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Patent US4221471A successfully refreshed from Google Patents.
US4221471A
Expired / Lapsed
US
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Liquid crystal memory device and method of utilizing same
Assignee: Motorola Solutions Inc
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Filing: 1977-06-24
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Granted: 1980-09-09
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Expires: 1997-06-24
Abstract
Abstract A liquid crystal memory device comprising a liquid crystal layer, means for preconditioning the layer so that at least some of its molecules will be slanted towards one of two possible tilt directions, means for causing at least some of the molecules of said liquid crystal layer to assume their preconditioned tilt direction, and means for determining which of said possible tilt directions has been assumed by the molecules of said liquid crystal layer is disclosed. The method of writing into this device comprises causing the molecules of selected portions of said liquid crystal layer to be preconditioned to slant towards one of two possible tilt directions, causing at least some of said preconditioned molcules to assume their preconditioned tilt direction, causing at least some of the molecules of other portions of said liquid crystal layer to be preconditioned to slant towards the other one of said two possible tilt directions, and causing at least some of said preconditioned molecules to assume their other preconditioned tilt direction.
Inventors
- 👤 Richard W. Gurtler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 14:23
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/135; B; B41; B41M; B41M5/00; B41M5/26; B41M5/28; B41M5/281; G02F1/1333; G02F1/1343; G02F1/134309; G02F1/137; G02F1/139; G02F1/1391; G11; G11C; G11C13/00; G11C13/04; G11C13/047; G11C13/06
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
185 words
A liquid crystal memory comprising: a nematic liquid crystal material disposed between parallel front and rear plates; means for preconditioning at least some of the molecules of said liquid crystal material so that their major axes are slightly slanted from a plane parallel to said plates towards one of two possible tilt directions; writing means for causing at least some of the molecules of said liquid crystal material to assume said one of said two possible tilt directions at one or more first locations; means for preconditioning said liquid crystal layer so that at least some of its molecules at one or more second locations distinct from said first locations will have their major axes slightly slanted towards the other one of two possible tilt directions; writing means for causing said some but not all of the molecules of said liquid crystal layer to assume said other one of two possible tilt directions at said second locations; and means for determining which of said two possible tilt directions has been assumed by the molecules of said liquid crystal layer at said first and second locations.
Claim 2
Dependent Claim
185 words
A liquid crystal memory comprising: a nematic liquid crystal material disposed between parallel front and rear plates; means for preconditioning at least some of the molecules of said liquid crystal material so that their major axes are slightly slanted from a plane parallel to said plates towards one of two possible tilt directions; writing means for causing at least some of the molecules of said liquid crystal material to assume said one of said two possible tilt directions at one or more first locations; means for preconditioning said liquid crystal layer so that at least some of its molecules at one or more second locations distinct from said first locations will have their major axes slightly slanted towards the other one of two possible tilt directions; writing means for causing said some but not all of the molecules of said liquid crystal layer to assume said other one of two possible tilt directions at said second locations; and means for determining which of said two possible tilt directions has been assumed by the molecules of said liquid crystal layer at said first and second locations.
Claim 3
Dependent Claim
33 words
The memory device of claim 1, wherein the long axes of said liquid crystal material are oriented parallel to said front and rear plates in the absence of any preconditioning or writing means.
Claim 4
Dependent Claim
18 words
The memory device of claim 1, wherein said liquid crystal material is disposed in a twisted nematic configuration.
Claim 5
Dependent Claim
28 words
The memory device of claim 1, wherein the means for preconditioning said molecules towards one of two possible tilt directions comprises surface treatment of one of said plates.
Claim 6
Dependent Claim
14 words
The memory device of claim 1, wherein said preconditioning means comprise a magnetic field.
Claim 7
Dependent Claim
14 words
The memory device of claim 1, wherein said writing means comprise an electric field.
Claim 8
Dependent Claim
22 words
The memory device of claim 1, wherein said preconditioning means comprise a magnetic field and said writing means comprise an electrical field.
Claim 9
Dependent Claim
21 words
The memory device of claim 1, wherein the means for determining which of said two possible tilt directions comprise optical beams.
Claim 10
Dependent Claim
21 words
The memory device of claim 1, wherein the means for determining which of said two possible tilt directions comprises capacitance discrimination.
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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) | 1983-09-09 | 1984-03-10 | 1984-09-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-09 | 1988-03-10 | 1988-09-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-09 | 1992-03-10 | 1992-09-09 | $7700.00 | Window Closed / Lapsed |