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. 20, 2010
Filed:
Jul. 31, 2008
Mayumi Kawada, Nagoya, JP;
Ken Shimizu, Nagoya, JP;
Mayumi Kawada, Nagoya, JP;
Ken Shimizu, Nagoya, JP;
Elmo Company, Limited, , JP;
Abstract
The zoom lenscomprises, sequentially from the object side, a stationary first lens grouphaving positive refractive power; a second lens group, having negative refractive power, and that moves on the optical axis when changing the magnification; a stationary third lens groupthat has positive refractive power; and a fourth lens group, having positive refractive power. The first lens groupcomprises six lenses. The second lens Lis a meniscus lens that is formed so as to have at least one aspherical surface. The aspherical surface of the second lens Lis formed at the shape wherein there is no displacement in the thickness from the center portion to the edge portion. Doing so enables the effective correction of distortion and off-axis aberration on the wide-angle side, and the provision of a high-performance zoom lens that is small and has a high variable magnification.