Master device

A device for producing a master device usable in a method for producing a recording medium, comprising a substantially spirally or concentrically running main track structure and at least one substantially spirally or concentrically running secondary track structure being formed on the master device, the secondary track structure being arranged on at least one side of the main track structure, and the secondary track structure having discontinuities, varying an optically detectable surface texture of the recording medium in such a way that at least one auxiliary information is represented on the recording medium, the device comprising:

• a first optical means for recording a main track structure by means of a first light beam on a base carrier;
• an electrooptical beam deflector through which the first light beam runs;
• a second optical means for recording a secondary track structure by means of a second light beam on the base carrier;
• the second light beam running through a second electrooptical beam deflector which adjusts a substantially constant radial distance between the center of the main track structure and the secondary track structure by means of an applied control signal;
• a secondary track structure generator controlling the second light beam at least depending on a first and/or second auxiliary information;
• at least one measuring camera on which the laser focus of both monochromatic light beams which is adjusted on the master is displayed;
• and
• at least one image processing unit which calculates the position of the laser focus of the main and secondary beams on the master substantially from the image information of at least one measuring camera.