The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 17, 2002
Filed:
Oct. 10, 2001
Kazuhiko Ono, Yokohama, JP;
Eiji Ikeda, Yokohama, JP;
Hiroshi Minoda, Yokohama, JP;
Akio Fukushima, Yokohama, JP;
Hiroaki Shioyama, Yokohama, JP;
Shigeki Inoue, Fujisawa, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A method for reproducing information on a dual layer disc which has two recording layers including layer and layer reproducible from one side of the [disk] disc, wherein each layer has a plurality of sectors. The method includes the steps of emanating an optical beam from a laser source, concentrating the optical beam on a recording layer with an objective lens, moving the objective lens in the direction of the thickness of the [disk] disc so that a focal point of the objective lens is focused on one layer of the two recording layers, obtaining a present layer information of a sector of the recording layer being reproduced from the reflected light from the [disk] disc, confirming a target layer information of a target recording layer of a target information, and moving the objective lens in a direction of the thickness of the [disk] disc until the focal point of the objective lens is focused on layer 1 when the present layer information is layer and the target layer information is layer