| 摘要 |
PURPOSE:To remarkably increase an output and to improve the S/N by connecting in series two pyroelectric elements whose polarization directions are different and connecting its series coupling point to a gate electrode of an FET. CONSTITUTION:Two pyroelectric elements 1, 2 whose polarization directions are different are coupled in series like a bridge and connected between positive and negative terminals 8, 9 of a power source, and its series coupling point 4 is connected to a gate electrode of an FET 3. Also, a drain electrode of the FET 3 is connected to one terminal 8, and a source electrode is connected to the other terminal 9 through a source resistance 6, and also, led to an output terminal 7. In this state, when heat ray of long wavelength is made incident simultaneously on the elements 1, 2 or cut-off, one element 1 is electrified in the positive direction and the other element 2 is electrified in the negative direction, therefore, the potential of the coupling point 4 is varied, and its potential variation is brought to impedance conversion by the FET 3, and can be led as a large signal to the terminal 7. |
