| 摘要 |
PROBLEM TO BE SOLVED: To confirm the whole display screen with specific lightness and to distinctively view characters and patterns by arranging a reflecting mirror inside a irradiating device main body and a light transmission filter in front of the irradiating device main body, and specifying the mixing ratio of ultraviolet rays and visible light emitted by the light transmission filter. SOLUTION: The reflecting mirror 2 is stored in the irradiating unit main body 1. The light transmission filter 4 is arranged at the front end of the irradiating unit main body 1. The light transmission filter 4 has high spectral transmissivity in the ultraviolet-ray area and low spectral transmissivity in the visible light area. The reflecting mirror 2 has high reflectivity in the near ultraviolet-ray area and low reflectivity in the visible light area. The mixing ratio of the ultraviolet rays and visible light emitted by the light transmission filter 4 is specified below 20:1. Consequently, when this is used for a road indicator, a signboard, etc., such special effect that the display effect is large even under band weather conditions is obtained. |
