US3963312A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Controllable liquid-crystal display device
Assignee: BBC Brown Boveri AG Switzerland
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Filing: 1974-09-11
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Granted: 1976-06-15
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Expires: 1994-09-11
Abstract
Abstract An improved liquid-crystal display exhibiting both a relatively bright background and good contrast between the background and displayed characters is disclosed. The display includes a liquid-crystal contained between a pair of support plates carrying transparent electrodes. First and second polarizers of differing characteristics are positioned on opposite sides of the liquid-crystal and a suitable reflector is combined with one of the polarizers.
Inventors
- 👤 Peter Wild
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:25
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/133528
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
112 words
A controllable liquid-crystal display device comprising: first and second transparent support plates, a transparent electrode on a plane surface of each of said transparent support plates, a liquid crystal contained between said first and second transparent support plates and said transparent electrodes, first and second approximately neutral polarizers, positioned on opposite sides of said liquid crystal, said polarizers being of such a type that said first polarizer in conjunction with another polarizer of the same type exhibits a high extinction ratio and said second polarizer in conjunction with another polarizer of the same type exhibits a relatively low extinction ratio; and a reflector of low light scattering characteristics adjacent said second polarizer.
Claim 2
Dependent Claim
112 words
A controllable liquid-crystal display device comprising: first and second transparent support plates, a transparent electrode on a plane surface of each of said transparent support plates, a liquid crystal contained between said first and second transparent support plates and said transparent electrodes, first and second approximately neutral polarizers, positioned on opposite sides of said liquid crystal, said polarizers being of such a type that said first polarizer in conjunction with another polarizer of the same type exhibits a high extinction ratio and said second polarizer in conjunction with another polarizer of the same type exhibits a relatively low extinction ratio; and a reflector of low light scattering characteristics adjacent said second polarizer.
Claim 3
Dependent Claim
27 words
A controllable liquid-crystal display device as in claim 1, wherein: the transmissivity for non-polarized light of said first polarizer is less than that of said second polarizer.
Claim 4
Dependent Claim
20 words
A controllable liquid-crystal display device as in claim 1, wherein: said first polarizer is a Polaroid type HN 42 polarizer.
Claim 5
Dependent Claim
20 words
A controllable liquid-crystal display device as in claim 1, wherein: said first polarizer is a Polaroid type HN 48 polarizer.
Claim 6
Dependent Claim
22 words
A controllable liquid-crystal display device as in claim 1, wherein: said reflector is formed of a slightly roughened and anodized aluminum foil.
Claim 7
Dependent Claim
20 words
A controllable liquid-crystal display device as in claim 1, wherein: said second polarizer is a Polaroid type HN 55 polarizer.
Claim 8
Dependent Claim
27 words
A controllable liquid-crystal display device as in claim 1, wherein: said second polarizer and said reflector are located between said liquid crystal and said second support plate.
Claim 9
Dependent Claim
22 words
A controllable liquid-crystal display device as in claim 7, wherein: said second polarizer is a film having uniformly oriented dichroic pigment molecules.
Claim 10
Dependent Claim
20 words
A controllable liquid-crystal display device as in claim 1, wherein: said liquid-crystal display device is comprised predominantly of thin-film layers.
References Cited (Backward Citations)
US3731986A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-06-15 | 1979-12-15 | 1980-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-15 | 1983-12-15 | 1984-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-15 | 1987-12-15 | 1988-06-15 | $7700.00 | Window Closed / Lapsed |