T. Ishida et al., DISCRETE-TRACK MAGNETIC DISK USING EMBOSSED SUBSTRATE, IEICE transactions on fundamentals of electronics, communications and computer science, E76A(7), 1993, pp. 1161-1163
Embossed disks with discrete magnetic tracks and servo marks are propo
sed and evaluated. The tracks and the servo marks are made by etching
the glass substrate. The guard band depth was decided to be 0.2 mum. U
sing the disks, the head positioning accuracy of 0.09 mum (rms) and th
e recording density of 192 tracks per millimeter were demonstrated.