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. 23, 2007
Filed:
Jun. 21, 2005
Akio Arakawa, Saitama, JP;
Yuichi Muramatsu, Saitama, JP;
Akio Arakawa, Saitama, JP;
Yuichi Muramatsu, Saitama, JP;
Tamron Co., Ltd., Saitama-Ken, JP;
Abstract
The invention discloses a macro lens that takes a retrofocusing function for the purpose of downsizing. The macro lens employs a floating mechanism to cover a wide photographing range from the equi-magnification to the infinity, and especially, attains a great imaging performance by appropriately compensating for spherical aberration, comatic aberration, and chromatic aberration of magnification. The macro lens comprised of first to fifth lenses in the order closer to the object; that is, the first lens serving as a negative meniscus lens with a convex surface oriented to the object, the fourth lens as a negative lens with a concave surface of great curvature oriented to the image plane, and the fifth lens as a negative lens with a surface of great curvature oriented to the object. The macro lens satisfies conditions as expressed in the following formulae:0.6≦1/≦1.3   (1)0.9≦4/5≦1.5   (2)where F is a focal length of the entire lens system, F1 is a focal length of the first lens, F4 is a focal length of the fourth lens, and F5 is a focal length of the fifth lens.