| 摘要 |
<p>PURPOSE:To improve S/N and to decrease malfunctions by setting parameters with the values of the capacitance of a pyroelectric element so that the magnitude of an infrared-ray detected signal with respect to the noises outputted from an amplifier becomes the largest value according to the magnitude of the noises generated in the pyroelectric element at the frequency of the infrared- ray detected signal obtained in the pyroelectric element. CONSTITUTION:The parameters of pyroelectric element 1 are determined so that the overall S/N when the pyroelectric element 1 and an amplifier 2 are combined is enhanced based on the relationship between the change in infrared- ray detected signal and noises generated in the pyroelectric element 1 owing to the parameters of the pyroelectric element and noises generated in the amplifier 2. The amplifier 2 amplifies said signal and noises. In this way, the overall S/N when the pyroelectric element 1 and the amplifier 2 are combined can be enhanced, malfunctions of an apparatus can be decreased and sensitivity can be set at a high level.</p> |
