1. Slot type photoelectric sensor
Mounting a light emitter and a receiver face to face on either side of a slot is a trough optoelectronic. The illuminator emits infrared or visible light, and the light receiver receives light in an unobstructed condition. However, when the object to be detected passes through the slot, the light is blocked and the photoelectric switch operates. A switch control signal is output to cut or turn on the load current to complete a control action. The detection distance of the slot switch is usually only a few centimeters due to the limitation of the overall structure.
2. Optotype photoelectric sensor
If the illuminator and the illuminator are separated, the detection distance can be increased. A photoelectric switch composed of an illuminator and a light collector is called an off-beam split type photoelectric switch, and is simply referred to as an on-beam type photoelectric switch. Its detection range can be several meters or even tens of meters. In use, the illuminator and the light receiver are respectively mounted on both sides of the path of the detection object, and when the detection object passes, the light path is blocked, and the light receiver outputs a switch control signal.
3. Reflective plate type photoelectric switch
A reflector-reflective (or mirror-reflective) photoelectric switch is installed in which the illuminator and the illuminator are housed in the same device, a reflector is placed in front of it, and the photoelectric control function is performed by the reflection principle. Under normal circumstances, the light emitted by the illuminator is reflected by the reflector and received by the light receiver. Once the light path is blocked by the detection object and the light receiver receives no light, the photoelectric switch operates to output a switch control signal.
4. Diffusion reflective photoelectric switch
Its detector head is also equipped with an illuminator and a light receiver, but there is no reflector in front. Under normal circumstances, the light illuminator emitted by the illuminator is not found. When the detection object passes, the light is blocked, and the light is partially reflected back, and the light receiver receives the light signal and outputs a switching signal.