| 摘要 |
PURPOSE:To make it possible to all of obstacles within a detection range, by respectively mounting a light emitter and a light receiver to upper/lower parts of the abutment parts of doors and expanding light beam emitted from the light emitter to the size of the detection range. CONSTITUTION:Light such as infrared rays emitted from a light emitter 2 is converted to light beam 6 expanded so as to be coincided with a predetermined detection range and taken in a light receiver 3. This light receiver 3 comprises light receiving elements such as photodiodes and the light receiving surfaces thereof are arranged in an array form over the detection range while the quantity of light received by the light receiving element is converted to an electric signal which is, in turn, sent to a processor circuit 7. Now, if an obstacle is present, the quantity of light respectively received by the light receiving elements changes and, therefore, if there is one light receiving element changed in the quantity of received light, a signal of ''obstacle is present'' is outputted from the processor circuit to make it possible to detect the presence of the obstacle caught in doors. |
