1. Through-beam type fiber sensor matrix
Through-beam type emits red light or infrared from the transmitter end, and the receiver end detects it. When an object interrupts the light beam, a signal is output.
2. Diffuse Reflection Type fiber sensor matrix
When the switch emits a light beam, the target generates diffuse reflection.
The emitter and receiver constitute a single standard component.
When a sufficient amount of scattered light returns to the receiver the switch's state changes.
link:http://www.garantta.com