Patent ID: 6295166
Filing Date: 2001-09-25
Classification: G02B,H04N

Abstract:
A projection lens for a projection type of television system comprising in order from the image side to the object side a positive power first lens having a convex surface on the image side, a positive power second lens having a convex surface on the image side, a third biconcave lens, a positive power fourth meniscus lens having a convex surface on the object side and a positive power fifth lens having a convex surface on the image side, said projection lens satisfying the following conditions:0.35<F.sub.12 /F<0.65-0.30<F.sub.3 /F<-0.130.5<F.sub.5 /F<0.850.35<BF/F<0.55where F.sub.12 is the composite focal length of the first and second lens, F.sub.3 is the focal length of the third lens, F.sub.5 is the focal length of the fifth lens, F is the focal length of the projection lens, and BF is the back focal distance of the projection lens.