Reading lens system

A Gauss-type reading lens system, comprising in order from the object side:

• a positive meniscus first lens element having a convex surface directed toward an object;
• a positive meniscus second lens element having a convex surface directed toward the object;
• a negative meniscus third lens element cemented with said second lens element and having a convex surface directed toward the object;
• a negative meniscus fourth lens element having a concave surface directed toward the object;
• a positive meniscus fifth lens element cemented with said fourth lens element and having a concave surface directed toward the object;
• and
• a biconvex sixth lens element;
• and
• wherein said reading lens system satisfies the following conditions:
• ______________________________________ f = 35.00 FNO 1:4.0 m = -0.126 .omega. = 19.2.degree. i r(i) d(i) n(i) .nu.(i) ______________________________________ 1 21.600 3.58 1.71615 53.6 2 58.500 0.10 3 10.688 3.25 1.77620 49.6 4 18.810 0.90 1.72311 29.5 5 7.547 11.38 6 -9.200 0.90 1.72311 29.5 7 -21.730 2.86 1.77620 49.6 8 -11.551 0.10 9 222.238 3.43 1.71615 53.8 10 -30.398 ______________________________________
• where f denotes the focal length of the overall system, FNO is the F number, m is the magnification, .omega. is the half view angle, r(i) is the radius of curvature of the (i)th surface, d(i) is the distance between the (i)th surface and the (i+1)th surface, n(i) is the refractive index of the lens defined by the (i)th and (i+1)th surfaces at the e-line, and .nu.(i) is the Abbe number of the lens defined by the (i)th and (i+1)th surfaces.