Patent ID: 7813231
Filing Date: 2010-10-12
Classification: G11B

Abstract:
1. An optical disc drive apparatus comprising: a pickup recording and reproducing data to and from an optical disc having a single spiral structure where lands and grooves are arranged alternately every rotation of the optical disc and are connected together at polarity switching locations; a rotation angle counter a high-frequency signal processor performing predetermined high-frequency analog processing on a sensed-light signal read out from the optical disc; a switching sector detector detecting the polarity switching locations based on an output signal of the high-frequency signal processor in order to clear, or load with a predetermined value, the rotation angle counter; a switching window signal generator generating a switching window signal having a predetermined time width based on the count value of the rotation angle counter; a timing signal generator generating a timing signal for each sector based on the output signal of the high-frequency signal processor; and a polarity switching signal generator generating a land/groove polarity switching signal based on the switching window signal and the timing signal.