Patent ID: 8530816

Claim:
A photoelectric conversion device comprising: a pixel array including a plurality of two-dimensionally arranged pixels, each of which has a photoelectric conversion element and outputs a pixel signal corresponding to an amount of light incident on the photoelectric conversion element; and a plurality of analog-to-digital converters (ADCs), each of which converts the pixel signal read from the pixel array into a digital value and outputs the digital value, wherein each ADC comprises: a pulse delay circuit including a plurality of connected delay unit stages, each of which delays a pulse signal during a delay time corresponding to a magnitude of a voltage of the pixel signal read from the pixel array; an encoder unit that outputs a digital value based on the number of stages of the delay units through which the pulse signal has passed during a predetermined time; and a correction unit that corrects the digital value output by the encoder unit by a rate corresponding to the number of stages of the delay units through which the pulse signal has passed during a predetermined period, and wherein the correction unit comprises a subtraction unit that subtracts a predetermined value from the digital value output from the encoder unit.