Patent US2003417A successfully refreshed from Google Patents.
US3655267A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light valves with high frequency excitation
Assignee: Research Frontiers Inc
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Filing: 1970-04-01
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Granted: 1972-04-11
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Expires: 1990-04-01
Abstract
Abstract A light valve having a cell containing a fluid suspension of minute particles dispersed therein capable of orientation by an electric field, has applied thereto an alternating voltage having a frequency at least as high as approximately 325 KHz, and preferably 400 KHz, or higher, to prevent agglomeration of the particles over long periods of use. Generally needle-shaped particles of herapathite may be employed.
Inventors
- 👤 Matthew Forlini
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:31
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/17; G02F1/172
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
117 words
A light valve including a cell containing a fluid suspension of minute particles dispersed therein capable of orientation by an electric field to change the transmission of light through the suspension, said cell having area electrodes on opposite sides of said fluid suspension for producing an electric field through the fluid suspension to change the light transmission thereof, in which the improvement comprises means for applying an alternating voltage to said electrodes having a frequency at least as high as approximately 325 kilo-hertz to change the light transmission of said fluid suspension, the peak to peak amplitude of said alternating voltage yielding a voltage gradient in said suspension not substantially greater than about 24 volts per mil.
Claim 2
Dependent Claim
117 words
A light valve including a cell containing a fluid suspension of minute particles dispersed therein capable of orientation by an electric field to change the transmission of light through the suspension, said cell having area electrodes on opposite sides of said fluid suspension for producing an electric field through the fluid suspension to change the light transmission thereof, in which the improvement comprises means for applying an alternating voltage to said electrodes having a frequency at least as high as approximately 325 kilo-hertz to change the light transmission of said fluid suspension, the peak to peak amplitude of said alternating voltage yielding a voltage gradient in said suspension not substantially greater than about 24 volts per mil.
Claim 3
Dependent Claim
21 words
A light valve in accordance with claim 1 in which said frequency is at least as high as approximately 400 kilo-hertz.
Claim 4
Dependent Claim
19 words
A light valve in accordance with claim 1 in which said minute particles are generally needle-shaped particles of herapathite.
Claim 5
Dependent Claim
19 words
A light valve in accordance with claim 2 in which said minute particles are generally needle-shaped particles of herapathite.
References Cited (Backward Citations)
US3512876A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-04-11 | 1975-10-11 | 1976-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-11 | 1979-10-11 | 1980-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-11 | 1983-10-11 | 1984-04-11 | $7700.00 | Window Closed / Lapsed |