| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens for projection that has a five-lens group structure, and employs a new magnification varying system to achieve a high magnification varying ratio and compactness.SOLUTION: A zoom lens for projection is used for an image display device that projects an image displayed on a display surface of an image display element to a projection target surface to be displayed in enlargement, and has a five-lens structure including first to fifth lens groups G1 to G5 arranged from an enlargement side to a reduction side. The first lens group G1 has a negative refractive power; the second lens group G2 has a negative refractive power; and the third lens group G3 has a positive refractive power. In varying magnification from a wide angle end to a telephoto end, the third lens group G3 is moved to the enlargement side, and the fourth lens group G4 is moved to the enlargement side; and the amount of movement D3 of the third lens group G3 during the magnification varying operation, and the amount of movement D4 of the fourth lens group G4 during the magnification varying operation satisfy the condition (1): 0.05<D3/D4<1.10. |
