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:
Jun. 17, 2003
Filed:
Aug. 06, 2001
Hiroyasu Ozaki, Tokyo, JP;
Pentax Corporation, Tokyo, JP;
Abstract
A telephoto lens system includes a positive first lens group, a negative second lens group and a positive third lens group. Upon focusing, the second lens group moves toward the image, and the telephoto lens system satisfies the following conditions: 1.35<f/f <1.80 . . . (1); 1.30<|f/f |<1.85 . . . (2); 0.48<f/f <0.75 . . . (3) and 0.10<|L f |<0.22 . . . (4); wherein f designates the focal length of the entire telephoto lens system; f designates the focal length of the first lens group; f designates the focal length of the second lens group; f designates the focal length of the third lens group; and L designates the distance between the second lens group and the third lens group when an object at an infinite photographing distance is in an in-focus state.