US5317431A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid crystal display device with scattering white layer and color filter
Assignee: Sharp Corp
•
Filing: 1992-11-20
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Granted: 1994-05-31
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Expires: 2012-11-20
Abstract
Abstract A liquid crystal display device including a first liquid crystal layer having a dichroic dye contained therein, and a second liquid crystal layer having light scattering properties. The first and the second liquid crystal layers are stratified separately from each other and superposed one above the other between a pair of glass plates. A color filter is provided on one of the plates. The threshold voltage of the first liquid crystal layer is, for example, lower than the threshold voltage of the second liquid crystal layer (V 1 <V 2 ). Accordingly, when the voltage applied to the liquid crystal is lower than the threshold voltage (V 1 ) of the first liquid crystal layer, the light is absorbed by the dichroic dye to produce a black spot. When the voltage is higher than the threshold voltage (V 1 ) of the first liquid crystal layer and lower than the threshold voltage (V 2 ) of the second liquid crystal layer, the second liquid crystal layer becomes white and cloudy thereby producing a white spot on the display. When voltage is higher than the threshold voltage (V 2 ), the light transmits both first and second liquid crystal layers, and the color filter can be directly visualized.
Inventors
- 👤 Hidefumi Yoshida
- 👤 Kazutaka Hanaoka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:53
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1334; G02F1/1347; G02F1/13476
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
80 words
A liquid crystal display device comprising first and second opposite plates, a first liquid crystal layer having a threshold voltage and a dichroic dye contained therein, a second liquid crystal layer having a threshold voltage different from that of the first liquid crystal layer and light scattering properties, and a color filter provided on one of the plates; the first and second liquid crystal layers being stratified separately from each other and superposed one above the other between the plates.
Claim 2
Dependent Claim
80 words
A liquid crystal display device comprising first and second opposite plates, a first liquid crystal layer having a threshold voltage and a dichroic dye contained therein, a second liquid crystal layer having a threshold voltage different from that of the first liquid crystal layer and light scattering properties, and a color filter provided on one of the plates; the first and second liquid crystal layers being stratified separately from each other and superposed one above the other between the plates.
Claim 3
Dependent Claim
27 words
A liquid crystal device according to claim 1, wherein at least one of the first and the second liquid crystal layers comprises a polymer dispersed liquid crystal.
Claim 4
Dependent Claim
28 words
A liquid crystal device according to claim 1, wherein the first and second liquid crystal layers are arranged continuously and stratified separately from each other between the plates.
Claim 5
Dependent Claim
49 words
A liquid crystal device according to claim 1, wherein a third plate is arranged between the first and the second plates; the first liquid crystal layer being arranged between the first and the third plates; the second liquid crystal layer being arranged between the third and the second plates.
Claim 6
Dependent Claim
31 words
A liquid crystal device according to claim 1, wherein a reflecting layer is arranged between the first and the second plates; the other plate being transparent and providing a displaying surface.
Claim 7
Dependent Claim
49 words
A liquid crystal device according to claim 5, wherein the threshold voltage of one of the first and the second liquid crystal layers on the side of the displaying surface is lower than the threshold voltage of the other liquid crystal layer on the side of the reflecting layer.
Claim 8
Dependent Claim
60 words
A liquid crystal device according to claim 1, wherein the first and the second liquid crystal layers comprise polymer dispersed liquid crystal capsules having different threshold voltages; the liquid crystal capsules of one of the liquid crystal layers having a lower threshold voltage and a larger diameter than those of the liquid crystal capsules of the other liquid crystal layer.
Claim 9
Dependent Claim
27 words
A liquid crystal device according to claim 1, wherein the first plate has an electrode means and the second plate has said color filter and picture electrodes.
Claim 10
Dependent Claim
26 words
A liquid crystal device according to claim 1, wherein a thick transparent plate is provided above the color filter when viewed from the liquid crystal layers.
Claim 11
Dependent Claim
34 words
A liquid crystal device according to claim 9, wherein the first plate has an electrode means, and the transparent plate is carried by the second plate and has said color filter and picture electrodes.
Claim 12
Dependent Claim
47 words
A liquid crystal device according to claim 10, wherein the transparent plate has first and second surfaces; the color filter being provided in the first surface of the transparent plate; the picture electrodes with thin film transistors being provided in the second surface of the transparent plate.
Claim 13
Dependent Claim
31 words
A liquid crystal device according to claim 11, wherein the transparent plate is bonded to the second plate with the first surface of the transparent plate faced to the second plate.
Claim 14
Dependent Claim
60 words
A liquid crystal display device as set forth in claim 1, wherein said one plate has first and second surfaces, said device further comprising electrode means on the other of said plates and picture electrodes including thin film transistors on the first surface of said one plate, said color filter being disposed on the second surface of said one plate.
References Cited (Backward Citations)
US3840695A
Cited
US4654117A
Cited
GB2137397A
Cited
US4581608A
Cited
US4560241A
Cited
US4709990A
Cited
EP0171766A1
Cited
US4671617A
Cited
US4773737A
Cited
WO1988002128A1
Cited
US5142389A
Cited
FR2595155A1
Cited
JPS6360427A
Cited
EP0347790A2
Cited
JPH03198028A
Cited
EP0435676A2
Cited
JPH04143723A
Cited
EP0488164A2
Cited
US5194973A
Cited
US5878741A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-05-30 | 1997-11-29 | 1998-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-05-30 | 2001-11-29 | 2002-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-05-30 | 2005-11-29 | 2006-05-31 | $7700.00 | Window Closed / Lapsed |