GB2066498A - Multi-layered Twisted Nematic Liquid Crystal Display Panel - Google Patents
Multi-layered Twisted Nematic Liquid Crystal Display Panel Download PDFInfo
- Publication number
- GB2066498A GB2066498A GB8040817A GB8040817A GB2066498A GB 2066498 A GB2066498 A GB 2066498A GB 8040817 A GB8040817 A GB 8040817A GB 8040817 A GB8040817 A GB 8040817A GB 2066498 A GB2066498 A GB 2066498A
- Authority
- GB
- United Kingdom
- Prior art keywords
- liquid crystal
- crystal layer
- layers
- layer
- orientation
- Prior art date
- Legal status (The legal status 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 status listed.)
- Granted
Links
- 239000004988 Nematic liquid crystal Substances 0.000 title claims abstract description 15
- 239000000758 substrate Substances 0.000 claims abstract description 15
- 239000004973 liquid crystal related substance Substances 0.000 claims description 60
- 239000013598 vector Substances 0.000 claims description 9
- 230000003287 optical effect Effects 0.000 claims description 8
- 239000011295 pitch Substances 0.000 claims description 3
- 230000005855 radiation Effects 0.000 claims 1
- 230000007935 neutral effect Effects 0.000 abstract description 2
- 239000010410 layer Substances 0.000 description 56
- ZUOUZKKEUPVFJK-UHFFFAOYSA-N diphenyl Chemical compound C1=CC=CC=C1C1=CC=CC=C1 ZUOUZKKEUPVFJK-UHFFFAOYSA-N 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 238000000034 method Methods 0.000 description 3
- 125000006850 spacer group Chemical group 0.000 description 3
- 239000013543 active substance Substances 0.000 description 2
- 235000010290 biphenyl Nutrition 0.000 description 2
- 239000004305 biphenyl Substances 0.000 description 2
- 230000008020 evaporation Effects 0.000 description 2
- 238000001704 evaporation Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 description 2
- ZCYVEMRRCGMTRW-UHFFFAOYSA-N 7553-56-2 Chemical compound [I] ZCYVEMRRCGMTRW-UHFFFAOYSA-N 0.000 description 1
- 239000004986 Cholesteric liquid crystals (ChLC) Substances 0.000 description 1
- 239000004593 Epoxy Substances 0.000 description 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 239000003365 glass fiber Substances 0.000 description 1
- 229910052740 iodine Inorganic materials 0.000 description 1
- 239000011630 iodine Substances 0.000 description 1
- 230000005693 optoelectronics Effects 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- -1 polyethylene Polymers 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 229920003002 synthetic resin Polymers 0.000 description 1
- 239000000057 synthetic resin Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL 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
- G02F1/00—Devices 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
- G02F1/01—Devices 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
- G02F1/13—Devices 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
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1347—Arrangement 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
- G02F1/13471—Arrangement 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
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL 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
- G02F1/00—Devices 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
- G02F1/01—Devices 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
- G02F1/13—Devices 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
- G02F1/137—Devices 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
- G02F1/139—Devices 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 orientation effects in which the liquid crystal remains transparent
- G02F1/1396—Devices 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 orientation effects in which the liquid crystal remains transparent the liquid crystal being selectively controlled between a twisted state and a non-twisted state, e.g. TN-LC cell
Landscapes
- Physics & Mathematics (AREA)
- Nonlinear Science (AREA)
- Mathematical Physics (AREA)
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Liquid Crystal (AREA)
- Devices For Indicating Variable Information By Combining Individual Elements (AREA)
Abstract
A display cell comprises polarisers 7a, 7b (only), between which are disposed adjacent twisted nematic liquid crystal layers 2a, 2b controlled by respective sets of electrodes 3a- 3d. The layers are of opposite twist sense, and the alignments adjacent the common central substrate 1b are mutually parallel, whereby O and E- rays in one layer continue as such in the other layer, producing a high rather than low order interference colour (e.g. if the layer thicknesses differ somewhat) which appears as a neutral grey rather than a variable hue. <IMAGE>
Description
SPECIFICATION
Improved Multilayered Twisted Nematic Liquid
Crystal Display Panel
Background of the Invention
The present invention relates to a liquid crystal display cell, and more particularly, to a multilayered twisted nematic liquid crystal display panel.
