| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a light path correction unit not producing astigmatism, and an optical pickup having a light path correction unit. <P>SOLUTION: This light path correction unit corrects the one light path of the two laser beams L1, L2 different in wavelength so as to be aligned. It has a birefringent plate 10 to correct the light path of the laser beam L2 to be aligned with that of the laser beam L1, a collimator lens 1 to make the laser beam L1 from the birefringent plate 10 parallel light and to pass the laser beam L2, and an astigmatism correction plate 2 arranged at the emission surface of the collimator lens 1 to correct the astigmatism of the laser beam L2 produced by the birefringent plate 10. <P>COPYRIGHT: (C)2007,JPO&INPIT |
