CDM 9

The CDM9 is a “swing arm”-type CD-mechanism with one stage radial balanced tracking actuator. The CDM9 is equipped with an integrated lightpath called: LDGU (Laser Detector Grating Unit). This LDGU reduces the number of optical components dramatically. The LDGU consists of a semiconductor laser including a monitor diode, a detector diode system and a grating which both separates the trans- mitted light beam and the reflected one and dissects the reflected beam into the two halves from which the tracking and focus error signals are generated towards the two pairs of detector diodes.

The only external optical components are the collimator lens and the objective lens. The CD-mechanism has a radial and focus electro- magnetic motor in order to keep follow the track and to stay focused on the information layer of the disc. The discmotor is an general used DC-motor with apermanent magnet system.