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. 06, 2012
Filed:
Jan. 27, 2010
Tsuneo Uchida, Chiba, JP;
Nobuyuki Adachi, Tokyo, JP;
Tsuneo Uchida, Chiba, JP;
Nobuyuki Adachi, Tokyo, JP;
Panasonic Corporation, Osaka, JP;
Abstract
Provided is a zoom lens system including a compact focusing lens unit and having a suppressed change in image magnification at the time of movement of the focusing lens unit. The zoom lens system of the present invention, in order from an object side to an image side, includes a first lens unit Ghaving positive optical power, a second lens unit Ghaving negative optical power, a third lens unit Ghaving negative optical power, and a fourth lens unit Ghaving positive optical power. At the time of zooming, all lens units moves in a direction along the optical axis such that intervals among respective lens units varies. Further, at the time of zooming, the third lens unit Gmoves in the direction along the optical axis such that the interval between the second lens unit Gand the third lens unit Gis made longer at a telephoto limit than the interval at a wide-angle limit. Still further, condition (6): −1.6<f/f<−0.7 is satisfied (where, fis a focal length of a focusing lens unit, and fis a composite focal length of the fourth lens unit Gand a lens unit subsequent thereto at a wide-angle limit).