Patent ID: 8253843

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; a second plastic lens element with negative refractive power having an aspheric concave object-side surface and an aspheric convex image-side surface, the second lens element being located behind the first lens element; a third plastic lens element with negative refractive power having an aspheric convex object-side surface and an aspheric concave image-side surface, the third lens element being located behind the second lens element; a fourth plastic lens element with positive refractive power having an aspheric convex object-side surface and an aspheric concave image-side 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.