| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup apparatus in which a plurality of kinds of optical recording media having different use wavelengthes are used with simple structure. <P>SOLUTION: This optical pickup apparatus are used for three kinds of optical recording media having different use wavelengthes, the apparatus has an objective lens 2 made of glass, a first light source emitting a first laser beam L<SB>1</SB>of first wavelength, a second light source 411 emitting a second laser beam L<SB>2</SB>of second wavelength, a third light source 511 emitting a third laser beam L<SB>3</SB>of third wavelength. A shape of the objective lens 2 is optimized so that spherical aberration when the first laser beam L<SB>1</SB>is made incident as parallel light is made to be the minimum. Also, a radiation state of the second laser beam L<SB>2</SB>is optimized so that spherical aberration when the second laser beam L<SB>2</SB>is made incident on the objective lens 2 is made to be the minimum, while a radiation state of the third laser beam L<SB>3</SB>is optimized so that spherical aberration when the third laser beam L<SB>3</SB>is made incident on the objective lens 2 is made to be the minimum. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
