| 摘要 |
<p>PURPOSE:To detect even a stationary human body by covering an infrared detecting means with a light shield plate endlessly, and forming an opening in the light shield plate and rotating it. CONSTITUTION:the photodetection surface 11 of the infrared detecting means 1 is covered with the light shield plate 100 endlessly and the opening 101 is bored in the light shield plate 100. Further, the light shield plate 100 is provided with a light converging means 21, the light shield plate 100 and means 21 constitute a light transmission means 120, and the light shield plate 100 is coupled with a rotating means 110 and rotated around an axis X-X of rotation. Then infrared rays emitted in the range between a light beam a-a in section containing the axis X-X of rotation and a light beam a'-a' in horizontal section containing the axis of incident light to the means 21 is converged on the photodetection surface 11 to sweep the space divisionally. Consequently, the infrared rays emitted by a person entering the light convergence range of the means 21 are detected intermittently by the means 1 and every time the person moves, the quantity of detected infrared rays varies, so it is accurately judged that the person approaches, stays in, or leaves the range.</p> |
