Patent ID: 6124984
Filing Date: 2000-09-26
Classification: G02B

Abstract:
A variable magnification zoom lens system having an optical axis comprising, in order from an object side,a first lens group consisting of two negative lenses and a positive lens and having an overall negative refractive power;a second lens group having a positive refractive power; anda third lens group, which is fixed along the optical axis and overall has a positive refractive power;with the first and second lens group arranged to be driven such that when zooming from a maximum wide-angle state to a maximum telephoto state, the distance between said first lens group and said second lens group is reduced, and at the same time, the distance between said second lens group and said third lens group is increased; andthe following conditions are fulfilled:0.7<f2/.vertline.f1.vertline.<1.53<f3/fw<10wherein:f1 is: the focal length of said first lens group;f2 is: the focal length of said second lens group;f3 is: the focal length of said third lens group; andfW is: an overall focal length of said zoom lens system in the maximum wide-angle state wherein said first lens group consists of, in order from the object side,a negative meniscus lens having a convex surface facing toward the object side; anda cemented lens made up of a bi-concave negative lens and a positive meniscus lens with said positive meniscus lens having a convex surface facing toward the object side.