Patent ID: 6418105
Filing Date: 2002-07-09
Classification: G11B

Abstract:
An optical disk recording device for recording data onto a write-once optical disk having a track wobbled on the basis of absolute time information, the optical disk recording device comprising: a beam projection section for projecting a light beam onto said optical disk; a photodetector having at least two light receiving surfaces divided in a radial direction of said optical disk for detecting reflected light from said optical disk; and wobble-signal reproduction circuitry for reproducing a wobble signal corresponding to a wobble of the track on the basis of first and second light detection signals output from the two light receiving surfaces of said photodetector, said wobble-signal reproduction circuitry including:first and second peak-holding circuits for, when said optical disk recording device is in a reproduction mode, detecting and holding respective upper envelopes of said first and second light detection signals output from said photodetector; first and second bottom-holding circuits for, when said optical disk recording device is in a recording mode, detecting respective lower envelopes of said first and second light detection signals output from said photodetector; and a subtraction circuit for producing a wobble signal by performing a subtraction between values held by said first and second peak-holding circuits when said optical disk device is in the reproduction mode and performing a subtraction between values held by said first and second bottom-holding circuits when said optical disk device is in the recording mode.