US Patent 7957075 Optical lens system for taking image

An optical lens system for taking image consisting of 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 and a concave image-side surface; a second lens element with negative refractive power having a concave object-side surface and a convex image-side surface, at least one of the object-side and the image-side surfaces of the second lens element being aspheric; and a third lens element with positive refractive power having a convex object-side surface and a convex image-side surface, at least one of the object-side and the image-side surfaces of the third lens element being aspheric.