Projection lens
 An improved projection lens capable of advantageously decreasing a distortional aberration by providing a longer back focal length, which includes which includes a first lens group including a concave lens and a plurality of convex lenses, which are formed in order from a screen; a light amount control member formed on an optical axis and behind the first lens group for controlling the amount of light transmitted from the first lens group; a second lens group formed on the optical axis behind the light amount control member; a third lens group formed on the optical axis and behind the light amount control member and including a plurality of lenses; and a block formed on the optical axis and behind the third lens group for adjusting a focal distance. 
LG Electronics Inc.
G G
G02B G02B
inventional inventional
Seung Gyu
Lee