Tracking servo device for optical storage disk using optical deflector element for adjusting beam spot on the disk

摘要

A tracking servo device for changing a position on an optical storage disk, at which the storage disk is irradiated by a light beam. The servo device is responsive to a tracking error signal indicative of a deviation of the irradiated position on the disk with respect to a recording track provided on the disk. The tracking servo device includes an optical deflector element having a waveguide disposed in a path of the light beam, for guiding the light beam therethrough toward a surface of the optical storage disk, so as to deflect the light beam during propagation thereof through the waveguide. The device further has a deflection control arrangement for controlling an angle of deflection of the light beam by the optical deflector element, based on the tracking error signal.