LED交通號誌燈中照明光杯之光學設計研究

目前傳統LED交通號誌燈是由近百顆低亮度LED所組成，當LED燈粒燒毀數目過多時，維修工程將變的極為麻煩及龐大且花費成本高。有鑑於此，本研究採用高效率LED做為光源設計出以少量LED及高能源使用效率之LED號誌燈模組。在本研究中，以ASAP光學模擬軟體針對號誌燈進行光強度分析，而在設計過中發現，以傳統單一反射鏡面方式之號誌燈，無法有效聚光。而為提高LED之光源之使用效率，本研究在反射鏡面內加上一光源反射杯，並針對此光源反射杯及各組件進行設計，設計所得之各組件尺寸為: 1、反射鏡面(曲率125，底部開口60mm，前端開口280mm)；2、光源反射杯(曲率40，底部開口80mm，前端開口120mm) ；3、透明擴散罩(凹點直徑2mm 間距3.75mm)，而在LED數量部分則為7顆單色LED。各組件製作完成並搭配以SMT製作之光學基板及驅動電源即可構成LED交通號誌燈模組，經由本計畫所設計之模組進行光強度值實測，結果發現其實測值符合CSN14546規範。

關鍵字

發光二極體；光源反射杯；交通號誌燈；高效率

並列摘要

The traditional LED (Light Emitting Diode) traffic light is made of more than hundred of low power LED. And it will cause power consumption, light failure and huge cost in maintenance. Therefore, in this investigation, the high efficiency LED is introduced to design a high efficiency traffic light modulus by using few LED. In this study, the ASAP (Advanced Systems Analysis Program) is used to simulate the luminous intensity. However, in the design process, it is found that the LED light can't focus well when just using a single reflector. In order to overcome the problem, an inner reflector is adopted to let the usage of the LED light becomes more efficient. After many simulations an data measurement, a good design is obtained. Its dimension for the traffic light modulus are (1) outer reflection: curvature is 125, bottom opening is 60 mm, front opening is 280 mm, (2) inner reflection: curvature is 40, bottom opening is 80 mm, front opening is 120 mm (3) diffuser: dimple diameter is 2 mm, the spacing between dimple is 3.75 mm. As for the quantity for LED, there are seven single color LED in this design. Seven 12 Watt yellow LEDs are used for the light source Finally, the component mentioned above are made and assembled into a LED traffic modulus. The modulus is lighted and the luminous intensity is measured. The measured data fits the required specifications of CNS 14546 in luminous intensity and just consumes one third of the power.