| 摘要 |
<p>PURPOSE:To decide the presence or absence of a human body even if there is no movement over the entire part of the human body by adjacently providing the detecting regions consisting of IR photodetectors and setting the sizes of the detecting regions at about the same size as the size of a part of the human body to be detected. CONSTITUTION:The IR photodetectors 2A to 2D are disposed on the focal plane of an optical system 1. The plural detecting regions A to D are formed through the optical system 1 on the same object surface in the same disposition as the disposition of the detectors 2A to 2D on the focal plane. The respective detectors 2A to 2D generate outputs as a change in the temp. difference from the background by the movement of the human body in the regions A to D. An amplifier 3 amplifies the outputs from the detectors 2A to 2D. A filter 41 removes the unnecessary low-frequency components and high-frequency components from the outputs of the detectors 2A to 2D. A comparing section 42 compares whether the peak value of the signal outputted from the filter 4 exceeds a preset reference value or not and outputs the same to an output section 5.</p> |
