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. 07, 2012
Filed:
Jul. 08, 2009
Akio Arakawa, Saitama, JP;
Yuichi Muramatsu, Saitama, JP;
Akio Arakawa, Saitama, JP;
Yuichi Muramatsu, Saitama, JP;
Tamron Co., Ltd., Saitama, JP;
Abstract
Zoom lens for SLR digital cameras. The lens is at least 75 degrees wider in field angle at the wide-angle end, about 3 to 4 in f-stops at the wide-angle end and approximately 6 to 7 at the telephoto end, and about a 15:1 zoom range. Four groups of lens pieces exert positive, negative, positive, and positive refractivities from the wide-angle end to the telephoto end as a result of the 1st and 2nd lens groups being split more, the 2nd and 3rd lens groups coming closer to each other, and the 3rd and 4th lens groups also coming closer to each other. The 3rd lens group has the leading set of lens pieces closer to objects and the trailing set of lens pieces can 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.