Patent ID: 7663806

Claim:
A projection lens comprising, in order from a magnification side: a first lens group having negative refractive power; and a second lens group having positive refractive power, wherein an aspheric lens is arranged on the most magnification side of the first lens group, the projection lens is substantially telecentric on a reduction side, and the following conditional expressions (1) and (2) are satisfied: 3 <Bf/f (1) 0.4 <H/L (2) where f denotes a focal length of the projection lens, Bf denotes an air-converted back focal length, H denotes a height of a principal ray at the maximum angle of view on a plane (i) which is orthogonal to an optical axis and (ii) which passes through a vertex of a lens surface on the most magnification side on the optical axis, and L denotes a length from the vertex of the lens surface on the most magnification side on the optical axis to a vertex of a lens surface on the most reduction side on the optical axis.