| 摘要 |
PURPOSE:To prevent the degradation in a characteristic and to provide stable performance even when a product is used in any attitude by canceling astigmatism occuring when an objective lens is moved in a direction perpendicular to an information track in an optical pickup. CONSTITUTION:In the optical pickup where the NA<=0.09 of the light source side of the objective lens 4, a semiconductor laser 1 and the objective lens 4 are arranged so that the longitudinal direction of the front focus of the a stigmatism of the objective lens image point side of the semiconductor laser 1 and the objective lens 4 become a perpendicular direction to a disk information track respectively. By the optical pickup, the astigmatism occuring in accordance with the movement of the lens is canceled when the objective lens is moved in the direction perpendicular to the information track. |
