The Light-Based Technologies Inside Your Favorite Digital Camera

IEEE – The Institute

August 10, 2015

By Kathy Pretz

This year marks the IEEE Photonics Society’s 50th anniversary as well as the International Year of Light and Light-Based Technologies. Here, we present some of the members who developed technologies that manipulated light to advance photography and medicine.

Cameras have become part of almost everyone’s culture. They are one of the world’s most popular consumer devices, and the images they produce surround us every day. They all rely on light—not only the external light sources used to enhance images but also the silicon semiconductors in cameras that sense light and produce pictures. Three IEEE Fellows ushered in some of the most transformative developments in photography. ...

... CAMERA ON A CHIP

It was in the 1990s while at NASA’s Jet Propulsion Laboratory, in Pasadena, Calif., working to make miniature high-quality cameras to fit into small spacecraft, that IEEE Fellow Eric R. Fossum developed an alternative to CCD. His active pixel sensor or CMOS-APS technology is now just called a CMOS image sensor. This camera-on-a-chip technology is used today in nearly all cellphone cameras, medical devices, surveillance systems, and video recording devices like the GoPro.

Fossum’s CMOS sensor adapted CCD signal processing to put an amplifier on each pixel of the image sensor so as to yield a higher-quality image. CMOS sensors use multiple transistors to amplify and move the charge provided by incoming photons of light, enabling the pixels to be read individually. This method is more energy efficient than CCDs, and the sensors can be manufactured more easily and at a lower cost, leading to less-expensive but higher-quality digital cameras. CMOS sensors have virtually replaced CCDs in today’s cameras.

Fossum was the recipient of the 2009 IEEE Andrew S. Grove Award for his invention.

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