Zoom lens and projector using zoom lens

Abstract

To provide a high performance compact zoom lens with a small lens aperture which projects an image from a light bulb such as a DMD in which an image is formed by changing reflecting directions of light on to a screen or the like in an enlarged fashion, according to the invention, there is provided zoom lens comprising, in order from a magnifying side thereof, a first lens group having a negative refractive power as a whole, a second lens group having a positive or negative refractive power as a whole and a third lens group having a positive refractive power as a whole, wherein changing the magnification of the whole lens system thereof is attained by configuring such that the first lens group and the second lens group are made to move on an optical axis in such a manner as to move in a direction from a magnifying side to a contracting side over a range from a wide angle end to an intermediate area and to move in a direction from the contracting side to the magnifying side over a range from the intermediate area to a telephoto end, and the third lens group is made to move on the optical axis in such a manner as to move in a direction from the contracting side to the magnifying side over a range from the wide angle end to the telephoto end.