Patent ID: 7230776

Claim:
An image scanning lens comprising, arranged in order from the object side: a first lens element having negative refractive power and a meniscus shape with its convex surface on the object side; a biconvex second lens element and a biconcave third lens element that are cemented together; a stop; a biconcave fourth lens element and a biconvex fifth lens element that are cemented together; and a sixth lens element having negative refractive power and a meniscus shape with its convex surface on the image side; wherein the following conditions are satisfied: −1.1< f 1/ f<− 0.5 0.3< f 23/ f< 0.7 0.1< R 3/ f< 0.3 −2.1< R 11/ R 1<−0.7 −1.8< R 7/ R 5<−0.9 where f 1 is the focal length of said first lens element, f is the focal length of the entire image scanning lens, f 23 is the composite focal length of said second lens element and said third lens element, R 3 is the radius of curvature of the object-side surface of said second lens element, R 11 is the radius of curvature of the image-side surface of said sixth lens element, R 1 is the radius of curvature of the object-side surface of said first lens element, R 7 is the radius of curvature of the object-side surface of said fourth lens element, and R 5 is the radius of curvature of the image-side surface of said third lens element.