Patent US2594136A successfully refreshed from Google Patents.
Patent US3756700A successfully refreshed from Google Patents.
US3756700A
Expired / Lapsed
US
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Method and apparatus for increasing optical density ratios of light valves
Assignee: Research Frontiers Inc
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Filing: 1972-02-09
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Granted: 1973-09-04
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Expires: 1992-02-09
Abstract
Abstract A method and apparatus is disclosed for increasing the optical density ratio of light valves. The optical density ratio is a measure of the range of light transmission of the light valve, and is the ratio between the optical density with the valve inactivated and the optical density when it is activated. To accomplish this change, the valve is constructed so that it contains more fluid suspension when it is in the off (inactivated) condition to produce a high optical density, and contains less fluid just prior to being activated as well as in the activated condition to controllably decrease its optical density. This increased amount of fluid in the off condition and decrease in the on condition increases the optical density ratio of the valve. Apparatus for incorporating this device into a photographic camera is also disclosed.
Inventors
- 👤 R Saxe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:23
CPC Classifications
G; G03; G03B; G03B9/00; G03B9/08; G02; G02F; G02F1/00; G02F1/01; G02F1/17; G02F1/172; G03B9/58
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
113 words
A method of increasing the optical density ratio of a light valve containing a fluid suspension having particles capable of being activated by an electric or magnetic field to change the amount of radiation passing through the valve, comprising the steps of: removing a portion of the fluid suspension to reduce the amount of particles in the path of radiation passing through the valve to reduce the optical density of the light valve, activating the particles by application of the electric or magnetic field restoring part of the fluid suspension that was removed to increase the amount of particles in the path of radiation passing through the valve, and deactivating the light valve.
Claim 2
Independent Claim
113 words
A method of increasing the optical density ratio of a light valve containing a fluid suspension having particles capable of being activated by an electric or magnetic field to change the amount of radiation passing through the valve, comprising the steps of: removing a portion of the fluid suspension to reduce the amount of particles in the path of radiation passing through the valve to reduce the optical density of the light valve, activating the particles by application of the electric or magnetic field restoring part of the fluid suspension that was removed to increase the amount of particles in the path of radiation passing through the valve, and deactivating the light valve.
Claim 3
Dependent Claim
17 words
The method of claim 1 including the steps of transferring the removed fluid suspension to a reservoir.
Claim 4
Dependent Claim
18 words
The method of claim 2 wherein the step of restoring includes transferring the fluid suspension from the reservoir.
Claim 5
Dependent Claim
11 words
The method of claim 3 wherein the fluid suspension contains herapathite.
Claim 6
Dependent Claim
142 words
A control device comprising first wall means and second wall means in an electric or magnetic field said first and second wall means defining a cell having a predetermined volume, and adapted to contain a fluid suspension having particles therein which are capable of being activated by an electric or magnetic field to change the amount of radiation passing through the valve said first wall means being mounted to vary the volume of said cell so that the cell will be adapted to contain a lesser amount of suspension and a lesser amount of particles when it is activated by said electric or magnetic field than when it is not activated so that the optical density of the light valve when activated is decreased and when not activated is increased in order to increase the optical density ratio of the light valve.
Claim 7
Dependent Claim
142 words
A control device comprising first wall means and second wall means in an electric or magnetic field said first and second wall means defining a cell having a predetermined volume, and adapted to contain a fluid suspension having particles therein which are capable of being activated by an electric or magnetic field to change the amount of radiation passing through the valve said first wall means being mounted to vary the volume of said cell so that the cell will be adapted to contain a lesser amount of suspension and a lesser amount of particles when it is activated by said electric or magnetic field than when it is not activated so that the optical density of the light valve when activated is decreased and when not activated is increased in order to increase the optical density ratio of the light valve.
Claim 8
Dependent Claim
18 words
The device of claim 5 wherein said first and second wall means comprise substantially parallel transparent wall members.
Claim 9
Dependent Claim
19 words
The device of claim 6 wherein said wall members are connected by a deformable member to define said cell.
Claim 10
Dependent Claim
12 words
The device of claim 7 wherein said deformable member comprises a bellows.
