Copying objective lens system

Claim 1

A copying objective lens system comprising a front lens group and rear lens group arranged symmetrically in respect to a stop positioned at the center, each of said front and rear lens group comprising a first and second lens components designated in the order from the object side toward the center for the front lens group and from the image side toward the center for the rear lens group, said first lens component being a cemented doublet lens having negative refractive power and consisting of a positive meniscus lens and a negative meniscus lens, said second lens component being a positive meniscus lens, said copying objective lens system having the following numerical data: ______________________________________ r.sub.1 = 0.1606 d.sub.1 = 0.0319 n.sub.1 = 1.62041 ν.sub.1 = 60.3 r.sub.2 = 0.2011 d.sub.2 = 0.0285 n.sub.2 = 1.64769 ν.sub.2 = 33.8 r.sub.3 = 0.1312 d.sub.3 = 0.0269 r.sub.4 = 0.2348 d.sub.4 = 0.0256 n.sub.3 = 1.55671 ν.sub.3 = 58.7 r.sub.5 = 0.3867 d.sub.5 = 0.0470 F/8.0 , f = 1.0 , f.sub.12 = -4.285 , f.sub.3 = 1.012 ______________________________________ wherein reference symbols r 1 through r 5 respectively represent radii of curvature of respective lens surfaces, reference symbols d 1 through d 5 respectively represent thicknesses of respective lenses and airspaces between respective lenses, reference symbols n 1 , n 2 and n 3 respectively represent refractive indices of respective lenses, and reference symbols ν 1 , ν 2 and ν 3 respectively represent Abbe's numbers of respective lenses, reference symbol f 12 represents the focal length of the first lens component, reference symbol f 3 represents the focal length of the second lens component, reference symbol f represents the focal length of the lens system as a whole.