Patent ID: 8873165

Claim:
An optical lens system comprising, in order from an object side to an image side: a stop; a first lens element with a positive refractive power having an aspheric convex object-side surface and an aspheric convex image-side surface; a second lens element with a negative refractive power having a meniscus shape, and a concave image-side surface, at least one of an object-side surface or the image-side surface of the second lens element being aspheric; a third lens element with a positive refractive power having a convex object-side surface and an image-side surface, and the image-side surface being convex or flat near an optical axis, both of the object-side surface and the image-side surface are aspheric; a fourth lens element with a positive refractive power having concave object-side surface and a convex image-side surface, at least one of the object-side surface or the image-side surface of the fourth lens element being aspheric; a fifth lens element with a negative refractive power having an aspheric object-side surface and an aspheric image-side surface, the image-side surface of the fifth lens element being concave near the optical axis, and at least one inflection point being formed on the image-side surface of the fifth lens element; wherein a focal length of the optical lens system is f, a focal length of the first lens element is f1, a focal length of the third lens element is f3, a focal length of the fourth lens element is f4, a focal length of the fifth lens element is f5, and they satisfy the conditions: 0.4 <f 4 /f< 1.0; −0.8 <f 5 /f<− 0.4; f 1 /f< 1.2 <f 3 /f.