| 摘要 |
PROBLEM TO BE SOLVED: To make possible a stable tracking servo by starting irradiation of coloring light for a mask layer after tracking control on a prescribed track is started. SOLUTION: Reproducing light and beam light for the tracking servo reflected by a super resolution medium 16 are sent to a photodetector 20 through various optical systems. At this time, a focus servo signal, a tracking servo signal and a reproducing signal are detected. The focus servo signal and the tracking servo signal are sent to a device driving an objective lens 15, and the focus servo and the tracking servo are performed. A coloring light source 17 and a coloring light controlling shutter 18 are controlled by a coloring light source drive system 19, and an error signal from a tracking servo system in a detector 20 is sent to the drive system 19. Thus, the control is performed so that a medium 16 isn't irradiated by the coloring light when the tracking servo is in an OFF state. That is, the irradiation of the coloring light is started after the tracking servo control is started. |
