Patent ID: 8139449
Filing Date: 2012-03-20
Classification: G11B

Abstract:
1. A method of eliminating errors in a seek operation on a recording medium, comprising: moving a reading device to a position that corresponds to or is within a predetermined number of tracks of a target location on a recording medium; checking whether or not an authorization signal is output for the position to which the reading device has been moved, the authorization signal being output when a frame synchronization signal has been detected from an output signal of the reading device consecutively a predetermined number of times; and extending a variable frequency range of a synchronization clock of a phase-locked loop (PLL) circuit when the authorization signal is not output, the synchronization clock being phase-synchronized to the output signal of the reading device, wherein the output signal is an eight-to-fourteen modulation (EFM) signal derived from an radio frequency (RF) circuit coupled to the reading device, wherein the authorization signal is not output when the synchronization clock of the PLL circuit is not synchronized to the EFM signal, wherein extending the variable frequency range of the synchronization clock is caused by increasing a gain of a phase detector in the PLL circuit, and wherein the gain of the phase detector is reset to an initial value when the authorization signal is output and a number of tracks to be moved is zero.