| 摘要 |
PROBLEM TO BE SOLVED: To provide a projection zoom lens which is inexpensive and offers a wide angle and good performance, and to provide a projection display device having the same.SOLUTION: A projection zoom lens substantially comprises, in order from the expansion side, a negative first lens group G1 that is stationary while zooming, a positive second lens group G2 that moves while zooming, a plurality of lens groups, and a final lens group that is stationary while zooming. Distance between each pair of adjacent lens groups changes while zooming. First through third lenses of the first lens group G1 arranged from the expansion side are: a first lens L11 which is a single lens having aspherical surfaces with a concave portion in a paraxial area on the expansion side and being negatively powered in the paraxial area; a second lens L12 which is a single lens having aspherical surfaces; and a third lens L13, respectively. A first lens group/front subgroup G1A comprising the first through third lenses L11-L13 has negative refractive power. The zoom lens satisfies conditional expressions associated with temperature coefficients of refractive indexes of the first lens L11 and second lens L12, a focal length of the third lens L13, and a focal length of the first lens group/front subgroup G1A.SELECTED DRAWING: Figure 1 |
