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:
Dec. 27, 2005
Filed:
Sep. 16, 2002
Ryuichi Katayama, Tokyo, JP;
Eiichi Ueda, Tokyo, JP;
Taku Tsuboi, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
In an optical head apparatus including a first light source for emitting a first light beam having a first wavelength, a second light source for emitting a second light beam having a second wavelength different from the first wavelength, an objective lens, a photodetector, and first and second optical combining/splitting elements, the first optical combining/splitting element receives the first light beam from the first light source to outgo most of the first light beam therefrom to the second optical combining/splitting element and receives the first and second light beams from the second optical combining/splitting element to outgo most of the first and second light beams therefrom to the photodetector. The second optical combining/splitting element receives the first light beam from the first optical combining/splitting element and the second light beam from the second light source to outgo most of the first and second light beams therefrom to the objective lens and receives the first and second light beams from the objective lens to outgo most of the first and second light beams therefrom to the first optical combining/splitting element.