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US4232946A
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Liquid crystal alignment layers
Assignee: Ebauches SA
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Filing: 1978-12-19
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Granted: 1980-11-11
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Expires: 1998-12-19
Abstract
Abstract Two alignment films are deposited on a liquid crystal substrate. Each film is deposited at an angle of about 5° with respect to the substrate surface. The projection on the substrate of one deposition beam forms an angle of 180° with the projecton on the surface of the other deposition beam. The resultant liquid crystal cell has a sharp threshold with good contrast, particularly for multiplexing applications.
Inventors
- 👤 Fereydoun Gharadjedaghi
- 👤 Bernard Le Fur
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:50
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1337; G02F1/133734; Y; Y10; Y10S; Y10S359/00; Y10S359/90
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
180 words
Method of manufacturing an electro-optic passive display cell having a helical nematic liquid crystal comprising two plates between which is disposed the said crystal, according to which one deposits on the inner face of each of the said plates an alignment film by evaporation under vacuum under an incidence ensuring an alignment of the molecules of the liquid crystal which thus orientate themselves along a direction determined by the process of evaporation, characterized by the fact that one realizes the said film by applying, on at least one of the said plates, two layers of an alignment material under an incidence of about 5°, the projection, on the plate, of the vector of application of one of the said layers forming an angle of 180° with the projection, on the plate, of the vector of application of the other layer, the whole in such a way that the molecules of the liquid crystal are then anchored on the said plate under an angle, smaller than 10°, such that the average anchoring angle on the two plates be smaller than 5°.
Claim 2
Dependent Claim
180 words
Method of manufacturing an electro-optic passive display cell having a helical nematic liquid crystal comprising two plates between which is disposed the said crystal, according to which one deposits on the inner face of each of the said plates an alignment film by evaporation under vacuum under an incidence ensuring an alignment of the molecules of the liquid crystal which thus orientate themselves along a direction determined by the process of evaporation, characterized by the fact that one realizes the said film by applying, on at least one of the said plates, two layers of an alignment material under an incidence of about 5°, the projection, on the plate, of the vector of application of one of the said layers forming an angle of 180° with the projection, on the plate, of the vector of application of the other layer, the whole in such a way that the molecules of the liquid crystal are then anchored on the said plate under an angle, smaller than 10°, such that the average anchoring angle on the two plates be smaller than 5°.
Claim 3
Dependent Claim
20 words
Method as claimed in claim 1, characterized by the fact that one applies successively the two layers of alignment material.
Claim 4
Dependent Claim
38 words
Method as claimed in claim 2, characterized by the fact that one gives to the first layer of the alignment film a thickness of about 50 A and to the second one a thickness of about 100 A.
Claim 5
Dependent Claim
38 words
Method as claimed in claim 2, characterized by the fact that between the applications on the plate of the two layers forming the alignment film one causes the plate to rotate on itself by an angle of 180°.
Claim 6
Dependent Claim
68 words
Method as claimed in claim 2, characterized by the fact that one uses a unique source of application of the two layers forming the alignment film and moves this source with respect to the plate, between the two operations of application of the said layers, in such a way that the projections on the plate of the two vectors of application form between themselves an angle of 180°.
Claim 7
Dependent Claim
20 words
Method as claimed in claim 1, characterized by the fact that one deposits simultaneously the two layers of alignment material.
Claim 8
Dependent Claim
69 words
Method as claimed in claim 2 or 6, characterized by the fact that one uses two sources of application of the two layers forming the alignment film, which are opposite to each other, and causes said sources to operate in such a way as to realize one of the said layers by means of one of the said sources and the other one by means of the other source.
Claim 9
Dependent Claim
30 words
Method as claimed in claims 7, characterized by the fact that one causes the said two sources of application of the two layers forming the alignment film to operate successively.
Claim 10
Dependent Claim
30 words
Method as claimed in claims 7, characterized by the fact that one causes the said two sources of application of the two layers forming the alignment film to operate simultaneously.
Claim 11
Dependent Claim
15 words
Passive electro-optic display cell obtained by carrying out the method as claimed in claim 1.
References Cited (Backward Citations)
US3967883A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-11-11 | 1984-05-12 | 1984-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-11 | 1988-05-12 | 1988-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-11 | 1992-05-12 | 1992-11-11 | $7700.00 | Window Closed / Lapsed |