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:
Apr. 01, 1980
Filed:
Nov. 10, 1977
Fuji Photo Optical Co., Ltd., Omiya, JP;
Abstract
A zoom lens system consists of a front lens group A comprising a negative meniscus lens L1 convex to front (i.e. object side) and a positive lens L3 having the face of greater curvature faced to front, and a rear lens group B comprising a positive lens L4 having the face of greater curvature faced to front, a positive menisucs lens L5 convex to front, a negative lens L6 having the face of greater curvature faced to rear and a positive lens L7. The front and rear lens groups A and B are moved in the opposite directions along the optical axis thereof to vary the focal length thereof. The above zoom lens system satisfies the following conditions where the focal length of the front lens group A is fA, the radius of curvature of the concave face of the negative meniscus lens L1 is r2, the radius of curvature of the front face of the positive lens L3 is r5, the radius of curvature of the convex face of the positive meniscus lens L5is r9 , the radius of curvature of the rear face of the negative lens L6 is r12 and the Abbe dispersion number of the positive lens L3 is .nu.3; -2.3<fA<-1.5, 0.45<r2<0.65, 0.5<r5<1.0, 0.4<r9<0.6, 0.3<r12<0.55, .nu.3<40.