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:
Feb. 10, 2004
Filed:
Aug. 28, 2002
Hiroyasu Ozaki, Tokyo, JP;
Pentax Corporation, Tokyo, JP;
Abstract
A high-magnification zoom lens system includes a positive first lens group, a negative second lens group, a positive third lens group, a negative fourth lens group, and a positive fifth lens group. Upon zooming from the short focal length extremity to the long focal length extremity, at least the positive first lens group, the positive third lens group, the negative fourth lens group, and the positive fifth lens group move from the image side toward the object side. The high-magnification zoom lens system satisfies the following conditions: 0.65<(fw*ft) /f1<0.95 . . . (1); −7.0<(fw*ft) /f2<−4.8 . . . (2); 0.80<X4/X5<0.95 . . . (3); wherein fw: the focal length of the entire high-magnification zoom lens system at the short focal length extremity; ft: the focal length of the entire high-magnification zoom lens system at the long focal length extremity; f1:the focal length of the positive first lens group; f2: the focal length of the negative second lens group; X4:the traveling distance of the negative fourth lens group upon zooming from the short focal length extremity to the long focal length extremity; and X5:the traveling distance of the positive fifth lens group upon zooming from the short focal length extremity to the long focal length extremity.