Optical sensor basics and its considering factors of these type of contactless switches, learn more from Vishay’s app note on transmissive optical sensor.
These sensors integrate an infrared emitter and photo detector in a single package. The most common types of optical sensors are transmissive and reflective sensors. Both types detect the presence of an object without any mechanical or electrical contact. The output signal of the sensor is used to control various functions of an application
Transmissive sensors, also called interrupter sensors, incorporate an infrared emitter and photo detector that face
each other as shown in fig. 1. When an object is located between the emitter and detector in the sensing path, it interrupts or breaks the optical beam of the emitter. The light energy reaching the detector changes. This change in light energy or photo current is used to affect an event in the application.