Patent ID: 7660049
Filing Date: 2010-02-09
Classification: G02B

Abstract:
1. An optical lens system for taking image comprising four lens elements with refractive power, from the object side to the image side: a first lens element with negative refractive power having a concave object-side surface and a convex image-side surface; a second lens element with positive refractive power having a convex object-side and a convex image-side surface; a third lens element with negative refractive power having a concave object-side surface and a convex image-side surface, the object-side surface and the image-side surface of the third lens element being aspheric; a fourth lens element with positive refractive power having a convex object-side surface and a concave image-side surface, the object-side surface and the image-side surface of the fourth lens element being aspheric; and an aperture stop located between the object and the second lens element; wherein an Abbe number of the first lens element is V1, an Abbe number of the third lens element is V3, and they satisfy the relation: