What is the role of the code disk in optical encoders?

The code disk is a crucial component in optical encoders, responsible for encoding positional data. It is a circular disk with alternating transparent and opaque sections. As the disk rotates with the motion of the encoder’s shaft, it interrupts a beam of light emitted from an LED, generating pulses as it passes through. These light pulses are then detected by a photodetector, which converts them into electrical signals. The pattern on the code disk determines whether the encoder functions as an incremental or absolute encoder, with the latter using unique patterns for each position. The precision and accuracy of the encoder are largely determined by the quality and design of the code disk.