Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!clyde!uunet!mcsun!cernvax!chx400!olsen!iony
From: iony@olsen.UUCP (Ion Yadigaroglu)
Newsgroups: comp.graphics
Subject: Re: digitizing images
Message-ID: <129@tobler.UUCP>
Date: 5 Dec 89 16:25:12 GMT
Reply-To: iony@tobler.UUCP (Ion Yadigaroglu)
Organization: Olsen & Associates, Zurich, Switzerland
Lines: 21

>>    This discussion brings to mind a project I've had for some time
>>    (not in any way started). I was thinking of modifying a CD player
>>    to make a microdensitometer. (...)
>
>Well, it's not this simple.  A CD player has a 2-axis positioning
>system (tracking and focus) that is specially designed to follow
>a spiral pattern of pits on a disc.  All of the signals that
>drive the focus and tracking servos come from that spiral track
>of data.
>

The idea is to keep the disk with its tracking info. While the laser
is over the film, you freeze the positioning and focus system.
Of course you have a little less time for doing both, but it seems
to me the feedback system might be flexible enough to handle this.
The biggest problem is avoiding that the circuits "panic" as they
are designed to handle only small breaks.

Thanx for the comments,

Ion