PURPOSE: To provide an optical disk and an optical disk drive with which tracking stable even to a system for recording data in the form of pits with edge positions as information is possible.
CONSTITUTION: The recording surface of the optical disk 1 having 0.28 to 0.63λ/n depth of the pits when the wavelength of a laser beam is defined as λand the refractive index of a substrate as n is irradiated with a laser beam which is linearly polarized light having a polarization direction in a direction parallel with the guide grooves of the optical disk to record and reproduce the optical disk 1. The reflected light from this optical disk 1 is detected by a bisection detector 25 and the signals emitted from the respective photodetectors of this bisection detector 25 are subjected to peak detection in a peak hold circuit 26. The optical disk drive is so constituted as to apply tracking servo by the value of a difference between signal quantities after the peak defect or the value obtd. by dividing the difference between these signal quantities by the sum of the signal quantities.
SAKAMOTO NOBORU
OTOTAKE MASABUMI
