| 摘要 |
A zoom lens for projection includes negative first group G1, positive second group G2, positive third group G3, negative fourth group G4, positive fifth group G5, and positive sixth group G6, arranged from the magnification side of the zoom lens. The reduction side of the zoom lens is telecentric. When the magnification is changed, the first group G1 and the sixth group G6 are fixed, and the second through fifth groups G2 through G5 move. The fourth group G4 is a negative lens having a concave surface facing the magnification side, and the fifth group G5 includes at least two positive lenses and at least two negative lenses. Further, the following formula (1) is satisfied: −5.0≦̸f4/fw≦̸−1.2  (1), where f4: the focal length of the fourth group; and fw: the focal length of the entire system of the zoom lens at a wide angle end.
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