| 摘要 |
PROBLEM TO BE SOLVED: To correct astigmatism of a convergent spot with a simple constitution in an optical pickup device equipped with a erecting mirror opposite to an objective lens. SOLUTION: The erecting mirror 35 for refracting and erecting beam flux emitted from a semiconductor laser 31 and transmitted through a beam splitter 33 in the direction of the objective lens 11 is arranged to be inclined at a prescribed angle θ to an optical axis of the objective lens 11. By inclining this erecting mirror 35 at the prescribed angle θ, the beam flux is made to generate an astigmatism to correct astigmatism of the convergent spot on an optical disk. |
