Carrier chrominance signal processing circuit

Abstract

Abstract PURPOSE:To sharpen a carrier chrominance signal with a simple constitution, by holding color information near the edge of a color in the carrier chrominance signal, and outputting the held color information during a part of the period of the leading or trailing process of the color edge detected by a detecting means. CONSTITUTION:In a color detecting system, a delay circuit 3 has the delay quantity of the integer-times of color sub-carrier cycles or of the odd-number-times of one half cycle of the color sub-carrier, an output (b) appears from a computing element 4 at the color edge, and it is made into a control signal (e) of a switch SW1 through a detecting circuit 5, a waveform shaping circuit 6 and a monostable multivibrator 7. The carrier chrominance signal passing through a delay circuit 2 is supplied to a terminal 1 of the switch SW1. The output of the switch SW1 is supplied through a delay circuit 9, whose delay quantity is an integer-multiple of the color sub-carrier cycle, to a terminal 2 of the switch SW1. At the color edge, the control signal (e) is made into an 'H', and the signal on the terminal 2 side is outputted to the output of the switch SW1. That is, at the color edge, the chrominance signal to have entered the delay circuit 9 immediately before the switch SW1 is switched to the terminal 2 side is repeatedly outputted, and the color information immediately before the edge is held and outputted.

Inventors

• 👤 Yutaka Ichii

Bibliographic Details