US4253740A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid crystal materials and devices containing them
Assignee: UK Secretary of State for Defence
•
Filing: 1978-09-08
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Granted: 1981-03-03
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Expires: 1998-09-08
Abstract
Abstract A liquid crystal material having a low threshold voltage for use in displays comprises a mixture of at least three liquid cyrstal materials at least two of which are selected from the following compounds. <IMAGE> <IMAGE> or the above compounds where in a cyclo hexane ring is substituted for one of the benzene rings, where X is a short alkyl group CnH2n+1 and n is an even integer, or where X is a short alkoxy group CmH2m+1 and m is an odd integer.
Inventors
- 👤 Edward P. Raynes
- 👤 Robert A. Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:27
CPC Classifications
C; C09; C09K; C09K19/00; C09K19/04; C09K19/42; C09K19/48
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
55 words
A liquid crystal material comprising a mixture of at least three liquid crystal compounds at least two of which compounds are represented by the formula ##STR17## where X is a short alkyl group C n H 2n+1 , n=2, 4, or 6, or the alkoxy group C m H 2m+1 O, m=1, 3, or 5.
Claim 2
Dependent Claim
55 words
A liquid crystal material comprising a mixture of at least three liquid crystal compounds at least two of which compounds are represented by the formula ##STR17## where X is a short alkyl group C n H 2n+1 , n=2, 4, or 6, or the alkoxy group C m H 2m+1 O, m=1, 3, or 5.
Claim 3
Dependent Claim
19 words
A material according to claim 1 and further comprising an amount of ##STR18## for enhancing the nematic temperature range.
Claim 4
Dependent Claim
19 words
A material according to claim 1 and further comprising an amount of ##STR19## for enhancing the nematic temperature range.
Claim 5
Dependent Claim
18 words
A material according to claim 1 and further comprising a small quantity of a cholesteric liquid crystal material.
Claim 6
Dependent Claim
16 words
A material according to claim 4 wherein the cholesteric material is a cholesteric cyano biphenyl material.
Claim 7
Dependent Claim
54 words
A liquid crystal device comprising a layer of liquid crystal material contained between two substrates at least one of which is transparent, an electrode structure arranged on the substrates for applying an electric field across at least selected parts of the layer, wherein the liquid crystal material is the material claimed in claim 1.
Claim 8
Dependent Claim
56 words
A material according to claim 1 and further comprising an amount of at least one material having the general formula ##STR20## where X is a short alkyl group C n H 2n+1 where n is 2, 4 or 6 or a short alkoxy group C m H 2m+1 O where m is 1, 3, or 5.
Claim 9
Dependent Claim
85 words
A liquid crystal material comprising a mixture of at least three liquid crystal materials at least two of which are selected from the following compounds ##STR21## where R is a short alkyl group C n H 2n+1 where n is 2, 4 or 6 or the alkoxy group CH 3 O, X is a short alkyl group C n H 2n+1 where n is 2, 4, or 6 or a short alkoxy group C m H 2m+1 O where m is 1, 3 or 5.
Claim 10
Dependent Claim
85 words
A liquid crystal material comprising a mixture of at least three liquid crystal materials at least two of which are selected from the following compounds ##STR21## where R is a short alkyl group C n H 2n+1 where n is 2, 4 or 6 or the alkoxy group CH 3 O, X is a short alkyl group C n H 2n+1 where n is 2, 4, or 6 or a short alkoxy group C m H 2m+1 O where m is 1, 3 or 5.
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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) | 1984-03-02 | 1984-09-01 | 1985-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-02 | 1988-09-01 | 1989-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-02 | 1992-09-01 | 1993-03-03 | $7700.00 | Window Closed / Lapsed |