US3708219A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light valve with flowing fluid suspension
Assignee: Research Frontiers Inc
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Filing: 1971-08-24
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Granted: 1973-01-02
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Expires: 1991-08-24
Abstract
Abstract A light valve having a cell containing a fluid suspension of minute particles dispersed therein capable of orientation by an electric or magnetic field to change the transmission of light through the suspension, and means for applying such a field thereto, includes circulating means for producing a flow of the fluid suspension through the cell during operation thereof to reduce or avoid agglomeration of the particles. Various means are described for producing a smooth generally laminar flow of the fluid suspension in the active region of the cell. The circulating means may include means for dispensing agglomerated particles which may be produced during cell operation. A sheet for polarizing material in the path of light from the valve, with its direction of polarization perpendicular to fluid flow in the cell, markedly increases the closing speed. Two valves with fluid flow at right angles increases the closing speed without seriously decreasing the density ratio between closed and open states.
Inventors
- 👤 R Saxe
- 👤 M Forlini
- 👤 F Lowell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:32
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/17; G02F1/172; G02F1/0102
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
128 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 light through the suspension, said cell having front and rear wall sections spaced apart a distance which is small compared to the lateral dimensions of the sections, and means for applying an electric or magnetic field to the suspension between said wall sections to change the light transmission thereof, in which the improvement comprises circulating means connected to said cell at spaced points thereof for producing a flow of said fluid suspension through said cell during operation thereof, and means for producing a smooth generally laminar flow of said fluid suspension between said wall sections.
Claim 2
Dependent Claim
128 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 light through the suspension, said cell having front and rear wall sections spaced apart a distance which is small compared to the lateral dimensions of the sections, and means for applying an electric or magnetic field to the suspension between said wall sections to change the light transmission thereof, in which the improvement comprises circulating means connected to said cell at spaced points thereof for producing a flow of said fluid suspension through said cell during operation thereof, and means for producing a smooth generally laminar flow of said fluid suspension between said wall sections.
Claim 3
Dependent Claim
132 words
A light valve including a cell 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 light through the suspension, said cell having front and rear wall sections spaced apart a distance which is small compared to the lateral dimensions of the sections, and means for applying an electric or magnetic field to the suspension between said wall sections to change the light transmission thereof, in which the improvement comprises circulating means including conduit means connected to said cell at spaced points thereof and means for producing a flow of said fluid suspension through said cell and conduit means, and means for producing a smooth generally laminar flow of said fluid suspension between said wall sections.
Claim 4
Dependent Claim
132 words
A light valve including a cell 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 light through the suspension, said cell having front and rear wall sections spaced apart a distance which is small compared to the lateral dimensions of the sections, and means for applying an electric or magnetic field to the suspension between said wall sections to change the light transmission thereof, in which the improvement comprises circulating means including conduit means connected to said cell at spaced points thereof and means for producing a flow of said fluid suspension through said cell and conduit means, and means for producing a smooth generally laminar flow of said fluid suspension between said wall sections.
Claim 5
Dependent Claim
51 words
A light valve in accordance with claim 2 in which said conduit means is connected to said cell to supply said fluid suspension to the cell on one side of the region between said wall sections and withdraw the fluid suspension from the cell on the opposite side of said region.
Claim 6
Dependent Claim
23 words
A light valve in accordance with claim 2 in which said circulating means includes means for dispersing agglomerated particles of said fluid suspension.
Claim 7
Dependent Claim
48 words
A light valve in accordance with claim 2 including a sheet of polarizing material positioned generally perpendicular to the direction of light passing through said cell, the direction of polarization of said sheet being effectively at a substantial angle to the direction of fluid flow in said cell.
Claim 8
Dependent Claim
27 words
A light valve in accordance with claim 5 in which said direction of polarization is effectively approximately perpendicular to the direction of fluid flow in said cell.
Claim 9
Dependent Claim
61 words
A pair of light valves in accordance with claim 2 positioned so that light passes through said valves in succession in a direction generally perpendicular to the direction of fluid flow therein, said cells being oriented so that the direction of fluid flow in one valve effectively makes a substantial angle with the direction of fluid flow in the other valve.
Claim 10
Dependent Claim
25 words
A pair of light valves in accordance with claim 7 in which the directions of fluid flow in said valves are effectively approximately mutually perpendicular.
Claim 11
Dependent Claim
146 words
A light valve including a cell containing a fluid suspension of minute particles dispersed therein capable of having their orientation changed by an electric field to change the transmission of light through the suspension, said cell having front and rear wall sections spaced apart a distance which is small compared to the lateral dimensions of the sections to confine the fluid suspension therebetween to a layer, and area electrodes of opposite sides of said layer for producing an electric field through the layer to change the light transmission thereof, in which the improvement comprises circulating means including an inlet and an outlet connected to said cell at spaced points for producing a flow of said fluid suspension through said cell during operation thereof, said cell being designed and adapted to produce a smooth generally laminar flow of said fluid suspension in the region between said electrodes.
