Patent ID: 7317585

Claim:
A compact imaging lens system comprising a first lens element on the object side and a second lens element on the image side; the first lens element having a first concave surface facing the object side and an opposite second convex surface on the image side, at least one of the concave and convex surfaces being aspheric; the second lens element having a negative refractive power and including opposite first and second surfaces respectively on object and image sides, the first surface of the second lens element being aspheric; said compact imaging lens system having no more than two lens elements, the first and second lens elements satisfying the following conditional expression: 0.6 < - f 1 f 2 < 1.2 where f 1 and f 2 respectively represent the focal lengths of the first and second lens elements; and the second surface of the first lens element and the first surface of the second lens element satisfying the following conditional expression: 0.45 < R 2 R 3 < 0.95 where R 2 and R 3 respectively represent the curvature radii of the second surface of the first lens element and the first surface of the second lens element.