| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve productivity, reduce production cost, and improve reliabil ity of a focusing error signal. <P>SOLUTION: An optical pickup device is provided with a 1st diffraction grating 45 for dividing an output light beam emitted from the light reception/ emission integral type element 31 into a zero order light beam and ± 1st order light beams, a 2nd diffraction grating 46 for diffracting the optical path of a returned light beam from an optical disk 2, and a 3rd diffraction grating 47 for diffracting a + 1st order light beam diffracted by the 2nd diffraction grating 46 by being disposed at the location where the 1st order light beam is entered to correct variations in an optical path, wherein the light reception/ emission integral type element 31 is disposed at the location where the - 1st order light beam diffracted by the 3rd diffraction grating 47 is entered and receives the - 1st order light beam to generate a focusing error signal FE and also receives the returned light beams from the optical disk 2 of ± 1st order light beams divided by the 1st diffraction grating 45 to generate a tracking error signal. <P>COPYRIGHT: (C)2003,JPO |
