| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a low-priced optical pickup unit which is mounted with a two-wavelength multi-laser light source and has optimum optical system magnification common to DVD and CD. <P>SOLUTION: Optical parameters such as an objective numerical aperture, the far field pattern of a semiconductor laser light source, and optical system magnification are set so that a DVD-side light spot diameter is ≤1.03 μm or crosstalk to a DVD-RAM 2 is ≤-22 dB and power on a CD-side optical disk surface is ≥40 mW at the time of absolute maximum rating light pulse output of a CD-side semiconductor laser beam source. Consequently, the optical pickup unit has the same reproducing performance for DVD and recording/reproducing performance for CD with the conventional optical pickup unit. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
