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. 20, 2013
Filed:
Jun. 28, 2011
Koji Kato, Saitama, JP;
Koji Kato, Saitama, JP;
Pentax Ricoh Imaging Company, Ltd., Tokyo, JP;
Abstract
A high-ratio zoom lens system includes a positive first lens group, a negative second lens group, a positive third lens group, and a positive fourth lens group, in that order from the object. Upon zooming from the short focal length extremity to the long focal length extremity, the first through fourth lens groups move along the optical axis of the zoom lens system while increasing the distance between the first and second lens groups, and decreasing the distance between the second and third lens groups. The following conditions are satisfied:0.9<3/4<1.3and−3.85<1234<−3.04wherein fdesignates the focal length of the third lensgroup, fdesignates the focal length of the fourth lens group, and fdesignates the combined focal length of the first, second and third lens groups when an object at infinity is in an in-focus state at the long focal length extremity.