Apparatus method for detecting tilt at inner and outer circumference and determining tilt degree based on times when focus error signals are detected

摘要

An apparatus and method for detecting a tilted disc, and an apparatus and method for reproducing data from the tilted disc are provided. The method for detecting a tilted disc comprises: radiating light on a predetermined location at the inner circumference of an optical disc and moving a pickup away from the optical disc; measuring a time T1 at which a focus error signal, generated when light is reflected from a recording layer of the optical disc, is output; radiating light on a predetermined location at the outer circumference of the optical disc and moving the pickup unit away from the optical disc; measuring a time T2 when a focus error signal, generated when light is reflected from the recording layer of the optical disc, is output; determining a tilt degree indicating value T which is a value for determining whether the optical disc is a tilted disc, using the measured times T1 and T2; and comparing the tilt degree indicating value T with a predetermined reference value R and determining whether the optical disc is a tilted disc.