The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 23, 1985
Filed:
Oct. 29, 1982
Charles L Olson, Oaklyn, NJ (US);
John F Monahan, Marlton, NJ (US);
RCA Corporation, New York, NY (US);
Abstract
A black-level clamp for a signal derived from a transducer such as a camera tube includes a controllable voltage offset generator such as a series capacitor or an amplifier. The television signal is sampled during the horizontal sync interval to produce a control signal indicative of the current black-level signal, and the control signal is applied to adjust the charge on the series capacitor to place one plate at a reference voltage or is compared with a reference level to produce a further control signal for adjusting the offset of the amplifier. In either case, drift of the reference voltage which may perturb the operation of the clamp is reduced by deriving the reference voltage from the television signal at times within the vertical blanking interval.