Projection zoom lens and projection type display device

摘要

A projection zoom lens includes: a first lens group having a negative refractive power provided most toward the magnification side, which is fixed when changing magnification; and at least two movable lens groups that move to change the relative distance therebetween in the direction of an optical axis when changing magnification. The first lens group is constituted by, in order from the magnification side to the reduction side, a front group which is fixed during focusing operations and a rear group having a negative refractive power that moves in the direction of the optical axis during focusing operations. The front group moves in the direction of the optical axis to correct field curvature. Conditional Formula (1) related to the focal length fw of the entire lens system at the wide angle end and the focal length fla of the front group is satisfied.
|fw/fla|<0.2  (1).

主权项

1. A projection zoom lens, comprising:
a first lens group having a negative refractive power provided most toward the magnification side, which is fixed when changing magnification; and at least two movable lens groups that move to change the relative distance therebetween in the direction of an optical axis when changing magnification; the first lens group consisting of, in order from the magnification side to the reduction side, a front group which is fixed during focusing operations and a rear group having a negative refractive power that moves in the direction of the optical axis during focusing operations; the front group moving in the direction of the optical axis to correct field curvature; and Conditional Formula (1) below being satisfied:
|fw/fla|<0.2  (1) wherein fw is the focal length of the entire lens system at the wide angle end; and fla is the focal length of the front group.