Patent ID: 7590034

Claim:
A reproducing apparatus for use with an optical disk having a first reference signal and a second reference signal which are recorded to deviate from a center of a track in opposite directions and which have the same pattern, the apparatus comprising: a system controller which controls an orientation of the optical disk relative to the reproducing apparatus to read data from the optical disk by determining a first level Ivfo 1 of the first reference signal and a second level Ivfo 3 of the second reference signal from a reproducing signal reproduced from the optical disk, determining a balance value K I according to the following equation: K I =(Ivfo 1 −Ivfo 3 )/(Ivfo 1 +Ivfo 3 ), detecting a servo error based upon the balance value K I , and controlling the orientation of the optical disk relative to reproducing apparatus using the detected servo error, and reproduces the data from the optical disk with respect to which the orientation is being controlled.