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:
Oct. 29, 1996
Filed:
Jul. 01, 1994
Shinichi Mihara, Tokyo, JP;
Hironori Shibata, Tokyo, JP;
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
A vari-focal lens system comprising, in order from the object side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power and a fourth lens unit having a positive refractive power; and configured so as to be set at a focal length at a telephoto position thereof from that at a wide-angle position thereof by moving the first lens unit monotonically toward the object side, displacing the second lens unit monotonically toward the image side, setting the third lens unit at a location on the object side of its original setting at the wide-angle position and moving the fourth lens unit from a location thereof to focus the vari-focal lens system on an object effectively located at infinite distance so as to widen an airspace reserved between the third lens unit and the fourth lens unit as compared to the airspace at the wide-angle position. The vari-focal lens system can be focused by moving the fourth lens unit.