| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical pickup device which can be made lightweight and highly reliable by using a one-group lens as the objective and correcting the coma aberration which influences the characteristics of the objective when a higher NA(Numerical Aperture) is intended. SOLUTION: The condenser optical system comprises a one-group objective 7 having 0.75 NA and is provided with an aberration correcting optical system 6 to correct the coma aberration produced by the inclination or shift of the center axes of the both surfaces of the objective 7 or by the inclination of the objective to the recording face 9 of an optical recording medium 10. |
