Patent ID: 8508855

Claim:
A projection lens comprising: a first lens group having positive refractive power; a second lens group having negative refractive power; and a third lens group having positive refractive power, which are sequentially arranged from the magnification side of the projection lens, wherein the reduction side of the projection lens is telecentric, and wherein the following formulas (1) and (2) are satisfied: 0.30 ≦d 23 /f 3 ≦0.65 (1); and 10 ≦|D 12 /ff| (2), where d 23 : space in air between the second lens group and the third lens group, f 3 : focal length of the third lens group, D 12 : total length of the first lens group and the second lens group in the direction of an optical axis, and ff: length from the most magnification-side surface in the entire system of the projection lens to a magnification-side focus point of the entire system of the projection lens.