公开(公告)号：US4973843A

公开(公告)日：1990-11-27

申请号：US400471

申请日：1989-08-29

申请人： Michihiro Murata ,  Shyzi Sawada ,  Muneharu Nishio ,  Satoru Ito

发明人： Michihiro Murata ,  Shyzi Sawada ,  Muneharu Nishio ,  Satoru Ito

IPC分类号： G01J1/02 ,  G01J5/02 ,  G01J5/34 ,  G08B13/191 ,  H01L31/0264 ,  H01L37/02

CPC分类号： H01L37/02 ,  G01J5/34 ,  G08B13/191

摘要： A pyroelectric sensor senses the infrared rays radiated from the human body and outputs the detected infrared rays as an electric signal. It detects the trespass of somebody on a room and is used for the prevention of crimes and the like. The pyroelectric sensor includes a substrate, an element-pair disposed on the surface of the substrate and an amplification circuit for amplifying the current signals output from the element-pair. The substrate is composed of a material having a thermal conductivity as low as not more than 0.04 cal/cm sec.degree. C. so as to prevent the heat from being released through the substrate. A hole is formed in the substrate. The amplification circuit amplifies the current signals of the element-pair, thereby dispensing with the impedance transformation which is inevitable in the prior art. Thus, the sensitivity of detection is improved and the manufacture of the sensor is facilitated.