Patent DE3936703C2 successfully refreshed from Google Patents.
US4141627A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electro-optic device
Assignee: RCA Corp
•
Filing: 1977-01-06
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Granted: 1979-02-27
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Expires: 1997-01-06
Abstract
Abstract Novel dyes of the formula ##STR1## wherein X can be hydrogen, alkyl, alkoxy, cyano, nitro, dialkylamino, halogen or --N═N--Y and Y can be phenyl, phenyl substituted in the para position with an alkyl, alkoxy, cyano, nitro, dialkylamino or halogen group, or a heterocyclic ring, can be added to known liquid crystal compositions to impart color to the mixtures and improved contrast to a liquid crystal electro-optic device containing such mixtures.
Inventors
- 👤 Allen Bloom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:13
CPC Classifications
C; C09; C09B; C09B29/00; C09B29/0014; C09K; C09K19/00; C09K19/52; C09K19/60
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
71 words
In an electro-optic device comprising a nematic liquid crystal composition having a positive dielectric anisotropy between two electrodes, the improvement wherein said nematic liquid crystal composition contains a dye of the formula ##STR7## wherein X can be hydrogen, alkyl, alkoxy, cyano, nitro, dialkylamino, halogen or --N═N--Y and Y can be phenyl, phenyl substituted in the para position with an alkyl, alkoxy, cyano, nitro, dialkylamino or halogen group, or a heterocyclic ring.
Claim 2
Dependent Claim
71 words
In an electro-optic device comprising a nematic liquid crystal composition having a positive dielectric anisotropy between two electrodes, the improvement wherein said nematic liquid crystal composition contains a dye of the formula ##STR7## wherein X can be hydrogen, alkyl, alkoxy, cyano, nitro, dialkylamino, halogen or --N═N--Y and Y can be phenyl, phenyl substituted in the para position with an alkyl, alkoxy, cyano, nitro, dialkylamino or halogen group, or a heterocyclic ring.
Claim 3
Dependent Claim
26 words
A device according to claim 1 wherein X is methoxy and Y is ##STR8## wherein R can be hydrogen, alkyl, alkoxy, cyano, nitro, dialkylamino or halogen.
Claim 4
Dependent Claim
14 words
A device according to claim 1 wherein X is methoxy and Y is p-diethylaminophenyl.
Claim 5
Dependent Claim
60 words
A nematic liquid crystal composition comprising a nematic liquid crystal having a positive dielectric anisotropy and a compound of the formula ##STR9## wherein X can be hydrogen, alkyl, alkoxy, cyano, nitro, dialkylamino, halogen or --N═N--Y and Y can be phenyl, phenyl substituted in the para position with an alkyl, alkoxy, cyano, nitro, dialkylamino or halogen group, or a heterocyclic ring.
Claim 6
Dependent Claim
60 words
A nematic liquid crystal composition comprising a nematic liquid crystal having a positive dielectric anisotropy and a compound of the formula ##STR9## wherein X can be hydrogen, alkyl, alkoxy, cyano, nitro, dialkylamino, halogen or --N═N--Y and Y can be phenyl, phenyl substituted in the para position with an alkyl, alkoxy, cyano, nitro, dialkylamino or halogen group, or a heterocyclic ring.
Claim 7
Dependent Claim
26 words
A composition according to claim 4 wherein the nematic liquid crystal is a mixture of p-methoxybenzylidene-p'-n-butylaniline, p-ethoxybenzylidene-p'-n-butylaniline and one or more compounds having the formula ##STR10##
Claim 8
Dependent Claim
6 words
wherein R is an alkyl group.
Claim 9
Dependent Claim
6 words
wherein R is an alkyl group.
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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) | 1982-02-26 | 1982-08-28 | 1983-02-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-26 | 1986-08-28 | 1987-02-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-26 | 1990-08-28 | 1991-02-27 | $7700.00 | Window Closed / Lapsed |