Patent ID: 7692877
Filing Date: 2010-04-06
Classification: G02B

Abstract:
1. An optical lens system for taking image comprising four lens elements, in order from the object side to the image side: a first lens element with positive refractive power having a convex object-side surface; a second lens element with negative refractive power having a concave object-side surface and a concave image-side surface, at least one of the object-side surface and the image-side surface of the second lens element being aspheric, inflection points being formed on the image-side surface of the second lens element; a third lens element with positive refractive power having a convex object-side surface and a convex image-side surface, an on-axis distance between the second lens element and the third lens element is T a fourth lens element with negative refractive power, at least one surface of the fourth lens element being aspheric; the optical lens system for taking image further having an aperture stop located between the object side and the second lens element.