Patent ID: 8780459

Claim:
An optical imaging lens system having non-cemented lens elements with refractive power in a total number of five, in order from an object side to an image side: a first lens element with positive refractive power having a convex object-side surface; a second lens element with positive refractive power; a third lens element with negative refractive power, and both the object-side and image-side surfaces thereof being aspheric; a fourth lens element having a convex image-side surface, and both the object-side and image-side surfaces thereof being aspheric; and a plastic fifth lens element having a concave image-side surface, with both the object-side and image-side surfaces thereof being aspheric, and having at least one inflection point positioned on at least one of the object-side and image-side surfaces thereof; wherein a maximal effective radial distance on the image-side surface of the fifth lens element is SD52, a maximal effective radial distance on the image-side surface of the fourth lens element is SD42, an axial distance between the object-side surface of the first lens element and the image-side surface of the fifth lens element is TD, an axial distance between the third lens element and the fourth lens element is T34, an axial distance between the second lens element and the third lens element is T23, a distance between a non-axial critical point of the image-side surface of the fifth lens element and the optical axis is Yp52, and they satisfy the following relations: 0.25<( SD 52 −SD 42)/ TD< 0.60; 0.1 <T 34 /T 23<2.8; and 0.3 <Yp 52 /SD 52<0.95.