Patent ID: 7440197

Claim:
An image forming lens comprising a stop and a single lens placed in this order from the object side, wherein if the object-side surface of the single lens having paraxial curvature radii to form biconvex surfaces is referred to as the first surface while the image-side surface is referred to as the second surface, both said first surface and said second surface of said single lens have an aspherical shape, and the following conditional expressions are satisfied: 0.18 <d 0 /f< 0.25 (1) 0.60 <R 1 /f< 0.85 (2) 1.40 <L 0 /f< 1.55 (3) where f: focal length d 0 : the distance from the stop to the first surface of the lens R 1 : the curvature radius of the first surface of the lens L 0 : the distance from the stop to the focal points.