| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent deterioration in quality of a reproducing signal, even when the characteristics of a laser diode vary. <P>SOLUTION: The optical pickup 1, is provided with: a step SP2 for measuring the light amount P1 of an optical beam emitted from a laser diode 3; a step SP4 for measuring the light amount P2 of the optical beam emitted from the laser diode 3 and sequentially transmitted through a 1/2 wavelength plate 5, an aperture 10, a polarization beam splitter 8, and an aperture 14; and a step SP4 for changing the transmittance at the polarization beam splitter 8 by adjusting the rotational angle θ of the 1/2 wavelength plate 5 and for adjusting the ratio of the light amount P2 to the light amount P1 at a prescribed value. Accordingly, the variation in the optical coupling efficiency of the optical pickup 1 is suppressed by adjusting the rotational angle of the 1/2 wavelength plate 5. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
