Imaging lens system

摘要

An imaging lens system includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element. The first lens element with positive refractive power has a convex object-side surface. The second lens element has positive refractive power. The third lens element has positive refractive power. The fourth lens element has refractive power. The fifth lens element with refractive power has a concave image-side surface at a paraxial region, and the image-side surface thereof changes from concave at the paraxial region to convex at a peripheral region, wherein both of an object-side surface and the image-side surface are aspheric.

主权项

1. An imaging lens system comprising, in order from an object side to an image side:
a first lens element with positive refractive power having a convex object-side surface at a paraxial region; a second lens element having positive refractive power; a third lens element having positive refractive power; a fourth lens element having refractive power; and a fifth lens element with refractive power having a concave image-side surface at a paraxial region, wherein the image-side surface of the fifth lens element changes from concave at the paraxial region to convex at a peripheral region, and both of an object-side surface and the image-side surface of the fifth lens element are aspheric; wherein a focal length of the imaging lens system is f, a curvature radius of an object-side surface of the second lens element is R3, a focal length of the fourth lens element is f4, a focal length of the fifth lens element is f5, and the following relationships are satisfied:
−0.80