Patent ID: 8218253
Filing Date: 2012-07-10
Classification: G02B

Abstract:
1. 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 second lens element with negative refractive power; a third lens element with positive refractive power having a concave object-side surface and a convex image-side surface; a plastic fourth lens element with negative refractive power having a concave image-side surface, an object-side and the image-side surfaces of the fourth lens element being aspheric; and in the optical lens system for taking image, the number of lens elements with refractive power being limited to four; wherein a focal length of the optical lens system for taking image is f, a focal length of the first lens element and the second lens element combined being f