US4544951A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Video clamping circuit
Assignee: Alps Alpine Co Ltd
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Filing: 1983-04-12
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Granted: 1985-10-01
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Expires: 2003-04-12
Abstract
Abstract A video clamping circuit adapted for satellite communication includes an operational amplifier for detecting the current flowing into a diode connected to the input terminal of the buffer amplifier of the circuit. The circuit further includes rectifying and smoothing elements for deriving a DC voltage from the output from the operational amplifier and adding the DC voltage to the signal of the output stage of the buffer amplifier in an anti-phase relation, so that an energy dispersal signal superimposed on a video signal is removed and waveform distortion is minimized.
Inventors
- 👤 Akiyuki Yoshisato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:46
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/14; H04N5/16; H04N5/18
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
116 words
In a video clamping circuit for receiving a video signal on which an energy dispersal signal is superimposed, which includes a clamping buffer circuit having a buffer amplifier having an input section and an output section, and a clamping diode connected to the input section of the buffer amplifier, the improvement comprising: means for detecting the current flowing through the diode and producing a detection signal indicative of a variation in an input signal level at the input section of the buffer amplifier; means for producing a cancellation signal from said detection signal; and means for superimposing the cancellation signal on an output signal at the output section of the buffer amplifier in an anti-phase relation.
Claim 2
Dependent Claim
116 words
In a video clamping circuit for receiving a video signal on which an energy dispersal signal is superimposed, which includes a clamping buffer circuit having a buffer amplifier having an input section and an output section, and a clamping diode connected to the input section of the buffer amplifier, the improvement comprising: means for detecting the current flowing through the diode and producing a detection signal indicative of a variation in an input signal level at the input section of the buffer amplifier; means for producing a cancellation signal from said detection signal; and means for superimposing the cancellation signal on an output signal at the output section of the buffer amplifier in an anti-phase relation.
Claim 3
Dependent Claim
38 words
The improved video clamping circuit of claim 1, wherein said means for producing a cancellation signal includes an operational amplifier for amplifying the detection signal, and means for rectifying and smoothing the amplified signal from the operational amplifier.
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) | 1988-09-30 | 1989-04-01 | 1989-10-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-30 | 1993-04-01 | 1993-10-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-30 | 1997-04-01 | 1997-10-01 | $7700.00 | Window Closed / Lapsed |