Patent US3837729A successfully refreshed from Google Patents.
US3837729A
Expired / Lapsed
US
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Liquid crystal display
Assignee: F Hoffmann La Roche AG
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Filing: 1973-05-14
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Granted: 1974-09-24
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Expires: 1993-05-14
Abstract
Abstract High efficiency reflection without ghosts or distracting background images is obtained in a liquid crystal display of the type having a twisted nematic structure. The display employs only a single polarizer on the front face of the display; while the rear surface is provided with a reflector assembly which will scatter and reflect polarized light without depolarizing the same. The reflector can comprise a transparent plate having a diffused surface facing the liquid crystal layer and a metalized reflecting backing on its opposite side. Alternately, the reflector assembly can comprise a metalized reflecting surface which is roughened to produce the required scattering effect.
Inventors
- 👤 T Harsch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:19
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1343; G02F1/134309; G02F1/134327; G02F1/1335; G02F1/133553; G02F1/137; G02F1/139; G02F1/1396; G02F2203/00; G02F2203/02
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
171 words
A liquid crystal electro-optical display comprising a layer of liquid crystal material of positive dielectric anisotropy disposed between front and rear transparent parallel plates, both of said plates being coated with films of transparent conducting material on the sides thereof facing said liquid crystal layer, the films of transparent conducting material on said front plate being on only selected areas thereof, means for effecting a twisted nematic structure in said layer of liquid crystal material, a polarizer on the side of said layer of liquid crystal material adjacent said front plate, said polarizer being the only one in said display, and a reflector assembly disposed on the other side of said layer of liquid crystal material adjacent said rear plate, the reflector assembly being such as to cause at least a portion of the light passing through areas of the front plate not coated with the conducting material to be returned from the reflector assembly so as to intersect an area of the front plate which is coated with conducting material.
Claim 2
Dependent Claim
171 words
A liquid crystal electro-optical display comprising a layer of liquid crystal material of positive dielectric anisotropy disposed between front and rear transparent parallel plates, both of said plates being coated with films of transparent conducting material on the sides thereof facing said liquid crystal layer, the films of transparent conducting material on said front plate being on only selected areas thereof, means for effecting a twisted nematic structure in said layer of liquid crystal material, a polarizer on the side of said layer of liquid crystal material adjacent said front plate, said polarizer being the only one in said display, and a reflector assembly disposed on the other side of said layer of liquid crystal material adjacent said rear plate, the reflector assembly being such as to cause at least a portion of the light passing through areas of the front plate not coated with the conducting material to be returned from the reflector assembly so as to intersect an area of the front plate which is coated with conducting material.
Claim 3
Dependent Claim
36 words
The liquid crystal display of claim 1 wherein said reflector assembly comprises a transparent plate having a diffusing surface on its side adjacent the rear transparent parallel plate and a reflective surface on its other side.
Claim 4
Dependent Claim
24 words
The liquid crystal display of claim 1 wherein said reflector assembly comprises a metalized reflector having a roughened surface adjacent said rear transparent plate.
Claim 5
Dependent Claim
16 words
The liquid crystal display of claim 3 wherein said reflector assembly is formed from metalized granules.
Claim 6
Dependent Claim
33 words
The liquid crystal display of claim 1 wherein the films of transparent conducting material on said front plate comprise conducting strips adapted to form an alphanumerical display, the conducting strips having cut-away portions.
Claim 7
Dependent Claim
22 words
The liquid crystal display of claim 1 whereIn said reflector assembly is such as to scatter polarized light without depolarizing the same.
References Cited (Backward Citations)
US3784280A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-23 | 1978-03-25 | 1978-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-23 | 1982-03-25 | 1982-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-23 | 1986-03-25 | 1986-09-24 | $7700.00 | Window Closed / Lapsed |