The convention multi-layered twisted nematic liquid crystal display panels, were known which has at least two layers each containing a liquid crystal material activated by each power supply means. As compared to long-standing singlelayer twisted nematic liquid crystal display panels, they had the following features:
(1) providing various different display schemes in an individual display panel;
(2) forming a logic which was operated in an electro-optical manner; and
(3) increasing the number of display segments according to that of the multi-layers contained therein when, in operating the display panel by a multi-plex driving technique (line scanning driving technique) for displaying purpose, the length of time at which a voltage was applied to each of the display segments, namely, duty factor, was made constant.
However, there were inherent problems that because of the multi-layered structure display contrast of the display panel degenerated to thereby effect substantially practicability of the panel.
Summary of the Invention
Accordingly, it is an object of the present invention to provide an improved multi-layered twisted nematic liquid crystal display panel.
It is another object of the present invention to provide an improved multi-layered twisted nematic liquid crystal display panel with a high display contrast.
Other objects and further scope of applicability of the present invention will become apparent from the detail description given hereinafter. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirt and scope of the invention will become apparent to those skilled in the art from this detailed description.
To achieve the above objects, pursuant to an embodiment of the present invention, a twisted nematic liquid crystal display is featured by that there is provided a first visible area providing a good display contrast in a first liquid crystal layer is positioned face to face with a second visible area providing a good display contrast in a second liquid crystal layer by transferring extraordinary rays in the first liquid crystal layer in the direction of the extraordinary rays in the second liquid crystal layer or transferring ordinary rays in the first liquid crystal layer in the direction of the ordinary rays in the second liquid crystal layer.
Brief Description of the Drawings
The present invention will be better understood from the detailed description given hereinbelow and by accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention and wherein:
Fig. 1 is a cross-sectional view of a multilayered twisted nematic liquid crystal display panel according to the present invention;
Figs. 2(A) through 2(E) show examples of conventional orientation direction of liquid crystal molecules in a conventional display panel;
Fig. 3 shows explanation of orientation vector foc representing orientation direction of the liquid crystal molecules, with a tile angle; and
Figs. 4(A) through 4(E) show examples of orientation direction of the liquid crystal molecules according to the present invention.
Description of the Invention
Referring now to Fig. 1 there is indicated a multi-layered twisted nematic liquid crystal display panel of the present invention. This display panel comprises three transparent substrates 1 a, 1 b, and 1 c, two liquid crystal layers 2a and 2b, four transparent electrodes 3a, 3b, 3c and 3d, four orientation layers 5a, 5b, Sc and 5d, two power sources 4a and 4b, spacers 6a and 6b, and two polarizers 7a and 7b.
Selected materials of the three substrates 1 a,
1 b and 1 c may be glass of soda, with a thickness of about 0.2 to about 3mm. They are combined in parallei with one another. On the inner surface of each of the three substrates 1 a, 1 b and 1 c, there is disposed each of the four transparent electrodes 2a, 2b, 2c and 2d made of In203, SnO2 or the like to provide electric energy to each of each of the liquid crystal layers 2a and 2b by each of the two power sources 4a and 4b. Each of the electrodes 3a to 3d is made of In203 etc.
deposited by evaporation, desirably patterned.
Each of the electrodes 3a and 3b is coupled to the power source 4a to drive the liquid crystal layer 2a. Each of the electrodes 3c and 3d is coupled to the power source 4b to drive the liquid crystal layer 2b.
Each of the four orientation layers 5a, 5b, Sc and 5d is formed on the surface of each of the four electrodes 3a to 3d and the three substrates 1 a to 1 c to provide orientation of liquid crystal molecules. Each of the layers 5a to 5d may be made of Ski02.
The well-known rubbing method of slant evaporation is applied to complete each of the layers 5a to 5d.
Each of the two liquid crystal layers 2a and 2b comprises nematic liquid crystal mixtures or cholesteric liquid crystal mixtures having a long pitch. Then, the twisted nematic liquid crystal display cell in which the longitudinal axes of the liquid crystal molecules at each surface of the three substrates 1 a, 1 b and 1 c are at right angles to each other. In each of the two liquid crystal layers 2a and 2b, the directions of the longitudinai axes of the liquid crystal molecules are identical to each other.
Around the periphery of each of the substrates 1 a, 1 b and 1 c, there is provided each of the spacers 6a and 6b for sealing each of the liquid crystal layers 2a and 2b. The spacers 6a and 6b may comprise epoxy synthetic resin with glass fiber particles. On the display side and the counter side, each of the polarizers 7a and 7b is provided.
Each of the polarizers 7a and 7b is a linearly polarization filter made of iodine or polyethylene.
In the case of a reflective type display panel, a reflector 8 is additionaliy provided behind the display panel.
