DEVICE FOR DETECTING THE NUMBER OF PERSONS

摘要

PURPOSE:To form a human number detecting device surely capable of detecting the number of persons even when a peripheral temperature is changed by calculating a background temperature and a human body surface temperature based on an output from a temperature detecting part and an output from a signal processing part when a visual field is included in a device and controlling sensitivity based on the background temperature and the human body surface temperature. CONSTITUTION:A difference waveform data is multiplied by G based on a temperature difference between the previously found background temperature TC and the temperature TD on the surface of human clothing. The value G is increased in accordance with the approach of the temperature difference (TD-TC) to '0' and has the same code as that of the temperature difference (TD-TC). When the corrected difference waveform exceeds a prescribed threshold alpha, the existence of a human body is decided and the number of maximum points of the waveforms is counted and outputted to an output part 6 as the number of persons. When the waveform does not exceeds the prescribed threshold alpha, absence of persons is decided, the background temperature TC and the temperature TD on the surface of personal clothing are calculated based on the input waveform data and the output of a temperature detecting part 7 to determine the G value of the succeeding input signal. Even when the peripheral temperature is changed, the number of persons can be surely detected.