US4261650A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing uniform parallel alignment in liquid crystal cells
Assignee: International Business Machines Corp
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Filing: 1978-12-18
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Granted: 1981-04-14
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Expires: 1998-12-18
Abstract
Abstract A method of treating the surface of substrates used in liquid crystal display cells so that the surface forces the liquid crystal director to be aligned uniformly over the entire surface and parallel to the substrate surface. The method includes the step of forming a plasma beam containing oxygen free-radicals, inert gas free-radicals such as argon, neon and helium, and free radicals of a compound containing the element to be deposited, for example, silicon, tin, indium, etc. Preferably a volatile organo-silicon or an organo-tin compound is used to supply the silicon or tin. The plasma beam is then directed at the substrate surface at an angle, preferably of about 30°, for a time sufficient to deposit a film. The liquid crystal display cell utilizing a substrate formed in this manner has a high contrast ratio as well as a sharp threshold in its electro-optical characteristics.
Inventors
- 👤 Gerard J. Sprokel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:52
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1337; C; C23; C23C; C23C16/00; C23C16/22; C23C16/30; C23C16/40; C23C16/401; C23C16/402; C23C16/44; C23C16/50; C23C16/513; Y; Y10; Y10S; Y10S359/00; Y10S359/90
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
104 words
A method of treating the surface of substrates used in liquid crystal display cells so that the surface forces the liquid crystal director to be aligned uniformly over the entire surface and parallel with the substrate surface comprising the steps of forming a r.f. plasma beam containing oxygen free radicals, inert gas free radicals and free radicals of a compound containing the element taken from the group consisting of silicon, tin and indium, and directing said plasma beam at an angle of incidence of 5° to 40° to said substrate for a time sufficient to deposit a film at least about 100 angstroms thick.
Claim 2
Independent Claim
104 words
A method of treating the surface of substrates used in liquid crystal display cells so that the surface forces the liquid crystal director to be aligned uniformly over the entire surface and parallel with the substrate surface comprising the steps of forming a r.f. plasma beam containing oxygen free radicals, inert gas free radicals and free radicals of a compound containing the element taken from the group consisting of silicon, tin and indium, and directing said plasma beam at an angle of incidence of 5° to 40° to said substrate for a time sufficient to deposit a film at least about 100 angstroms thick.
Claim 3
Dependent Claim
20 words
A method as described in claim 1 whereby said plasma beam is directed at an angle of 25° to 35°.
Claim 4
Dependent Claim
15 words
A method as described in claim 1 whereby said plasma beam contains argon free radicals.
Claim 5
Dependent Claim
20 words
A method as described in claim 1 whereby said plasma beam contains free radicals of a volatile organo silicon compound.
Claim 6
Dependent Claim
20 words
A method as described in claim 1 whereby said plasma beam contains free radicals of a volatile organo tin compound.
Claim 7
Independent Claim
136 words
A method of treating the surface of substrates used in liquid crystal display cells so that the surface forces the liquid crystal director to be aligned uniformly over the entire surface and parallel with the substrate surface comprising the steps of forming a r.f. plasma beam containing oxygen free radicals, directing said plasma beam at an angle of incidence of about 90° to said substrate for a time sufficient to clean said substrate, forming a r.f. plasma beam containing oxygen free radicals, inert gas free radicals and free radicals of a compound containing the element taken from the group consisting of silicon, tin and indium, and directing said plasma beam at an angle of incidence of 20° to 40° to said substrate for a time sufficient to deposit a film at least about 100 angstroms thick.
Claim 8
Independent Claim
136 words
A method of treating the surface of substrates used in liquid crystal display cells so that the surface forces the liquid crystal director to be aligned uniformly over the entire surface and parallel with the substrate surface comprising the steps of forming a r.f. plasma beam containing oxygen free radicals, directing said plasma beam at an angle of incidence of about 90° to said substrate for a time sufficient to clean said substrate, forming a r.f. plasma beam containing oxygen free radicals, inert gas free radicals and free radicals of a compound containing the element taken from the group consisting of silicon, tin and indium, and directing said plasma beam at an angle of incidence of 20° to 40° to said substrate for a time sufficient to deposit a film at least about 100 angstroms thick.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-04-13 | 1984-10-13 | 1985-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-04-13 | 1988-10-13 | 1989-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-04-13 | 1992-10-13 | 1993-04-14 | $7700.00 | Window Closed / Lapsed |