From: ken Watson (watsok@frii.com)
Date: 09/12/00-05:20:25 PM Z
Sil,
RCA patented the first CCD device. It was used as memory as I remember.
maybe 1k bits worth. This then passed to G.E. when they bought them and
maybe now KODAK bought this from GE.
Actually a CMOS sensor is not as good as a CCD. It's noise level is in
inherently higher. The big advantage cmos brings is power and almost every
other semiconductor device is cmos today. It also requires only one power
supply. CCD's almost always require two.
Sorry for being imprecise about the CCD vs CMOS sensor in my prior post. But
I did read recently about the restriction on export of large sensors out of
Japan and national security was given as the reason.
..-----Original Message-----
..From: Sil Horwitz [mailto:silh@earthlink.net]
..Sent: Tuesday, September 12, 2000 4:59 PM
..To: alt-photo-process-l@skyway.usask.ca
..Subject: RE: Advances in CCD to go with Canon
..
..
..At 2000/09/12 01:38 PM -0500, you wrote:
..>I believe Japan is forbidden to sell a CCD sensor in excess of 4M pixels,
..>national security issue. I have heard that KODAK has a 5 Million pixel
..>design that they are putting on the merchant market and for internal use.
..>These are the largest sensors I have read about lately.
..
..Spoke with a Kodak rep at the recent PSA Conference, and he
..explained that
..Kodak owns the CCD patents and licenses all other makers. I don't
..think the
..size problem is a "national security" issue, but Kodak's . The new sensor
..is CMOS, and uses a different principle than CCD (CMOS is
..transistor-related; CCD is a Charge Coupled Device which has limitations
..and is expensive to fabricate). From what I understand (the rep wasn't
..clear on this) the CMOS sensor has almost limitless resolution, but is
..slower than the CCD. We're all to hear lots more on this before long.
..
..Hard to keep up, isn't it? So why doesn't someone invent (or dig up some
..old ideas that couldn't be used as the technology wasn't previously
..available) a simple method for creating UV+ in exactly the light
..frequencies needed for alternative processes? It can be done, but no one
..has yet figured out how, as far as I know.
..
..
..Sil Horwitz, FPSA
..Technical Editor, PSA Journal
..teched@psa-photo.org
..silh@earthlink.net
..Visit http://www.psa-photo.org/
..Personal page: http://home.earthlink.net/~silh/
..
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