Composite Video Color Signal Generator
Original Publication Date: 1985-Jan-01
Included in the Prior Art Database: 2005-Feb-18
Described is a method of altering the colors being displayed on a conventional television (TV) by varying the phase angle of the color sync burst. A color composite signal used to drive a conventional color TV (NTSC color standard) consists of four parts: the luminance, the hue (color), the chrominance, and the color sync burst. The color sync burst is a burst of 8 to 11 cycles of the 3.58 MHz subcarrier transmitted on the back porch of each horizontal blanking pulse. Fig. 1 shows the burst signal in a horizontal blanking interval. This burst is to provide a reference phase for the 3.58 MHz subcarriers. The color sync burst synchronizes the phase of the color oscillator inside the TV The oscillator signal is used by the synchronous demodulators to detect the chrominance signal in the composite video.