Patent US4270841A successfully refreshed from Google Patents.
US4270841A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light valve containing suspension of perhalide of alkaloid acid salt
Assignee: Research Frontiers Inc
•
Filing: 1978-10-31
•
Granted: 1981-06-02
•
Expires: 1998-10-31
Abstract
Abstract A light valve comprises a cell containing a suspension of light-polarizing particles in a liquid suspending medium, the light polarizing particles being particles of a light-polarizing perhalide of a polycarboxylic acid salt of an alkaloid.
Inventors
- 👤 Robert L. Saxe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 08:55
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/17; G02F1/172; C; C09; C09K; C09K19/00; C09K19/52
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
39 words
In a light valve, comprising a cell containing a suspension of light-polarizing particles in a liquid suspending medium, the improvement wherein said light polarizing particles are particles of a light-polarizing perhalide of a polycarboxylic acid salt of an alkaloid.
Claim 2
Dependent Claim
39 words
In a light valve, comprising a cell containing a suspension of light-polarizing particles in a liquid suspending medium, the improvement wherein said light polarizing particles are particles of a light-polarizing perhalide of a polycarboxylic acid salt of an alkaloid.
Claim 3
Dependent Claim
26 words
The light valve according to claim 1, wherein said polycarboxylic acid is an aromatic, aliphatic or cycloaliphatic organic acid having at least two carboxylic acid groups.
Claim 4
Dependent Claim
16 words
The light valve according to claim 2, wherein polycarboxylic acid contains at least one hydroxy group.
Claim 5
Dependent Claim
24 words
The light valve according to claim 2, wherein said polycarboxylic acid has two to six carboxylic acid groups and zero to six hydroxy groups.
Claim 6
Dependent Claim
13 words
THe light valve according to claim 2, wherein said polycarboxylic acid is symmetrical.
Claim 7
Dependent Claim
26 words
The light valve according to claim 2, wherein said polycarboxylic acid contains up to 25 carbon atoms with 2-4 carboxylic acid groups and 0-6 hydroxy groups.
Claim 8
Dependent Claim
46 words
The light valve according to claim 1, wherein said polycarboxylic acid is selected from the group consisting of oxalic, malonic, succinic, glutaric, adipic, pimelic, suberic, azelaic, sebacic, fumaric, maleic, mesaconic, glutaconic, itaconic, muconic, aconitic, malic, tartaric, citric, mucic, trihydroxyglutaric, xylonic, terephthalic, pyromellitic, and naphthyl dicarboxylic acid.
Claim 9
Dependent Claim
32 words
The light valve according to claim 1, wherein said light polarizing perhalide is cinchonidine terephthalate periodide, cinchonidine pyromellitate periodide, cinchonidine mucate periodide, quinine terephthalate periodide, quinine pyromellitate periodide, or quinine mucate periodide.
Claim 10
Dependent Claim
16 words
The light valve according to claim 1, wherein said alkaloid is a heterocyclic organic nitrogen base.
Claim 11
Dependent Claim
14 words
The light valve according to claim 9, wherein said alkaloid is a quinine alkaloid.
Claim 12
Dependent Claim
26 words
The light valve according to claim 1, wherein said alkaloid is selected from the group consisting of pyridine, picoline, diphenyl oxazole, quinoline, quinaldine, caffeine and toluidine.
Claim 13
Dependent Claim
20 words
The light valve according to claim 11, wherein said quinine alkaloid is selected from the group consisting of quinine, cinchonidine.
References Cited (Backward Citations)
US1955923A
Cited
US1951664A
Cited
US2178996A
Cited
US2176516A
Cited
US2289712A
Cited
US3512876A
Cited
US3773684A
Cited
US4131334A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-06-01 | 1984-12-01 | 1985-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-01 | 1988-12-01 | 1989-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-01 | 1992-12-01 | 1993-06-02 | $7700.00 | Window Closed / Lapsed |