A laser sensor uses a “laser” to emit a visible beam in a straight line concentratedly which can be received by a receiver either in a single or separated housing.
Generally speaking, according to the detection principle, laser sensors fall into four categories as follows:
- A reflective laser sensor emits a laser beam toward the object by the emitter and takes the reflected beam from the surface by the receiver. Both emitter and receiver are in a single housing.
- A retro-reflective laser sensor contains an emitter and a receiver in a single housing. A signal beam is formed between emitter and receiver by a reflector. An interruption in the signal by an object will be detected by the sensor which leads to its recognition.
- A through-beam laser sensor emits the laser beam from the emitter toward the receiver in a separate housing. The sensor detects objects by sensing whether the laser beam emitted from the emitter has been interrupted by them or not.
- Laser distance sensors consist of an emitter, receiver and receiver lens in a single housing. The emitter emits a laser beam and receives the reflected light from the surface. According to the change in the light entry angle by the receiver, the sensor can recognize the changes in the distance to the target.