| 摘要 |
PROBLEM TO BE SOLVED: To retain the power generating capacity of a solar battery used for an electric power source for a spontaneously illuminating traffic sign for a long time. SOLUTION: A solar battery 2 is provided as an electric power source for an emitting source to illuminate marks 1 of a traffic sign. A membrane having a photocatalytic activity as a self-cleaning membrane 16 is attached to the light-receiving face 15 for solar beam of the solar battery 2. Even when an organic substance such as exhaust gas sticks to the light-receiving face 15, it is decomposed and removed by the photocatalytic activity of the self-cleaning memberane. Further, sand, dust, dirt, etc., in the air are easily washed out with rainwater or the like, since oil components serving as an adhesive, is decomposed. |
