Patent ID: 7053889

Claim:
A circuit for detecting an active video area for a display device, the circuit comprising: a comparison signal generator which compares continuously received R, G, and B signals with a predetermined black level and outputs a comparison signal which indicates the existence of a video signal; a horizontal starting point detecting unit which detects a horizontal starting point, which is a minimum coordinate in a horizontal direction of the display device, in which the comparison signal has a predetermined first logic level; a horizontal ending point detecting unit which detects a horizontal ending point, which is a maximum coordinate in the horizontal direction of the display device, in which the comparison signal has the predetermined first logic level; a vertical starting point detecting unit which detects a vertical starting point, which is a minimum coordinate in a vertical direction of the display device, in which the comparison signal has the predetermined first logic level; and a vertical ending point detecting unit which detects a vertical ending point, which is a maximum coordinate in the vertical direction of the display device, in which the comparison signal has the predetermined first logic level; wherein a predetermined reference pattern is embedded in the R, G, and B signals.