| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a hologram laser unit whose reliability is improved and which can be made small and light, and an optical pickup device. <P>SOLUTION: A first wavelength laser beam emitted from each of first and second semiconductor laser elements 51 and 52 and reflected on the information recording surface of an optical recording medium 26 through a hologram laser unit 1 and a 5λ/4 plate 23 to be polarized in a first polarizing direction is made to pass through a second polarized hologram diffraction grating 8, and diffracted in a direction toward a light receiving element 9 by a first polarized hologram diffraction grating 7. A second wavelength laser beam reflected on the information recording surface of the optical recording medium 26 to be polarized in the first polarizing direction is converted in a second polarizing direction by the 5λ/4 plate 23. The second wavelength laser beam polarized in the second polarizing direction is diffracted in the direction toward the light receiving element 9 by a second polarized hologram diffraction grating 8. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
