Patent ID: 8605059

Claim:
A method for driving an input/output device comprising: a display circuit; and a photodetector circuit, the method for driving comprising the steps of: supplying a display signal to the display circuit during a first display mode; not supplying the display signal to the display circuit during a second display mode; supplying a display data signal to the display circuit during the first display mode; supplying N (N is a natural number of 2 or more) reset signals to the photodetector circuit during a first photodetection mode; supplying M (M is a natural number smaller than N) reset signals to the photodetector circuit during a second photodetection mode; supplying N select signals to the photodetector circuit during the first photodetection mode; supplying M select signals to the photodetector circuit during the second photodetection mode; performing a reset operation in accordance with the reset signals by the photodetector circuit; performing a photocurrent detecting operation to generate data according to an intensity of light entering the photodetector circuit after the reset operation by the photodetector circuit; and performing a selecting operation to output the data as a data signal in accordance with the select signals by the photodetector circuit.