Optical disk and optical disk drive device

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 connecting 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 of the disk,
• each 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 multiple recognition patterns which are each formed of a sequence of pits, and
• the interval between the recognition patterns in said header portion is varied, said device comprising:
• means for generating a light spot and causing the light spot to scan along the information recording track;
• means for receiving light reflected from the disk;
• means for detecting the amount of reflected light;
• and
• means for matching patterns responsive to said means for detecting the amount of reflected light, for detecting the recognition pattern.