Four engineers and IEEE Fellows credited with major innovations in image sensors have won the £1 million Queen Elizabeth Prize for Engineering. Nobel Prize winner George E. Smith and Michael F. Tompsett won for the charge coupled device (CCD) imager, sharing the prize with Nobukazu Teranishi who improved on the CCD by inventing the pinned photodiode and with Eric R. Fossum who invented the CMOS imager, the technology that succeeded the CCD in most applications and allowed for the proliferation of cameras in smartphones and other mobile devices.
In a CCD, each pixel is a potential well. Light falling on the pixel converts to charge by the photoelectric effect. The charge accumulates in the well and is then pushed from well to well until it reaches circuitry that measures the amount of charge and produces a digital representation of it.
The award must be particularly sweet for Tompsett, who missed out on the 2009 Nobel Prize for the CCD imager. At the time of the invention in 1969, Smith was Tompsett’s boss at Bell Laboratories. Smith and the late Willard Boyle came up with the CCD while trying to invent a new kind of memory. Smith has said the invention’s application in imaging was immediately obvious, but it was Tompsett who actually made it happen.