Patent ID: 7957079

Claim:
An optical lens system for taking image comprising, in order from the object side to the image side: an aperture stop; a first lens element with positive refractive power having a convex object-side surface; a plastic second lens element with negative refractive power having a concave object-side surface and a concave image-side surface, the object-side and the image-side surfaces of the second lens element being aspheric; a third lens element with positive refractive power having a concave object-side surface and a convex image-side surface; a fourth lens element with negative refractive power having a convex object-side surface and a concave image-side surface; and in the optical lens system for taking image, the number of lens elements with refractive power being limited to four; wherein a radius of curvature of the object-side surface of the second lens element is R3, a radius of curvature of the image-side surface of the second lens element is R4, they satisfy the relation: −0.40<( R 3 +R 4)/( R 3 −R 4)<0.85.