Patent ID: 6683830
Filing Date: 2004-01-27
Classification: G11B,H03L,Y10S

Abstract:
An apparatus for detecting a defect in a wobble pattern on an optical medium, the apparatus comprising:a phase-locked loop (PLL) generating phase-locked looped wobble signals and wobble clock signals in response to wobble signals indicative of the wobble pattern; a window signal generator generating wobble window signals indicative of a wobble window period which comprises a window width condition based on the phase-locked looped wobble signals; a wobble lock/unlock detector detecting whether the wobble signals exist during the wobble window period and generating wobble lock/unlock signals setting one of a wobble unlock state when the wobble signals do not exist and satisfy a preset wobble unlock condition and a wobble lock state when the wobble signals do exist and satisfy a preset wobble lock condition; and a wobble defect detector counting the wobble window signals in response to the wobble lock/unlock signals indicating that the wobble signals do not exist during the wobble window period, detecting a wobble defect in response to the counted wobble window signals satisfying a defect decision condition, and outputting a defect detection signal indicative thereof.