| 摘要 |
<P>PROBLEM TO BE SOLVED: To compose so that manufacture is easy and highly accurate positioning for a diffraction element can be performed by preventing occurrence of flare. <P>SOLUTION: A lens actuator is provided with a cylindrical hole part 1a in which a diffraction element 3 is a disk shape provided with an outer peripheral plane becoming an engagement shaft part 3b and a plane part 3c at an upper plane, and a lens holder 1 is provided with: a cylindrical hole part 1a which is extended on an inside plane by being tilted to an optical axis L of an objective lens 2 and the engagement shaft part 3b of the diffraction element 3 is inserted into; and a plane sloping surface part 1b abutting on the plane part 3c of the diffraction element 3 by being tilted to a virtual plane perpendicular to the optical axis L of the objective lens 2 in the cylindrical hole part 1a. <P>COPYRIGHT: (C)2008,JPO&INPIT |
