Patent ID: 7961406
Filing Date: 2011-06-14
Classification: G02B

Abstract:
1. An optical lens system for taking image comprising, in order from the object side to the image side: a first lens element with positive refractive power having a convex object-side surface; an aperture stop; a second lens element with negative refractive power; a third lens element having a convex object-side surface; and a fourth lens element with negative refractive power having a concave object-side surface, an image-side surface of the fourth lens element being aspheric, inflection points being formed on the image-side surface of the fourth lens element; a distance from the image-side surface of the fourth lens element to an image plane along an optical axis being BFL, a total track length of the optical lens system for taking image being TTL, they satisfying the relation: in the optical lens system for taking image, the number of lens elements with refractive power being limited to four.