| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-performance and compact zoom lens having a small lens aperture and enlarging and projecting an image from a light valve, which forms the image by changing the reflecting direction of light, such as a DMD to a screen or the like. SOLUTION: The zoom lens is constituted of a first lens group having positive or negative refractive power as a whole, a second lens group having negative refractive power as a whole, a third lens group having positive or negative refractive power as a whole, a fourth lens group having positive refractive power as a whole, and a fifth lens group having positive refractive power as a whole in order from an enlargement side. The first lens group and the fifth lens group are fixed during variable power operation, the second lens group and the third lens group move on an optical axis in a direction from the enlargement side to a reduction side from a wide angle end to a middle area, and in a direction from the reduction side to the enlargement side from the middle area to a telephoto end, and the fourth lens group moves on the optical axis in the direction from the reduction side to the enlargement side from the wide angle end to the telephoto end, thereby achieving the variable power of the lens entire system. COPYRIGHT: (C)2007,JPO&INPIT
|
