Who patented the first digital imager? Michael F. Tompsett says he did. (Although the signal is only digital after it’s gone through the video analog-to-digital converter chip that he also invented.)
Did Willard Boyle and George Smith invent the charge coupled device? “Their name is on the patent,” says IEEE Fellow and former Bell Labs colleague of the pair of new Nobel Prize Winners,“but all patents are a product of their time and others may have had an input.”
But did they invent “an imaging semiconductor circuit” as the Nobel citation goes? No, he says. “That was me.”
The CCD that Boyle and Smith invented was not for imaging, it was intended as a memory circuit. According to both Tompsett and the United States Patent Office, it was Tompsett who invented the imager that first demonstrated the electronic photography and video in use today. Tompsett is the sole inventor listed on United States Patent Number 4,085,456 “Charge transfer imaging devices.” The patent covers two, subtly different, types of imagers one of which is the CCD imager.
“All the imaging and reduction to practice was me,” says the physicist who in the 1970s ran Bell Labs’ CCD group, which developed TV resolution imagers.
Tompsett had been an imaging guy even before he arrived at Bell Labs. In England he invented an infrared camera tube, which was subsequently developedt, and used by the U.S. and British militaries, fire brigades and search and rescue teams, and won a Queen’s Award in Britain, he says. He also invented another silicon-imager that “never saw the light of day” because it was quickly eclipsed by the CCD. And he also came up with a solid-state thermal imager that’s now been commercialized for night vision.
But imaging isn’t his only important contribution. He also developed a technology that was key to growing the gallium arsenide layers of early LEDs and is still in use today. He invented the first solid-state MOS modem and a video analog-to-digital converter chip that is now manufactured by the millions. He now works on healthcare software as founder of Theramanager, in New Providence, N.J.
“I don’t have to hang my reputation [on the CCD imager]” he says, but “it would be nice to at least share the credit.”
You’d expect this to be a galling time for him. Even the picture he’s confronted with in newspapers and this web site is an affront: a staged photo of Boyle and Smith manipulating a camera in 1974. Neither Nobelist was involved with Bell Labs imaging chip work at the time, and Tompsett himself built the camera they are supposedly working with. He was keen to acknowledge the contributions of Ed Zimany and the rest of his group, particularly Carlo Sequin who joined Bell Labs 9 months after the invention and helped refine the imaging chips. Together, Tompsett and Sequin also wrote the first book on CCDs.
But talking to him the morning of 8 October, he seems more concerned with technical inaccuracy in an IEEE Spectrum article than his place in history. With regard to getting a Nobel Prize he says: “I hadn’t seriously thought about myself.”
“You’re not going to change [who wins] the Nobel,” he says. However, he does believe the citation should be corrected.
Image from Tompsett's CCD patent.
Post modified and updated on October 9, 2009