Claim 12
Dependent Claim
146 words
A light valve including a cell containing a fluid suspension of minute particles dispersed therein capable of having their orientation changed by an electric field to change the transmission of light through the suspension, said cell having front and rear wall sections spaced apart a distance which is small compared to the lateral dimensions of the sections to confine the fluid suspension therebetween to a layer, and area electrodes of opposite sides of said layer for producing an electric field through the layer to change the light transmission thereof, in which the improvement comprises circulating means including an inlet and an outlet connected to said cell at spaced points for producing a flow of said fluid suspension through said cell during operation thereof, said cell being designed and adapted to produce a smooth generally laminar flow of said fluid suspension in the region between said electrodes.
Claim 13
Dependent Claim
23 words
A light valve in accordance with claim 9 in which said circulating means includes means for dispersing agglomerated particles of said fluid suspension.
Claim 14
Dependent Claim
44 words
A light valve in accordance with claim 9 in which said inlet and outlet are positioned and adapted to supply said fluid suspension on one side of the region between said electrodes and withdraw the fluid suspension from the opposite side of said region.
Claim 15
Dependent Claim
57 words
A light valve in accordance with claim 11 in which said inlet and outlet are positioned on respectively opposite sides of the region between said electrodes, at least one of said inlet and outlet being spaced a substantial distance from said region between the electrodes to aid in producing said smooth generally laminar flow in said region.
Claim 16
Dependent Claim
70 words
A light valve in accordance with claim 11 in which said cell has inlet and outlet sections between said opposite sides of the region between said electrodes and the respective inlet and outlet, the spacing between the front and rear walls of the cell at at least one of said inlet and outlet sections being substantially greater than the spacing of the wall sections at the region between said electrodes.
Claim 17
Dependent Claim
38 words
A light valve in accordance with claim 13 in which the spacing between the front and rear walls at both of said inlet and outlet sections is substantially greateR than the spacing at the region between said electrodes.
Claim 18
Dependent Claim
75 words
A light valve in accordance with claim 11 including a barrier wall positioned within said cell between said region between the electrodes and said inlet and extending along the respective side of said region for at least a major portion of the length thereof, the height of said barrier wall being less than the separation of the front and rear walls at the location thereof to thereby allow a flow of the fluid suspension thereover.
Claim 19
Dependent Claim
77 words
A light valve in accordance with claim 15 including a second barrier wall positioned within said cell between said region between the electrodes and said outlet and extending along the respective side of said region for at least a major portion of the length thereof, the height of said second barrier wall being less than the separation of the front and rear walls at the location thereof to thereby allow a flow of the fluid suspension thereover.
Claim 20
Dependent Claim
51 words
A light valve in accordance with claim 15 in which said inlet is adjacent one end of said respective side of the region between the electrodes, and the width of said barrier wall tapers from wider to narrower dimensions from the inlet end toward the other end of said respective side.
Claim 21
Dependent Claim
56 words
A light valve in accordance with claim 16 in which said inlet and said outlet are adjacent corresponding ends of the respective sides of said region between the electrodes, and the width of said barrier walls taper from wider to narrower dimensions from respective inlet and outlet ends toward the other ends of the respective sides.
Claim 22
Independent Claim
47 words
The method of preventing minute suspended particles in a fluid suspension from significantly agglomerating in a light valve cell comprising producing a smooth generally laminar flow of the fluid suspension to prevent significant agglomerating of the particles and flowing said laminar flow through the light valve cell.
Claim 23
Independent Claim
47 words
The method of preventing minute suspended particles in a fluid suspension from significantly agglomerating in a light valve cell comprising producing a smooth generally laminar flow of the fluid suspension to prevent significant agglomerating of the particles and flowing said laminar flow through the light valve cell.
Claim 24
Dependent Claim
23 words
The method of claim 19 wherein the fluid suspension is caused to flow through the light valve by means of a circulating system.
Claim 25
Dependent Claim
18 words
The method of claim 19 wherein the smooth generally laminar flow is produced by means of a barrier.
Claim 26
Dependent Claim
84 words
A light valve including a cell adapted to contain 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 light through the suspension, said cell having front and rear wall sections, means for applying an electric or magnetic field to the suspension between said wall sections to change the light transmission thereof and means for producing a smooth generally laminar flow of the fluid suspension between said wall sections.
Claim 27
Dependent Claim
84 words
A light valve including a cell adapted to contain 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 light through the suspension, said cell having front and rear wall sections, means for applying an electric or magnetic field to the suspension between said wall sections to change the light transmission thereof and means for producing a smooth generally laminar flow of the fluid suspension between said wall sections.
Claim 28
Dependent Claim
20 words
The light valve of claim 22 including a circulating means for producing a flow of fluid suspension through said cell.
Claim 29
Dependent Claim
20 words
The light valve of claim 23 wherein said means for producing a smooth generally laminar flow includes a barrier means.
Claim 30
Dependent Claim
46 words
The light valve of claim 24 wherein the circulating means is connected to said cell to supply fluid suspension to the cell on side of a region between said wall sections and withdraw the fluid suspension from the cell on the opposite side of said region.
References Cited (Backward Citations)
US3610730A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-02 | 1976-07-03 | 1977-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-02 | 1980-07-03 | 1981-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-02 | 1984-07-03 | 1985-01-02 | $7700.00 | Window Closed / Lapsed |