
SUMMARY OF THE INVENTION In view of the desireability of such a feature, the present invention has as its principle object the provision of a display device for letters, numerals, etc., which is capable of multicolored indication.
In order to accomplish such an object, according to the present invention, field emission type electron sources are employed as cathodes; phosphor dots are arranged in opposition to the electron sources which emit differed colored light from one another when bombarded and caused to luminesce by electrons released from the electron sources, and the cathodes opposite to those of the phosphor dots which are of the same color of light emission are electrically connected to form a single constituent element in the form of letters, numerals, etc., by the use of the phosphor dots of the same luminescent color.
The present invention will be described in detail hereunder with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING FIG. la is a cross-sectional view and FIG. lb is a fragmentary view partly in section of an embodiment of the present invention; and
FIG. 2 is a detail view of the construction of essential portions for explaining the operation of another embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. la and lb are views showing an embodiment of the present invention; wherein, FIG. la is a sectional view of the structure of the embodiment, and FIG. l b illustrates the construction of the embodiment as assembled. Reference numeral 1 designates a substrate which also serves as a partition wall for defining a vacuum space 12. Each of the cathodes 2 formed on the substrate 1 has a projection which is sufficiently sharp at its tip to generate electrons by field emission. An anode 3 serves to draw out field emission electron currents from the respective cathodes. Numeral 4 indicates an insulator for supporting the anode 3 and for providing the necessary electrical insulation between the cathodes and the anode. Shown at 4' are apertures which are provided in the anode 3 in opposition to the respective cathode projections. An insulator 5 functions to define the vacuum space in which the electron beams which have passed through the apertures 4 are accelerated. A transparent partition wall 6 functions to define the vacuum space, and is made of an insulator. Numeral 7 denotes phosphor dots of various colors applied on that surface of the transparent partition wall 6 which is located on the side of the vacuum space 12. A transparent electrode 7' is formed between the phosphor dots 7 and the transparent partition wall 6.
With such a construction, a voltage which is positive or the anode side'is applied between the cathodes 2 and the anode 3 (the power source being omitted from the drawing in this figure), to impress an electric field of sufficient intensity on the tips of the projections of the cathodes 2 to cause emission. Thus, field emission currents are generated from the pointed ends of the projections of the cathodes. When the material of the cathodes is, for example, tungsten, molybdenum or the like, the field emission arises at an electric field strength of approximately 10" (volts/cm). Therefore, assuming that the radius of curvature of the tip of each cathode projection is 1,000 (A), a voltage of (V) or so may be applied between the cathode 2 and the anode 3.
Subsequently, the electron beams from the cathode projections pass through the corresponding apertures 4' which are provided in the anode 3. Thereafter, they are accelerated by an accelerating voltage (whose power source is not shown) applied between the anode 3 and the surface with the phosphor dots 7 applied thereon, namely, the transparent electrode 7'. After thus acquiring energy enough to stimulate the phosphor 7 so as to bring it into luminescence, the electron beams impinge on the corresponding phosphor dots opposite to the cathode projections and cause them to emit light. Of course, the space in which the electron beams permeate may be kept at a low pressure in this case.
Further, according to the present invention, the cathodes opposing the phosphor dots of the same color of light emission are electrically connected in the respective patterns of the letters, numerals, etc., to make groups of cathodes, so that they may be simultaneously operable. Thus, a single constituent element of letters, numerals, etc., is formed in conjunction with groups of phosphor dots having the same luminescent color. Display colors can accordingly be selected in dependence on the colors of the groups of phosphor dots which oppose the cathode groups that are operated. More specifically, the anode corresponding to the single constituent element of letters, numerals, etc., formed by each respective cathode group is electrically connected so that an electric field may be applicable at the same time to the group of cathode projections belonging to the particular constituent element of letter, numerals, etc., as will be explained in conjunction with FIG. 2. In this way, the selective operation of the letter elements is made possible in dependence on which letter elements the anodes applied with the voltages correspond to.
