Patent ID: 7450483

Claim:
An information carrier apparatus for accessing an information carrier having at least one track formed therein, the information carrier apparatus comprising: a times crossed detection section for detecting the number of times that a head structured to access the information carrier has crossed the track; an eccentricity direction detection section for detecting an eccentricity direction of the information carrier based on the number of times; an eccentricity distance detection section for detecting an eccentricity distance of the information carrier based on the eccentricity direction and the number of times; and an eccentricity correction section for correcting eccentricity of the information carrier based on the eccentricity direction and the eccentricity distance, wherein the eccentricity direction detection section includes: a ramp wave application signal generation section for generating a ramp wave application signal by applying a ramp wave signal to a times crossed relationship signal which represents the relationship between the number of times and a rotation phase of the information carrier; a differential value generation section for generating a plurality of differential values by differentiating a value represented by the ramp wave application signal with the rotation phase; and a differential value comparison section for comparing the plurality of differential values, and wherein the eccentricity direction of the information carrier is detected based on the comparison result of the plurality of differential values.