Patent US3612762A successfully refreshed from Google Patents.
US3612762A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic gain control system for camera tube
Assignee: TDK Micronas GmbH
•
Filing: 1969-03-26
•
Granted: 1971-10-12
•
Expires: 1989-03-26
Abstract
Abstract In low-light level television systems, certain camera tubes employ multiplier-channel plates which determine the gain of the camera tube. This gain is automatically controlled in the present invention by developing a control signal representative of the amplitude of the video signal produced by the camera tube and feeding it back to the multiplier-channel plate in such polarity and magnitude as to maintain the video signal at a substantially constant level.
Inventors
- 👤 Louis E Wuellner
- 👤 Roger C Thieme
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 02:21
CPC Classifications
H; H01; H01J; H01J31/00; H01J31/08; H01J31/26; H01J31/48; H04; H04N; H04N23/00; H04N23/70; H04N23/749
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
123 words
A television system comprising: an image tube having means for converting an optical image into an electron image, an electron multiplier for amplifying said electron image, said multiplier having a pair of electrodes at opposite sides thereof, means for storing the amplified electron image, and means for scanning said image storing means to provide a video output signal representing said optical image, means responsive to the amplitude of said video signal for generating a feedback control signal, and means responsive to said feedback control signal for applying a unidirectional potential across said electrodes at opposite sides of said electron multiplier, said potential automatically varying in accordance with said feedback control signal to maintain the amplification of said electron multiplier within a predetermined range.
Claim 2
Dependent Claim
123 words
A television system comprising: an image tube having means for converting an optical image into an electron image, an electron multiplier for amplifying said electron image, said multiplier having a pair of electrodes at opposite sides thereof, means for storing the amplified electron image, and means for scanning said image storing means to provide a video output signal representing said optical image, means responsive to the amplitude of said video signal for generating a feedback control signal, and means responsive to said feedback control signal for applying a unidirectional potential across said electrodes at opposite sides of said electron multiplier, said potential automatically varying in accordance with said feedback control signal to maintain the amplification of said electron multiplier within a predetermined range.
Claim 3
Dependent Claim
71 words
The system according to claim 1, wherein said electron multiplier is a channel plate multiplier having said pair of electrodes on opposite sides thereof, said electrodes being parallEl and having conductive coatings thereon and a plurality of hollow longitudinal fibers having secondary electron emissive coatings therein disposed between said electrodes, said means responsive to said feedback control signal including a variable voltage power supply applying said unidirectional potential to said electrodes.
Claim 4
Dependent Claim
37 words
The system according to claim 2, wherein said multiplier has linear and saturation regions of amplification response characteristics, and said means responsive to said feedback control signal limits the operation of said multiplier below its saturation region.
Claim 5
Dependent Claim
22 words
The system according to claim 2 further including a video amplifier interposed between said storing means and said feedback control signal-generating means.
Claim 6
Dependent Claim
64 words
The system according to claim 2, wherein said image converting means includes an extended area photoelectric cathode and said image storing means includes an extended area target, a first source of fixed operating voltage connected between said cathode and one of said parallel electrodes, and a second source of fixed operating voltage connected between the other of said parallel electrode plates and said target.
Claim 7
Dependent Claim
45 words
The system according to claim 5, wherein said feedback control signal-generating means includes an automatic gain control circuit having circuit means for detecting the peaks of said video output signal and for reconverting the detected peaks of said video signal into a unidirectional potential signal.
Claim 8
Dependent Claim
57 words
The system according to claim 6, wherein said means responsive to said feedback control signal includes an oscillator responsive to said unidirectional potential signal, a full-wave rectifier, a transformer for coupling said oscillator to said rectifier, and a filter network, the output terminals of said filter network being connected to said pair of electrodes of said multiplier.
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) | 1974-10-11 | 1975-04-12 | 1975-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-11 | 1979-04-12 | 1979-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-11 | 1983-04-12 | 1983-10-12 | $7700.00 | Window Closed / Lapsed |