PYROELECTRIC TYPE INFRARED RAY APPARATUS

摘要

PURPOSE:To minimize extraneous noise of an infrared rays apparatus by limiting the band with an amplifying section to process signals utilizing two threshold voltages. CONSTITUTION:As a human body approaches an infrared rays sensor 1 and infrared rays is incident thereinto, the heat potential of a pyroelectric type infrared rays sensor changes and an electric signal corresponding to the movement of the human body is sent to first and second amplifying sections 10 and 20. A band limiting function is added to both the amplifying sections to remove noise components due to a lamp or the like of an automobile or the like. The second amplifying section 20 also processes signals utilizing two threshold voltages to alter the amplification factor between the daytime when visible light is incident and the night.