| 摘要 |
A load handling device carrying light sensitive means and a light source moves relatively to a load with a focused beam from the light source scanning the load. The light sensitive means receives light of said beam reflected from the load, and any variations of the reflected light because of variations in the load, will cause the light sensitive means to particularly condition a control circuit for the load handling device. By utilizing a light sensitive means such as two photoelectric cells, variations in ambient light do not significantly affect the operation of the light sensitive means and control circuit. |
