Design and Application of the Led Edge-Lit Curved Light Guide Bar on the Automotive Lighting Devices (Ii)

[[abstract]]本計畫探討 LED 側入光曲面導光條，應用在車用警示照明元件的設計。LED 已逐 漸成為主流節能燈源，在平面顯示裝置、標誌與儀器燈號的應用已非常成熟，但現有 應用多直接將 LED 直下式排列封裝成現有燈具外型，雖具有高亮度與節能的優點，但 有均勻性不足、炫光與 LED 數量太多的問題。LED 側光導光板技術常使用在平面顯示 器背光模組，但現有研究多為平面，若要應用到照明設計，則需考量造型變化成曲面 時的光學設計，如何能達成均勻導光與出光成為側光導光條的設計重點。本計畫以兩 年為期進行曲線導光條設計與最佳化的研究，並以車用尾燈應用為載具，使用光學模 擬軟體 TracePro 做為光學特性分析工具，於導光條單側或兩側設置 LED，將光線導入 曲面導光條，研究導光特徵如截頂角錐、V-cut 等，與特徵幾何參數對出光特性的影響， 並探討導光條幾何曲率與厚度變化對光線傳遞的影響，並提出導光條特徵分佈的模糊 最佳化策略，使燈組能呈現一均勻出光，並符合美國 SAE 車尾燈設計規範。完成設計 與南部車燈製作廠商合作，進行原形尾燈製作，進行車尾燈配光測試與改善回饋，並 探討未來應用於其他照明設計的可行性。[[abstract]]This project investigates the optical design of LED edge-lit curved light guide bar and applies to the design automotive lighting devices. LEDs have become the main stream of illumination light sources due to the advantages of long life, low power consumption, and small size. LEDs have been widely applied to the LCD displays, consumer products, and instrument signals. However, the designs are mostly of direct backlight module which uses array LEDs with diffusive films above. The applications of direct types LED array to automotive lighting devices often cause problems such as low uniformity, glaring light, and too many LEDs required. Edge-lit light guide plates have been widely used in the back light model of LCD, and the related research topic have also been extensively explored. The geometry of the lighting devices in the automotive lighting is often curved. However, the literatures regarding the design of curved light guide components are very limited. The light guiding and illumination uniformity are key issues for curved light guide bars. This project proposes a two-year study to investigate the design of edge-lit curved light guide bars and the optimization scheme for uniform light emitting. This study analyzes the influence of light guide features and component curvature to the optical characteristics. An automotive taillight with LED edge-lit light bar is used as an illustrated example. The angles and the distribution of the V-cut on the light bar are varied to satisfy the requirements of Society of Automotive Engineers (SAE) regulations and the illumination uniformity requirements. This research applies the optical simulation software, TracePro to simulate optical characteristics of a light bar with various light guide features such as v-cuts and pyramids and the related geometric parameters to achieve an optimum design. A Fuzzy optimization scheme is applied to vary the feature density along the light bar. Finally a prototype of the automotive taillight with the proposed design will be fabricated and the lighting performance will be measured to verify and improve the designs. The proposed design can be readily applied to other edge-lit lighting devices with curved geometry.[[note]]NSC102-2221-E327-01