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:
Mar. 19, 2013
Filed:
Mar. 10, 2011
Akio Arakawa, Saitama, JP;
Yuichi Muramatsu, Saitama, JP;
Akio Arakawa, Saitama, JP;
Yuichi Muramatsu, Saitama, JP;
Tamron Co., Ltd., Saitama, JP;
Abstract
A variable power zoom lens of four groups of lens pieces respectively exerting positive, negative, positive, and positive refractivities varies the power from the wide-angle end to the telephoto end as a result of the 1st and 2nd lens groups being separated more, the 2nd and 3rd lens groups, and the 3rd and 4th lens groups, coming closer to each other. The 3rd lens group has a leading set of lens pieces closer to the object side having a positive refractivity as a whole and the trailing set of lens pieces have negative refractivity as a whole, and the trailing set alone are moved to be orthogonal to the optical axis to compensate for defocus in the imaging plane. The 2nd lens group is displaced closer to objects for focusing.