Working principle:

An incremental encoder is a rotary sensor that converts rotational displacement into a series of digital pulse signals. These pulses are used to control angular displacement. The conversion of angular displacement in the Eltra encoder uses the photoelectric scanning principle. The reading system is based on the rotation of a radial indexing disk (code disk) composed of alternating light-transmitting windows and opaque windows and is vertically illuminated by an infrared light source, which projects the image of the code disk onto the receiver surface. The receiver is covered with a diffraction grating with the same window width as the code disk.