Patent ID: 9690082
Date: 2017-06-27
CPC Classifications: G02B

Claim:
1. An wide-angle projection lens comprising, in order from a projection side to an image source side along an optical axis: a first lens group with negative refractive power; a second lens group with positive refractive power; and a third lens group with positive refractive power; wherein the third lens group comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens, all of which are arranged in order from the projection side to the image source side along the optical axis, wherein the first lens and the second lens are cemented together to form a cemented lens, wherein the third lens and the fourth lens are cemented together to form a cemented lens and there is no air gap between the third lens and the fourth lens, wherein the wide-angle projection lens satisfies: 4.0<|tt/bf|<5.0 where tt is a total track length of the wide-angle projection lens and bf is a back focal length of the wide-angle projection lens, wherein the third lens has a negative refractive power.