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:
Feb. 05, 2013
Filed:
Mar. 22, 2011
Kimihiro Saito, Kanagawa, JP;
Norihiro Tanabe, Kanagawa, JP;
Hirotaka Miyamoto, Kanagawa, JP;
Takahiro Miura, Kanagawa, JP;
Kimihiro Saito, Kanagawa, JP;
Norihiro Tanabe, Kanagawa, JP;
Hirotaka Miyamoto, Kanagawa, JP;
Takahiro Miura, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
There is provided an optical pickup including: an optical-system having an object-lens illuminating a first light for information recording or reproducing on a recording layer as a target and a second light on an optical-recording medium including a reference plane having a reflection-layer and the recording-layer at a layer position different from that of the reference-plane and on which information recording is performed through mark formation, and a focus-aligned-position-adjusting unit adjusting a focus-aligned position of the first light through the object-lens by changing collimation thereof incident to the object-lens; and a focusing-mechanism driving the object-lens in a focusing direction, wherein, when a depth of focus λ/NAdefined by a wavelength λ of the first light and a numerical aperture NA of the object lens is set to α and the maximum-surface-blur range is denoted by D, the optical-system is designed so that a use magnification ratio β satisfies |β|≧√(D/α).