Microfiche scanning

[John Foust]

At 07:21 PM 4/21/2005, you wrote:
>You could just remove the fiche viewer screen.  You don't need the
>screen to form the image, you only need the (virtual) image from the
>viewer's lens system to be focussed in the same plane as the scanner's
>optics.  Actually, since the image is usually focussed on the back
>surface of the viewer screen, you'd want to remove it anyway.

Pointing the scanner at the plane in space that happens to be the 
viewing plane of the fiche viewer isn't going to result in an image.
The scanner wants to see reflected light.  Focusing the fiche 
projection at the scanner's sensor is a different sort of problem 
that would involve changing the scanner's optics, no?

> Similarly, you don't need to remove the scanner's lamp, except perhaps
>to eliminate stray reflections that would cause glare and reduce
>contrast.  You would just disconnect its power if that were the
>requirement.

In an ideal world, you'd want be able to use off-the-shelf scanner
software.  Driving the scanner's electronics on your own might
allow you to bypass its checks for the lamp operation.

- John