| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens suitable for enlarging and projecting on a screen an original image formed by a luminous flux optically modulated by a microdevice and to provide an image display device equipped with the same.SOLUTION: A zoom lens constitutes a projection optical system of an image display device which enlarges and projects on a projection surface an image displayed on a display surface of an image display element, and comprises a first lens group having negative refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having positive refractive power, and a fifth lens group having negative refractive power, arranged in order from the projection surface side to the image display element side. A focal length F5n of a negative lens closest to the image display element in the fifth lens group and a focal length F5p of a positive lens closest to the image display element in the fifth lens group satisfy -1.9<F5n/F5p<-1.1. |
