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:
Jul. 06, 1982
Filed:
Dec. 15, 1980
Christopher M Engel, Arlington Heights, IL (US);
George J Tzakis, Glenview, IL (US);
Zenith Radio Corporation, Glenview, IL (US);
Abstract
A DC coupling reduction circuit for use in a television receiver having a DC restoration circuit comprises means for developing a dynamic adjustment signal by attenuating a video signal by a selected percentage, inverting the attenuated signal and low pass filtering the attenuated and inverted signal. The dynamic adjustment signal is combined with a viewer selected direct current black level reference signal to produce a combined signal which is coupled to the black clamp level determining input of the DC restoration circuit whereby the black level of the video signal is clamped at a potential which is a function of the video signal. Preferably, the cut-off point of the cathode ray tube of the television receiver is set at a level between the levels of the combined signals produced in response to a video signal representing a white image and a video signal representing a black image.