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:
Oct. 16, 2007
Filed:
Jan. 27, 2006
Kenji Ogiwara, Hachioji, JP;
Kenji Ogiwara, Hachioji, JP;
Konica Minolta Opto, Inc., Tokyo, JP;
Abstract
An optical pickup apparatus is provided with a light source device to emit selectively an ordinary polarized light ray and an extraordinary polarized light ray by controlling a polarization condition of a light flux having a wavelength of λ1; and a light converging optical system. An objective lens has a phase structure made of a doubly refracting medium in which an ordinary ray refractive index nfor the ordinary polarized light ray is different from an extraordinary ray refractive index n(n≠n) for the extraordinary polarized light ray so that the phase structure has a function for not changing a transmitted wavefront of an incident light ray being one of the ordinary polarized light ray and the extraordinary polarized light ray and for changing a transmitted wavefront of an incident light ray being the other one of the ordinary polarized light ray and the extraordinary polarized light ray.