Photoelectric sensor uses photoelectric element as detection element. Firstly, the measured change is transformed into signal change, and then the optical signal is further transformed into electrical signal with the help of photoelectric element. Photoelectric sensor is generally composed of light source, optical path and photoelectric element. Photoelectric detection method has the advantages of high precision, fast response, non-contact, many measurable parameters, simple structure, flexible forms and small volume. In recent years, with the development of photoelectric technology, photoelectric sensors have become a series of products, and their varieties and output are increasing day by day. Users can choose products of various specifications according to their needs, which has been widely used in various light industrial automata.

1 photoelectric strip deviation detector

The strip deviation detector is used to detect the size and direction of the deviation of the strip material from the correct position in processing, so as to provide the deviation correction signal for the deviation correction control circuit. It is mainly used in the production process of printing and dyeing, paper feeding, film and tape.

The principle of photoelectric strip deviation detector is shown in Figure 1. The light emitted by the light source converges into a row beam through the lens 1, casts it on the lens 2, and then converges on the photoresist. On the way of the parallel beam to the lens 2, part of the light is blocked by the measured strip, so that the luminous flux transmitted to the photoresist is reduced.

It can be predicted that with the rapid development of automation technology, photoelectric sensors will be more and more widely used as detection devices in light industry automatic production lines.