Optical disk apparatus for reading and writing data on an optical disk

Abstract

In an optical disk apparatus, an optical head is moved in a radial direction of an optical disk having a track spirally or concentrically formed in a state that a groove and a land are adjacent, and detecting device for detecting reflected light from the optical disk, and a track error signal, which is obtained by detecting light from the optical disk along with the movement of the optical head, and a track addition signal are generated, a signal A showing a central position of a groove, a signal C showing a central position of a land, signals B and D showing a groove-land changing position are generated based on the track error signal and the track addition signal, and a direction of the movement of the optical head is detected in accordance with the generation order of the signal A showing a central position of a groove, the signal C showing a central position of a land, and the signals B and D showing a groove-land changing position. Whereby, the direction of the movement of the optical head with respect to the optical disk can be correctly detected.