| 摘要 |
PROBLEM TO BE SOLVED: To provide a CMOS image sensor having a comparator, in which current consumption and chip size can be reduced, while reducing offset voltage efficiently, and to provide its offset voltage removing method. SOLUTION: The CMOS image sensor comprises an image-capturing means 120 for capturing an analog signal corresponding to the image of an object, an analog/digital(A-D) conversion means 220 for converting analog signal into digital signal utilizing a lamp signal, and a lamp signal generating means 410 for outputting a lamp signal to the A-D conversion means, wherein the A-D conversion means comprises a chopper comparator receiving an analog signal and a lamp signal. Further, the sensor has an input capacitor for receiving the start voltage of a lamp signal, to induce a voltage having the level of the start voltage at the time of reset mode, and to induce a voltage having a level corresponding to the lamp signal at counter mode time, in order to eliminate the offset voltage of a CMOS image sensor.
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