| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup device where a focus error signal can be detected accurately in the case of receiving reflected light of different wavelengths from a plurality of kinds of recording mediums, and to provide an information recording and reproducing device thereof. <P>SOLUTION: The optical pickup device splits reflected light obtained by reflecting the light of the different wavelengths emitted from a plurality of light sources by the recording mediums into a prescribed number by a diffraction element, and focuses the reflected light at a position at a prescribed distance in a prescribed direction. Thus, the light of the different wavelengths (LA31, LA33, LB32 and LB34) can be focused at different positions and different distances while the focal distance of a focusing means coincides with a distance between the recording surfaces of the recording mediums and the focusing means. <P>COPYRIGHT: (C)2007,JPO&INPIT |
