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:
Apr. 15, 2014
Filed:
May. 30, 2012
Katsuhiro Takamoto, Sakai, JP;
Kazuhiko Inoue, Sakai, JP;
Sadanobu Imamura, Sakai, JP;
Kohei Wataru, Nishinomiya, JP;
Katsuhiro Takamoto, Sakai, JP;
Kazuhiko Inoue, Sakai, JP;
Sadanobu Imamura, Sakai, JP;
Kohei Wataru, Nishinomiya, JP;
Konica Minolta Advanced Layers, Inc., Tokyo, JP;
Abstract
A variable-focal-length lens system for projection which achieves focusing by movement of the entire system has a second to a fourth lens group as focal-length-varying lens groups and a first lens group as a distance-compensation lens group. The second to fourth lens groups individually move in the optical axis direction to vary the group-to-group distances so as to vary the focal length of the entire system. During focusing, the first lens group moves in the optical axis direction such that, as the projection distance varies from a remote distance to a close distance, curvature of field varies to the under side.