| 摘要 |
<P>PROBLEM TO BE SOLVED: To record or reproduce information to/from two or more kinds of optical disks different in thickness of protective substrates by satisfactorily correcting spherical aberration, and to achieve downsizing by using optical components in common. <P>SOLUTION: An optical pickup 3 which performs recording and/or reproduction to/from two or more optical disks different in the thickness of the protective substrates for protecting signal recording surfaces comprises: a light source part 31 which emits an optical beam of a fixed wavelength; a 1st objective lens 32 which cancels spherical aberration corresponding to the protective substrate of a 1st thickness and condenses light on a signal recording surface; a 2nd objective lens 33 which cancels spherical aberration corresponding to the protective substrate of a 2nd thickness and condenses the light on a signal recording surface; a polarization change-over part 34 which changes over the polarization state of the optical beam emitted from the light source 31; and a polarization beam splitter 35 which guides the optical beam to the 1st or 2nd objective lenses 32, 33 depending on the polarization state of the optical beam changed over by the polarization change-over part 34. <P>COPYRIGHT: (C)2007,JPO&INPIT |
