Patent ID: 7570552

Claim:
An optical disk apparatus for recording data on a recordable type optical disk utilizing a pattern of emission of a laser, said optical disk apparatus comprising: an objective lens that focuses laser light on the optical disk; a focus control unit that changes tilt value of the objective lens in the radial direction of the optical disk; and a reflected light measurement unit that measures a plurality of values of light quantity reflected on the optical disk, the plurality of values respectively corresponding to a plurality of the tilt values, wherein the focus control unit corrects the tilt value of the objective lens by setting the tilt of the objective lens to a tilt value corresponding to the smallest value of the light quantity measured by the reflected light measurement unit, wherein a process of tilting the objective lens so as to make the optical axis of the laser substantially perpendicular to the optical disk and a process of making the distance between the optical disk and the objective lens substantially equal to the focal length during recording are performed only in a data recording area of the optical disk by referring to a table for storing information on whether to permit or inhibit the process of tilting the objective lens relative to a position of the optical disk in the radial direction thereof so as to make the optical axis of the laser substantially perpendicular to the optical disk.