| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem that when the sun is located nearby an extension of a road sign board from a viewing point during reading of the road sign board on a vehicle during a travel, a sign board surface becomes dark owing to backlight and readability is too bad to maintain traffic safety, and uniform characters cannot be obtained at positions of ribs and a column by a method of improving the readability by making a hole and a slit in the center part of a character on the sign board and taking light in. <P>SOLUTION: A photovoltaic power generation plate is fitted to the back of the sign board and electric power is generated. LEDs fitted to the signboard plate surface are made to emit light with the generated electric power to improve the visibility. The LEDs are fitted tracing the center position of white reflective sheet of characters and marks of the sign board to improve the readability. The photovoltaic power generation plate is set in the opposite direction from the sign board. A large current flows with intense backlight and the sign board plate surface illuminates intensely. A small current flows with weak backlight and weak illumination is obtained, so the LEDs automatically illuminate according to the intensity of the backlight to improve the visibility. <P>COPYRIGHT: (C)2013,JPO&INPIT |
