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:
Aug. 31, 1993
Filed:
Mar. 05, 1992
Toshiaki Tsuji, Ibaraki, JP;
Atsuhisa Kageyama, Ibaraki, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
In a video signal gradation corrector used in a television receiver, an output of a look-up table memory is supplied to a constant-multiplication circuit, an output signal of the constant-multiplication circuit and an output signal of a look-up table operating circuit are added by an adder, and the result of addition is set into the look-up table memory. Further, a video scene change detecting circuit is provided between an output terminal of the look-up table operating circuit and a coefficient control terminal of the constant-multiplication circuit, and a coefficient of the constant-multiplication circuit is changed in accordance with a change in video scene. Thereby, a correction is made which is not affected by noises, is stable and smooth, and follows the change in video scene.