Patent ID: 9383560
Filing Date: 2016-07-05
CPC Classification: G02B,G03B

Claim Text:
1. A zoom lens for projection substantially consisting of six lens groups of: 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 having negative refractive power; a fifth lens group having positive refractive power; and a sixth lens group having positive refractive power in this order from a magnification side, wherein the zoom lens is configured in such a manner that the first lens group and the sixth lens group are fixed and the second through fifth lens groups move during magnification change, wherein a reduction side is telecentric, wherein first through fourth lenses from the magnification side in the fifth lens group are a negative meniscus-shaped single lens with its convex surface facing the magnification side, a positive single lens, a biconcave lens and a biconvex lens, respectively, and the biconcave lens and the biconvex lens are cemented together, and wherein each single lens consists of one lens which is not cemented.