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:
Jun. 23, 1992
Filed:
Aug. 27, 1990
Hidemitsu Nikoh, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A color-signal enhancing circuit of the invention comprises a pair of first and second high-pass filters, a control circuit, and a pair of first and second gain controllers. The high-pass filters provide a predetermined frequency region restriction to color difference signals. The control circuit may comprise a first and second gain controllable amplifiers which provide a predetetermined coefficient to outputs from the high-pass filters, an adder which adds outputs from the first and second amplifiers, and a convertor which provides to an output of the adder a coefficient calculated in a predetermined operation in accordance with the polarity of input signals inputted thereto. In an alternative arrangement, a pair of the high-pass filters may be replaced by a pair of low-pass filters. The gain control signal is obtained from the information on high frequency components or on low frequency components of color difference signals and, with this single gain control signal, the gains of the color difference signals inputted are controlled, whereby it is possible to enhance color signals in such a way that there will be no appearance of false colors at turning points of color changing.