| 摘要 |
<P>PROBLEM TO BE SOLVED: To easily exhibit desired optical characteristics such as aberration by minimizing influence of production variations. <P>SOLUTION: An objective lens 8 to be mounted on an optical pickup 7 of an optical disk device 1 has a third-order decentering sensitivity DCm3, a fifth-order decentering sensitivity DCm5, and a fifth-order thickness sensitivity TSA5, which are each converted to a third-order thickness sensitivity TSA3. The objective lens 8 is also designed so that wave front aberration deterioration TOR calculated by expression (10) satisfies the Marechal criterion, by regulating thickness variation and decentering variation and setting the third-order thickness sensitivity TSA3 to fall within the range of expression (13). Thereby, the objective lens 8 exhibits the desired optical characteristics since wave front aberration can be suppressed if decentering error DER and thickness error TER are within the ranges of decentering variation and thickness variation during manufacturing. <P>COPYRIGHT: (C)2011,JPO&INPIT |
