Patent ID: 6069743
Filing Date: 2000-05-30
Classification: G02B

Abstract:
A zoom lens system comprising;a first lens group having positive power:a second lens group having negative power; andan aperture stop on an image side of the second lens group,wherein said first lens group comprises at least one diffractive surface, and satisfies the following conditions:0.001<f.sub.S /f.sub.DOE <0.025 (1)0.1<f.sub.S /f.sub.1 <0.6 (5)where f.sub.1 is a focal length of said first lens group, f.sub.S =.sqroot.(f.sub.W .times.f f.sub.T), f.sub.W and f.sub.T are focal lengths of said zoom lens system at a wide-angle end thereof and a telephoto end thereof, respectively, and f.sub.DOE is a focal length of said diffractive surface.