Charge-Coupled Device (CCD)

1969

William Boyle
George Smith

“We are the ones who started this profusion of little cameras all over the world.”

William Boyle

Charged Coupled Devices (CCD’s) are a special type of chip that reacts to light. They are inexpensive and especially useful in imagining, enabling digital photography and video.

William Boyle and George Smith worked for Bell Labs. Their research on “Charge Bubble Devices” advanced slowly. Eventually, they were told in a week they’d be reassigned to the more promising memory division.

In 1969, faced with losing their funding and lab, the two brainstormed. In one hour, they outlined the idea which became the CCD, the sensor driving all early digital video and photography. Forty years later their one-hour invention won them the 2009 Nobel Prize.

The device itself is made up of “charge bubbles” — a series of metal-oxide semiconducting capacitors (MOS). Light changes the photons to electrons that are then flushed to a capacitor. Boyd and Smith figured out how to quickly measure each row of MOS light to create still and moving pictures.

MOS, like most imaging, only captures black and white. However, by filtering for red, green, and blue then combining them electronically, the technology produces color images. Cameras typically then combined and enhance the images into smaller and more manageable files, typically a JPEG.

Boyle and Smith’s CCD soon became ubiquitous, famously used to capture and send images from the moon back to earth where other equipment would have been too heavy and bulky.

Other Bell Labs researchers are critical, arguing that Boyle and Smith stumbled upon CCD’s accidentally and did not think up or use the technology for imaging. “They wouldn’t know an imaging device if it stared them in the face,” said Eugene Gordon who, along with Michael Tompsett, applied CCD’s to imaging.

“I can clearly remember the day that George and I developed the concept for the CCD,” answers Boyle. “It’s pretty firm in my mind. I’ve documentation that disproves most of what they’re saying, and the rest of what they’re saying is not at all logical.”. Smith simply called them “liars.”

CCD chips made for early video equipment and digital cameras. However, CMOS chips eventually overtook CCD chips for most imaging solutions. The advantage of CMOS is it reads directly from the chip, rather than reading line by line, making it faster and ultimately less expensive.