| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-performance projection lens capable of realizing a wider viewing angle and also made excellent in various kinds of aberration correction as a projection lens enlarging and projecting a picture on a display surface to a screen, and to provide a projection type picture display device using the projection lens and made short in depth. SOLUTION: The projection lens has a 1st lens group having negative refractive power and a 2nd lens group having positive refractive power in order from an enlargement side to a reduction side, and satisfies following conditional expressions (1) to (4), then has the viewing angle of≥110°. The conditional expression (1) is 25.0<Fb, the conditional expression (2) is F<0.65H, the conditional expression (3) is 30F<¾EP¾, and the conditional expression (4) is 4F<T. Provided that Fb means an air-converted distance (mm) to an image point from the reduction side final surface of a lens, H means the maximum image height (mm) on the reduction side, F means the focal distance (mm) of the entire projection lens, EP means an exit pupil distance (mm), and T means the air-converted distance (mm) of space between the 1st lens group and the 2nd lens group. COPYRIGHT: (C)2005,JPO&NCIPI
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