Staas & Halsey
Circuit for fetching (1-7) run-length-limited coded write data
 In writing (1-7) RLL coded write data into a magnetic disk, a write data fetching circuit wherein a clock signal of a frequency three times a fundamental frequency of a write clock signal is generated based on a signal from a servo head of the magnetic disk, three clock signals are generated from the clock signal, one of the three clock signals and the write clock signal are synchronized, and the write data output in accordance with the write clock signal is subjected to (1-7) RLL encoding using a clock signal synchronized with one of the three clock signals, whereby stable (1-7) RLL encoding is made possible without the use of a precise clock signal with a 50 percent duty ratio. 
Fujitsu Limited
H
H03M
inventional
Fumiaki Hiroyuki Masahiro
Nagakura Mase Nishimura