| 摘要 |
An optical pickup records information on an optical recording medium and retrieves information from the optical recording medium by radiating a light beam on the optical recording medium. The optical pickup includes a light source which emits the light beam. The optical pickup also includes an object lens which directs the convergent light beam to a recording layer of the optical recording medium. The optical pickup further includes an aberration correction lens assembly located between the light source and the object lens. The aberration correction lens assembly includes at least one movable lens which is movable in an optical axis direction. The aberration correction lens assembly moves the movable lens to convert the light beam to a convergent light beam or a divergent light beam so as to correct spherical aberration. A distance between a principal plane of the aberration correction lens assembly on a light emergent side and a principal plane of the object lens falls within a range determined in accordance with a numerical aperture of the object lens, a focal length of the aberration correction lens assembly on the light emergent side, and a focal length of the object lens.
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