Modulation system for optical recording

Abstract

In an optical recording system, a media disk for writing information has a plurality of information tracks with preformatted clock location indications written on the tracks. Writing is accomplished by making a written indication at a predetermined location between preformatted clock locations where the predetermined location is representative of the particular data to be written. Proper location of the preformatted clock location indicia on adjacent tracks provides for proper track crossing information when track addressing occurs as well as proper address location on particular tracks.

What is claimed is: 
     
       1. A disk shaped record carrier for optical recording comprised of: a plurality of concentric information tracks each track having a track center line, each track having a plurality of preformatted clock locations prewritten into each of said concentric information tracks at equally spaced intervals,   the record carrier having said preformatted clock locations placed on adjacent concentric information tracks in a predetermined pattern of locations away from the track center line and within a guard band separating tracks to have the concentric tracks present a radial pattern indicative of track crossing patterns as a result of the predetermined pattern of off-center clock locations,   said record carrier being adapted to record information using a selected one or none of a predetermined plurality of possible writing locations between each pair of clock locations, where the particular location between clock locations is representative of two binary data bits. .Iadd.   
     
     
       2.  A disk shaped carrier for optical recording comprised of: a plurality of information tracks, each track having a track center line, each track having in at least one portion thereof a plurality of preformatted locations offset from said track center line in a predetermined pattern, said pattern including at least one preformatted location offset to one side of a track followed by at least one preformated location offset to the other side. .Iaddend. .Iadd.3. The disk shaped carrier of claim 2 wherein said tracks are concentric. .Iaddend. .Iadd.4. The disk shaped carrier of claim 2 wherein said locations lie   
     
     
        within the guard band between tracks. .Iaddend. .Iadd.5.  A disk shaped carrier for optical recording comprised of: a plurality of information tracks, each track having a track center line, each track having in at least one portion thereof a plurality of preformated locations offset from track center in a predetermined pattern which provides tracking information on reading thereof for the tracking   
     
     
        servo. .Iaddend. .Iadd.6.  Apparatus comprising: a disk shaped carrier for optical recording;   a plurality of tracks for recording information on the disk, each track having a track center line on which data locations are recorded in at least a portion thereof; and   a plurality of discrete preformatted offset locations offset from said track center line in a predetermined pattern, the pattern including locations offset to one side of track center alternating with locations offset to the other side, the offset locations placed in a pair of lines parallel to the track center line and offset one each on opposite sides of the track center line. .Iaddend. .Iadd.7. Apparatus according to claim 5 in which data locations are recorded on the track center line only between preformatted offset locations. .Iaddend. .Iadd.8. Apparatus according to claim 7 wherein said preformatted offset locations are located on the disk   
     
     
        in an area separate from any data location. .Iaddend. .Iadd.9.  Apparatus according to claim 7 wherein those preformatted offset locations of adjacent tracks which are offset to the side closest to the adjacent 
     
     
        tracks are placed radially adjacent one another. .Iaddend. .Iadd.10. Apparatus according to claim 5 wherein said preformatted offset locations lie in guard bands between tracks. .Iaddend. .Iadd.11. Apparatus according to claim 6 wherein those preformatted offset locations of adjacent tracks which are offset to the side closest to the adjacent track are placed radially adjacent one another. .Iaddend. .Iadd.12. Apparatus according to claim 5 wherein those preformatted offset locations of adjacent tracks which are offset to the side closest to the adjacent tracks are placed 
     
     
        radially adjacent one another. .Iaddend. .Iadd.13.  Apparatus according to claim 5 in which a plurality of preformatted offset locations offset to one side are followed by a plurality of preformatted locations offset to 
     
     
        the other side of the track center. .Iaddend. .Iadd.14.  A disk shaped carrier for optical recording comprised of: a plurality of tracks, each track having a track center line on which data locations are recorded in at least one portion thereof; and   a plurality of discrete offset locations offset to both sides of the track center line in a predetermined pattern which provides tracking information on the reading thereof. .Iaddend.