Optical pickup apparatus for optical record media and identification apparatus for identifying the type of optical record media

摘要

An optical pickup apparatus for an information reproducing apparatus is adapted to reproduce one of at least first and second type optical record media which is loaded on the information reproducing apparatus. The first and second type optical record media have distances from surfaces to information record planes different from each other. The optical pickup apparatus is provided with: a light emission device for emitting a reading light; an objective lens for focusing the emitted reading light onto the information record plane of the loaded one of the first and second type optical record media such that a focus condition of the focused reading light is optimum with respect to the first type optical record medium; a correction device for correcting a spherical aberration of the focused reading light with respect to the second type optical record medium due to a difference in the distances from the surfaces to the information record planes between the first and second type optical record media when the second type optical record medium is loaded; and a light receiving device for receiving a reflection light of the focused reading light from the information record plane of the loaded one of the first and second optical record media.