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:
May. 09, 2006
Filed:
Jul. 08, 2004
Applicants:
Keiichi Kuba, Hachiohji, JP;
Hiroyuki Minakata, Hachiohji, JP;
Inventors:
Keiichi Kuba, Hachiohji, JP;
Hiroyuki Minakata, Hachiohji, JP;
Assignee:
Olympus Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B 15/14 (2006.01);
U.S. Cl.
CPC ...
Abstract
A vari-focal optical system having a composition comprising at least a first negative lens unit, a second positive lens unit, a third negative lens unit and a fourth positive lens unit, and changes a magnification from a wide position to a tele position by moving at least the second lens unit and the third lens unit. This optical system is configured to have a short total length and reserve sufficient airspaces for the magnification change by locating a front principal point of the second lens unit on the object side of the second lens unit.