US4184750A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Novel liquid crystal dyestuffs and electro-optic devices incorporating same
Assignee: RCA Corp
•
Filing: 1978-04-24
•
Granted: 1980-01-22
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Expires: 1998-04-24
Abstract
Abstract Novel liquid crystal dyestuffs of the formula <IMAGE> wherein Y and Z are different and can be nitro or cyano and -N(R)2 wherein R is alkyl or alkylene, preferably of 1 to 4 carbon atoms, and X can be hydrogen, methyl, fluoro or chloro, can be added to known liquid crystal compositions to impart color to the mixtures and improve contrast in a liquid crystal electro-optic device containing such mixtures.
Inventors
- 👤 Allen Bloom
- 👤 Ling K. Hung
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:03
CPC Classifications
C; C09; C09B; C09B56/00; C09B56/02
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
76 words
In an electro-optic device comprising a nematic liquid crystal composition with a positive dielectric anisotropy between two electrodes, the improvement which comprises the addition to the liquid crystal composition of a liquid crystal dyestuff of the formula: ##STR17## wherein Y and Z are different one is nitro or cyano and the other is --N(R) 2 wherein R is alkyl or alkylene, of 1 to 8 carbon atoms, and X can be hydrogen, methyl, fluoro or chloro.
Claim 2
Dependent Claim
76 words
In an electro-optic device comprising a nematic liquid crystal composition with a positive dielectric anisotropy between two electrodes, the improvement which comprises the addition to the liquid crystal composition of a liquid crystal dyestuff of the formula: ##STR17## wherein Y and Z are different one is nitro or cyano and the other is --N(R) 2 wherein R is alkyl or alkylene, of 1 to 8 carbon atoms, and X can be hydrogen, methyl, fluoro or chloro.
Claim 3
Dependent Claim
19 words
A device according to claim 1 wherein Y is a nitro group and Z is a --N(R) 2 group.
Claim 4
Dependent Claim
19 words
A device according to claim 1 wherein Y is a cyano group and Z is a --N(R) 2 group.
Claim 5
Dependent Claim
18 words
A device according to claim 1 wherein R is an alkyl group of 1 to 4 carbon atoms.
Claim 6
Dependent Claim
10 words
A device according to claim 2 wherein X is methyl.
Claim 7
Dependent Claim
10 words
A device according to claim 3 wherein X is methyl.
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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) | 1983-01-21 | 1983-07-23 | 1984-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-01-21 | 1987-07-23 | 1988-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-01-21 | 1991-07-23 | 1992-01-22 | $7700.00 | Window Closed / Lapsed |