Patent ID: 7361899

Claim:
An infrared sensor comprising: an imaging area disposed on a semiconductor substrate and including a plurality of infrared detection pixels which detect infrared rays; row selection lines connected to the infrared detection pixels disposed in a row direction; a signal line connected to the infrared detection pixels disposed in a column direction; a constant current source connected to the signal line; a row selection ciruit applying a voltage to the infrared detection pixels via the row selection line and generating a column voltage in the signal line; a column amplifier connected to the signal line, the column amplifier including a first amplifying transistor which generates an amplification voltage obtained by amplifying the column voltage and a first clamp ciruit which holds threshold voltage information of the first amplifying transistor in a gate of the first amplifying transistor; a removing ciruit including a second amplifying transistor which has conductivity opposite to that of the first amplifying transistor and a second clamp ciruit which holds threshold voltage information of the second amplifying transistor in a gate of the second amplifying transistor, the removing ciruit being connected to the column amplifier to remove a bias component generated by a bias current, which flows through the column amplifier, from the amplification voltage; and a reading ciruit reading an output voltage from the column amplifier, the output voltage being obtained by excluding at least the bias component from the amplification voltage.