Optical Encoders

Optical encoders are a type of rotary encoder, sometimes known as an optical shaft encoder. Optical encoders identify positional change using a sensor, as light passes through the encoder disk or wheel. They have four main components: an LED light, a movable disk, an attached (fixed) mask, and the encoder’s sensor. The sensor behind the mask of the optical encoder identifies the current pattern and, as the disk moves, windows in the mask show the movement and position of the optical encoder. The track contains two sensors, offset to emit different signals. These can be used to gather information about speed. Phased-array optical encoders offer even more advanced options. Magnetic encoders work in the same way as an optical encoder but use magnetic fields rather than light. As optical encoders are exceptionally precise, they can be used in any applications where resolution is important. Therefore, office equipment and medical equipment use optical encoders extensively. Phased-array versions are suitable for tougher environments.