| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain a zoom lens which is suitably used in a liquid crystal projector, having satisfactory optical performances over the whole screen, by correcting various aberrations accompanying zooming satisfactorily, and to obtain an image projecting apparatus having the zoom lens. <P>SOLUTION: The zoom lens for projection has five or more lens groups, in which a lens group having negative refractive power is placed in the most front side and in which a lens group existing at the most rear side in lens groups which are moved on the optical axis at zooming, from a short focal length side to a long focal length side has a positive or negative refractive power, and remaining lens groups have all positive refractive power and it is characterized in that diffraction optical elements are provided on one or more lens surfaces which constitute the zoom lens. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
