The Principle And Main Types Of Photoelectric Sensors

The photoelectric sensor emits "light" such as visible light and infrared rays through the emitter, and detects a change in the amount of light reflected by the detecting object or the occluded light through the receiver, thereby obtaining an output signal. The principle of the photoelectric sensor: the light-emitting element of the emitter emits light and is received by the light-receiving element of the receiver.

Photoelectric sensor main type Reflective type: The light emitting element and the light receiving element are built in one sensor amplifier. Receiving reflected light from the detected object. Transmissive type: The transmitter/receiver is in a separate state. If a detection object is placed between the transmitter/receiver, the light from the transmitter is blocked.

Retro-reflective type: The light-emitting element and the light-receiving element are built in one sensor amplifier. Receiving reflected light from the detected object.

The light of the light-emitting element is reflected by the light-reflecting plate and received by the light-receiving element. If you enter the detection object, it will be blocked.

Narrow beam reflection type: Spot illumination is performed on the detection object, and reflected light from the detection object is received and detected.・Detects small targets.・Detectable mark.・It can be detected from the gap of machinery.・Detection points are visible.

Limited reflection type: A structure that uses an angle between the transmitter and the receiver to detect only the restricted area where the respective optical axes intersect.・The background influence is small.・The distance should be short.・Detects small bumps.

The distance setting type of the photoelectric sensor: the spot is irradiated onto the detection object, and is detected by the difference in angle from the light reflected by the detection object.・Not affected by backgrounds with high reflectance.・Stable detection is possible even if the color of the detected object and the reflectance of the material are different.・High-precision detection of small objects is possible.