本論文提出一種新型光學設計，將LED光源以朝下方式照射至反射杯，並結合柱狀透鏡陣列將光線展開至橫向方向，以改善傳統結構中配光不足與截止線模糊的情形。柱狀透鏡陣列在此架構中扮演關鍵角色，可有效重新分配反射光場，使最亮區域推移至接近截止線的位置，提升整體照度分佈的均勻性與增加光形邊緣之清晰度。 傳統腳踏車頭燈多採用LED下打結合簡易反射杯的設計，雖具備基本亮度輸出，但在光形控制方面存在明顯限制。部分產品雖透過遮擋方式產生明確的截止線，然而此類光形多為遮光後的結果，損失中心的照度值。 本光學設計在維持系統結構簡潔的前提下，能有效強化光形的橫向展開效果，使截止線更為明確，並使照度最強點貼近截止線，有助於降低雜散光對暗區照度的干擾，進一步提升整體對比度。整體而言，本研究所提出的設計在光形控制與模組化實現方面具備實務價值，可作為未來腳踏車照明系統優化的設計參考，亦具有進一步延伸應用之潛力。;This thesis proposes a novel optical design, where an LED light source is directed downward onto a reflector, combined with a cylindrical lens to expand the light horizontally. This design aims to address the insufficient light distribution and blurred cutoff lines typically found in traditional structures. The cylindrical lens plays a crucial role in this setup by effectively redistributing the reflected light field, shifting the brightest area closer to the cutoff line, improving overall illuminance uniformity, and enhancing the sharpness of the light pattern edges. Traditional bicycle headlights often use a simple reflector combined with a downward-facing LED, providing basic brightness output but facing significant limitations in beam control. While some products create a distinct cutoff line through shielding, this approach often results in a loss of illuminance in the center. This optical design effectively enhances the lateral light distribution while maintaining a simple system structure, making the cutoff line more distinct. The brightest point is brought closer to the cutoff line, helping to reduce stray light interference in darker areas and further improving the overall contrast. Overall, the design proposed in this study offers practical value in light pattern control and modular implementation, serving as a reference for future optimization of bicycle lighting systems and offering potential for further extended applications.
