| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem that the projection field angle of a projection lens for an image projection device is normally fixed, however, when a distance between a projection screen and the image projecting device is fixed according to an indoor environment, projected images are made too large or small, resulting in inconvenience. <P>SOLUTION: Among lens groups composing the projection lens, at least one lens is divided into a plurality of areas of different powers. The image projection device which incorporates this projection lens and allows a change in projection field angle by rotating the projection lens, is provided. <P>COPYRIGHT: (C)2008,JPO&INPIT |
