Patent ID: 7710659
Filing Date: 2010-05-04
Classification: G02B

Abstract:
1. A projection zoom lens comprising, in order from a magnification side thereof: a first lens group having a negative refractive power; a second lens group having a positive refractive power; a third lens group having a positive refractive power; a fourth lens group having a positive refractive power; and a fifth lens group having a positive refractive power; wherein the first lens group includes a first lens of an aspherical lens whose concave surface is directed to a reduction side of the projection zoom lens, the second lens group includes a second lens of a positive lens, the third lens group includes, in order from the magnification side, a third lens of a positive lens and a fourth lens of a negative lens, the fourth lens group includes, in order from the magnification side, a fifth lens of an aspherical lens whose concave surface is directed to the magnification side, a sixth lens of a negative lens, a seventh lens of a positive lens and an eighth lens of a positive lens, the fifth lens group includes a ninth lens of a positive lens, and the projection zoom lens is telecentric on the reduction side thereof.