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Takehisa ISHIDA Osamu MORITA Makoto NODA Satoru SEKO Shoji TANAKA Hideaki ISHIOKA
Embossed disks with discrete magnetic tracks and servo marks are proposed 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 µm. Using the disks, the head positioning accuracy of 0.09µm (rms) and the recording density of 192 tracks per millimeter were demonstrated.
Hiroaki YADA Takamichi YAMAKOSHI Noriyuki YAMAMOTO Murat ERKOCEVIC Nobuhiro HAYASHI
A novel external clocking magnetic disk recording channel is proposed and examined. Timing not only for data recovery but for recording is given by a bit clock which is synchronized with dedicated clock marks on patterned discrete track media. Jitter of the bit clock is 2.5 ns (rms), which is good enough for data rates up to about 20 Mbit/s. Using an MR/Inductive head and PRML (Partial Response Maximum Likelihood) signal processing, an error rate of 110-6 is obtained at linear density 3146 bit/mm.