| 摘要 |
<P>PROBLEM TO BE SOLVED: To accurately detect an approaching vehicle by an internal-lighting-type road sign which detects headlights of the vehicle and imposes brightness variation. <P>SOLUTION: This road sign includes: a sign body 3 in which an LED as a light-emitting member 12 is arranged in a casing, in which a display board 13 provided with a sign pattern is attached to one surface of the casing, and which is constituted so that the sign pattern applied to the display board 13 can be displayed in a transmitted manner by receiving a light from the LED arranged in the casing; and a light-emission control means which imparts the brightness variation to the LED in the sign body 3 on the basis of an output from a light-receiving element 10 receiving the light from the headlight of the vehicle 8. The light-emission control means performs control for imparting the brightness variation to the LED when the amount of the light received by the light-receiving element 10 becomes equal to/larger than a predetermined value in a unit time. <P>COPYRIGHT: (C)2011,JPO&INPIT |
