Light sensor and also commonly called Photoelectric Sensor. This sensor uses light-sensitive elements to detect objects and consists of a transmitter/emitter (Light Source) and receiver (receiver).
on retro-reflective sensor type of emitter and receiver sensor is in one device / combined so that it is quite simple, the receiver’s task in the type of through-beam sensor, has been replaced by a reflector, the emitted beam comes out, will be reflected back by the reflector and received by the receiver, so that when the beam emitted does not reach the receiver, then the sensor output will work.
