| 摘要 |
PROBLEM TO BE SOLVED: To provide a compact and inexpensive projection optical system capable of performing proximity projection with excellent image performance while securing a wide viewing angle.SOLUTION: In a projection image display device, an enlarged image having less aberration is formed by a refractive optical section 40, image light can be temporarily condensed and then diverged by positive power of a first curved mirror 21, and the image light can be further diverged by negative power of a second curved mirror 22. An image whose aberration such as distortion is suppressed is projected onto a screen while a very wide viewing angle is secured even with the overall length of a system being shortened. By such means as an adjustment of power distribution to the refractive optical section 40 and the first and second curved mirrors 21 and 22, high machining accuracy is not required for the first curved mirror 21 and the size of the second curved mirror 22 or the like is reduced while a cost of the refractive optical section 40 being suppressed. |
