Patent ID: 7599130

Claim:
An image reading lens comprising: in order from an object side of the image reading lens, a first lens of a negative lens having a meniscus shape directing a concave surface toward the object side thereof; a second lens having a biconvex shape; a stop; a third lens of a positive lens having a meniscus shape directing a convex surface toward an image side thereof; and a fourth lens of a negative lens having a meniscus shape directing a concave surface toward the object side thereof, the image reading lens satisfying conditional expressions: 2.4< f 3/ f< 3.5 0.007< D 2/ f< 0.028 wherein f represents a focal length of the image reading lens, f 3 represent a focal length of the third lens, and D 2 represents a spacing between an image-side surface of the first lens and an object-side surface of the second lens.