encoder head pitch, or, quit your griping.

An encoder head is very simple. Look inside an opto mechanical mouse for an
example. All the parts can easily be put on one circuit board: LED,
detector (quad), op amps, level comparator. A analyzer grating is is placed
above the detector.
Rather than gripe about HP not building what you want, build one yourself.
This has got to be the simplest thing in your CAM system to build.
As an aside, I will mention that I've done consulting work for encoder
manufacturers, in optical design.
You won't have the fancy electronics that the encoder people can build now.
They have integrated multi element detectors with amplifiers, phase decoders
and counters all on one piece of silicon. If you really want something to
lust after, try to get that!

If anyone is interested, we can talk about the Talbot effect.

Mouse electronics count fringes. A serial port mouse sends the position
data to the computer when inquired or when state changes. I wonder if these
could be adapted to DRO's?

Elliot Burke