Fixed focus projection lens

Abstract

A fixed focus projection lens, from the magnifying side to the narrowing side of the lens sequentially comprising: a front lens group and a rear lens group, the front lens group has 8 to 11 lenses, the front lens group has a front aspherical lens, the rear lens group has 8 to 11 lenses, the rear lens group has a rear aspherical lens, for satisfying 1.5<|fa/f|<3 and 4<Bf/f<5, f is the focal length of the system, fa is the focal length of the front lens group from the first lens to the fifth lens, Bf is the rear focal length obtained by air conversion, the rear lens group has an aperture.

Dependencies are inferred from the claim text.