October 6th, 2009 ! What a great day for the solid-state imaging community ! The Nobel Prize Physics goes to Willard Boyle and George Smith, two Bell Labs co-workers who invented the Charge-Coupled Device (CCD) ! In one of my first blogs I addressed the year 1969 when so many great things happened. Although W. Boyle and G. Smith published their first CCD paper in 1970, probably they did most of the invention work in 1969. With the announcement of the Nobel Prize Winners, it makes 1969 even greater than it ever was.
Let me first congratulate W. Boyle and G. Smith for receiving the greatest award one can get for his/her work : the Nobel Prize.
I am wondering whether they ever realized that their invention would have such a great impact :
- on the society : these days everyone has a digital still camera, many have a camcorder all provided with a CCD, some even with three CCDs. All TV images we see today are being captured by means of CCD cameras, many medical diagnoses are relying on CCD images as well. Other application fields are security, astronomy and scientific cameras. In many applications these days CCDs are being challenged by CMOS image sensors, but it can easily be understood and I think that everyone agrees that CCDs paved the way in solid-state imaging, for CMOS as well,
- on the semiconductor business : several companies (mainly based in Japan) made quite a profitable consumer business out of CCDs : examples were/are Sony, Panasonic, Sharp, Toshiba, NEC, FujiFilm. Non-Japanese companies working in the CCD field were/are Kodak, Philips, E2V, Fairchild, DALSA, LG, Thomson, Sarnoff, SITe, Ford Aerospace, … (sorry if I forget some),
- on the imaging technology : after the introduction of the CCDs, the classical imaging tube quickly disappeared from the scene. CCDs were more compact, lighter in weight, less power hungry, lower supply voltage, no burn-in effects, no image lag, no maintenance and immune to electro-magnetic fields. CCDs only had advantages over the imaging tubes, even their price was lower. The CCDs opened a great new field of imaging applications that were never possible without solid-state image sensors,
- on scientific and technical community : the basic CCD invention of Boyle and Smith was a great inspiration for many other great engineers : Walden invented the buried channel CCD, Esser invented the peristaltic CCD, Kosonocky was the one who invented the floating diffusion and White added the correlated-double sampling. But I think that the CCD performance improved quite a lot after the introduction of the pinned-photodiode by Teranishi. From that moment, the CCD business really started to boom. I do realize that I forget many important other inventions, but they were all inspired by the one of W. Boyle and G. Smith.
Although I never met Willard Boyle and/or George Smith, personally I have to thank them as well. Purely by coincidence I came into contact with CCDs in 1976 when I was looking after a subject for my Master thesis. A young Ph.D. student at the University explained to me the basic working principle of the CCDs. I was immediately attracted by the mix of digital pulses and analog CCD signals and especially by the possible applications foreseen for the CCDs (the early applications were mainly based on the analog memory capabilities of a CCD). Later I realized that CCDs are very complex devices and do need a lot of basic semiconductor device physics to understand all aspects of their working concept. After I obtained my Master degree I continued to work on CCDs for my Ph.D. project. At that time I tried to replace the light-absorbing poly-silicon gates by means of transparent conductive indium-tin-oxide. When I finished my Ph.D. studies, I joined Philips and during the recruitment interview, one of the interviewers told me it would be better for my career to switch to another topic than CCD imaging. Strange but true, the same person hired me to work on … (as you can guess) CCDs and even today after so many years, I am still involved in the same topic, being solid-state imaging.
Thank you very much Willard and George for the great invention you did, it completely changed my personal life as well as the one of many others. Solid-state imaging is a great field to work in, and it is a great, rewarding feeling that the Nobel Prize Physics goes to the two people who created the fundaments of it !
Thanks Willard, Thanks George and Many Congratulations !
October 6th, 2009.