For example, as seen in FIG. 1b, three cathode groups of similar configuration are associated with each anode 3 so that each letter, numeral, etc., formed by a cathode group may effect illumination of respective groups of phosphor dots arranged in a corresponding pattern providing illumination in one of three select colors depending upon which cathode group associated with a given anode is energized.
FIG. 2 is a diagram for explaining the operation of the selection of the display color and the selection of the letter element as stated above. The figure typically illustrates the structure of the cathodes as well as an anode of one constituent element of letters, numerals, or the like, .and the electrical connection therefor. In FIG. 2, numeral 2 indicates the cathode projections, among which projections 2 1 and 2 4 are opposite phosphor dots having the same luminescent color. Similarly, a set of the projecting cathodes 2 2 and 2 5 are opposite phosphor dots having the same color of light emission, which is different from the color of the light emission, the phosphor dots opposite the protruding cathodes 2 l and 2 4.
The cathode projections 2 3 and 2 6 are similarly opposite to phosphor dots which are of the same luminescent color to each other, but which differ from the aforesaid two sets of phosphor dots.
As shown in the figure, the perspective cathode projections of the sets, namely, projections 2 l and 2 4, projections 2 2 and 2 5 and projections 2 3 and 2 6 are electrically connected in common, and the respective sets are selected by means of a switch 9. Since, in the case of FIG. 2, only the single element is representatively shown, the anode 3 is common to the cathodes.
While the switch 9 is for the selection of the display color, a switch 10 serves to select the particular element. The switch 10 is adapted to close a single contact, or a plurality of contacts at the same time. As apparent from the foregoing explanation, the voltage of a power source 11 is selectively applied between the anode 3 selected by the switch 10 and the group of cathode projections selected by the switch 9. In consequence, letters or numerals represented by the combination of the respective constituent elements of the letters or numerals as prescribed by the selection of the contacts of the switch 10 are displayed in the color selected by the switch 9.
The above description has been. made of a mere example of structure. By way of example, it is, of course,
possible to reverse the relation of the electric connections between the anodes and the cathodes as for the selections of the elements and colors of the letters, numerals or the like, or to additionally provide control electrodes for the intensity modulation of the electron beams.
As described above in detail, in accordance with the present invention, the multicolored indication of letters, characters, numerals, etc., which has hitherto been impossible is easily attained. In particular, if the modern technique of integrated circuits in the production of semiconductor devices is applied to the present invention, the cathode protrusions can be manufactured with sufficient density, for example, at intervals of several tens (,um). Thus, changes in the position of a light emitting portion as attendant on the selections of the display colors can be made sufficiently small. In addition, owing to an increase in the number of letter or character elements, letters or characters can be indicated in their natural form, and even complicated letters or characters can be displayed. Furthermore, owing to the utilization of the field emission type electron sources, the time response for lighting and extinction becomes extremely quick, and it is also realized to reduce required power and to prolong life.
What is claimed is:
l. A color display device comprising an insulating substrate, a transparent insulator defining a vacuum space along with said substrate, a plurality of groups of field emission type electron sources formed in respective patterns on said substrate and serving as cathodes, a plurality of groups of phosphor dots applied on the surface of said transparent insulator on the inside of said vacuum space in positions to oppose said electron sources and having predetermined colors of light emission, means to commonly connect said electron sources of each group into a number of constituent elements forming patterns of identical configuration equal to the number of colors of phosphor dots so that those of said phosphor dots opposing each group of electron sources and which have the same color of light emission oppose one constituent element of said group of electron sources forming a respective pattern, anodes arranged respectively between each opposing group of phosphor dots and electron sources in order to draw out electrons from the commonly connected cathodes by field emission, apertures provided in said anodes in a manner to oppose said electron sources, a transparent electrode provided between said transparent insulator and said phosphor dots, first selector means to selectively connect said commonly connected cathodes to energizing potential, and second selector means to selectively connect said anodes to energizing potential, whereby said electrons drawn out from said cathodes by voltages applied between said cathodes and anodes by said first and second selector means are accelerated by a voltage impressed on said transparent electrode and impinge on said phosphor dots of the same color of light emission.
