| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an objective lens and an optical pickup optical system in which high light utilization efficiency is obtained, deterioration of wave front aberration during tracking is suppressed, and excellent recording/reproduction is achieved for a plurality of kinds of optical recording media. <P>SOLUTION: In the objective lens converging first optical flux having wavelength λ1 on the information recording plane of a first optical recording medium, and converging second optical flux having longer wavelength λ2 than the wavelength λ1 on the information recording plane of second optical recording medium, converging third optical flux having longer wavelength λ3 than the wavelength λ2 on the information recording plane of third optical recording medium, at least one of lens surfaces of the optical lenses is divided into a plurality of sections concentric around an optical axis, when image-forming magnification in the first luminous flux in the objective lens is m1, image-forming magnification in the second luminous flux is m2, and image-forming magnification in the third luminous flux is m3, m1>m2>0, -0.060≤m3≤-0.020 are satisfied. <P>COPYRIGHT: (C)2008,JPO&INPIT |
