| 摘要 |
<p>An optical recording/reproduction device capable of assuring focusing on a recording layer as a target of a single-layer disc and a multi-layer disc. When controlling focusing on the information recording layer as a target in a recording medium, firstly, the spherical aberration correction state is set in accordance with the thickness of the light transmitting protection layer (cover layer) in the target information recording layer. Alternatively, it is set in accordance with the average value of the light transmitting layers (cover layers) of a plurality of information recording layers. A focus search operation is performed by moving the objective lens in the optical axis direction. During this operation, the polarity of the focusing control error signal and the level of the reflected light intensity signal generated as the reflected light information are observed for performing focusing.</p> |
