CMOS Image Sensor

The chip inside a camera that turns light into a digital image, with amplification built into every pixel — the dominant sensor today.

A CMOS image sensor is an active-pixel sensor built with CMOS manufacturing: each pixel has a photodiode that collects light-generated charge, which a handful of transistors then amplify and read out on the spot (commonly a 4-transistor design). In the early 1990s, Mitsubishi Electric and NASA’s Jet Propulsion Laboratory (Eric Fossum and colleagues) each independently built CMOS active-pixel sensors; they’re cheap, low-power, and can integrate analog-to-digital conversion and image processing on the same chip, and sales overtook CCDs in 2007 — today CMOS is overwhelmingly dominant. Sony is the largest manufacturer. For robotics, the sensor determines a camera’s resolution, frame rate, low-light noise, and dynamic range, as well as its shutter type: most CMOS sensors use a rolling shutter that exposes row by row, which skews the image under fast motion, so VIO and high-speed grasping applications often pick global-shutter models instead.

ExampleWhen picking a wrist camera for a robot arm, check the shutter type, pixel size, and frame rate on the spec sheet; for a fast-moving arm, choose a global-shutter CMOS sensor so object edges in the image don’t come out skewed.

Also called

CIS, Active-Pixel Sensor

Related

RGB Camera · Global Shutter / Rolling Shutter · Image Signal Processor · Event Camera · Depth Camera · MIPI CSI-2

Sources

Active-pixel sensor - Wikipedia