Re: [CAD_CAM_EDM_DRO] Laser mouse based DRO

Lasers are terrible illumination sources for photography.
Since they are a coherent light source they produce a
speckle pattern on object illuminated. If you want to
use photography you use an incoherent light source like a LED
or an incandescent lamp.

Also photographing with a CCD would be far too expensive
for this application.

Pete.

----- Original Message -----
From: "Matthew Glenn Shaver" <mshaver@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Monday, August 22, 2005 10:20 AM
Subject: Re: [CAD_CAM_EDM_DRO] Laser mouse based DRO


> On Mon, 2005-08-22 at 09:53 -0400, Peter Reilley wrote:
>
>> For our applications it must be highly repeatable.
>
> True. I thought it worked by "photographing" successive images of the
> surface that it was tracking with a ccd image sensor, then detecting
> relative movement by analyzing the shifted position in the images. An
> experiment would be interesting:
>
> Clamp one of these mice to the spindle such that it just clears the
> table of a screw driven slide (like the X axis of a Bridgeport). Zero
> the position (hopefully some existing software could be used, rather
> than having to write something special just for the test), then move
> back & forth randomly. Finally, return to the original position and see
> if the position is still zero.
>
> Or, I could call Agilent & ask them this question ;) .
>
> Matt
>
> P.S. Maybe I'll do that - call Agilent that is...