DRO increased resolution

On 7 Apr, Jon Elson wrote:

> >
> > There may be a space limitation on this hypothetical kluge. I was
> > wondering what happens if you used say 3 of the 360 line strips,
> > mounted them
> > side by side, each 1/3 of a division offset from the previous. I
> > don't have
> > the signaling worked out but could it not give you much finer
> > resolution?
>
> I really doubt this would work. The gratings would have to maintain a
> phase
> shift over the entire length of the encoder, to a small fraction of one
> line pitch.
> That would be VERY hard to do with glass scales, impossible with mylar
> films.

Jon;

I agree you about with the problems of three films, but say a person
wanted to simple double the resolution. Could he not simply add a second
DECODER, 45 degrees removed from the first ? ( Forget the logic
involved - we're assuming the counts are going into a uC )

Alan

--

Alan Rothenbush | The Spartans do not ask the number of the
Academic Computing Services | enemy, only where they are.
Simon Fraser University |
Burnaby, B.C., Canada | Agix of Sparta