摘要 |
<p>The solid object (24) to be detected moves into the observation region (14) of the detector (10), which is crossed by many beams of light (18). The beams of light are produced by an array of flashing lamps (22) on a carrier frame (12). Control signals are sent through a wire (20) to a carrier frame (16) holding an array of photocells (26) and ensure that the photocells are only receptive when the lamps are ON.</p> |