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US4009938A
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Liquid crystal display device
Assignee: Suwa Seikosha KK
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Filing: 1973-12-06
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Granted: 1977-03-01
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Expires: 1993-12-06
Abstract
Abstract A liquid crystal display device uses nematic liquid crystal compounds having a high positive dielectric anisotropy for rotating the plane of polarized light. The optical activity of a composition including such materials can be eliminated by impressing a sufficiently high voltage across a cell containing such materials. These properties make it possible to use such compositions as the basis of a device which is, in effect, an optical shutter.
Inventors
- 👤 Yoshio Yamazaki
- 👤 Toshihiro Suzuki
- 👤 Sadao Kanbe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:38
CPC Classifications
C; C09; C09K; C09K19/00; C09K19/04; C09K19/42; C09K19/46
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
155 words
A liquid crystal display device having a low-threshold voltage for altering the transit of polarized light therethrough comprising two opposed transparent plates, unidirectionally-oriented transparent electrodes on the inner faces of said plates, the directions of orientation of said electrodes differing by about 90°, said electrodes being connectable to a voltage source, polarizing filters disposed at the outer surfaces of said plates and a nematic liquid crystal composition between said plates, said composition comprising a first compound having the structural formula ##STR41##where X and X' are selected from the group consisting of alkyl radicals having 2-7 carbon atoms, alkoxy radicals having 1-2 carbon atoms and acyloxy radicals having 4-7 carbon atoms in the alkyl portions thereof and a second liquid crystal compound having the formula ##STR42##where X" is selected from the group consisting of alkyl radicals having 3-6 carbon atoms and acyloxy radicals and alkyl carbonate groups having 4-7 carbon atoms in the alkyl portions thereof.
Claim 2
Dependent Claim
155 words
A liquid crystal display device having a low-threshold voltage for altering the transit of polarized light therethrough comprising two opposed transparent plates, unidirectionally-oriented transparent electrodes on the inner faces of said plates, the directions of orientation of said electrodes differing by about 90°, said electrodes being connectable to a voltage source, polarizing filters disposed at the outer surfaces of said plates and a nematic liquid crystal composition between said plates, said composition comprising a first compound having the structural formula ##STR41##where X and X' are selected from the group consisting of alkyl radicals having 2-7 carbon atoms, alkoxy radicals having 1-2 carbon atoms and acyloxy radicals having 4-7 carbon atoms in the alkyl portions thereof and a second liquid crystal compound having the formula ##STR42##where X" is selected from the group consisting of alkyl radicals having 3-6 carbon atoms and acyloxy radicals and alkyl carbonate groups having 4-7 carbon atoms in the alkyl portions thereof.
Claim 3
Dependent Claim
73 words
A liquid crystal display device as defined in claim 1 wherein said first compound is ##STR43##with R 1 and R 2 alkyl radicals of 2-7 carbon atoms, said second compound is ##STR44##with R 3 being an alkyl radical of 3-6 carbon atoms and further comprising a third compound having the structure ##STR45##where R 4 is an alkyl radical of 1-2 carbon atoms and R 5 is an alkyl group having 1-3 carbon atoms.
Claim 4
Dependent Claim
62 words
A liquid crystal display device as defined in claim 1 wherein said first compound is a P,P'-dialkylazoxybenzene, with alkyl radicals having 2-7 carbon atoms, and a second compound is a P-alkylcarbonate-P'-cyanophenylbenzoate with an alkyl radical having 4-7 carbon atoms and further comprising a P-alkoxy, P'-alkyl azoxybenzene with an alkoxy radical having 1-2 carbon atoms and an alkyl radical having 2-7 carbon atoms.
Claim 5
Dependent Claim
49 words
A liquid crystal display device as defined in claim 1 wherein said first compound is a P-alkoxy, P'-alkylazoxybenzene, with said alkoxy group having 1-2 carbon atoms and said alkyl group having 2-7 carbon atoms and said second is a P-alkyl, P'cyanophenylbenzoate with said alkyl group having 3-6 carbon atoms.
Claim 6
Dependent Claim
23 words
A liquid crystal display device as defined in claim 1 comprising a composite of P-methoxy-P'-n-butylazoxybenzene and P-n-butyl-P'-cyanophenylbenzoate in the weight ratio of 8:2.
Claim 7
Dependent Claim
25 words
A liquid crystal display device as defined in claim 2 comprising a composite of P-methoxy-P'-n-butylazoxybenzene and P-,P'-di-n-butyl-azoxybenzene and P-n-pentyl-P'-cyanophenylbenzoate in the weight ratio of 4:4:2.
Claim 8
Dependent Claim
62 words
A liquid crystal display device as defined in claim 1 wherein said first compound is P-methoxy-P'-n-butyl-azoxybenzene, and said second compound is P-n-hexylcarbonate-P'-cyanophenylbenzoate and further comprising a third compound, p-methoxy-p'ethyl-azoxybenzene, said first and third compounds being present in such quantity relationship that they constitute a eutectic mixture, the weights of said eutectic mixture and said second compound being in the ratio of 8:2.
Claim 9
Dependent Claim
44 words
A liquid crystal display device as defined in claim 1 wherein said first compound is P-methoxy-P'n-butylazoxybenzene, and said second compound is P-n-pentyl-P'cyanophenylbenzoate and further comprising a third compound P-,P'-di-n-butylazoxybenzene and a fourth compound p-n-hexylcarbonate -P'-cyanophenylbenzoate, the weights of said compounds having the relationship 3.4:1.6:3.0:2.0.
Claim 10
Dependent Claim
39 words
A liquid crystal display device as defined in claim 1 wherein the positive dielectric anisotropy and the quantity of the nitrile in said composition are such that the positive dielectric anisotropy of said composition is at least about 2.
Claim 11
Dependent Claim
20 words
A liquid crystal display device as defined in claim 9 wherein the threshold voltage is at most about 3.0 volts.
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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) | 1980-02-29 | 1980-08-30 | 1981-03-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-29 | 1984-08-30 | 1985-03-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-29 | 1988-08-30 | 1989-03-01 | $7700.00 | Window Closed / Lapsed |