Patent ID: 7301487

Claim:
An image sensor comprising: a pixel unit that outputs a first signal including an offset voltage inherent to a pixel; a correlated double sampling (CDS) unit that performs correlated double sampling of a second signal that is obtained from the first signal by cancelling the offset voltage inherent to the pixel, and outputs the second signal after the correlated double sampling as a third signal including an offset voltage due to the CDS unit; and an analog-to-digital converter (ADC) unit that performs analog-to-digital conversion of a fourth signal that is obtained from the third signal by cancelling the offset voltage due to the CDS unit, wherein the pixel unit includes: a first element that has a first offset voltage and outputs a first detected value including the first offset voltage, and the CDS unit includes: a second element that has a second offset voltage and is provided with the first detected value to output a second detected value including the second offset voltage; a third element that has a third offset voltage and is provided with the second detected value to output a third detected value including the third offset voltage; a first condenser that is arranged between the second element and the third element; a reference-signal output unit that outputs a reference signal; and a first switch that is arranged between the reference-signal output unit and the third element.