Patent ID: 7916401

Claim:
An optical lens system for taking image comprising, in order from an object side to an image side: an aperture stop; a first lens element with positive refractive power having a convex object-side surface and a convex image-side surface; a plastic 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 plastic third lens element with negative refractive power having a convex object-side surface and a concave image-side surface, at least one of the object-side and the image-side surfaces of the third lens element being aspheric; in the optical lens system for taking image, the number of the lens elements with refractive power being limited to three, a focal length of the optical lens system for taking image is f, a focal length of the first lens element is f 1 , a focal length of the second lens element is f 2 , a focal length of the third lens element is f 3 , an Abbe number of the first lens element is V 1 , an Abbe number of the second lens element is V 2 , an on-axis distance between the second lens element and the third lens element is T 23 , and they satisfy the relations: 0.8 <f/f 1<1.8; 0 <|f/f 2|<0.8; 0 <|f/f 3|<0.7; 20 <V 1 −V 2<38; 0.13 <T 23 /f< 0.21.