An absolute encoder consists of a light source, code disc pivoted in a precision ball bearing and opto-electronic scanning device. The LED is the light source which shines through the code disc onto the screen behind while the tracks on the code disc are evaluated by an opto-array behind the reticle. Each position covers the reticle with dark spots on the code disk and interrupts the light beam on the photo transistor. This transforms the code on the disc into electronic signals with fluctuations in the intensity of the light source measured by additional photo transistor and another electronic circuit covers these. Once the electronic signals are amplified and converted they become available for evaluation.