US4088393A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Field effect mode liquid crystal display materials
Assignee: Omron Corp
•
Filing: 1975-12-31
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Granted: 1978-05-09
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Expires: 1995-12-31
Abstract
Abstract A redox dopant for incorporation into the electrolytic conducting medium of an electro-optical display to increase the life of the electrodes in the same. Suitable dopants include ascorbic acid, hydroquinone, or parabenzoquinone incorporated into the twist nematic liquid crystal layer of a field effect display device.
Inventors
- 👤 Masao Hirano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:16
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1343; G02F1/13439; C; C09; C09K; C09K19/00; C09K19/52; C09K19/58; C09K19/582
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
69 words
In an electro-optical display device of the field mode including first and second electrodes comprising conductivity surfaces on opposed plates, a layer of liquid crystal medium having twisted nematic properties at room temperature disposed between said electrodes, and means for establishing an electrical potential between said electrodes, the improvement comprising a dopant comprising ascorbic acid in solution in the liquid crystal medium to increase the life of the electrodes.
Claim 2
Dependent Claim
69 words
In an electro-optical display device of the field mode including first and second electrodes comprising conductivity surfaces on opposed plates, a layer of liquid crystal medium having twisted nematic properties at room temperature disposed between said electrodes, and means for establishing an electrical potential between said electrodes, the improvement comprising a dopant comprising ascorbic acid in solution in the liquid crystal medium to increase the life of the electrodes.
Claim 3
Dependent Claim
22 words
The display device of claim 1 in which said dopant comprises from 0.05% to 1% by weight of said liquid crystal medium.
Claim 4
Dependent Claim
22 words
The display device of claim 1 in which said dopant comprises from 0.1% to 0.3% by weight of said liquid crystal medium.
Claim 5
Dependent Claim
12 words
The display device of claim 1 in which said electrodes are transparent.
Claim 6
Dependent Claim
26 words
The display device of claim 4 in which said electrodes are formed of a material selected from the group consisting of tin oxide and indium oxide.
Claim 7
Dependent Claim
24 words
The display device of claim 1 in which said liquid crystal medium is selected from the group consisting of Schiff bases, esters, and biphenyls.
Claim 8
Dependent Claim
18 words
The display device of claim 1 in which said liquid crystal medium is of the Schiff base type.
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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) | 1981-05-08 | 1981-11-07 | 1982-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-08 | 1985-11-07 | 1986-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-08 | 1989-11-07 | 1990-05-09 | $7700.00 | Window Closed / Lapsed |