Recording and reproduction apparatus for optical discs

摘要

The apparatus includes a laser diode (1) which is used together with a photodiode (5) that monitors light intensity. The signal of the photodiode is fed back to an active element (2) that provides a regulating signal output to control the current supplied to the laser diode. A reference level is set by an evaluation unit (7) whose output is coupled to the active element. A receiver diode (8) provides inputs to the evaluation unit and responds to reflected signals from the disc.