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:
Aug. 24, 2010
Filed:
Jan. 05, 2007
Yasuhiro Tanaka, Hyogo, JP;
Tomohiko Sasano, Osaka, JP;
Michihiro Yamagata, Osaka, JP;
Daisuke Ogata, Hyogo, JP;
Yasuhiro Tanaka, Hyogo, JP;
Tomohiko Sasano, Osaka, JP;
Michihiro Yamagata, Osaka, JP;
Daisuke Ogata, Hyogo, JP;
Panasonic Corporation, Osaka, JP;
Abstract
Disclosed is an optical head apparatus comprising: a light source; a collimating means of converting a beam of light emitted from the light source into a substantially parallel beam of light; a focusing means of focusing the light onto an information medium surface; a beam splitting means of splitting the beam of light modulated by the information medium; and a light receiving means of receiving the light modulated by the information medium, wherein a lens having a negative power and a lens having a positive power are arranged in this order as viewed from the collimating means side between the collimating means and the focusing means, and at least either one of the lenses is moved along an optical axis to correct spherical aberration occurring on the information medium surface, and wherein the distance from the lens having the positive power to the focusing means is set substantially equal to the focal length of the lens having the positive power.