| 摘要 |
<P>PROBLEM TO BE SOLVED: To make it possible to keep the focusing diameter small to reproduce signals with less noise by not lowering the power and lowering the pupil limb intensity when reproducing but increasing it when recording to improve the efficiency of the laser beam to secure the power. <P>SOLUTION: This optical pickup has two light sources to emit almost the same wave-length laser beams, and a recording means to record by focusing the first laser beam from the first light source 1 on the recording medium through the objective lens. It disposes a concave lens 3 in the light path to guide the second laser beam from the second light source 2 to the recording medium, and makes the pupil limb intensity of the second laser beam in the objective lens higher than the limb intensity of the first laser beam to reproduce signals. Thus, it can secure the recording power on the recording medium by improving the efficiency of the laser beam when recording, while making the focusing diameter small on the recording medium when reproducing, and can reproduce signals by setting the output power of the light source 2 to the power sufficiently low in RIN. <P>COPYRIGHT: (C)2008,JPO&INPIT |
