Patent ID: 7061696

Claim:
A single focus lens comprising, arranged along an optical axis in order from the object side: a stop on the object side of the single focus lens; a first lens component of positive refractive power, having a meniscus shape, having both surfaces of aspheric shape, and having a convex object-side surface; a second lens component of positive refractive power near the optical axis, having a meniscus shape near the optical axis, having both surfaces of aspheric shape, having a convex object-side surface near the optical axis, and having a part of negative refractive power within the effective diameter of the object-side surface of the second lens component; wherein the following conditions are satisfied: 0.20 <R 1 /f< 0.70 0.05 <D 2 /f 1<0.3 0.3<|( pa−pb )/ pa|< 1.3 where R 1 is the radius of curvature on the optical axis of the object-side surface of the first lens component, f is the focal length of the entire single focus lens on the optical axis, D 2 is the distance on the optical axis from the image-side lens surface of the first lens component to the object-side lens surface of the second lens component, f 1 is the focal length of the first lens component on the optical axis, pa is the optical distortion at the maximum image height, and pb is the optical distortion at fifty percent of the maximum image height.