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. 30, 1987
Filed:
Jul. 18, 1985
Yoshiki Mizutani, Nagaokakyo, JP;
Hiroshi Ito, Nagaokakyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A contour detecting filter (8, 10, 11) sequentially inputs series of sampling values obtained by sampling composite video signals, which are composed of frequency-multiplexed video luminance signals and chrominance signals and include chrominance subcarriers, at a frequency four times that of the chrominance subcarriers to detect four sampling values point-symmetrically positioned around a reference sampling value and having the same-phased chrominance subcarriers by utilizing delay circuits. The reference sampling value and the four sampling values are so employed as to perform arithmetic on second order differentiations in the direction of horizontal scanning lines and the vertical direction on the screen thereby to detect the contour signal of the reference sampling value. A contour detecting filter (12) detects contour signals in the direction of horizontal scanning lines from composite video signals utilizing a vertical low-pass filter (14) and a horizontal high-pass filter (15) which are cascade-connected with each other while detecting contour signals in the vertical direction on the screen by utilizing a vertical high-pass filter (16) and a horizontal low-pass filter (17) which are cascade-connected with each other. Switched and outputted are the contour signals in the direction of the horizontal scanning lines and the vertical direction on the screen.