What is meant by “artwork side of encoder disk?
The thick side of the optical encoder module is the emitter (the light source) and the thin side is the detector. The encoder disk is a piece of .007″ thick Mylar photographic film with the emulsion pattern developed on one side. The detector (the thin side of the module) sees a slightly cleaner, sharper image when the emulsion side is closest to it. The US Digital EM1 module uses a nonsymmetrical index code. The index channel will only work when the disk is not upside down. A code wheel consists of a disk and a hub. The code wheel cannot normally be installed upside down because it only fits into the encoder housing one way. However, when bare disks (disks without a hub) are purchased, instructions are included that specify which side is up.
