Part of the Electronics glossary:

A photosensor is an electronic component that detects the presence of visible light, infrared transmission (IR), and/or ultraviolet (UV) energy. Most photosensors consist of semiconductor having a property called photoconductivity , in which the electrical conductance varies depending on the intensity of radiation striking the material.

The most common types of photosensor are the photodiode, the bipolar phototransistor, and the photoFET (photosensitive field-effect transistor). These devices are essentially the same as the ordinary diode , bipolar transistor , and field-effect transistor , except that the packages have transparent windows that allow radiant energy to reach the junctions between the semiconductor materials inside. Bipolar and field-effect phototransistors provide amplification in addition to their sensing capabilities.

Photosensors are used in a great variety of electronic devices, circuits, and systems, including:

  • fiber optic systems
  • optical scanners
  • wireless LAN
  • automatic lighting controls
  • machine vision systems
  • electric eyes
  • optical disk drives
  • optical memory chips
  • remote control devices

This was last updated in April 2005
Posted by: Margaret Rouse

Related Terms

Definitions

  • frequency jammer

    - Frequency jamming is the disruption of radio signals through use of an over-powered signal in the same frequency range. When most people think of frequency jamming, what comes to mind are radio, r... (WhatIs.com)

  • anode

    - An anode is the electrode in a polarized electrical device through which current flows in from an outside circuit. Conversely, a cathode is the eletrode in a polarized electrical device through whi... (WhatIs.com)

  • cathode

    - A cathode is the metallic electrode through which current flows out in a polarized electrical device. Conversely, an anode is the electrode in a polarized electrical device through which current fl... (WhatIs.com)

Glossaries

  • Electronics

    - Terms related to electronics, including definitions about electrical components and words and phrases about computers, laptops parts, digital cameras, televisions and home appliances.

  • Internet applications

    - This WhatIs.com glossary contains terms related to Internet applications, including definitions about Software as a Service (SaaS) delivery models and words and phrases about web sites, e-commerce ...

Ask a Question About photosensorPowered by ITKnowledgeExchange.com

Get answers from your peers on your most technical challenges

Tech TalkComment

Share
Comments

    Results

    Contribute to the conversation

    All fields are required. Comments will appear at the bottom of the article.