Patent US3666957A successfully refreshed from Google Patents.
US3666957A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Brightness limiter for image intensifiers
Assignee: Bendix Corp
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Filing: 1971-01-25
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Granted: 1972-05-30
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Expires: 1991-01-25
Abstract
Abstract The invention is directed to a system for automatically limiting the output brightness of an image intensifier having a microchannel plate (MCP). The intensifier includes a radiationsensitive surface which is located in the proximity of the input surface of the MCP. An output screen is located in the proximity of the output surface of the MCP. The two surfaces of the MCP are maintained at different voltages which accelerate electrons through the MCP to cause the multiplication of electrons therein. The output brightness of the intensifier is directly proportional to the current supplied to the output screen. This current is dependent upon the voltage supplied across the microchannel input and output surfaces. Therefore, the system senses the output screen current and changes the voltage applied across the MCP to limit the sensed current and the output brightness to some desired level.
Inventors
- 👤 William R Wyess
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 15:48
CPC Classifications
H; H01; H01J; H01J43/00; H01J43/04; H01J43/06; H01J43/18; H01J43/24; H01J43/246; H01J43/30
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
175 words
A system for limiting the intensity of the output image of a microchannel plate intensifier comprising: a microchannel plate having an input surface and an output surface; a radiation sensitive input screen in the proximity of said input surface, and an output screen capable of sustaining an output image in the proximity of said output surface so that image information present in input radiation impinging upon said input screen is intensified and discernable on said output screen; means for maintaining said input screen at a first constant voltage; means for maintaining said output screen at a second constant voltage; current sensitive voltage means for applying a varying voltage across said microchannel plate, said current sensiTive voltage means including a voltage controlled oscillator and means for changing the voltage amplitude of the output of said oscillator resistive means in series with said output screen for sensing current flow to said output screen, said current sensitive voltage means being responsive to said means for sensing to change said variable voltage in response to said output screen current.
Claim 2
Independent Claim
175 words
A system for limiting the intensity of the output image of a microchannel plate intensifier comprising: a microchannel plate having an input surface and an output surface; a radiation sensitive input screen in the proximity of said input surface, and an output screen capable of sustaining an output image in the proximity of said output surface so that image information present in input radiation impinging upon said input screen is intensified and discernable on said output screen; means for maintaining said input screen at a first constant voltage; means for maintaining said output screen at a second constant voltage; current sensitive voltage means for applying a varying voltage across said microchannel plate, said current sensiTive voltage means including a voltage controlled oscillator and means for changing the voltage amplitude of the output of said oscillator resistive means in series with said output screen for sensing current flow to said output screen, said current sensitive voltage means being responsive to said means for sensing to change said variable voltage in response to said output screen current.
Claim 3
Dependent Claim
20 words
The system of claim 1 wherein said means for changing includes electron control means responsive to said output screen current.
Claim 4
Dependent Claim
24 words
The system of claim 2 wherein said electron control means is a transistor, the control electrode of said transistor being coupled to said resistor.
Claim 5
Dependent Claim
24 words
The system of claim 3 wherein said transistor decreases said oscillator output voltage when said screen current is sufficient to render said transistor conductive.
Claim 6
Dependent Claim
30 words
The system of claim 4 further including first multiplier-rectifier means interposed between said oscillator and said input surface so that a varying DC voltage is applied across said microchannel plate.
Claim 7
Dependent Claim
69 words
The system of claim 5 wherein said means for maintaining said input screen includes a second multiplier-rectifier interposed between said input screen and an AC supply; and said means for maintaining said output screen includes a third multiplier-rectified interposed between said output screen and an AC supply; said constant voltages being DC voltages having a level at least as high as the peak voltages of the respective AC supply.
Claim 8
Dependent Claim
13 words
The system of claim 3 wherein said transistor is a field effect transistor.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-30 | 1975-11-29 | 1976-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-30 | 1979-11-29 | 1980-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-30 | 1983-11-29 | 1984-05-30 | $7700.00 | Window Closed / Lapsed |