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:
May. 31, 1988
Filed:
Nov. 17, 1986
Kazuhiro Yamanishi, Higashiosaka, JP;
Kouichi Igata, Hirakata, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A luminance signal processing circuit includes a delay circuit for delaying a signal by one horizontal period, a first adder for adding an input signal and an output signal of the delay circuit, a filter circuit for passing a specified frequency band of an output of the first adder, a first coefficient circuit for multiplying an output of the filter circuit with a specified coefficient, a second adder for adding an output of the first coefficient circuit and the input signal to use the sum output signal as the input signal to the delay circuit, a subtracter for subtracting the output signal of the delay circuit from the input signal of the delay circuit, an amplitude limiter for limiting the amplitude of an output of the subtracter, and a second coefficient circuit for multiplying an output of the amplitude limter with a specified coefficient. An output signal of the second coefficient circuit is substracted from the input signal to reduce noise in the input signal, or added to the input signal to emphasize the input signal. In the presence of vertical correlation, this circuit acts as a comb filter with a varied passing range depending on frequency to effectively reduce visible noise. In the absence of vertical correlation, the output signal is hardly affected and the noise reduction is not effected, so that the vertical resolution is not lowered.