The Application of Temporal Vision and Pulse Width Modulation Driving on LED Traffic Light

[[abstract]]本計劃是改變&；#63847；同之輸入功&；#63841；、驅動頻&；#63841；及負載週期等控制&；#63851；&；#63849；驅動LED，以人眼進&；#64008；實驗觀察驗證。在實驗與測試過程中，簡化&；#63851；&；#63849；測試過程、提升實驗效&；#63841；，建&；#63991；最佳化&；#63851；&；#63849；設定。為節省LED交通號誌所需之電力及降低其消耗功率及延長LED壽命，並維持亮度在一定的標準，讓駕駛人可以在任何時候清楚的辨識號誌，本計畫將根據人眼視覺暫留的特性，利用脈波驅動LED號誌，使其達到節能的效果。利用脈波驅動LED使LED呈現人眼所無法發現的閃爍狀態下，亮度維持與持續發光時的狀態相同。人眼視覺暫留大約在0.05秒，頻率大約在每秒20Hz左右。因此可藉由脈波寬度調變來改變輸出電壓或電流的責任週期，再根據人眼視覺暫留頻率，可控制輸出方波電流寬度，來調整LED輸出亮暗強度。[[abstract]]In order to save the consuming energy of LED traffic light、extend the life time of it and maintain its emission intensity, this proposal will use Pulse width modulation to drive the LED traffic light and save the energy based on the human temporal vision.To drive the LED use pulse width modulation under the flushing condition which human eyes can not tell, the emission intensity of LED will percepted as brighter than the one under contious driving condition. The period of human temporal vision is about 0.05 second. The corresponding frequency is about 20 Hz. Thus, we can adjust the emission output intensity of LED by control the pulse width or duty cycle of the LED driving pulses.In this proposal we will study the effects of frequency、duty cycle and amplitude of LED driving pulses on the emission intensity of human perception. The system for human perception experiment will be setup.[[note]]NSC98-2622-E327-015-CC