| 摘要 |
<p>A system controller (30) discriminates the kinds of a plurality of optical disks (D) having different numbers of signal recording layers based on a focus error signal generated by means of an RF block (21) from the output of a servo processor (31), which is outputted when the processor detects the reflected light of laser light from the signal surface of the disk (D), at the time of focusing the laser light on the signal surface of the disc (D) by displacing an objective lens in the direction of optical axis, while the signal surface of the disk (D) is irradiated with the laser light through the objective lens and sets the operation mode of the disks (D) in accordance with the kinds of the disks (D).</p> |
