Photo-interrupters are transmission-type photo sensors that integrate optical receiving and transmitting elements in a single package. A sensor is composed of an infrared emitter on one upright and a shielded infrared detector on the other. By emitting a beam from one to the other, the sensor can detect when an object passes between them breaking the beam. They involve the process of light blocking. There are two types of photo-interrupters: the insertion and the dual mould. The insertion photo-interrupters are general-purpose units featuring injection mould processing of both optical transmitting and receiving elements. Dual mould photo-interrupters are more compact and their mould resin construction means higher efficiency of transmitters and receivers. Their epoxy resin is relatively weak with respect to temperature resistance, resistance to solvents and mechanical resistance. Photo-interrupters have a variety of applications. The most common is for general object detection, which is used in motion detectors in burglary alarm systems. They are also components of automatic doors and trigger the opening mechanism. Additionally, they are found in pellet dispensing and in the construction of optical limit switches. They are widely used in the measurement of speed and are usually installed in printers, fax machines and scanners.

  • Phoenix Components (UK) Ltd 1 Product

  • IMO Precision Controls Ltd 2 Products