With the aid of provision of each of the polarizers 7a and 7b, a display to the viewer 9 is highly enabled by the changes of the liquid crystal molecules in orientation direction in response to power supply by each of the power sources 4a and 4b.
Figs. 2(A) through 2(E) show examples of conventional orientation direction of liquid crystal molecules in a conventional dispay panel having the same mechanical structure, except for optoelectronic properties such as orientation direction, as the display panel of Fig. 1. All the examples are in the counterclockwise optical rotation in the layers 2a and 2b.
More particularly, each of Figs. 2(A) and 2(B) shows those of orientation direction in the liquid crystal layer 2a in contact with the orientation layer 5a and with the orientation layer 5b. Each of
Figs. 2(C) and 2(D) shows those of orientation direction in the liquid crystal layer 2b in contact with the orientation layer Sc and with the orientation layer 5d.
In all these drawings, each of characters "r22,, "r:", "r2" and "r," represents an orientation rector provided with the respective liquid crystal molecules. Fig. 3 shows explanation of each vector with a tilt angle A0 against each of the electrodes 3a, 3b, 3c and 3d. In Fig. 3, numeral 2 indicates liquid crystal molecules and numeral 5 indicates either of the orientation layers 5a to 5d.
In the conventional liquid crystal display panel having orientation as specified in Figs. 2(A) through 2(D), a visible area with a display contrast is defined by Fig. 2(E) common to the liquid crystal layers 2a and 2b. When the display panel is viewed along the direction 12 or 13 which does not agree to the Z-axis, interference color remarkably develops at the display area where none of the liquid crystal layers 2a and 2b has an electric power, thereby leading to degradation of the display contrast.
The reason is that difference in light-path lengths by double refraction present between the liquid crystal layers 2a and 2b reduces the display contrast. The double refraction develops by optical rotation dispersion. The light-path lengths by the double refraction are represented by d. An' where d is a thickness of each of the liquid crystal layers 2a and 2b and An' is a component of the double refraction. The values of the light-path lengths are different from each other between the liquid crystal layers 2a and 2b.
More particularly, since the vector r21 in the Fig.
2(A) and the vector r2 in Fig. 2(C) are at the right angle, the components of extraordinary ray and of ordinary ray are altered to each other while ray is passing through the liquid crystal layers 2a and 2b. Accordingly, the resultant light-path length is defined by the formula of ida An'd An'l where da is a thickness of the layer 2a and db is a thickness of the layer 2b.
Usually, the value of da is not equal to that of db. In a combination with the polarizers 7a and 7b' interference color in a low order develops to thereby produce noise visible color and accordingly, reduce the display contrast.
Unlike the above conventional orientation, as features of the present invention, the vectors r: and r2 are different from each other at a substantially 1 800 angle so that extraordinary ray in the liquid crystal layer 2a is transferred in the direction of the extraordinary ray in the layer 2b and, in addition, the ordinary ray in the layer 2a is transferred in the direction of the ordinary ray in the layer 2b.
Figs. 4(A) to 4(E) show examples of orientation direction of the liquid crystal molecules according to the present invention. The directions of the optical rotations are set to be reversed between the liquid crystal layers 2a and 2b.
More particularly, each of Figs. 4(A) and 4(B) show those of orientation direction in the layer 2a in contact with the orientation layer 5a and with orientation layer 5b. Each of Figs. 4(C) and 4(D) show those of orientation direction in the layer 2b in contact with the orientation layer Sc and with the orientation layer 5d. According to a preferred embodiment of the present invention, the liquid crystal display panel is completed as follows:
The value of the tile angle AO is set to be about 2 to about 5 . The thickness of each of the layers 2a and 2b is set to be about 6 ym. The directions of the optical rotations are set to be reversed between the layers 2a and 2b.In the layer 2a, there is disposed a liquid crystal mixture having a clockwise optical rotation, e.g., biphenyl type
ROTN 403 produced by Hoffmann-La Roche Inc.
with about 0.15 weight% of an optically active substance, CB-15 produced by BDH Chemicals
Ltd. In the layer 2b, there is disposed a liquid crystal mixture having a counterclock wise optical rotation, e.g., biphenyl type ROTN 403 with about 1.0 weight% of the optical active substance, C-l 5 produced by BDH Chemicals Ltc.
The absolute values of the helical pitches in the layers 2a and 2b are substantially identical to each other in order that the electro-optic property is in harmony with the layers 2a and 2b. Each of the polarizers 7a and 7b may be selected to be L83 produced by Sanritsu Electric Company Ltd. In the case of the reflective liquid crystal display panel, the reflector 8 is additionally provided comprising aluminum plate which has been subject to a sandblast treatment.
