| 摘要 |
An objective lens is included in an optical pickup device that records and/or reproduces an information signal onto and/or from an optical recording medium. The objective lens has a numerical aperture of 0.82 or higher, has first and second surfaces that are both aspherical, and focuses a light beam onto the optical recording medium. The first and second surfaces have surface-to-surface eccentricity therebetween that causes an aberration, the aberration being correctable by tilting an optical axis of the objective lens relative to a central axis of the light beam incident on the objective lens. The aberration caused by the surface-to-surface eccentricity includes a third-order coma aberration. When the optical axis is tilted relative to the central axis of the incident light beam so that the third-order coma aberration becomes substantially 0 mlambda rms, each of astigmatism, spherical aberration, and high-order coma aberration becomes 20 mlambda rms or less.
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