Broken Light Sensor

• Broken-light sensors are nothing but, Photo interrupters.
• A photo interrupter is a transmission-type photosensor that integrates optical receiving and transmitting elements in a single package. Since the method involves light blocking ROHM calls this device a photo interrupter.
• A long-life GaAs infrared photodiode is utilized for output while a single phototransistor and photo IC are integrated for light detection.

Working

• The photo interrupter consists of light emitting elements and light receiving elements aligned facing each other in a single package.
• The transmitter part in the sensor emits light which is either transmitted or gets blocked(interrupted) by some object and reflects.
• The receiver receives this interrupted light which is reflected and senses the interruption.
• Photo interrupters are non-contact (optical) switches, improving reliability by preventing wear-and-tear due to abrasion (contact).

Types of Photo Interrupters

• Transmissive photo interrupter.
• Optoelectronics Photo interrupter.
• Dual mold photo interrupters.
• Insertion type photo interrupters.
• Dual mold photo interrupters are generally more compact than their insertion-type counterparts.