Preformatted guide tracks and co-written control tracks for multichannel optical recording

Abstract

A method for multi-track optical data recording comprising the steps of providing an optical recording medium that includes a plurality of parallel, preformatted guide tracks, with sufficient space between adjacent guide tracks for recording a plurality of data tracks; providing relative motion between the optical recording medium and an optical head in a direction generally parallel to the guide tracks; imaging a guide track onto a detector array disposed relative to the optical recording medium; and generating a first tracking error signal representing the cross-track displacement of the guide track relative to the optical head. The method further comprises driving a closed-loop servo system to reduce the residual tracking runout of the guide track and simultaneously recording a band of data tracks in the unpreformatted space adjacent to the guide track and one or more control tracks parallel to the data tracks.