“People told me, ‘You’re an idiot to work on this,’” Eric Fossum recalls of his early experiments with an alternate form of digital image sensor at NASA’s Jet Propulsion Laboratory (JPL).
His invention of the complementary metal oxide semiconductor (CMOS) image sensor would go on to become NASA’s single most ubiquitous spinoff technology, dominating the digital imaging industries and enabling cell phone cameras, high-definition video, and social media as we know it.
By the early 1990s, sensors based on the charge-coupled device (CCD), had enabled high-quality digital photography, but Fossum believed he could make imagers with smaller and lighter machinery using CMOS technology to create what he called active pixel sensors. It had been tried before, but CMOS technology had since improved, and Fossum and his team figured out how to eliminate visual noise that had stymied earlier attempts.
Using CMOS sensors, they were able to produce images using lower voltages and charge transfer efficiencies than CCD imagers required, and almost all the other camera electronics could be integrated onto the computer chip with the pixel array, a development that would make CMOS imagers more compact, reliable, and inexpensive.
With a license from the California Institute of Technology, which manages JPL, in 1995 Fossum and colleagues founded a company, which they later sold, to develop the technology.
In the end, it was the cell phone camera, which needed to be small and energy-efficient, that drove the widespread mass production of CMOS image sensors. Resulting improvements to the technology and its manufacture drove costs down and quality up until CCD-based devices couldn’t compete.
CMOS imagers have enabled small, high-definition video cameras, including the popular body-mountable action cameras marketed by San Mateo, California-based GoPro.
By 2015, the technology’s market, which also includes the automotive, surveillance, and medical industries, reached nearly $10 billion.