| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem that a tracking control operation is adversely affected by stray light rays reflected on one signal recording layer of a two-layer optical disk when reproducing a signal recorded in another signal recording layer thereof. <P>SOLUTION: The optical pickup device is provided with: an objective lens 8 for condensing a laser beam on a signal recording layer; a diffraction grating 2 for generating main and sub beams from the laser beam; and a photodetector 10 composed of a sub-beam receiving part irradiated with a sub-beam reflected from an operation signal recording layer which is a signal recording layer on which a focusing control operation is currently carried out to generate a tracking error signal and a main beam receiving part irradiated with a main beam reflected from the operation signal recording layer to generate a reproduction signal. A main beam reflected on a unoperated signal recording layer being a signal recording layer, where a focusing control operation is not operated, is converged into the main beam receiving part. <P>COPYRIGHT: (C)2009,JPO&INPIT |