2. A color display device as defined in claim I wherein said electron sources are interconnected so that said constituent elements corresponding to each pattern are reproduced in number equal to the number of different colors of phosphor dots provided.
3. A color display device as defined in claim 1 wherein said anodes have the configuration of the pattern formed by the constituent elements with which they are operatively associated.
4. A color display device as defined in claim 1 further including means for applying an accelerating voltage to said transparent electrode to create an accelerating field between said anodes and said phosphor dots.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US3500102 *||May 15, 1967||Mar 10, 1970||Us Army||Thin electron tube with electron emitters at intersections of crossed conductors|
|US3622828 *||Dec 1, 1969||Nov 23, 1971||Us Army||Flat display tube with addressable cathode|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US4008412 *||Aug 18, 1975||Feb 15, 1977||Hitachi, Ltd.||Thin-film field-emission electron source and a method for manufacturing the same|
|US4178531 *||Jun 15, 1977||Dec 11, 1979||Rca Corporation||CRT with field-emission cathode|
|US4540983 *||Sep 29, 1982||Sep 10, 1985||Futaba Denshi Kogyo K.K.||Fluorescent display device|
|US4575765 *||Oct 21, 1983||Mar 11, 1986||Man Maschinenfabrik Augsburg Nurnberg Ag||Method and apparatus for transmitting images to a viewing screen|
|US4721885 *||Feb 11, 1987||Jan 26, 1988||Sri International||Very high speed integrated microelectronic tubes|
|US4857799 *||Jul 30, 1986||Aug 15, 1989||Sri International||Matrix-addressed flat panel display|
|US4908539 *||Mar 24, 1988||Mar 13, 1990||Commissariat A L'energie Atomique||Display unit by cathodoluminescence excited by field emission|
|US5063323 *||Jul 16, 1990||Nov 5, 1991||Hughes Aircraft Company||Field emitter structure providing passageways for venting of outgassed materials from active electronic area|
|US5063327 *||Jan 29, 1990||Nov 5, 1991||Coloray Display Corporation||Field emission cathode based flat panel display having polyimide spacers|
|US5083958 *||Jun 6, 1991||Jan 28, 1992||Hughes Aircraft Company||Field emitter structure and fabrication process providing passageways for venting of outgassed materials from active electronic area|
|US5136205 *||Mar 26, 1991||Aug 4, 1992||Hughes Aircraft Company||Microelectronic field emission device with air bridge anode|
|US5141459 *||Feb 21, 1992||Aug 25, 1992||International Business Machines Corporation||Structures and processes for fabricating field emission cathodes|
|US5150019 *||Oct 1, 1990||Sep 22, 1992||National Semiconductor Corp.||Integrated circuit electronic grid device and method|
|US5153483 *||Apr 10, 1991||Oct 6, 1992||Futaba Denshi Kogyo Kabushiki Kaisha||Display device|
|US5203731 *||Mar 5, 1992||Apr 20, 1993||International Business Machines Corporation||Process and structure of an integrated vacuum microelectronic device|
|US5334908 *||Dec 23, 1992||Aug 2, 1994||International Business Machines Corporation||Structures and processes for fabricating field emission cathode tips using secondary cusp|
|US5347201 *||Sep 11, 1992||Sep 13, 1994||Panocorp Display Systems||Display device|
|US5347292 *||Oct 28, 1992||Sep 13, 1994||Panocorp Display Systems||Super high resolution cold cathode fluorescent display|
|US5371433 *||Feb 10, 1994||Dec 6, 1994||U.S. Philips Corporation||Flat electron display device with spacer and method of making|
