Circuit for detecting active video area for display device, method for detecting active video area for display device and coordinate mapping method using detected active video area

A method for detecting an active video area for a display device, the method comprising:

• (a) comparing continuously received R, G, and B signals with a predetermined black level and outputting a comparison signal which indicates the existence of a video signal;
• (b) detecting 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;
• (c) detecting 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;
• (d) detecting 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
• (e) detecting 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.

A method for mapping coordinates of a video source to coordinates of a display device, the method comprising:

• (a) selecting a predetermined area of the video source;
• (b) generating a predetermined reference pattern;
• (c) transmitting R, G, and B signals in which the reference pattern is embedded, to the display device;
• (d) comparing the R, G, and B signals with a predetermined black level and outputting a comparison signal which indicates the existence of a video signal;
• (e) detecting a horizontal starting point, a horizontal ending point, a vertical starting point, and a vertical ending point using the comparison signal;
• and
• (f) converting the selected predetermined area of the video source into an area of the display device, according to a predetermined mapping relationship and the detected horizontal starting point, the detected horizontal ending point, the detected vertical starting point, and the detected vertical ending point.

A display device for receiving a video signal from a video source and displaying the video signal, the device comprising:

• a detection circuit which receives R, G, and B signals, in which a predetermined reference pattern is embedded, and detects an active video area;
• a micro-controller (MCU) which converts a selected area of the video source into the counterpart area of the display device using coordinate information of the selected area of the video source and the active video area of the display device;
• and
• a function control circuit which receives information on the converted area of the display device and performs a predetermined function in the converted area of the display device.