林晃巖臺灣大學:光電工程學研究所顏俊翔Yan, Chun-ShiangChun-ShiangYan2010-07-012018-07-052010-07-012018-07-052008U0001-2907200822591500http://ntur.lib.ntu.edu.tw//handle/246246/188386同調光源在影像系統中的應用逐漸受到重視，例如：雷射投影顯示系統，且因為許多元件的表面對於光波長而言是相當的粗糙，因此會在影像上產生許多不規則的暗點及亮點而降低影像的品質，而這種不規則的暗亮點分布就是所謂的光斑。們建立一個模擬模型來分析在成像系統中不規則結構所造成的光斑。我們分析的方法除了從理論上的數學推導外，也利用模擬的方式來分析更複雜的情況。本論文分成兩大部分，第一部分是研究光斑的基本特性以及形成的條件，而利用此我們可以進一步討論在顯示器面板上的微結構對於影像的影響；而第二部分我們研究抑制光斑的方法，包含角度分集(angular diversity)及波長分集(wavelength diversity)。模擬結果來討論，我們了解如何在顯示器面板上安排不規則微結構，而使光斑現象受到抑制；而且也了解到在許多種顯示器都會產生光斑，不僅止於雷射顯示器。對於在影像系統中設計被動元件用來抑制光斑，本論文提供了定性與定量的理論基礎。Application of coherent light in displays is gradually respected (e.g. laser projection system). In coherent imaging system, when image an object with a random surface fluctuation, a random intensity distribution would appear, as would degrade the image quality. We call the random intensity distribution a speckle pattern.n this thesis, we set up a simulation model to analyze speckle phenomena due to a random structure in imaging system. Our analysis includes not only mathematic derivation in theory, but also further discussion about more complicated situation by simulation. This thesis can be divided into two parts. One is investigation of basic character and cause of speckle, and further, we discuss the effect of micro-structure on display panel upon image. Another is investigation of methods of suppressing speckle, as contains angular diversity and wavelength diversity.rom the simulation results and discussions, we understand how to arrange irregular micro-structure on display panel to avoid speckle. Besides, we also understand that speckle appears in many displays, not only laser displays; This thesis also set up a steppingstone for designing static elements to suppress speckle in image in the future.致謝 i要 iibstract iiiable of Contents ivist of Figures viihapter 1 Introduction 1.1 Introduction of Laser Projection Displays 1.2 Introduction of Speckle Phenomena 2.3 Motivation 3.4 Analysis Method 4.5 Content 5hapter 2 Analysis of Speckle 6.1 Description of Random Surfaces 8.2 Image formation 11.3 Rough surface properties 13.4 Speckle phenomena in a 4-f imaging system 19.4.1 Spatial frequencies of speckle 20.4.2 Cause of speckle 23.4.3 Speckle size 24.5 Micro-lens structure in an imaging system 29.5.1 Regular micro-lens structure 32.5.2 Irregular micro-lens structure 34hapter 3 Speckle reduction 40.1 Produce independent speckle patterns 41.1.1 Summation of N independent speckle patterns 42.1.2 Moving diffuser on the object plane 44.1.3 Shifting the pupil position 47.2 Angle diversity 50hapter 4 Wavelength diversity 54.1 Wavelength dependence of speckle 55.2 Chromatic speckle 59.3 Simulation results and discussions 65.3.1 Preliminary simulation analysis 66.3.2 Feature size 71.3.3 Non-uniform transmittance 74.3.4 Other distributions 81.3.5 Detector size 82.4 Further discussion 83hapter 5 Conclusion and Future work 85eference 881074537 bytesapplication/pdfen-US光斑不規則表面同調光源影像系統角度分集波長分集specklerandom surfacecoherent sourcesimaging systemsangle diversitywavelength diversitythesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/188386/1/ntu-97-R95941054-1.pdf