OPTICAL DISK AND OPTICAL DISK DRIVE

摘要

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 0.63lambda/n depth of the pits when the wavelength of a laser beam is defined as lambdaand 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.