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AssigneePanasonic Corporation
InventorsKatsuhiko Hayashi, Yasuhiro Tanaka, Michihiro Yamagata, Kazuhiko Ishimaru
Estimating the term…
An optical pickup 1 includes a collimator lens 13 for changing the shape of a laser light by moving on the optical axis AX from a base point. An objective lens 15 is set so as to form a spot of which size, when the collimator lens 13 is located at the base point, is minimum at a point apart from the light source side surface of an information recording medium 20 by a distance of Lc defined by an expression (1): Lc=(L0+Ln)/2 (1), wherein Lc is named as a thickness to the designed center; L0 is a distance between the light source side surface of the information recoding medium and an information recording face located nearest to the light source side surface; and Ln is a distance between the light source side surface of the information recording medium and an information recording face located farthest from the light source side surface.
An optical pickup for focusing a laser light onto a plurality of information recording faces provided in parallel with each other in an information recording medium, comprising:
An objective lens for focusing a laser light onto a plurality of information recording faces provided in parallel with each other in an information recording medium, the objective lens being used in an optical pickup, the optical pickup including:
Dependencies are inferred from the claim text.