Photoelectric switch is an important application of photoelectric sensors, widely used in automatic production process. Photoelectric switch is blocked by the speed of light is detected object or reflection, the light intensity change, and then transformed into current size, to determine the object exists. The launch of the electromagnetic wave application is one of the most infrared photoelectric switch.

Photoelectric switch according to detection methods can be divided into, mirror reflection, diffuse reflection type correlation type and tank type, etc. Diffuse reflection type photoelectric switch the transmitting and receiving, in the absence of an object, the light of the launcher, the receiver is less than not form loop, when there is a through the object, reflects the light coming from an emitter to the receiver, resulting in a signal, the photoelectric switch have requirements to measure objects emit light ability. Mirror launch photoelectric switch has a matching mirror, usually, light will be back to photoelectric switch the receiver by reflecting mirror, when you have an object, the light is blocked, also created a detection signal. Correlation photoelectric switch, combined form, a switch is used to reflect, a switch is used to receive, to detect objects pass through the middle. When detecting objects can partition the light, the photoelectric switch is the most reliable choice. Groove photoelectric switch is a u-shaped switch, transmitter and receiver are located on both sides of the u-shaped slot opposite position, and to detect the object from the u-shaped groove through the middle, cut off the light of the launcher, to determine whether there are objects, this kind of photoelectric switch is suitable for measuring high speed change objects, good reliability.