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:
Aug. 10, 2010
Filed:
Jan. 27, 2009
Yuichi Muramatsu, Saitama, JP;
Dayong LI, Saitama, JP;
Yuichi Muramatsu, Saitama, JP;
Dayong Li, Saitama, JP;
Tamron Co., Ltd., Saitama, JP;
Abstract
The present invention is directed to a wide-angle zoom lens that attains the field of view ranging from 80 to 115 degrees in field angle with the zooming power of 2× or even higher, and that is capable of approximately compensating for various types of aberration such as spherical aberration, aberration of distortion, astigmatism and the like. The wide-angle zoom lens of multi groups of lens pieces, namely, a 1st lens group of negative refractivity, a 2nd lens group of negative refractivity, and a 3rd lens group of positive refractivity varies the power from the wide-angle end to the telephoto end with the 1st and 2nd lens groups coming closer to each other, and the 2nd and 3rd lens groups being varied in interval therebetween. The zoom lens attains the widest field of view of 80 degrees or over in field angle in the relations as expressed in the following formula:2.0<  (1)where fw is a focal length of the entire optics when the zoom lens gets set at the wide-angle end, and ft is the focal length of the entire optics at the telephoto end.