Method for detecting and compensating disk tilt and apparatus used it

摘要

This invention relates to a method for detecting and compensating the disk tilt of an optical disk and an apparatus using it. The disk tilt causes the coma which degrades the carrier-to-signal ratio of a pickup. To reduce the coma induced by the disk tilt of an optical disk, the pickup of the present invention adapts a two-dimension (2-D) grating to produce a plurality of laser beams for detecting the disk tilt in the radial and tangential direction of the optical disk. In addition, according to the radial and tangential tilts of the disk, an actuation device adjusts a reflection angle of a reflective mean to change the incident angles of the laser beams for the compensation of the coma induced by the disk tilt of the optical disk.