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:
Jul. 27, 1993
Filed:
Jul. 15, 1992
Hironori Shibata, Tokyo, JP;
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
The invention relates to a compact, lightweight and inexpensive zoom lens system which, even when used with a small image sensor, allow the convex lenses to have a sufficient peripheral thickness and the concave lenses to have a sufficient central thickness and which comprises, in order from the object side, a first unit having a positive refracting power, a second unit having a negative and being movable during zooming, a third unit having a positive refracting power and remaining fixed in place and a fourth unit having a positive refracting power and being movable during zooming and focusing; said third unit comprising, in order from the object side, two lenses in all, one being a positive lens having a strong curvature on the object side and the other a negative lens having a strong curvature on the image side, and said third and fourth units each having at least one aspherical surface whose refracting power decreases as it is spaced away from the optical axis and conforming to the following conditions (1) and (2):