| 摘要 |
<p>PROBLEM TO BE SOLVED: To facilitate the execution of a test by providing a test means for detecting the output states of each light-receiving elements, when a light beam is interrupted by a light-interrupting means and when not interrupted. SOLUTION: The detection of an object, including persons in a detecting area A is performed. That is, in a light-receiving circuit 2a, if there is no object to interrupt the light beam of each axis (the optical axis between the projector element D1 and the light-receiving element R1 to the optical axis between the projector element Dn and the light-receiving element Rn ) in the detecting area A, each output of each of the light-receiving elements R1 to Rn is detected as '1'. Then, if the light beam having plural light axes is interrupted by an object in the detecting area A due to a person, the outputs of their axes become '0'. An amplifying/level detecting circuit 6 processes a signal from the light- receiving circuit 2a, generates a detecting signal and outputting this. Then, the output of an optical sensor array is inputted to a CPU processing unit 10 and whether the object is a train, person, etc., is determined, based on how the light beam of the optical axis has been interrupted.</p> |
