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:
Nov. 10, 1987
Filed:
Feb. 06, 1986
Hiroshi Ito, Nagaokakyo, JP;
Yoshiki Mizutani, Nagaokakyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A contour detecting filter device samples composite video signals of the system by sampling signals at a frequency four times the chrominance subcarrier frequency thereof through an A-D converter (2), to input sampling value series thus sampled in a delay circuit group (81-84). Detected from the delay circuit group are four sampling values (P1, P2, P4, P5) which are point-symmetrically positioned around a noted sampling value (P3) on the screen and having the same-phased chrominance subcarriers. The noted sampling value and the four sampling values are employed to perform arithmetic on second order differentiations in the direction of horizontal scanning lines and in the vertical direction on the screen by a coefficient multiplier (85), an adder (86) and a multiplier (87), thereby to detect the contour signal of the noted sampling value. Therefore, it is not necessary to separate luminance signals from the composite video signals, from which the contour signals can be directly detected.