| 摘要 |
<p>A light projector (26) projects light to a door opening (6) of an automat ic door device. Upon receiving the light projected from the light projector (26) and passed through the door opening (6), a light receiver (28) generate s a light reception signal. A door controller (32) stops the light projectio n by the light projector (26) and then causes the light projector (26) to st art light projection. When the light receiver (28) does not generate a light reception signal with light projection by the light projector (26) stopped and simultaneously when the light receiver (28) generates a light reception signal with light projection by the lightprojector (26) started, an auxiliar y sensor (24) is determined to be normal, and in other cases, it is determin ed to be abnormal.</p> |
