Patent ID: 6236637
Filing Date: 2001-05-22
Classification: G11B

Abstract:
An optical disk drive device using an optical disk having information recording tracks formed of land and groove tracks arranged in a land/groove single-spiral configuration in which each land track is connected to adjacent groove tracks at connection points which occur each revolution so that land and groove tracks alternate every revolution to form a continuous spiral,said disk being divided into a plurality of annular zones, each revolution of said information recording track belonging to one of the zones depending on the position of the revolution in the radial direction,each revolution of the information recording track being divided into a plurality of sectors of a unit length of information recording in a scanning direction,said disk having a header portion at the head of each sector,said header portion including a recognition pattern which is formed of a sequence of pits having a pattern which is not used as a pattern for data or address in the information recording part,said header portion for each sector having a plurality of sub-headers, including an address sub-header, and first and second recognition patterns,the first recognition pattern being shifted in one radial direction by half a track pitch with respect to the center of the track of the sector and the second recognition pattern being shifted in the other radial direction by half a track pitch with respect to the center of the track of the sector,said device comprising:means for generating a light spot and causing the light spot to scan along the track,means for receiving light reflected from the disk;means for detecting the amount of reflected light; andmeans for matching patterns responsive to said means for detecting the amount of reflected light, for detecting the recognition pattern.