| 摘要 |
[Problem] In a zoom lens for projection, to maintain high performance even with a high variable magnification ratio. [Solution] A zoom lens substantially configured by an intermediate group consisting of the following: a first lens group (G1) that is disposed on the farthest enlargement side, is fixed at the time of magnification, and has a negative refractive power; a final lens group (G6) that is disposed on the farthest reduction side, is fixed at the time of magnification, and has a positive refractive power; and a plurality of moving lens groups (G2-G5) that are disposed between the first lens group (G1) and the final lens group (G6), and that move at the time of magnification. The zoom lens, wherein the following formulae are satisfied: 1.00<(Rf2-Rr2)/(Rf2+Rr2) … (1); 0.00≤(Rr2-Rf3)/(Rr2+Rf3)<0.15 … (2). Provided that Rf2 is the front-side radius of curvature of the lens (L11) second from the enlargement side of the moving lens group on the farthest reduction side, that Rr2 is the rear-side radius of curvature of the second lens (L11), and that Rf3 is the front-side radius of curvature of the lens (L12) third from the enlargement side of the moving lens group on the farthest reduction side. |
