US 6,982,940 B1
Method and apparatus for recording and/or reproducing information to arbitrarily set frequency conversion multiplying factor
Hidehiko Kando, Matsudo (Japan); Hiroyuki Minemura, Kokubunji (Japan); and Hirofumi Sukeda, Tokorozawa (Japan)
Assigned to Hitachi, Ltd., Tokyo (Japan)
Filed on May 25, 2000, as Appl. No. 9/578,387.
Claims priority of application No. 11-145969 (JP), filed on May 26, 1999.
Int. Cl. G11B 7/00 (2006.01)
U.S. Cl. 369—47.54 7 Claims
OG exemplary drawing
 
6. An information reproducing method comprising the steps of:
irradiating a recording track on a recording medium with an energy beam;
detecting an intensity of an energy beam reflected or transmitted by said recording medium, out of said energy beam with which said recording medium is irradiated;
reproducing information recorded on said recording medium, from an intensity signal of said reflected or transmitted energy beam, the recording track being wobbling or deforming with a predetermined period;
generating a reproducing clock from a signal obtained by detecting the wobble or deformation of said recording track;
discriminating reproduced data by taking said reproducing clock as a reference;
detecting pre-recorded information including data for determining different kinds of recording mark arrangements of control data on said recording medium; and
setting a conversion multiplying factor between a period of the signal obtained by detecting said wobble or deformation and a period of said reproducing clock, based on said pre-recorded information of control data detected by said detecting step.