|US5397957 *||Nov 10, 1992||Mar 14, 1995||International Business Machines Corporation||Process and structure of an integrated vacuum microelectronic device|
|US5404074 *||Jun 16, 1993||Apr 4, 1995||Sony Corporation||Image display|
|US5424605 *||Apr 10, 1992||Jun 13, 1995||Silicon Video Corporation||Self supporting flat video display|
|US5442255 *||Aug 12, 1993||Aug 15, 1995||Sharp Kabushiki Kaisha||Electron emitting device|
|US5463269 *||Mar 6, 1992||Oct 31, 1995||International Business Machines Corporation||Process and structure of an integrated vacuum microelectronic device|
|US5465024 *||Feb 24, 1992||Nov 7, 1995||Motorola, Inc.||Flat panel display using field emission devices|
|US5477105 *||Jan 31, 1994||Dec 19, 1995||Silicon Video Corporation||Structure of light-emitting device with raised black matrix for use in optical devices such as flat-panel cathode-ray tubes|
|US5498925 *||May 19, 1995||Mar 12, 1996||At&T Corp.||Flat panel display apparatus, and method of making same|
|US5536193 *||Jun 23, 1994||Jul 16, 1996||Microelectronics And Computer Technology Corporation||Method of making wide band gap field emitter|
|US5541473 *||Feb 1, 1993||Jul 30, 1996||Silicon Video Corporation||Grid addressed field emission cathode|
|US5548185 *||Jun 2, 1995||Aug 20, 1996||Microelectronics And Computer Technology Corporation||Triode structure flat panel display employing flat field emission cathode|
|US5551903 *||Oct 19, 1994||Sep 3, 1996||Microelectronics And Computer Technology||Flat panel display based on diamond thin films|
|US5569973 *||Jun 6, 1995||Oct 29, 1996||International Business Machines Corporation||Integrated microelectronic device|
|US5572042 *||Apr 11, 1994||Nov 5, 1996||National Semiconductor Corporation||Integrated circuit vertical electronic grid device and method|
|US5589731 *||Feb 1, 1993||Dec 31, 1996||Silicon Video Corporation||Internal support structure for flat panel device|
|US5597338 *||Sep 25, 1995||Jan 28, 1997||Canon Kabushiki Kaisha||Method for manufacturing surface-conductive electron beam source device|
|US5597518 *||Nov 2, 1994||Jan 28, 1997||Silicon Video Corporation||Method for producing self supporting flat video display|
|US5600200 *||Jun 7, 1995||Feb 4, 1997||Microelectronics And Computer Technology Corporation||Wire-mesh cathode|
|US5601966 *||Jun 7, 1995||Feb 11, 1997||Microelectronics And Computer Technology Corporation||Methods for fabricating flat panel display systems and components|
|US5612712 *||Jun 7, 1995||Mar 18, 1997||Microelectronics And Computer Technology Corporation||Diode structure flat panel display|
|US5614353 *||Jun 7, 1995||Mar 25, 1997||Si Diamond Technology, Inc.||Methods for fabricating flat panel display systems and components|
|US5628659 *||Apr 24, 1995||May 13, 1997||Microelectronics And Computer Corporation||Method of making a field emission electron source with random micro-tip structures|
|US5644327 *||Jun 7, 1995||Jul 1, 1997||David Sarnoff Research Center, Inc.||Tessellated electroluminescent display having a multilayer ceramic substrate|
|US5652083 *||Jun 7, 1995||Jul 29, 1997||Microelectronics And Computer Technology Corporation||Methods for fabricating flat panel display systems and components|
|US5672083 *||Jun 7, 1995||Sep 30, 1997||Candescent Technologies Corporation||Fabrication of flat panel device having backplate that includes ceramic layer|
|US5674351 *||Nov 2, 1994||Oct 7, 1997||Candescent Technologies Corporation||Self supporting flat video display|
|US5675216 *||Jun 7, 1995||Oct 7, 1997||Microelectronics And Computer Technololgy Corp.||Amorphic diamond film flat field emission cathode|
