Patent ID: 8665223

Claim:
A display device that displays an image and receives light simultaneously or alternately, comprising: a plurality of display elements which emit light and display an image; a plurality of light-receiving elements which receive light entering a display surface of said display device; said light-receiving elements receive light two times in generating information indicating whether at least one region corresponding to specific light receiving elements are covered or approached, once during a light-emitting state of the display device and once during a state where light is not emitted by the display device; and wherein a determination regarding whether the at least one region corresponding to the specific light receiving elements are covered or approached is based on a difference in amount of received light of said two times and further wherein the difference in amount of received light is analyzed across the region in order to determine if two or more regions of the display are simultaneously covered or approached, and wherein a center of gravity for each position is determined if it is determined that the two or more regions of the display are simultaneously covered or approached and wherein a frame memory stores light reception information from the display device and differential image data derived from the frame memory is provided to image processing circuitry for determining the two or more regions of the display that are covered or approached.