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:
Mar. 19, 2002
Filed:
Jan. 31, 2000
Tohru Nakamura, Hachioji, JP;
Hirofumi Tsuchida, Kunitachi, JP;
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
The invention relates to a zoom lens system of two-group construction, one lens for each group, which is less susceptible to aberration variations even upon zooming and can be much more increased in terms of lens aperture and zoom ratio. The zoom lens system of two-group construction comprises, in order from an object side thereof, a first lens group G having negative refracting power and a second lens group G having positive refracting power and in which a focal length thereof is varied by moving both the lenses while an optical axis separation therebetween is varied. The first lens group G consists of one concave lens having a strong concave surface directed toward an image plane side of the zoom lens system and formed of a homogeneous medium, and the second lens group G consists of one convex lens formed of a homogeneous medium. A stop S is located between the first lens group G and the second lens group G The first lens group G moves largely from the object side toward an image side of the zoom lens system while the second lens group G moves from the image side toward the object side during zooming from a wide-angle end to a telephoto end of the zoom lens system.