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:
Jan. 04, 2005
Filed:
Feb. 08, 2002
Yoshitsugu Araki, Tsurugashima, JP;
Takanori Maeda, Tsurugashima, JP;
Yoshitsugu Araki, Tsurugashima, JP;
Takanori Maeda, Tsurugashima, JP;
Pioneer Corporation, Tokyo-To, JP;
Abstract
An information recording and reproducing apparatus for optically recording/reproducing information to/from a two-layer optical disk comprises a cylindrical lens, which gives astigmatism to a reflected light from a target information recording layer, two caustic curve positions are arranged in the front and in the rear of the optical detector, and an unnecessary reflected light from an another information recording layer has two caustic curve positions arranged in the rear of the optical detector. In this condition, assuming an astigmatism direction of the cylindrical lens is inclined at 45 degree angle to a track direction, a projected image of the target information recording layer is inclined at 90 degree angle to an another projected image of the another information recording layer in a light receiving surface of the optical detector.