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:
Jul. 02, 2002
Filed:
Sep. 24, 1998
Fumisada Maeda, Tokyo, JP;
Isao Ichimura, Tokyo, JP;
Kenji Yamamoto, Tokyo, JP;
Kiyoshi Ohsato, Chiba, JP;
Toshio Watanabe, Kanagawa, JP;
Sony Corporation, , JP;
Abstract
A recording/reproducing apparatus for an optical recording medium in which a laser light beam is illuminated on an optical recording medium using a double-lens type objective lens made up of at least a first lens and a second lens to record and/or reproduce the information. The apparatus includes a first lens for converging the laser light illuminated from a light source, a second lens arranged between the first lens and the optical recording medium and a voice coil motor for causing relative movement of the first and second lenses for varying the distance therebetween in the direction along the optical axis. The first lens is moved to vary the distance between the first and second lenses. This enlarges the numerical aperture and diminishes the effect of aberration to enable high-density recording and/or reproduction of information signals to a high recording density.