Patent ID: 6081487
Filing Date: 2000-06-27
Classification: G11B

Abstract:
An apparatus for controlling positioning of a laser for writing information on a rotatable disk which has at least one set of substantially parallel embedded tracks between which information is writable by laser means, said apparatus comprising:a source of laser radiation;laser beam splitting means for receiving said laser radiation and for producing therefrom a first laser beam for writing and a second laser beam for tracking;mirror means for directing said second laser beam towards said disk in a direction substantially parallel to said first beam and at a fixed distance from said first beam;means for oscillatorily moving said second laser beam in a direction back and forth across an edge of one of said tracks;means for converting laser radiation from said second beam which has been reflected from said disk to a digital electrical signal to provide a position indication of said second beam with respect to said track; andmeans for moving said laser source in response to said position indication.