Patent ID: 9645356
Date: 2017-05-09
CPC Classifications: G02B

Claim:
1. An optical imaging system comprising, in order from an object side to an image side: a first lens element having refractive power, wherein at least one of an object-side surface and an image-side surface of the first lens element is aspheric; a second lens element with positive refractive power having an object-side surface being concave in a paraxial region thereof and an image-side surface being convex in a paraxial region thereof, wherein at least one of the object-side surface and the image-side surface of the second lens element is aspheric; a third lens element with negative refractive power having an image-side surface being concave in a paraxial region thereof, wherein at least one of an object-side surface and the image-side surface of the third lens element is aspheric; a fourth lens element with positive refractive power having an object-side surface being concave in a paraxial region thereof and an image-side surface being convex in a paraxial region thereof, wherein at least one of the object-side surface and the image-side surface of the fourth lens element is aspheric; and a fifth lens element with negative refractive power having an object-side surface being convex in a paraxial region thereof and an image-side surface being concave in a paraxial region thereof, wherein at least one of the object-side surface and the image-side surface of the fifth lens element is aspheric, and the image-side surface of the fifth lens element has at least one inflection point; wherein the optical imaging system has a total of five lens elements with refractive power; the first lens element, the second lens element, the third lens element, the fourth lens element, and the fifth lens element are singlet lens elements; there is an air gap in a paraxial region between every two of the first lens element, the second lens element, the third lens element, the fourth lens element and the fifth lens element that are adjacent to each other.