Provided are a
projection lens and a projection device. According to the invention, the
projection lens is more miniaturized. The
projection lens (40) comprises, in order from the
magnification side, a first lens group (G1) having a positive or negative refractive power, an aperture stop, and a second lens group (G2) having a positive refractive power, and the first lens group (G1) comprises, in order from the
magnification side, a first sub-lens group (G1m) having a negative
refractive index, and a second sub-lens group (G1p) having a positive
refractive index. The projection lens satisfies the following
conditional expression: 0.1 < 1 / fg1p-1 / fg1m < 0.25 (1)
omega > 50 (2) 2.5 < (DL1 * LL) * F / IH2 < 6.5 (3) 3.0 < BF / F < 5.0 (4) where fg1p is a composite
focal length of the first sub-lens group (G1m), fg1m is a composite
focal length of the second sub-lens group (G1p), value (
omega) is a maximum half-
field angle of the projection lens, value (IH) is an image circle, value (DL1) is an
effective radius of the lens closest to the screen side, value (LL) is a total length of the lens, and BF / F is a total length of the lens. The value (F) is the combined
focal length of all the lenses, and the value (BF) is the back focal length air conversion value.