Photo-interrupters (also called Opto-interrupters, or Opto-switches) are part of the optosensors or photoelectric sensors family. Photoelectric sensing employs two optoelectronic devices: a transmitter, also called an emitter, and a detector, or receiver. The transmitter emits a visible or infrared (IR) light beam; the detector detects the light from the transmitter. More complex configurations may have multiple transmitters and detectors.
Benefits of photo-interrupters
The use of interrupter or reflector modules eliminates most of the optical calculations and geometric and conversion problems in mechanical position sensing applications. These modules are specified electrically at the input and output simultaneously — i.e., as a coupled pair — and have defined constraints on the mechanical input. All the designer need do is provide the input current and mechanical input (i.e., pass an infrared-opaque object through the interrupter gap) and monitor the electrical output.