Path: utzoo!attcan!uunet!cs.utexas.edu!mailrus!bbn!eddie!mit-amt!mit-caf!fritz
From: fritz@mit-caf.MIT.EDU (Frederick Herrmann)
Newsgroups: sci.electronics
Subject: Re: Batty monitors and cheap video
Message-ID: <3254@mit-caf.MIT.EDU>
Date: 30 Sep 89 21:15:33 GMT
References: <1989Sep28.122217.26867@watcsc.waterloo.edu> <57732@psuecl.bitnet>
Reply-To: fritz@mit-caf.UUCP (Frederick Herrmann)
Distribution: sci.electronics
Organization: Microsystems Technology Laboratories, MIT
Lines: 26

In article <57732@psuecl.bitnet> peg@psuecl.bitnet writes:
>> First of all, take a 4kX1 bit DRAM and somehow expose the silicon. \
>
>Do you have a clean room handy? :-)

As a matter of fact, there are a couple of dandy ones in my building.
But the easy way is to buy parts in windowed packages.

>> To use the thing as a camera, just charge up the thing to all 1's, \
>> wait for a 
>> bit, and then check which bits are discharged by the ambient light.
>
>Well, this actually works, in a manner of speaking.  The devices are called
>CCD's, charged coupled devices, and are used for picture tubes in most

Let's be careful with terminology here.  You don't need CCDs to build
an IC imager, as the `RAMera' demonstrates.  A CCD is a kind of
`analog shift register' which moves packets of charge between the
the channels of adjacent MOSFETs.  In the IC `picture tubes' you mention,
CCD are used to shift out the contents of the image sensor array in
a serial format for video output.

I think Ciarcia had a RAMera-like project in Byte a few years back.


				- Fritz
				  fritz@caf.mit.edu