Patent ID: 8873358

Claim:
A skew detection method comprising: in a signal processing device: acquiring a main reproduction signal, a first reproduction signal and a second reproduction signal simultaneously from a main track, and a first adjacent track and a second adjacent track located on each side of the main track, respectively; delaying the main reproduction signal based on main coefficients of a main filter associated with the main track and second coefficients of a second filter associated with the second adjacent track; combining a first output signal of a first filter associated with the first adjacent track and second output signal of the second filter with the delayed main reproduction signal to generate an output signal without crosstalk; determining an error based on comparison between the output signal with a predetermined target value; controlling first coefficients of the first filter and the second coefficients of the second filter based on the determined error; and detecting a skew of an optical disc from values of the first coefficients and the second coefficients.