| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a zoom lens suitable for a liquid crystal projector, for example, having high optical performance over the whole projection distance by appropriately correcting various aberrations due to focusing while attaining miniaturization of the whole lens system. <P>SOLUTION: The zoom lens includes: a lens group GF with a negative reflecting power GF immovable for zooming which is disposed on the largest expansion side; a lens group GR with a positive refractive power immovable for zooming which is disposed on the largest contraction side; and at least one lens group which is disposed between the lens group GF and the lens group GR and moves in the optical axis direction for zooming. The lens group GF includes a lens group (A) with a negative refractive power which moves during focusing and a lens group B with a positive refractive power immovable during focusing. The lens group GF has a lens GFa with a negative refractive power on the largest expansion side, and a lens group GR has a lens GRb with a positive refractive power on the largest contraction side. Moreover, Abbe numbers of the lens GFa and the lens GRb are defined appropriately, respectively. <P>COPYRIGHT: (C)2011,JPO&INPIT |
