Patent ID: 6396799
Filing Date: 2002-05-28
Classification: G11B

Abstract:
An optical disk drive device using an optical disk having information recording tracks in the form of land and groove tracks, said disk being divided into a plurality of annular zones, each of said land and grove tracks belonging to one of said plurality of annular zones and being divided into a plurality of sectors, said disk having a header portion at the head of each sector and an identification code in each header indicating the zone to which the corresponding header belongs,said device comprising: means for generating a light spot and causing the light spot to scan along tracks of said disk; means for receiving light reflected from the disk; means for reproducing a signal based on the reflected light; means for reading said identification code of a header from the reproduced signal during track crossing, during track access or when a tracking servo of said disk drive device is not operating; and means for controlling the rotational speed of said optical disk on the basis of the result of reading said identification code.