| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup device capable of recording or reproducing information onto or from three kinds of optical information recording media of standards different from each other. <P>SOLUTION: The optical pickup device reproduces and/or records information from/onto a first optical information recording medium having a first protection substrate with thickness t1 by using luminous flux from a first light source 1 of wavelength λ1, and reproduces and/or records information from/onto second and third optical information recording media having respective second and third protection substrates with respective thickness t2, t3 (t3>t2>t1) by using luminous flux from second and third light sources 2, 3 of wavelengths λ2, λ3 (λ1<λ<2<λ3) respectively, wherein the optical pickup device uses a common objective lens 8 comprising one lens group to reproduce and/or record information from/onto the first to third optical information recording media and has a substrate thickness difference correction means 7 to correct spherical aberration changed due to the difference in the thickness of the first to third protection substrates. <P>COPYRIGHT: (C)2008,JPO&INPIT |
