| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup device and an optical disk device satisfying both a spot diameter of a short wavelength laser beam converged on an optical disk and light intensity of a spot of a long wavelength laser beam even when a light source for emitting two wavelength laser beams is used. <P>SOLUTION: This optical pickup device is provided with a light source 1 for emitting a short wavelength first laser beam and a long wavelength second laser beam, a first diffraction grating 2a having a center area 31 and first and second peripheral areas 32 and 33 adjacent to both sides thereof to diffract the first laser beam to 0th-order light and ± 1st-order light, and an objective lens 8 for converging the first and second laser beams on an optical disk 20. Diffraction grating phases of the center area 31 are different by +90° and -90° with respect to those of the first and second peripheral areas 32 and 33. For diffraction efficiency of the 0th-order light of the first laser beam, diffraction efficiency of the center area 31 is smaller than that of the first and second peripheral areas. <P>COPYRIGHT: (C)2008,JPO&INPIT |