Accordingly to the above orientation, there is obtained a shaded area 12 providing a good display contrast in Fig. 4(E). An area in which there is obtained the good display contrast in the layer 2a is positioned to face to face with another area in which there is obtained the good display contrast in the layer 2b. Since the orientation vectors rt and r2 are deviated at substantially 1 800, the resuitant difference of the light-path lengths of the light passing through the both layers 2a and 2b is defined by "da An'+db Ant", thereby generating a high order interference color.
The high order interference color is observed as neutral gray providing an unatractive display.
Preferably, the value of "d An" where d is a thickness of either of the layers 2a and 2b, and
An is an index of double refraction, is set to be within about 0.4 to about 0.6 both inclusive or about 1.0 to about 2.0 both inclusive. The term
An is defined as "ne-no" where ne is a refractive index of extraordinary ray and nO is that of ordinary ray.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications are intended to be included within the scope of the following
Claims (4)
1. A twisted nematic liquid crystal display cell comprising:
first, second and third substrate means;
a first pair of electrode means each formed on the first and the second substrate means, and a second pair of electrode means each formed on the second and the third substrate means;
the first and the second substrate means forming a first cavity in combination and the second and the third substrate means forming a second cavity in combination;
a first liquid crystal layer disposed in the first cavity and a second liquid crystal layer disposed in the second cavity;
polarizer means provided for at least a surface of the first substrate means not carrying the electrode means;
the optical rotations of the molecules in the first and the second liquid crystal layers being directed in opposite directions to each other;;
the absolute values of helical pitches of the first and the second liquid crystal layers being substantially identical; and
an orientation layer formed on each of the first and the second pairs of electrode means for aligning liquid crystal molecules in each of the first and the second liquid crystal layers so that there is provided a first visible area providing a good display cointrast in the first liquid crystal layer is positioned to face to face with a second visible area providing a good display contrast in the second liquid crystal layer by transferring extraordinary rays in the first liquid crystal layer in the direction of extraordinary rays in the second liquid crystal layer or transferring ordinary rays in the first liquid crystal layer in the direction of ordinary rays in the second liquid crystal layer.
2. The display cell of claim 1, wherein orientation vectors representing the direction of liquid crystal molecules oriented in each of the first and the second liquid crystal layers are such that each of the first and the second liquid crystal layers can pass radiation and the orientation vector of the first liquid crystal layer in contact with the second substrate means separating the first and the second cavities is substantially at 1 800 deviation from the orientation vector of the second liquid crystal layer in contact with the second substrate means.
3. The display cell of claim 1, wherein in each of the first and the second liquid crystal layers there is maintained a multiplied value with a thickness and a double refractive index of each of the first and the second liquid crystal layers within about 0.4 to about 0.6 both inclusive of about 1.0 to about 2.0 both inclusive.
4. A twisted nematic liquid crystal display cell substantially as herein described with reference to
Figures 1,3 and 4 of the accompanying drawings.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16666079A JPS5688112A (en) | 1979-12-20 | 1979-12-20 | Liquid crystal display device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2066498A true GB2066498A (en) | 1981-07-08 |
| GB2066498B GB2066498B (en) | 1983-07-13 |
Family
ID=15835368
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8040817A Expired GB2066498B (en) | 1979-12-20 | 1980-12-19 | Multi-layered twisted nematic liquid crystal display panel |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JPS5688112A (en) |
| DE (1) | DE3048024C2 (en) |
| GB (1) | GB2066498B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0408036A2 (en) * | 1989-07-12 | 1991-01-16 | In Focus Systems, Inc. | High resolution LCD display system |
