Rotary encoder

This article is a stub. You can help Deskthority by expanding it.

In computer input terms, a rotary encoder is a device which measures the rotation of a roller or wheel so that the host device may relay this back to the computer.

The best-known implementation is that of a finely-spoked wheel flanked by a pair of LEDs and photo-diodes. Through this arrangement, the electronics detect the rotation of the wheel as the flanges alternatively cut the light beams. This is the standard implementation of the axis rollers in opto-mechanical pointing devices.

Gallery

• 
  Side view of volume control encoder
• 
  Opto-mechanical rotary encoder in a computer mouse
• 
  Alps electromechanical rotary encoder in a Key Tronic Professional Series Mouse