摘要 |
An infrared security sensor device includes a light projector 1A, 1B having a projecting light power control unit 5 for controlling the light receiving sensitivity of a light receiver 2A, 2B by switching a light projecting power thereof to one of a plurality of steps in dependence on the level of a detection signal and a status determining unit 7 for determining an optical axis adjusting time and an alert time. The light projector 1A, 1B is further provided with an adjustment selecting sector 6 capable of selecting one of the manual and automatic adjusting sectors 10 and 11 such that during the optical axis adjustment the light projecting power can be manually adjusted by the manual adjusting sector 10. |