Patent ID: 7122798

Claim:
An infrared image sensor comprising: a substrate having an image area on which infrared radiation is made incident, and a non-image area out of the image area; a plurality of first heat-sensitive parts arranged in columns and rows on the image area of the substrate, each of the plurality of the first heat-sensitive parts having a thermoelectric conversion function of converting a temperature into an electric signal in the state where a bias current is applied thereto, and a structure of absorbing the infrared radiation; a plurality of second heat-sensitive parts provided in the non-image area of the substrate, the plurality of second heat-sensitive parts provided to correspond to the respective rows and having the same thermoelectric conversion function as that of the first heat-sensitive parts; a bias current supply circuit which supplies the bias current to the first heat-sensitive parts and the second heat-sensitive parts; an output circuit which outputs the electric signal of the first heat-sensitive parts; and a bias current control circuit which controls the bias current to be fed to the first heat-sensitive parts, according to an electric signal of the second heat-sensitive parts; wherein the bias current control circuit is configured to supply the same bias current as fed to the first heat-sensitive parts to the second heat-sensitive parts, and the bias current control circuit comprises, a source follower circuit which inverses the electric signal from the second heat-sensitive parts and outputs an inversed signal; and a control circuit which controls the bias current flowing through the first heat-sensitive parts, with the inversed signal used as a control voltage.