US4722594A
Expired / Lapsed
US
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Two-dimensional optical information processing apparatus
Assignee: Nortel Networks Ltd
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Filing: 1985-11-14
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Granted: 1988-02-02
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Expires: 2005-11-14
Abstract
Abstract Bistable operation of ferroelectric liquid crystal smectic I* or smectic F* cells is disclosed which uses a greater liquid crystal layer thickness than is achievable with smectic C* material while yet retaining bistability of operation. One or more such cells are employed in two-dimensional information processing apparatus.
Inventors
- 👤 William A. Crossland
- 👤 Anthony B. Davey
- 👤 Neil Collings
- 👤 Matthew F. Bone
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:21
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/137; G02F1/139; G02F1/141
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
81 words
Two-dimensional optical information processing apparatus incorporating at least one ferroelectric liquid crystal cell exhibiting bistability of operation, which cell has a smectic I* or F* phase liquid crystal layer confined between opposed electroded plates whose inward facing surfaces have been treated to promote planar alignment of the adjacent liquid crystal molecules in the same direction at each of the two surfaces, which plates serve to define a liquid crystal layer with a thickness in the range from 4 to 40 microns.
Claim 2
Dependent Claim
81 words
Two-dimensional optical information processing apparatus incorporating at least one ferroelectric liquid crystal cell exhibiting bistability of operation, which cell has a smectic I* or F* phase liquid crystal layer confined between opposed electroded plates whose inward facing surfaces have been treated to promote planar alignment of the adjacent liquid crystal molecules in the same direction at each of the two surfaces, which plates serve to define a liquid crystal layer with a thickness in the range from 4 to 40 microns.
Claim 3
Dependent Claim
19 words
Apparatus as claimed in claim 1, wherein the or each liquid crystal layer thickness is less than 20 microns.
Claim 4
Dependent Claim
19 words
Apparatus as claimed in claim 1, wherein a pleochroic dye is dispersed in the or each liquid crystal layer.
Claim 5
Dependent Claim
16 words
Apparatus as claimed in claim 1, wherein the or each cell is a transmission type cell.
Claim 6
Dependent Claim
16 words
Apparatus as claimed in claim 1, wherein the or each cell is a reflex type cell.
Claim 7
Dependent Claim
20 words
Apparatus as claimed in claim 1, wherein the or each cell is adapted to operate in an amplitude modulation mode.
Claim 8
Dependent Claim
20 words
Apparatus as claimed in claim 1, wherein the or each cell is adapted to operate in a phase modulation mode.
Claim 9
Dependent Claim
13 words
Apparatus as claimed in claim 1, which apparatus is a joint transform correlator.
Claim 10
Dependent Claim
13 words
Apparatus as claimed in claim 1, which apparatus is a frequency plane correlator.
References Cited (Backward Citations)
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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) | 1991-02-01 | 1991-08-03 | 1992-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-02-01 | 1995-08-03 | 1996-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-02-01 | 1999-08-03 | 2000-02-02 | $7700.00 | Window Closed / Lapsed |