| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an infrared detection apparatus which is capable of suppressing influences of an unwanted low frequency component without reducing an S/N ratio of a current/voltage conversion circuit. <P>SOLUTION: An infrared detection apparatus 1 comprises a correction circuit 6 which reduces an unwanted component that is a low frequency component equal to or lower than a predetermined frequency from input of a quantizer 42 in an A/D conversion section 4. The correction section 6 feeds back the unwanted component from output of a first filter section 51 constituting a part of a digital filter 5 to a non-inverted input terminal of an operational amplifier 412 in an integrator 41 constituting a part of the A/D conversion section 4. Since an input signal from a current/voltage conversion circuit 3 is inputted to an inverted input terminal of the operational amplifier 412, a signal obtained by removing the unwanted component from the input signal is inputted to the quantizer 42. Therefore, an input signal of the A/D conversion section 4 is avoided from exceeding an input allowable range because of influences of the unwanted component. <P>COPYRIGHT: (C)2013,JPO&INPIT |
