Optical disk apparatus and method of tilt control

An optical disk apparatus comprising:

• an objective lens that condenses light on an information recording layer of an optical disk which has a first area with a first track pitch and a second area with a second track pitch different from the first track pitch, to form an optical spot;
• a tilt driver that inclines the objective lens;
• a positioning unit that positions the optical spot on a target track;
• a position error detector that detects a position error of the optical spot from the target track to which the positioning unit positions the optical spot;
• a tilt detection correcting unit that calculates a tilt error signal based on a first position error detected by the position error detector when the optical spot is positioned on a target track in the first area and a second position error detected by the position error detector when the optical spot is positioned on a target track in the second area;
• and
• a tilt controller that controls the tilt driver based on the tilt error signal calculated by the tilt detection correcting unit.