Claim 11
Dependent Claim
12 words
The device of claim 7 wherein said deformable member comprises poly tetraflourethylene.
Claim 12
Dependent Claim
28 words
The device of claim 7 including a reservoir to which the fluid suspension is transferred when said cell is varied to contain a lesser amount of fluid suspenison.
Claim 13
Dependent Claim
12 words
The device of claim 10 including activating means to activate said cell.
Claim 14
Dependent Claim
42 words
The device of claim 11 including control means to control said cell so that it is reduced in size to contain a lesser amount of fluid and thereby a lesser amount of particles before the cell is activated by the activating means.
Claim 15
Dependent Claim
42 words
The device of claim 12 wherein the control means deactivates said cell after a predetermined time period and causes said cell to increase in size so that it will contain an increased amount of fluid and thereby an increased amount of particles.
Claim 16
Dependent Claim
161 words
A camera mechanism comprising: means comprising an iris aperture a light valve mounted to cover the iris aperture and act as a shutter including: a cell adapted to contain a fluid suspension having particles therein which are capable of being activated by the electric or magnetic field to change the amount of radiation passing through the cell and through the means comprising the iris aperture and said cell being constructed to vary its volume so that the cell can alternatively contain a greater or lesser amount of suspension and a greater or lesser amount of particles means adapted to apply an electric or magnetic field to the suspension to activate the suspension, said means being coordinated with the volume of the cell so that the suspension is activated when the volume is lesser and inactive when the volume is greater, whereby the shutter can be dark in the inactivated condition and permit a substantial transmission of radiation in the activated condition.
Claim 17
Dependent Claim
161 words
A camera mechanism comprising: means comprising an iris aperture a light valve mounted to cover the iris aperture and act as a shutter including: a cell adapted to contain a fluid suspension having particles therein which are capable of being activated by the electric or magnetic field to change the amount of radiation passing through the cell and through the means comprising the iris aperture and said cell being constructed to vary its volume so that the cell can alternatively contain a greater or lesser amount of suspension and a greater or lesser amount of particles means adapted to apply an electric or magnetic field to the suspension to activate the suspension, said means being coordinated with the volume of the cell so that the suspension is activated when the volume is lesser and inactive when the volume is greater, whereby the shutter can be dark in the inactivated condition and permit a substantial transmission of radiation in the activated condition.
Claim 18
Dependent Claim
42 words
The camera mechanisM of claim 14 including control means which deactivates said cell after a predetermined time period and causes said cell to increase in size so that it will contain an increased amount of fluid and an increased amount of particles.
Claim 19
Dependent Claim
145 words
A light valve including a cell for containing a fluid suspension of minute particles dispersed therein capable of having their orientation changed by an electric or magnetic field to change the transmission of radiation through the suspension, said cell having first and second wall sections spaced apart a distance which is small compared to the lateral dimensions of the sections and means for applying an electric or magentic field to the suspension between said wall sections to change the radiation transmission thereof, said first wall section being positioned for movement with respect to said second wall section to increase and decrease the volume of said cell and whereby the movement is coorinated with said means for applying an electric or magnetic field so that said field is applied to the suspension when said volume is being decreased and not applied when said volume is increased.
Claim 20
Dependent Claim
145 words
A light valve including a cell for containing a fluid suspension of minute particles dispersed therein capable of having their orientation changed by an electric or magnetic field to change the transmission of radiation through the suspension, said cell having first and second wall sections spaced apart a distance which is small compared to the lateral dimensions of the sections and means for applying an electric or magentic field to the suspension between said wall sections to change the radiation transmission thereof, said first wall section being positioned for movement with respect to said second wall section to increase and decrease the volume of said cell and whereby the movement is coorinated with said means for applying an electric or magnetic field so that said field is applied to the suspension when said volume is being decreased and not applied when said volume is increased.
References Cited (Backward Citations)
US2470139A
Cited
US3119270A
Cited
US3512876A
Cited
US3424515A
Cited
US3492062A
Cited
US3560077A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-03 | 1977-03-05 | 1977-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-03 | 1981-03-05 | 1981-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-03 | 1985-03-05 | 1985-09-04 | $7700.00 | Window Closed / Lapsed |