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US3736378A Expired / Lapsed US ⏱️ 0.0 years remaining

Video signal processing stage which performs plural functions

Assignee: RCA Licensing Corp
•
Filing: 1972-04-24
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Granted: 1973-05-29
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Expires: 1992-04-24
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Abstract

Abstract A signal processing stage for a television receiver which performs the combined functions of video demodulation, automatic gain control voltage generation, horizontal synchronizing pulse separation, and vertical synchronizing pulse separation in a single circuit.

Inventors

  • 👤 P Haferl

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 12:27
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/04; H04N5/08; H04N5/10

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 217 words
The combination comprising: a semiconductor rectifier having anode and cathode electrodes; a first transistor having an emitter electrode coupled to a point of reference potential, a collector electrode coupled to the anode electrode of said rectifier, and a base electrode; signal supply means having a first terminal applying composite video input signals to the cathode electrode of said rectifier to be demodulated thereby, and also having a second terminal; a first load circuit coupling the anode electrode of said rectifier to the second terminal of said signal supply means; a second load circuit coupling the second terminal of said signal supply means to said point of reference potential and having an impedance characteristic substantially less than that of said first load circuit; and means for supplying trigger pulses to the base electrode of said first transistor to alter its conductivity state and the effective load impedance presented to said input signals during the horizontal synchronizing pulse interval of said composite video signal; whereby first output signals are developed at the anode electrode of said rectifier by said first load circuit during the active line interval of said composite signal and whereby second output signals are developed at the cathode electrode of said rectifier by said second load circuit during the horizontal retrace interval of said composite signal.
Claim 2
Dependent Claim 217 words
The combination comprising: a semiconductor rectifier having anode and cathode electrodes; a first transistor having an emitter electrode coupled to a point of reference potential, a collector electrode coupled to the anode electrode of said rectifier, and a base electrode; signal supply means having a first terminal applying composite video input signals to the cathode electrode of said rectifier to be demodulated thereby, and also having a second terminal; a first load circuit coupling the anode electrode of said rectifier to the second terminal of said signal supply means; a second load circuit coupling the second terminal of said signal supply means to said point of reference potential and having an impedance characteristic substantially less than that of said first load circuit; and means for supplying trigger pulses to the base electrode of said first transistor to alter its conductivity state and the effective load impedance presented to said input signals during the horizontal synchronizing pulse interval of said composite video signal; whereby first output signals are developed at the anode electrode of said rectifier by said first load circuit during the active line interval of said composite signal and whereby second output signals are developed at the cathode electrode of said rectifier by said second load circuit during the horizontal retrace interval of said composite signal.
Claim 3
Dependent Claim 58 words
The combination of claim 1 wherein the emitter electrode of said first transistor and said second load circuit are each coupled to a point of ground potential in order that said first output signal at the anode electrode of said rectifier will be clamped to said ground potential during the horizontal retrace interval of said composite video signal.
Claim 4
Dependent Claim 45 words
The combination of claim 2 wherein said first transistor is initially biased to a non-conductive condition, and is rendered conductive by positive-going trigger pulses supplied to its base electrode at a time substantially coincident with the horizontal synchronizing pulse interval of said composite video signal.
Claim 5
Dependent Claim 37 words
The combination of claim 2 wherein said first load circuit includes a first resistor and a first capacitor coupled in parallel between the anode electrode of said rectifier and the second terminal of said signal supply means.
Claim 6
Dependent Claim 34 words
The combination of claim 4 wherein said second load circuit includes a second capacitor and second resistor serially coupled between the second terminal of said signal supply means and said point of ground potential.
Claim 7
Dependent Claim 50 words
The combination of claim 5 wherein there is also included a second transistor having a collector electrode coupled to the second terminal of said signal supply means, a base electrode coupled to a point of bias potential, and an emitter electrode coupled to the anode electrode of said semiconductor rectifier.
Claim 8
Dependent Claim 59 words
The combination of claim 6 where said second transistor is initially biased to a Non-conductive condition, and is rendered conductive by negative-going pulses developed at the anode electrode of said semiconductor rectifier during the vertical synchronizing pulse interval of said composite video signal to develop corresponding vertical synchronizing pulses at the collector electrode of said second transistor when conductive.

References Cited (Backward Citations)

US3432615A Cited
US3632872A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1976-05-28 1976-11-27 1977-05-29 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1980-05-28 1980-11-27 1981-05-29 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1984-05-28 1984-11-27 1985-05-29 $7700.00 Window Closed / Lapsed

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