| 摘要 |
PURPOSE:To prevent malfunction by stopping temporarily an operation of an integration circuit, when a pulse amplifier has entered into an output saturation state, and fixing an output of a photoelectric switch to its previous operation. CONSTITUTION:When a surge of huge pulse width is inputted by flash light, etc., a pulse amplifier 2 is saturated and an output is fixed for a prescribed period. As a result, one of a positive pulse detector 3 or a negative pulse detector 10 generates an output of a logical level of '1', therefore, the fifth AND gate 22 is closed. Accordingly, an operation of an integration circuit 9 stops. When the output saturation state of the pulse amplifier 2 is released, the internal operation is restarted. Accordingly, a photoelectric switch 27 executes a detecting operation continuously by only suspending the operation while the output of the pulse amplifier 2 is being saturated. In this way, a malfunction caused by a fact that the output of the pulse amplifier is saturated can be eliminated. |
