Active-pixel sensor

An active-pixel sensor (APS) is an image sensor, which was invented by Peter J.W. Noble in 1968, where each pixel sensor unit cell has a <a href="/facts/Photodetector/7cSkXS6s">photodetector</a> (typically a <a href="/facts/Pinned_photodiode/152Rpk06">pinned photodiode</a>) and one or more active <a href="/facts/Transistor/Bmr8zwL0">transistors</a>. In a <a href="/facts/Metal%25E2%2580%2593oxide%25E2%2580%2593semiconductor/eTDJT2Km">metal–oxide–semiconductor</a> (MOS) active-pixel sensor, <a href="/facts/MOSFET/eTDJT2Km">MOS field-effect transistors</a> (MOSFETs) are used as <a href="/facts/Amplifiers/pnRgxncC">amplifiers</a>. There are different types of APS, including the early NMOS APS and the now much more common <a href="/facts/Complementary_MOS/NJIWYgBl">complementary MOS</a> (CMOS) APS, also known as the CMOS sensor. CMOS sensors are used in <a href="/facts/Digital_camera/LSGTserm">digital camera</a> technologies such as <a href="/facts/Camera_phone/EzCfpkdl">cell phone cameras</a>, <a href="/facts/Web_camera/1vTYrHWw">web cameras</a>, most modern digital pocket cameras, most <a href="/facts/Digital_single-lens_reflex_camera/1gq1Y1qt">digital single-lens reflex cameras</a> (DSLRs), <a href="/facts/Mirrorless_interchangeable-lens_camera/dWbPnzRF">mirrorless interchangeable-lens cameras</a> (MILCs), and lensless imaging for, e.g., blood cells.
CMOS sensors emerged as an alternative to <a href="/facts/Charge-coupled_device/l6xffIcz">charge-coupled device</a> (CCD) image sensors and eventually outsold them by the mid-2000s.
The term active pixel sensor is also used to refer to the individual pixel sensor itself, as opposed to the image sensor. In this case, the image sensor is sometimes called an active pixel sensor imager, or active-pixel image sensor.

Active-pixel sensor open-in-new

Active-pixel sensor