To obtain the digital optical sensor very immune to external noise in order to miniaturize a camera furthermore.

Each output signal from photo diodes 403 is extracted through each amplifier 403 and each switch 404. Each output from the amplifier 403 is converted into a digital signal by each A/D converter 406 and each output from each A/D converter 406 is stored in each relevant latch circuit 407 respectively. Information from the latch circuit 407 is outputted in time series by scanning each switch 408. Since an A/D converter is provided corresponding to elements arranged in the horizontal direction, a remarkable margin is provided to the speed of A/D conversion.