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:
Jul. 03, 2007
Filed:
Jul. 13, 2005
Applicants:
Hideharu Okami, Chiba, JP;
Yoshiyuki Abe, Chiba, JP;
Tokuyuki Nakayama, Chiba, JP;
Inventors:
Assignee:
Sumitomo Metal Mining Co., Ltd., Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
G02B 5/22 (2006.01);
U.S. Cl.
CPC ...
Abstract
An absorption type multi-layer film ND filter having a substrate and an optical multi-layer member consisting essentially of metal layers each composed chiefly of nickel (Ni) and dielectric layers each formed of any one of SiO, AlOand a mixture of these; the layers being alternately layered on the substrate. An Ni type metallic material having a small wavelength dependence of transmittance in the visible spectral range is used in the metal layers serving as light attenuation layers, and this enables materialization of an ND filter which can attain transmittance attenuation that is flat for wavelengths.