| 摘要 |
A zoom lens for projection consists of a negative first lens group, which is fixed during magnification change, a middle group, which includes plural lens groups that move during magnification change, and a positive last lens group, which is fixed during magnification change, in this order from a magnification side. A reduction side is non-telecentric. Both of a lens group closest to the magnification side and a lens group closest to the reduction side in the middle group have positive refractive power, and move from the reduction side toward the magnification side during magnification change from a wide-angle end to a telephoto end. The last lens group includes at least two positive lenses and at least two negative lenses. A positive lens is arranged closest to the reduction side in the last lens group. A predetermined conditional expression about a focal length of the last lens group is satisfied. |