| US5113272A (en) * | 1990-02-12 | 1992-05-12 | Raychem Corporation | Three dimensional semiconductor display using liquid crystal |
| US5798807A (en) * | 1993-02-03 | 1998-08-25 | Prehn; Horst | Image modulation process and device for generating optical effects |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56130715A (en) * | 1980-03-17 | 1981-10-13 | Sharp Corp | Multilayered liquid-crystal display device |
| US4443065A (en) * | 1980-12-09 | 1984-04-17 | Sharp Kabushiki Kaisha | Interference color compensation double layered twisted nematic display |
| DE3204426A1 (en) * | 1982-02-09 | 1983-08-18 | Siemens AG, 1000 Berlin und 8000 München | Device for producing characters on a light-sensitive recording carrier |
| IT1196057B (en) * | 1983-03-23 | 1988-11-10 | Borg Instr Gmbh | POLYCHROME LIQUID CRYSTAL INDICATOR DEVICE AND PROCEDURE TO OPTIMIZE THE CONTRAST OF LIQUID CRYSTAL CELLS WITH FIELD EFFECT |
| DE3310427A1 (en) * | 1983-03-23 | 1984-09-27 | Borg Instruments GmbH, 7537 Remchingen | Method for optimising the contrast of field-effect liquid crystal cells |
| DE3438756C2 (en) * | 1984-10-23 | 1987-03-12 | Borg Instruments GmbH, 7537 Remchingen | Double rotary cell display device |
| DE3721751A1 (en) * | 1987-07-01 | 1989-01-12 | Eps Elektronik | Optoelectronic filter preferably for video cameras |
| JPH087348B2 (en) * | 1988-10-27 | 1996-01-29 | シャープ株式会社 | Liquid crystal display |
| US4920364A (en) * | 1989-05-10 | 1990-04-24 | Xerox Corporation | Liquid crystal dynamic attenuator for laser printers |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS542580B2 (en) * | 1974-07-01 | 1979-02-09 | ||
| JPS52148150A (en) * | 1976-06-04 | 1977-12-09 | Hitachi Ltd | Liquid crystal display unit |
| JPS5922924B2 (en) * | 1976-11-19 | 1984-05-30 | セイコーエプソン株式会社 | liquid crystal display device |
| US4231640A (en) * | 1977-07-07 | 1980-11-04 | Sharp Kabushiki Kaisha | Matrix type liquid crystal display panel |
| US4375317A (en) * | 1978-11-16 | 1983-03-01 | Sharp Kabushiki Kaisha | Multi-layered liquid crystal display panel |
-
1979
- 1979-12-20 JP JP16666079A patent/JPS5688112A/en active Pending
-
1980
- 1980-12-19 DE DE19803048024 patent/DE3048024C2/en not_active Expired
- 1980-12-19 GB GB8040817A patent/GB2066498B/en not_active Expired
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0408036A2 (en) * | 1989-07-12 | 1991-01-16 | In Focus Systems, Inc. | High resolution LCD display system |
| EP0408036A3 (en) * | 1989-07-12 | 1992-05-13 | In Focus Systems, Inc. | High resolution lcd display system |
| US5113272A (en) * | 1990-02-12 | 1992-05-12 | Raychem Corporation | Three dimensional semiconductor display using liquid crystal |
| US5798807A (en) * | 1993-02-03 | 1998-08-25 | Prehn; Horst | Image modulation process and device for generating optical effects |
Also Published As
| Publication number | Publication date |
|---|---|
| DE3048024C2 (en) | 1987-07-09 |
| GB2066498B (en) | 1983-07-13 |
| JPS5688112A (en) | 1981-07-17 |
| DE3048024A1 (en) | 1981-10-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4634229A (en) | Liquid crystal display | |
| US5847789A (en) | Reflective type liquid crystal display device | |
| US4436379A (en) | Two-layer liquid crystal display panel | |
| US4232948A (en) | Liquid crystal display device | |
| US4653865A (en) | Liquid crystal display device | |
| US5889570A (en) | Reflection--type liquid crystal displaying device | |
| EP0311339B1 (en) | Liquid crystal display | |
| EP0886169B1 (en) | Reflective liquid crystal display device | |
| US4277144A (en) | Electro-optic passive display cell | |
| KR920004895B1 (en) | Liquid crystal display | |
| JPH0349412B2 (en) | ||
| KR960012001B1 (en) | A double-layered super-twisted nematic liquid crystal display panel | |
| GB2066498A (en) | Multi-layered Twisted Nematic Liquid Crystal Display Panel | |
| US5721600A (en) | Reflective liquid crystal display with optical compensation plates | |
| KR0131015B1 (en) | LCD display device | |
| US5015074A (en) | Polychrome screen | |
| US4923286A (en) | Display cell | |
| US4375317A (en) | Multi-layered liquid crystal display panel | |
| KR100249919B1 (en) | Lcd apparatus with optical compensation plates | |
| US5737046A (en) | Birefringence control type liquid crystal display device | |
| JPS5938591B2 (en) | liquid crystal display device | |
| FI87495B (en) | FLYTKRISTALLSKAERM. | |
| EP0356458A1 (en) | Ferroelectric liquid crystal devices | |
| JP2605064B2 (en) | Liquid crystal display device | |
| JP2813222B2 (en) | Liquid crystal display device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PE20 | Patent expired after termination of 20 years |
Effective date: 20001218 |