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:
May. 31, 2011
Filed:
Jun. 15, 2007
Fumitomo Yamasaki, Nara, JP;
Sadao Mizuno, Osaka, JP;
Katsuhiko Hayashi, Osaka, JP;
Hideki Aikoh, Osaka, JP;
Fumitomo Yamasaki, Nara, JP;
Sadao Mizuno, Osaka, JP;
Katsuhiko Hayashi, Osaka, JP;
Hideki Aikoh, Osaka, JP;
Panasonic Corporation, Osaka, JP;
Abstract
Provides a coupling lens which, when used in combination with an objective lens for a plurality of types of optical discs such as a high density disc, DVD, CD or the like, is capable of compensating for various types of aberrations including those caused by wavelength changes and thus providing good recording or reproduction characteristics with a good wavelength dispersion compensation ability; and an optical head and an optical disc apparatus (drive). A coupling lens is incorporated into an optical head for collecting laser light emitted from a plurality of light sources and having different wavelengths on an information recording face of different types of optical information recording mediums respectively. The coupling lens comprises a first lens and a second lens which are substantially in close contact with each other such that optical axes thereof match each other and designed such that the laser light having different wavelengths are refracted by the close contact face. The coupling lens is afocal for the shortest wavelength among the different wavelengths of the laser light.