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. 25, 2012
Filed:
Dec. 15, 2009
Kentarou Nakamura, Tokyo, JP;
Kentarou Nakamura, Tokyo, JP;
Konica Minolta Opto, Inc., Tokyo, JP;
Abstract
Provided is an objective optical element which can appropriately correct degradation from spherical aberration upon fluctuation of a light source wavelength while maintaining light use efficiency, just by changing the magnification of the objective optical element, and which can record/reproduce information to/from different optical discs. Also provided is an optical pickup device using the objective optical element. When a light flux having two different wavelengths λ, λ(wherein λ<λand λ−λ=5 nm) within a range of wavelength λis introduced to the objective optical element to measure the wavefront aberration, the following third order and fifth order spherical aberrations in unit of λrms are obtained: SA3(λ), SA5(λ), SA3(λ), SA5(λ). If ΔSA3=|SA3(λ)−SA3(λ)|, ΔSA5=|SA5(λ)−SA5(λ)|, the following expression is satisfied: 0.18>ΔSA3>ΔSA5>0 (1).