US Patent 7983119 Optical disc apparatus

An optical disc apparatus reliably executes a seek operation even if an optical disc is warped. Tilt adjustment values spanning from the inner circumference to the outer circumference of an optical disc are stored. When seeking from a start address to a destination address, a tilt adjustment value A at the start address and a tilt adjustment address C at the destination address are not directly used. A tilt adjustment value k·C (k<1) is used during a coarse seek operation until the neighborhood of the destination address and a tilt adjustment value C is used during a fine seek operation from the neighborhood of the destination address to the destination address.