| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an infrared detector for improving the SN ratio of a current/voltage conversion part while suppressing unnecessary influence of low frequency components to the output of the current/voltage conversion part. <P>SOLUTION: A current/voltage conversion part 3 has a first arithmetic amplifier 31 in which a pyroelectric element 2 is connected to an inverted input port. Between an output port and the inverted input port of the arithmetic amplifier 31, a capacitor C1 as a capacitance element for AC feedback is connected. Between the output port and the inverted input port of the arithmetic amplifier 31, a reset switch 33 is connected in parallel to the capacitor C1. The reset switch 33 is on-off controlled by a reset signal from a control section 6 and, when the reset switch is on, functions as a discharging part forming a discharge path for discharging the electric charge accumulated in the capacitor. The control section 6 has an oscillator generating a clock signal at the intervals so predetermined as to remove low frequency components equal to or lower than a predetermined frequency, and outputs a reset signal on the basis of the clock signal. <P>COPYRIGHT: (C)2012,JPO&INPIT</p> |
