GPI's Line of Small, High Resolution Encoders
Product Announcement from Gurley Precision Instruments
Only 0.75" dia x 0.9" long, the R119 is available with a 3-mm diameter shaft, or as a blind hollow-shaft encoder with flexible tether mount. This thumb-sized optical encoder generates quadrature square waves at up to 10,000 cycles per revolution (40,000 counts/rev after user's quadrature decode) plus a once-per-rev index signal. Output device is an RS-422 differential line driver. Also check out out Model R112 if these dimensions do not fit your specifications.
Gurley Precision Instruments is an ISO9001-Certified company that offers rotary and linear optical encoders, as well as related accessories.