CMOS sensor

(redirected from Active-pixel sensor)
Also found in: Acronyms.

CMOS sensor

A CMOS-based chip that records the intensities of light as variable charges similar to a CCD chip. Although initially used in less expensive digital cameras, the quality of CMOS sensors has improved steadily.

CMOS sensors have advantages over CCDs. They can be made like other CMOS chips on standard CMOS fabrication lines, which makes fabrication less costly, and auxiliary circuitry, such as analog-to-digital conversion, can be combined on the same chip. In addition, CMOS chips use less power than CCDs.

Active-Pixel Sensors
Another advantage is speed. Also called "active-pixel sensors," CMOS sensors perform in parallel with amplifiers in each pixel that convert charges to electrical voltages. In contrast, CCDs transfer their charges to shift registers before converting to voltage at a single amplifier stage.

Sony's Exmor CMOS Sensor
Exmor shortens the analog path even more by performing A/D conversion on each column of pixels. While all CMOS sensors perform noise cancellation in the analog domain, Exmor also deploys it in the digital domain. Contrast with CCD sensor. See CMOS camera and digital camera.

References in periodicals archive ?
Launched in November 98, the PB-720 uses Photobit's active-pixel sensor technology, a breakthrough solution that combines camera signal processing functions on a single chip.
Image sensors rely on a variety of technologies to perform this, but the majority use an array of CCD (charge-coupled device) or CMOS (complementary-metal oxide semiconductor) sensors such as active-pixel sensors.
85-megapixel sensor for Kodak's new DCS line of professional digital cameras; a 100 x 135 mm sensor for mammography applications that takes up an entire eight-inch wafer and is one of the world's largest sensors; radiation-tolerant sensors for aerospace applications such as star trackers and sun sensors; and active-pixel sensors that combine a true snapshot synchronous shutter with very high readout rates for use in high-speed scientific image analysis.