Patent US3901271A successfully refreshed from Google Patents.
Patent US3564261A successfully refreshed from Google Patents.
US3564261A
Expired / Lapsed
US
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Electrolytic light scattering shutter system
Assignee: Melpar Inc
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Filing: 1969-04-01
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Granted: 1971-02-16
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Expires: 1989-04-01
Abstract
Abstract An optical shutter in the form of an electrochemical cell responds to an intense light flash to switch from a light transmitting condition to a light scattering condition. The cell includes a pair of electrodes separated by an electrolyte, and normally provides an optical path therethrough. A fast response photoelectric detector is positioned adjacent the cell to sense any intense flash of light falling on the cell, and thereupon to trigger a capacitive discharge through the electrodes and electrolyte of the cell via a high speed switching circuit. The electrolyte decomposes in response to the passage of electric current therethrough to evolve large quantities of gaseous products which form a film of fine bubbles at the electrodes. The bubbles constitute an irregular reflecting surface effective to scatter incident light. Transparency is resumed upon clearing of the bubbles, which may be accomplished by applying supersonic vibrations to the solution, or by elapse of time.
Inventors
- 👤 Albert F Hadermann
- 👤 Stephen C Ban
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:38
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/19; G02F1/195
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
46 words
The light valve according to claim 1 further including means connected to said electrodes for producing an electric current through said cell of sufficient intensity and brevity to rapidly and at least partially decompose said electrolyte to from said layer of bubbles across said light path.
Claim 2
Dependent Claim
20 words
The light valve according to claim 2 wherein said electrolyte is an aqueous solution of an alkali metal tribasic phosphate.
Claim 3
Dependent Claim
30 words
The light valve according to claim 3 wherein said electric current producing means includes a capacitor, and means for selectively applying a voltage stored on said capacitor across said electrodes.
Claim 4
Dependent Claim
34 words
The light valve according to claim 4 further including photosensitive means responsive to light incident on said electrolytic cell to actuate said means for selectively applying voltage, to discharge said capacitor through said electrolyte.
Claim 5
Dependent Claim
39 words
The light valve according to claim 5 wherein said means for selectively applying voltage is constructed and arranged to be actuated by said photosensitive means only in response to a predetermined intensity of light incident on said electrolytic cell.
Claim 6
Dependent Claim
31 words
The light valve according to claim 3 wherein the alkali metal of the tribasic phosphate in said aqueous solution is an element selected from the group consisting of potassium and sodium.
Claim 7
Dependent Claim
17 words
The light valve according to claim 2 wherein said at least one electrode is a conductive screen.
Claim 8
Dependent Claim
32 words
The light valve according to claim 2 wherein said cell has a prismatic right regular cross section and wherein said electrodes are opaque highly reflective sheets for reflecting light along said path.
Claim 9
Independent Claim
109 words
The method of selectively attenuating light through a predetermined optical path, including the steps of: inserting into said path an electrolytic cell having a normally transparent window therethrough including at least one planar electrode and an electrolyte responsive to a sufficiently large impulse of electrical current to produce gas bubbles in said electrolyte causing scattering of light along said path and through said window; and selectively passing through said cell, including said planar electrode and said electrolyte, a current impulse of sufficient magnitude to produce electrolytic decomposition with the evolution of gas bubbles throughout said electrolyte, to cause said scattering of light incident on said bubbles via said window.
Claim 10
Dependent Claim
29 words
The method of claim 10 further including the step of agitating said cell to cause said bubbles to coalesce and thereby permit light to again pass through said window.
Claim 11
Dependent Claim
16 words
The method of claim 11 wherein said agitating is performed by ultrasonic vibration of said electrolyte.
Claim 12
Dependent Claim
100 words
An electrooptical shutter, comprising: an electrolytic cell, said cell including: a pair of spaced-apart electrodes; a light path through said cell, including said electrodes; and an electrolyte occupying the space between and contacting said electrodes; and means connected to said electrodes and responsive to a flash of light for passing an impulse of electric current through said cell of sufficient magnitude to chemically decompose said electrolyte to produce a layer of bubbles adjacent at least one of said electrodes for reflectively scattering light incident on said cell which would otherwise normally pass substantially unobstructed through said plates, electrodes, and electrolyte.
Claim 13
Dependent Claim
18 words
The shutter according to claim 13 wherein said electrolYte is an aqueous solution of alkali metal tribasic phosphate.
Claim 14
Dependent Claim
42 words
The shutter according to claim 13 wherein said cell is of prismatic form, and wherein said electrodes are are parallel to one another and have highly reflective confronting surfaces for providing reflection of light along said path after refraction through said cell.
Claim 15
Dependent Claim
15 words
The shutter according to claim 13 wherein each of said electrodes comprises a conductive screen.
Claim 16
Dependent Claim
115 words
An electrolytic light valve, comprising an electrolytic cell having two spaced electrodes, said spaced electrodes being constructed and arranged to normally provide a light path through said cell; an electrolyte occupying the space between and contacting said electrodes, said electrolyte being a solution capable of dissociation into a relatively large mass of gaseous ions in response to passage of electric current therethrough; and means including a photosensitive device for transferring a pulse of electric current through said electrolyte via said electrodes of sufficient ampere-seconds to dissociate a sufficient quantity of said electrolyte to cover at least one of said electrodes with gaseous bubbles in response to an increase of light impinging on said photosensitive device.
Claim 17
Dependent Claim
27 words
The invention according to claim 16 further including means for at will clearing said layer of bubbles, said last means including means for ultrasonically agitating said electrolyte.
Claim 18
Dependent Claim
79 words
The invention according to claim 16 further including means for at will clearing said layer of bubbles, said last means including means for ultrasonically agitating said electrolyte. means including a photosensitive device for transferring a pulse of electric current through said electrolyte via said electrodes of sufficient ampere-seconds to dissociate a sufficient quantity of said electrolyte to cover at least one of said electrodes with gaseous bubbles in response to an increase of light impinging on said photosensitive device.
References Cited (Backward Citations)
US3121169A
Cited
US3360328A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-02-15 | 1974-08-17 | 1975-02-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-15 | 1978-08-17 | 1979-02-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-15 | 1982-08-17 | 1983-02-16 | $7700.00 | Window Closed / Lapsed |