US3652149A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable light-filtering device with a redox compound which functions as its own electrolyte
Assignee: Polaroid Corp
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Filing: 1969-09-02
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Granted: 1972-03-28
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Expires: 1989-09-02
Abstract
Abstract This invention relates to light filters employing redox compounds that are substantially light-transmitting in their oxidized state and capable of forming a stable colored free radical upon the addition of electrons. The colored free radical formed in response to the flow of electric current renders the device light-absorbing. To restore the original lighttransmitting properties, the colored free radical may be readily reoxidized, for example, by reversing the direction of current flow.
Inventors
- 👤 Howard G Rogers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:03
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/705; C; C09; C09K; C09K9/00; C09K9/02; F; F21; F21S; F21S41/00; F21S41/10; F21S41/12; F21S41/135; G02; G02B; G02B5/00; G02B5/20; G02B5/22; G02B5/24; G02F; G02F1/00; G02F1/01; G02F1/15; G02F1/1503; G02F1/153; G03G; G03G17/00; G03G17/02
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
68 words
A variable light-filtering device comprising a pair of spaced, parallel, coextensive light-transmitting electrodes, a layer of a light-transmitting redox compound (a) capable of functioning as its own electrolyte and (b) capable of forming a stable colored free radical upon the addition of electrons confined between said electrodes and means for flowing an electric current in a predetermined direction through said device, said redox compound being the sole electrolyte.
Claim 2
Dependent Claim
13 words
A device according to claim 2 wherein said layer contains an oxidizing agent.
Claim 3
Dependent Claim
15 words
A device according to claim 2 including means for reversing the direction of current flow.
Claim 4
Dependent Claim
16 words
A device according to claim 4 including means for automatically predetermining said direction of current flow.
Claim 5
Dependent Claim
20 words
A device according to claim 2 wherein said layer comprises a solution of said redox compound in a light-transmitting solvent.
Claim 6
Dependent Claim
11 words
A device accordiNg to claim 6 wherein said solvent is water.
Claim 7
Dependent Claim
15 words
A device according to claim 6 wherein said solvent is an electrically stable organic liquid.
Claim 8
Dependent Claim
18 words
A device according to claim 2 wherein said layer comprises said redox compound in a light-transmitting solid matrix.
Claim 9
Dependent Claim
12 words
A device according to claim 9 wherein said matrix is a gel.
Claim 10
Dependent Claim
12 words
A device according to claim 9 wherein said matrix is a polymer.
Claim 11
Dependent Claim
13 words
A device according to claim 2 wherein said redox compound is a polymer.
Claim 12
Dependent Claim
51 words
A device according to claim 2 including a third electrode in contact with said layer of compound and positioned outside the field of light-transmittancy of said pair of light-transmitting electrodes, and means for maintaining said pair of light-transmitting electrodes at the same potential and said third electrode at a different potential.
Claim 13
Dependent Claim
13 words
A device according to claim 2 wherein said compound is a diazapyrenium compound.
Claim 14
Dependent Claim
13 words
A device according to claim 14 wherein said compound is N, N''-dimethyl-2,7-diazapyrenium difluoroborate.
Claim 15
Dependent Claim
13 words
A device according to claim 2 wherein said compound is a pyrazidinium compound.
Claim 16
Dependent Claim
14 words
A device according to claim 16 wherein said compound is dipyrido(1,2- Alpha ;2'',1''-c)-pyrazidinium dibromide.
Claim 17
Dependent Claim
14 words
A device according to claim 2 wherein said compound is a 4, 4''-dipyridylium compound.
Claim 18
Dependent Claim
13 words
A device according to claim 18 wherein said compound is N, N''-dimethyl-4,4''-dipyridylium dichloride.
Claim 19
Dependent Claim
13 words
A device according to claim 18 wherein said compound is N, N''-dibenzyl-4,4''-dipyridylium dichloride.
Claim 20
Dependent Claim
12 words
A device according to claim 18 wherein said compound is poly-N,n-octylene-4,4''-dipyridylium dibromide.
Claim 21
Dependent Claim
12 words
A device according to claim 18 wherein said compound is poly-N,n-butylene-4,4''-dipyridylium dibromide.
Claim 22
Dependent Claim
37 words
In an enclosure provided with transparent means for transmitting light from an external source into said enclosure, the improvement which comprises positioning in coextensive relationship with said transparent means, a light-filtering device as defined in claim 2.
References Cited (Backward Citations)
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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) | 1975-03-28 | 1975-09-27 | 1976-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-28 | 1979-09-27 | 1980-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-28 | 1983-09-27 | 1984-03-28 | $7700.00 | Window Closed / Lapsed |