| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an objective lens capable of attenuating, in laser beams with two wavelength ranges, an unnecessary beam of a small-numerical-aperture laser beam in a long wavelength side while appropriately narrowing a spot of a large-numerical-aperture laser beam in a short wavelength side, and to provide an optical pickup device. <P>SOLUTION: An objective lens R includes lens surfaces R1 and R2 that focus laser beams into a spot with a predetermined numerical aperture, and an anti-reflection film R1a formed on the lens surface R1. BD light, DVD light, and CD light are incident on the lens surface R1 in a parallel light state. The anti-reflection film R1a is so formed that an incident angle Dθ where the reflectance to the DVD light matches the reflectance to the BD light, is set within a maximum incident angle or more of the DVD light and the maximum incident angle or less of the BD light. <P>COPYRIGHT: (C)2013,JPO&INPIT |
