| 摘要 |
A light grid detects objects in a monitored area. The grid includes a number of transmitters that emit light rays pulses. A number of receivers, corresponding to the number of transmitters, receive the light rays. Respectively one transmitter is assigned to one receiver to define a light axis. With a clear monitoring area, the light rays emitted by the transmitter impinge on the corresponding receiver. The transmitters and the corresponding receivers are activated cyclically and individually, one after another. An evaluation unit generates a switching signal in dependence on the signals received at the receivers. A control unit coupled between the receivers and the evaluation unit eliminates interfering light shares in the signals received at the receivers. The control unit is deactivated during time intervals in which the transmitters emit transmitting pulses. |
