| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a pickup objective lens that ensures a sufficient operating distance and reduces aberration generated due to change in ambient temperature, and to provide an optical pickup device and an optical disc apparatus. <P>SOLUTION: A plurality of zone regions are provided on at least one side of a pickup lens 14 and steps are formed between the zone regions. These steps are formed so as to have an amount of step causing a phase difference by laser light for reducing an aberration to be generated at the pickup lens 14 due to variation of the ambient temperature. Provided that the numerical aperture of the pickup lens 14 is NA, the focal length is f (mm), and the working distance is WD (mm), the pickup lens 14 is configured to meet NA≥0.85, 1.1≤f≤1.8, and WD≥0.3. <P>COPYRIGHT: (C)2010,JPO&INPIT |
