Patent ID: 9568714
Date: 2017-02-14
CPC Classifications: G02B,G06F,G06K

Claim:
1. A projection lens, comprising a first lens, a reflective optical device, a second lens and a third lens from an image side of the projection lens to an object side of the projection lens in turn, wherein the first lens is of a negative focal power, an image side of the first lens is concave; the reflective optical device enables a light path to be bended; the second lens is of a positive focal power, an object side of the second lens is convex; and the third lens is of a positive focal power, an object side of the third lens is convex, wherein a diaphragm is arranged between the first lens and the second lens, the projection lens meets the following formulas: wherein ImgH equals to a half-length of an object diagonal, D represents a vertical height from the image side of the first lens to a center axis perpendicular to an object, f3 represents a focal length of the third lens, and f represents a focal length of the lens assembly.