Patent ID: 7038857

Claim:
A projection zoom lens comprising, from an image side to an object side, a first lens group having a negative refractive power, consisting of a number of lens elements and being movable along an optical axis of the projection zoom lens; a second lens group having a positive refractive power, consisting of a number of lens elements and being movable along the optical axis of the projection zoom lens; and an aperture stop arranged between two lens elements of the second lens group and being axially movable therewith; the projection zoom lens satisfying the following conditions: −0.90<P2/P1<−0.78 −1.99<P1/PF<−1.67 1.50<P2/PF<1.55 0.58<PF/BF<0.68 5.37<TT/PF<5.82 3.40<TT/BF<3.80 −1.34<EX/BF<−1.13 Where P1 represents the refractive power of the first lens group, P1 represents the refractive power of the second lens group, PF represents the focal length of the projection zoom lens as a whole at the wide-angle end, BF represents the back focal length of the projection zoom lens as a whole at the wide-angle end, TT represents the total optical track of the projection zoom lens as a whole at the wide-angle end, and EX represents the exit pupil position of the projection zoom lens as a whole at the wide-angle end.