Patent ID: 7038987
Filing Date: 2006-05-02
Classification: G11B,H03L

Abstract:
1. An optical disc device comprising: a first wobble cycle counter for receiving a wobble reference signal that is synchronized with a wobble signal obtained from wobbles on tracks of an optical disc, and a clock of a constant cycle, and counting the cycle of the wobble reference signal with the constant-cycle clock; a second wobble cycle counter for receiving the wobble reference signals, and a data sync clock that is synchronized with data obtained from the optical disc, and counting the cycle of the wobble reference signal with the data sync clock; a comparator for deriving a difference between a count value outputted from the first wobble cycle counter and a count value outputted from the second wobble cycle counter; and a comparison result judgement unit for judging whether the difference of the count values obtained by the comparator is within a range of preset values or not, and outputting a judgement result indicating whether the data sync clock fluctuates or not.