DISTRIBUTION OF CLOCK INDICIA FOR A QUASI-CONSTANT LINEAR-VELOCITY DISK

摘要

A disk (10) (magnetic, magneto-optical or optical) includes tracks (10) carrying information with pre-stored cues, preferably sync blocks (30) evenly distributed along each track for phase locking a write clock (55) so as to subsequently write user data between the sync blocks in the presence of random fluctuations in the velocity of the disc. The tracks are grouped into a plurality of annular zones (16) encircling the center of the disk, the ratio of the inner radius (or outer radius) of a given area and the corresponding radius of the adjacent inner zone is a rational number, n / d, which is the same for each adjacent pair of zones. Each track in a given zone, i, has a fixed number of radially aligned sync blocks, Pi, calculated from the écuation Pi = (n / d) i-1) x (d) N-1 where i is 1 for the innermost and is N to the outermost area area.