|US5679043 *||Jun 1, 1995||Oct 21, 1997||Microelectronics And Computer Technology Corporation||Method of making a field emitter|
|US5686790 *||Jun 22, 1993||Nov 11, 1997||Candescent Technologies Corporation||Flat panel device with ceramic backplate|
|US5686791 *||Jun 7, 1995||Nov 11, 1997||Microelectronics And Computer Technology Corp.||Amorphic diamond film flat field emission cathode|
|US5703435 *||May 23, 1996||Dec 30, 1997||Microelectronics & Computer Technology Corp.||Diamond film flat field emission cathode|
|US5763997 *||Jun 1, 1995||Jun 9, 1998||Si Diamond Technology, Inc.||Field emission display device|
|US5798604 *||Jan 5, 1996||Aug 25, 1998||Candescent Technologies Corporation||Flat panel display with gate layer in contact with thicker patterned further conductive layer|
|US5801485 *||Jun 20, 1995||Sep 1, 1998||U.S. Philips Corporation||Display device|
|US5831382 *||Sep 27, 1996||Nov 3, 1998||Bilan; Frank Albert||Display device based on indirectly heated thermionic cathodes|
|US5861707 *||Jun 7, 1995||Jan 19, 1999||Si Diamond Technology, Inc.||Field emitter with wide band gap emission areas and method of using|
|US5866988 *||Jan 29, 1996||Feb 2, 1999||Canon Kabushiki Kaisha||Electron beam apparatus and method of driving the same|
|US5880705 *||Mar 7, 1997||Mar 9, 1999||Sarnoff Corporation||Mounting structure for a tessellated electronic display having a multilayer ceramic structure and tessellated electronic display|
|US5986399 *||Feb 24, 1998||Nov 16, 1999||U.S. Philips Corporation||Display device|
|US6127773 *||Jun 4, 1997||Oct 3, 2000||Si Diamond Technology, Inc.||Amorphic diamond film flat field emission cathode|
|US6184626 *||Oct 8, 1998||Feb 6, 2001||Canon Kabushiki Kaisha||Electron beam apparatus and method of driving the same|
|US6296740||Apr 24, 1995||Oct 2, 2001||Si Diamond Technology, Inc.||Pretreatment process for a surface texturing process|
|US6498592||Nov 10, 2000||Dec 24, 2002||Sarnoff Corp.||Display tile structure using organic light emitting materials|
|US6515640 *||Apr 15, 1998||Feb 4, 2003||Canon Kabushiki Kaisha||Electron emission device with gap between electron emission electrode and substrate|
|US6629869||Jun 7, 1995||Oct 7, 2003||Si Diamond Technology, Inc.||Method of making flat panel displays having diamond thin film cathode|
|US6897855||Feb 16, 1999||May 24, 2005||Sarnoff Corporation||Tiled electronic display structure|
|US6995502||Feb 4, 2002||Feb 7, 2006||Innosys, Inc.||Solid state vacuum devices and method for making the same|
|US7005783||Feb 4, 2002||Feb 28, 2006||Innosys, Inc.||Solid state vacuum devices and method for making the same|
|US7095169||Oct 10, 2003||Aug 22, 2006||Hitachi, Ltd.||Flat panel display device|
|US7592970 *||Oct 1, 2004||Sep 22, 2009||Dennis Lee Matthies||Tiled electronic display structure|
|US7864136||Aug 30, 2006||Jan 4, 2011||Dennis Lee Matthies||Tiled electronic display structure|
|US8704244 *||Feb 5, 2010||Apr 22, 2014||Ccs, Inc.||LED light emitting device|
|US20050078104 *||Oct 1, 2004||Apr 14, 2005||Matthies Dennis Lee||Tiled electronic display structure|
|US20110278606 *||Feb 5, 2010||Nov 17, 2011||Hirokazu Suzuki||Led light emitting device|
|EP0496450A1 *||Jan 16, 1992||Jul 29, 1992||Philips Electronics N.V.||Display device|
|WO1991005363A1 *||Sep 17, 1990||Apr 18, 1991||Motorola, Inc.||Flat panel display using field emission devices|
|WO1992002030A1 *||Oct 17, 1990||Feb 6, 1992||International Business Machines Corporation||Process and structure of an integrated vacuum microelectronic device|
|U.S. Classification||345/75.2, 313/497, 313/351, 313/494, 313/336|