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研究生: 楊淑媚
Yang, Shu-Mei
論文名稱: 微米級尺寸發光二極體陣列之光學特性模擬分析
Optical Simulation and Analysis of Micron Scaled LED Array
指導教授: 趙煦
Chao, Shiuh
林建中
Lin, Chien-Chung
口試委員: 武東星
Wuu, Dong-Sing
盧廷昌
Lu, Tien-Chang
黃智方
Huang, Chih-Fang
學位類別: 博士
Doctor
系所名稱: 電機資訊學院 - 光電工程研究所
Institute of Photonics Technologies
論文出版年: 2019
畢業學年度: 107
語文別: 英文
論文頁數: 86
中文關鍵詞: 發光二極體微發光二極體顯示器色差
外文關鍵詞: LED, microLED, display, color variation
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  • 微米級LED顯示器技術已被視為是下世代顯示器的主流技術之一。微米級LED具有許多優良的特性,例如廣色域、高亮度、低耗電以及快速響應時間。未來在擴增實境(Augmented Reality, AR)和混合實境(Mixed Reality, MR)的應用,更被視為最具有競爭力的技術。
    本研究提出一套模擬架構,用於計算全彩微米級RGB LED顯示器的的光型和色差,包含miniLED 與microLED,並據此進行性能的評估。透過這項研究,我們探討了影響微米級RGB LED 顯示器光學性能的重要因子,包含有無基板、基板厚度、基板切割角、模塑層的形狀及氣泡等。透過模擬得知,其中基板厚度及切割角將在光學性能的設計上扮演重要的角色。基板及切割角的最佳化可影響光場分布並改善角度色差和圖像品質。而且,圖案化的基板可以提高光提取效率。然而由於紅光、綠光和藍光的光場分布不一致也增加了色差,需要透過精心的光學設計才能使光分佈均勻。我們並製作相對應的樣品,通過實驗驗證,顯示與模擬結果具有良好的一致性。
    通過這項研究,可得知影響微米級LED顯示器光學性能的重要因子。我們認為本研究工作對於未來使用microLED技術實現下一世代高品質顯示器,具有重要的參考價值。


    Micron-scale LED display technology has been recognized as one of the mainstream technologies for next generation displays. Micron-scale LEDs have many excellent features such as wide color gamut, high brightness, low power consumption, and fast response time, and are considered to be the most competitive technologies in future Augmented Reality (AR) and Mixed Reality (MR) applications.
    This study proposes a simulation scheme for calculating the light pattern and color variation of a full-color micron-scale RGB LED display, including miniLEDs and microLEDs, and evaluating performance accordingly. Through this study, we explored important factors affecting the optical performance of micron-scale RGB LED displays, including the presence or absence of substrates, substrate thickness, substrate cutting angle, shape of the molded layer, and bubbles. Through simulation, the thickness of the substrate and the cutting angle will play an important role in the design of optical properties. Optimization of the substrate and cutting angle can affect the light field distribution and improve angular color variation and image quality. We also fabricated corresponding samples and measured the optical performance, which were verified and showed good agreement with the simulation results.
    Through this research, important factors affecting the optical performance of micron-sized LED displays are known. We believe that this research work has important reference value for the realization of next-generation microLED high-quality displays in the future.

    Content 摘 要 Abstract 致謝詞 1. Introduction 1 1.1 MicroLEDs, miniLEDs and macroLEDs 2 1.2 Micro-LED display technology and development trend 3 1.3 Research review 7 1.3.1 Opto-electrical characteristics 7 1.3.2 Light extraction efficiency 8 1.3.3 Color mixing method 9 1.3.4 Angular color variation 10 1.3.5 Crosstalk 12 1.4 Outline of the thesis 13 2. Theory 15 2.1 Basics of LED 15 2.1.1 Fundamental principles 15 2.1.2 LED opto-electrical characteristics 18 2.1.3 LED radiation pattern 21 2.2 Radiometry versus Photometry 23 2.3 Colorimetry 25 2.3.1 Color-matching functions and tristimulated values 25 2.3.1 Chromaticity diagram 26 3. Device fabrication and measurement 29 3.1 Device fabrication 29 3.2 Measurement setup 31 3.3 LIV and spectrum measurement 32 4. Modeling and calculation 34 4.1 Simulation condition and method 34 4.1 Color variation calculation 38 5. Results and discussion 40 5.1 Chip size 41 5.2 Substrate effect 44 5.3 Substrate cutting angle 46 5.4 Patterned sapphire substrate 49 5.5 Substrate thickness dependence 51 5.5.1 Substrate thickness vs light extraction efficiency 51 5.5.2 Substrate thickness vs light pattern 53 5.5.3 Substrate thickness vs color variation 58 5.6 The influence of molding layer shape 63 5.7 The influence of air bubbles in molding layer 64 5.8 Crosstalk 66 5.8.1 Intensity crosstalk 67 5.8.2 Color mixing crosstalk 68 6. Comparison of measurement and simulation 71 6.1 Comparison of light distribution 71 6.2 Comparison of color variations 75 7. Summary 77 References 79

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