System for creating, reading and writing on rotatable information storage media, an apparatus for controlling laser positioning

摘要

An apparatus for controlling the positioning of a laser light source for reading and writing information on a form of recording blank with reference tracks utilizes the edges of the reference tracks. A laser source has its beam split in two parts. A first of these beams is used for writing, while the second of these beams is directed to a track edge across which it is moved in an oscillatory fashion by a mirror. The light reflected from the track is converted into an electrical signal which is analyzed to provide an indication of the position of the laser light source with respect to the track edge used.