Patent ID: 6975574

Claim:
A tilt servo control device of an information recording/reproducing apparatus for recording information on and reproducing information from an optical recording medium set into said apparatus, said apparatus comprising an optical system for leading a laser beam emitted from a light source to a recording surface of the optical recording medium and a laser beam reflected by the recording surface of the recording medium to a photo detector and a read signal generator for generating a read signal in accordance with an output signal of the photo detector, said device comprising: a recording medium type determining device for determining a type of said optical recording medium; a tilt drive signal generator for generating a tilt drive signal so as to reduce a tilt angle between a normal to the recording surface of said optical recording medium at a position of said laser beam irradiating said recording surface and an optical axis of said laser beam by a method for generating a tilt drive signal corresponding to the type determined by said recording medium type determining device; a tilt angle adjuster for adjusting said tilt angle; and a driver for driving said tilt angle adjuster in accordance with said tilt drive signal, wherein said tilt angle adjuster includes a liquid crystal panel having a plurality of regions arranged in said optical system, and said driver drives each of said plurality of regions of said liquid crystal panel in accordance with said tilt drive signal so that the tilt angle is optimized when said laser beam is irradiated into either a pre-write section or an embossed section of the optical recording medium.