| 摘要 |
<p>PURPOSE: To facilitate identification of a sensor which can detects a translucent paper at operation with low intensity and can operate to a limit. CONSTITUTION: A sensor comprises a light source 182 and a detector 184 which are optically centered. The detector, in response to the light having lighting intensity which is equal or above a threshold value, generates the first output signal level, and, in response to the light having lighting intensity which is equal or below the threshold value, generates the second output signal level. In addition, the sensor contains an ability for selectively changing a lighting intensity of light radiated from the light source to a lower level between a threshold value intensity and a normal operation intensity.</p> |
