| 摘要 |
<p>An optical pickup including: first and second light sources (601; 701) for generating laser beams having different wavelengths, corresponding to first and second media (100) having different thicknesses, respectively; an objective lens (200) having diverging and focusing portions, for focusing the laser beams from the first and second light sources (601; 701) onto the first and second media (100), respectively; at least one photodetector (602; 702) for receiving the laser beams which are emitted from the first and second light sources (601; 701) and reflected, respectively, by the first and second media (100); and a collimating lens (400) arranged on the optical path between the objective lens (200), and the first and second light sources (601; 701). The optical pickup is compatible with both existing digital versatile disks (DVDs), and high-definition (HD)-DVDs, which need a blue light source near 405 nm and an objective lens having a numerical aperture of 0.6 or more. <IMAGE></p> |
