| 摘要 |
PROBLEM TO BE SOLVED: To improve contrast and to improve the discriminability of a driver, by displaying a holography screen used as a display plane with a black or gray color under surrounding light. SOLUTION: After start of a projection device 2, a screen 3 is scanned by a laser beam or is irradiated with an appropriate light source such as, for example, a hologen lamp. The surface of the screen 3 is coated with only flexible holography material. The screen 3 is irradiated with a small projection device 2 mounted on a surface of an outer tube. A driver 1 watches a virtual image 4 at such a distance that adjustment of eyes for the display device is not required. The screen 3 is holography having a white projection surface. This holography is applied to a background of frosting black, color or gray. Or, it is applied to a transparent surface in front of a frosting black box absorbing light for transmitting light projection. |
