| 摘要 |
PURPOSE: An LED street light automatically controlling illuminance is provided to secure the safety of a driver and a pedestrian as much as possible, by increasing the level of illumination on a foggy day and by reducing the level of illumination on a ordinary day. CONSTITUTION: A sensor(210) adheres to a street to measure the concentration of outdoor fog or the level of illumination on the road surface. The sensor provides the information through a communications unit to a control unit(220). The control unit controls the light output of an LED device(230) according to a predetermined output value to correspond to the concentration of fog sensed by the sensor. The control unit controls the light output of the LED device in proportion to the speed of a driving vehicle. The control unit controls the light output of the LED device according to the output value corresponding to the measured level of illumination on the road. [Reference numerals] (210) Sensor; (220) Control unit; (230) LED device |
