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:
Sep. 06, 2005
Filed:
Dec. 10, 2003
Hitoshi Tanaka, Saitama, JP;
Takamitsu Sasaki, Saitama, JP;
Kunihiko Shimizu, Saitama, JP;
PENTAX Corporation, Tokyo, JP;
Abstract
A step-zoom lens includes two movable lens groups; a lens group support unit; and a cam ring having a cam groove. The cam groove includes a finite number of focal-length steps, so as to perform a focusing operation between infinite and closest photographing positions at each focal-length step. The cam groove includes a wide-angle mode section, a telephoto mode section, and a mode switching section. The closest photographing positions in two adjacent focal-length steps and the infinite photographing positions in two adjacent focal-length steps are adjacent to each other, respectively. One focal-length step of the infinite photographing position at a longest focal length in the wide-angle mode section is provided at one end of the mode switching section, and another focal-length step of the infinite photographing position at a shortest focal length in the telephoto mode section is provided at the other end.