Patent ID: 7813057

Claim:
An optical lens system for taking image comprising, from the object side to the image side: a first lens element with positive refractive power, an Abbe number of the first lens element being V 1 , and it satisfying the relation: 50<V 1 <60; a second lens element with negative refractive power having a concave object-side surface and a convex image-side surface, the second lens element being located behind the first lens element; a third lens element having a convex object-side surface and a concave image-side surface, the third lens element being located behind the second lens element, at least one of the object-side and the image-side surfaces of the third lens element being aspheric; a fourth lens element having at least one aspheric surface, the fourth lens element being located behind the third lens element; and an aperture stop being located before the second lens element; wherein: in the optical lens system for taking image, the number of the lens elements with refractive power is only four; the fourth lens element is made of plastic material and has a convex object-side surface and a concave image-side surface, both the object-side surface and the image-side surface of the fourth lens element are aspheric.