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. 19, 1999
Filed:
Sep. 02, 1997
Hiroshi Koizumi, Kawasaki, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A zoom lens system for use in a camera having a color filter and a CCD achieves a magnification ratio of about 2.9 or greater and a back focus of about 9.2 or greater. The zoom lens system includes in order from an object side of the lens system, a first lens group having a negative refracting power, a second lens group spaced from the first lens group and having a positive refracting power and a third lens group spaced from the second lens group and having a positive refracting power. One or both of the fifth and an eighth lens surface has an aspherical surface, the fifth and eighth lens surfaces being counted from the object side. The second lens group includes five lenses with an extra lens being located at a far end of the second lens group relative to the object side. Each of the first, second and third lens groups is movable from a first position when the lens system is in a wide position to a second position when the lens system is in a tele position.