基於凸面螢幕的多投影式光場三維顯示系統之優化

Abstract

光場顯示作為一種新興的三維顯示技術，相較於其它裸眼式立體顯示技術而言，此技術由於可以提供細膩的水平視差及連續的運動視差，所以近年來已經變成研究的熱點之一。 本篇論文中，將原先使用的多投影式光場顯示系統其中的螢幕作變化，將螢幕從原本平面式改變成凸面形式，因而引進了一項新的參數: 曲率半徑在本系統中作探討，討論曲率半徑與其他項參數如: 螢幕的水平散射角、投影機到螢幕距離、觀賞者到螢幕距離、投影機間隔角等之間的變化以及現象，並且對整體系統重新評估，選取各項參數之間的最佳配置以及設計出最佳的觀賞區間，得到最佳的凸面式光場顯示系統，最後與平面式光場顯示系統兩者作比較。 模擬分析上利用光學模擬軟體來模擬，調變不同的參數，將模擬結果所呈現的影像作圖像探討以及形變量的數值分析，最後得出最佳的顯示系統配置，而在實作的分析上，由於在實作上需要設計出能夠固定彎曲的螢幕架子，本論文中利用了3D列印的方式製作所需要的曲面架以及平面架，最後將模擬以及實作的影像與數值分析作討論，對兩者顯示系統作總結，說明凸面光場顯示系統的優點以及缺點。 最後利用輝度計量測出兩種顯示系統下的亮度值，設計出一套評估方式，搭配模擬以及實作的量測，討論兩者的亮度差異，也得出凸面顯示系統將會比平面顯示系統在模擬以及實驗分別提升5.25%以及6.84%。

As an emerging 3D display system, when compared with other auto-stereoscopic displays, light field display provides continuous motion parallax, and also a delicate horizontal parallax. As such, it has become one of the research hotspots. In this thesis, the screen of the original multi-projector light-field display system changed from the conventional planar screen to a convex screen, so a new parameter (radius of curvature) will be discussed in the system. Then, the relationship between the radius of curvature and the horizontal scattering angle of the screen, the distance between the projectors and screen, the viewing distance between the viewer and screen, and the angle between the projector and projector are discussed. The overall system is re-evaluated to determine the optimal values for the parameters, the best configuration and the best design of the viewing area. The performance is compared with a conventional planar light-field display system. In the simulation analysis, we used an optical simulation software 〖LightTools〗^TM to simulate different parameters. The simulated image is analyzed, and the result is used to change the shape variables and determine the best display system design. In the analysis of the prototype, a 3D printed frame is used to bend the display at desired curvatures to construct the apparatus for the purpose of experimental verification of the simulation. The comparison between the simulated image and actual image are discussed. Finally, both the planar and convex display systems are summarized to illustrate the advantages and disadvantages of this convex light field display system. In the last section, we used the luminance measurement to measure the brightness of the planar and convex display systems. We designed a set of evaluation methods to analyze the brightness difference between the two display systems using simulation and experimental measurements. The brightness of the convex display was found to be higher than that of the planar display. In the simulation, the brightness of the display is increased by 5.25%. In the experimental verification, the brightness is increased by 6.84%. In both the simulations and experimental measurements, the image performance for the convex light-field display is better when compared with that of the previous planar display