Patent US4492432A successfully refreshed from Google Patents.
US4492432A
Expired / Lapsed
US
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Homeotropic nematic display with internal reflector
Assignee: BBC Brown Boveri AG Switzerland
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Filing: 1981-07-14
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Granted: 1985-01-08
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Expires: 2001-07-14
Abstract
Abstract Nematic liquid crystal display is provided with front side polarizer (13) and homeotropic orientation in the non-field state. The nematic liquid crystal (6) has a negative dielectric anisotropy. The display cell has an internal reflector (11) consisting of an insulating oxide layer with built-in aluminum flakes and a front side polarizer (8, 13). This display provides a reflection display with no back lighting.
Inventors
- 👤 Meinolph Kaufmann
- 👤 Hanspeter Schad
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:23
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/133553; G02F1/133528; G02F1/137; G02F1/139; G02F1/1393; G02F1/13363; G02F1/133638; G02F1/1337; G02F1/133742; G02F1/13712
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
128 words
A liquid crystal display comprising: a cell consisting of two plane-parallel plates with a maximal cell thickness of 6 microns; a pair of electrode layers on the inner surfaces of said two plane-parallel plates wherein at least one of said electrode layers is transparent; a nematic liquid crystal having a negative dielectric anisotropy and a double refraction anisotropy between 0.04 and 0.15 and having rubbed orientational surfaces of said two plane-parallel plates to give the nematic liquid crystal a homeotropic orientation, wherein said rubbed orientational surfaces are treated with silane after rubbing; an internal reflector mounted on one of said electrode layers and consisting of aluminum flakes and an insulating oxide layer with said aluminum flakes embedded therein; a polarizer mounted on one of said two plane-parallel plates.
Claim 2
Dependent Claim
128 words
A liquid crystal display comprising: a cell consisting of two plane-parallel plates with a maximal cell thickness of 6 microns; a pair of electrode layers on the inner surfaces of said two plane-parallel plates wherein at least one of said electrode layers is transparent; a nematic liquid crystal having a negative dielectric anisotropy and a double refraction anisotropy between 0.04 and 0.15 and having rubbed orientational surfaces of said two plane-parallel plates to give the nematic liquid crystal a homeotropic orientation, wherein said rubbed orientational surfaces are treated with silane after rubbing; an internal reflector mounted on one of said electrode layers and consisting of aluminum flakes and an insulating oxide layer with said aluminum flakes embedded therein; a polarizer mounted on one of said two plane-parallel plates.
Claim 3
Dependent Claim
38 words
Liquid crystal display according to claim 1 wherein said insulating oxide layer consists of: CeO 2 , MgO, SiO 2 , TiO, TiO 2 , ZrO 2 , Al 2 O 3 or Gd 2 O 3 .
Claim 4
Dependent Claim
19 words
Liquid crystal display according to claim 1 wherein said silane used to orient the liquid crystal molecule is DMOAP.
Claim 5
Dependent Claim
17 words
Liquid crystal display according to claim 1 wherein said aluminum flakes are 2 to 10 μm long.
Claim 6
Dependent Claim
14 words
Liquid crystal display according to claim 1 wherein said polarizer is a linear polarizer.
Claim 7
Dependent Claim
14 words
Liquid crystal display according to claim 1 wherein said polarizer is a circular polarizer.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-01-08 | 1988-07-09 | 1989-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-01-08 | 1992-07-09 | 1993-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-01-08 | 1996-07-09 | 1997-01-08 | $7700.00 | Window Closed / Lapsed |