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. 01, 2008
Filed:
Jul. 23, 2004
Tsuguhiro Abe, Chiba, JP;
Tsuguhiro Abe, Chiba, JP;
Sony Corporation, Tokyo, JP;
Abstract
To reduce the optical path length of the entire optical system in a reproduction or recording optical system of an optical recording medium, and promote miniaturization and reductions in costs of apparatuses. An optical head apparatus has an optical system an including a light source and a translucent optical element and irradiates light exiting from the light source, after having been transmitted through the optical element, onto the optical recoding medium. The optical element has a surface or surfaces having negative power on the light-source side and a surface or surfaces having positive power on the optical-recording-medium side. In order to increase the power of the surface or surfaces, one or more of these surfaces are formed as a hologram surface on which a concentric hologram pattern is formed.