| 摘要 |
PROBLEM TO BE SOLVED: To provide a telecentric retrofocus lens having simple constitution, made bright and compact and to have a wide angle, restraining the occurrence of chromatic aberration of magnification and distortion to be little, easily used for an enlarging and projecting projection device and realizing high-definition image projection. SOLUTION: The projection lens has a 1st positive lens group having two negative lenses being concave meniscus lenses, a biconcave lens and at least one convex lens, and a 2nd lens group set behind the longest space and having positive refractive power in order from an enlargement side, and satisfies the following expression; 1<f2/f<4, provided that the focal distance of an i-th lens group is (fi) and the focal distance of an entire system is (f). COPYRIGHT: (C)2006,JPO&NCIPI
|
