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:
Jun. 24, 2014
Filed:
Nov. 09, 2011
Hideki Tanaka, Fuchu, JP;
Kentarou Nakamura, Nakano-ku, JP;
Kiyono Tateyama, Hino, JP;
Konica Minolta, Inc., Tokyo, JP;
Abstract
An optical pickup apparatus including an objective lens capable of enhancing temperature characteristics and wavelength characteristics, and which enables compatibility for three types of optical discs of BDs, DVDs, and CDs by using the objective lens in common, an optical information recording and reproducing apparatus, and an objective lens suitable for it. In a first optical path difference providing structure in which at least a first basic structure and a second basic structure are superimposed on each other, an amount of a level difference in an optical axis direction can be reduced, whereby it becomes possible to suppress the lowering of a diffraction efficiency when wavelength changes. Further, in the first basic structure and the second basic structure deterioration of the spherical aberration due to the change of the refractive index of the objective lens can be corrected by utilizing a phenomenon that the wavelength of the light source rises similarly due to a rise in the environmental temperature.