Patent attributes
A liquid crystal display apparatus according to the present invention includes a pixel array unit 1 having signal lines and scanning lines respectively arranged side by side, a signal line drive circuit 2 which drives the signal lines, a scanning line drive circuit 3 which drives the scanning lines, a signal processing output circuit 4 which serially outputs the picked-up image data supplied from the sensors, and a sync signal generation circuit 5. A black-white change obtained in the picked-up image data when a finger is brought close to or brought into contact with the pixel array unit 1 is detected, and the coordinate position of the finger is identified taking the ambient brightness into consideration. Regardless of whether the surroundings are bright or dark, therefore, the coordinate position can be detected with high precision. Furthermore, when conducting the coordinate detection, the picked-up image data corresponding to all pixels are not detected, but the picked-up image data are detected every a plurality of pixels in both the signal line direction and the scanning line direction. Therefore, the time taken to detect the coordinates can be shortened.