| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image display device having a narrow viewing angle capable of contributing to energy saving by eliminating waste of energy caused by having a wider viewing angle than required. <P>SOLUTION: An image display device includes: a convex lens means 12 with a focal distance f; a projection optical system 10 having an iris surface located at a distance of nearly a from an incident surface provided on an incident surface 14 side of the convex lens means 12; and a transmission type image display means (liquid crystal panel) 8 capable of forming an image on the incident surface 14. A spatial image-forming iris surface 18 is formed at a distance b satisfying an equation of (1/a)+(1/b)=1/f from an outgoing surface 16 of the convex lens means 12. <P>COPYRIGHT: (C)2013,JPO&INPIT |
