DISK-SHAPED RECORDING MEDIUM, OPTICAL SPOT POSITION CONTROL DEVICE, AND OPTICAL SPOT POSITION CONTROL METHOD

摘要

In a case of performing recording/playing with an information recording layer with a first light irradiation, and controlling the recording/playing positions on the information recording layer by a second light irradiating as to a position control information recording layer provided separately from the information recording layer, corrections to shifts in recording positions and playing positions that occurs as a result of shifts in the optical axes of the first and second lights.;A disc-shaped recording medium has multiple pit row phases wherein, the pit rows having a spacing between one round of pit formable positions that is limited to a predetermined first spacing are formed in a spiral shape or concentrically, and with pit rows arrayed in the radius direction, the spacing in the pit row forming direction of the pit formable positions is set to positions shifted by a predetermined second spacing. Therefore multiple pit rows can be arrayed in within the width of one conventional track, and a tracking servo can be used for the selected pit rows in accordance with the correction amount of the playing position, in which case corrections can be made with high precision that is narrower than one track width.