| 摘要 |
PROBLEM TO BE SOLVED: To enhance the performance of an optical pickup by making the objective lens receiving surface of an objective fixing structure be in a conical shape or a tapered shape to respectively adjust optical axes of two kinds of objective lenses parallel with respect to the upper part or the lower part of the objective lens fixing structure of a rotary shaft and to reduce an optical axis deviation at the time of changing over two kinds of objective lenses. SOLUTION: An objective lens 2 is mounted on the lens receiving surface 11a of an objective lens fixing structure 11 to be fixed. Since the lens receiving surface 11a is made to be in a tapered shape or a conical shape, the outer circumferential edge of the lens 2 and the surface 11a become to perform a line contact. Consequently, since the structure of this pickup is different from a structure in which the lens receiving surface 11a and the objective lens 2 perform a surface contact, optical axes of the two kinds of the objective lenses can be respectively adjusted parallel with respect to the upper part or the lower part of the objective lens fixing structure 11 or the rotary driving shaft and it is made possible to reduce the optical axis deviation at the time of changing over the objective lenses. |
