Patent ID: 8270092
Filing Date: 2012-09-18
Classification: G02B

Abstract:
1. A zoom lens for projection comprising: a first lens group having negative refractive power; a second lens group having positive refractive power; a third lens group having positive refractive power; a fourth lens group; and a fifth lens group having positive refractive power, which are sequentially arranged from the magnification side of the zoom lens, wherein the first lens group and the fifth lens group are fixed, and the second lens group, the third lens group and the fourth lens group move along the optical axis of the zoom lens when magnification of the zoom lens is changed, and wherein each of the first lens group and the second lens group is composed of two lenses, and wherein each of the third lens group and the fifth lens group is composed of a positive lens, and wherein the fourth lens group is composed of five lenses, and wherein the reduction side of the zoom lens is telecentric.