WOBBLE SIGNAL DETECTION DEVICE AND INFORMATION RECORDING DEVICE

摘要

PROBLEM TO BE SOLVED: To releive the influence of prepits upon the fluctuation of the amplitude and phase of a wobble signal on a recording medium which has prepits formed on a groove wobbling with a predetermined frequency and a land with predetermined intervals and extract the wobble signal with small phase fluctuation. SOLUTION: A light beam applied to a recording medium 1 which has information recording tracks wobbling with a predetermined frequency and prepits formed in regions between the tracks with predetermined intervals. The reflected light of the applied light beam is detected by a light detecting means which has a structure divided into two in a direction parallel with the information recording track and a wobble signal is detected in accordance with a difference signal between the outputs of the two divided parts of the light detecting means. A prepit suppression unit 30 removes or suppresses a prepit signal component superposed upon the difference signal and a BPF 31 extracts a wobble signal from an output signal whose prepit signal component is removed or suppressed and the extracted wobble signal is binarized by a comparator 32.