Patent ID: 8570661

Claim:
A projection lens system, in this order from a screen-side to an SLM-side thereof, comprising: a first lens group of negative refractive power, the first lens group comprising a first lens; and a second lens group of positive refractive power, the second lens group, in this order from the screen-side to the SLM-side of the projection lens system, comprising: a second lens of positive refractive power; a third lens of positive refractive power; a fourth lens of negative refractive power; and a fifth lens of positive refractive power; the projection lens system satisfying the following condition formulas: 1.95<|F1/Fw|<2.15, 0.5<|f4/Fw|<0.7, and 1.05<|f5/Fw|<1.25, where F1 is the effective focal length of the first lens group, f4 is the focal length of the fourth lens, and f5 is the focal length of the fifth lens, Fw is the effective focal length of the projection lens system which is in a wide-angle state; wherein the projection lens system satisfies the following condition formula: 0.45<|Vd4/Vd5|<0.55, where Vd4 and Vd5 are the Abbe numbers of light at the wavelength of 587.6 nm in the fourth lens and the fifth lens fifth, respectively.