High Dynamic Range Display Systems
Total Page:16
File Type:pdf, Size:1020Kb
HIGH DYNAMIC RANGE DISPLAY SYSTEMS by RUIDONG ZHU B.S. HARBIN INSTITUTE OF TECHNOLOGY, 2012 A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the College of Optics and Photonics at the University of Central Florida Orlando, Florida Fall Term 2017 Major Professor: Shin-Tson Wu ©2017 Ruidong Zhu ii ABSTRACT High contrast ratio (CR) enables a display system to faithfully reproduce the real objects. However, achieving high contrast, especially high ambient contrast (ACR), is a challenging task. In this dissertation, two display systems with high CR are discussed: high ACR augmented reality (AR) display and high dynamic range (HDR) display. For an AR display, we improved its ACR by incorporating a tunable transmittance liquid crystal (LC) film. The film has high tunable transmittance range, fast response time, and is fail-safe. To reduce the weight and size of a display system, we proposed a functional reflective polarizer, which can also help people with color vision deficiency. As for the HDR display, we improved all three aspects of the hardware requirements: contrast ratio, color gamut and bit-depth. By stacking two liquid crystal display (LCD) panels together, we have achieved CR over one million to one, 14-bit depth with 5V operation voltage, and pixel-by-pixel local dimming. To widen color gamut, both photoluminescent and electroluminescent quantum dots (QDs) have been investigated. Our analysis shows that with QD approach, it is possible to achieve over 90% of the Rec. 2020 color gamut for a HDR display. Another goal of an HDR display is to achieve the 12-bit perceptual quantizer (PQ) curve covering from 0 to 10,000 nits. Our experimental results indicate that this is difficult with a single LCD panel because of the sluggish response time. To overcome this challenge, we proposed a method to drive the light emitting diode (LED) backlight and the LCD panel simultaneously. Besides relatively fast response time, this approach can also mitigate the imaging noise. Finally yet importantly, we improved the display pipeline by using a HDR gamut mapping approach to display HDR contents adaptively based on display specifications. A psychophysical experiment was conducted to determine the display requirements. iii To my beloved parents and friends. iv ACKNOWLEDGMENTS First and foremost, I would like to thank Prof. Shin-Tson Wu and his wife Cho-Yan Hiseh, both of whom have supported me mentally and spiritually. Prof. Wu is a visionary leader of our group and his guidance and suggestions helped me a lot during my Ph.D. years. Besides, he is always encouraging us to try out new ideas and explore new research frontiers. Whenever we need guidance, either academically or mentally, Prof. Wu will be there to help us out. I feel so blessed to be in the LCD family. In addition, I can never forget the delicious radish omelet Shinmu cooked for us! I would also like to thank my committee members: Prof. M. G. Moharam, Prof. Patrick L. LiKamWa and Prof. Jiyu Fang. Thank you for taking your time revising my thesis and helping me with my society awards and scholarship applications. Working in the LCD group feels like living in an adventurous family: there are always so many wonders to explore with my family members! During my journey, quite a few people helped me for my research adventure. Here I would like to thank Dr. Su Xu, Dr. Jie Sun, Dr. Yuan Chen, Dr. Jin Yan, Dr. Yifan Liu, Dr. Sihui He, Dr. Zhenyue Luo, Dr. Qi Hong, Dr. Daming Xu, Dr. Fenglin Peng, Yun-Han Lee, Haiwei Chen, Guanjun Tan, Juan He, Fangwang Gou, and Yuge Huang. Without your help, I will never achieve what I have done today. Besides my group members, I am also grateful to my other friends in both the academic world and the industry. I would like to thank Prof. Jiun-Haw Lee from National Taiwan University, who gave us a lot of advices and insightful information about OLED displays. I would also like to thank Mr. Tim Large, Dr. Neil Emerton and Dr. Abhijit Sakar at Microsoft for giving me a fun and challenging research experience. v Finally yet importantly, I would like to express my deepest gratitude to my parents for their unconditional support, both mentally and financially during my Ph.D. years. Thank you for respecting my choices and without your help life here would be much more challenging. vi TABLE OF CONTENTS LIST OF FIGURES ........................................................................................................................ x LIST OF TABLES ....................................................................................................................... xiv CHAPTER ONE: INTRODUCTION ............................................................................................. 1 1.1. High ambient contrast augmented reality systems ............................................................... 1 1.2. High dynamic range displays ............................................................................................... 2 CHAPTER TWO: HIGH AMBIENT CONTRAST AUGMENTED REALITY SYSTEMS ....... 8 2.1 A high ambient contrast augmented reality system ............................................................ 10 2.2 The tunable transmittance LC film...................................................................................... 11 2.3 Design Principle of the functional reflective polarizer ....................................................... 15 2.4 Functional reflective polarizer embedded AR system for color vision deficiency ............. 18 2.4.1. Origin of color vision deficiency ................................................................................ 18 2.4.2. Performance of our function reflective polarizer ........................................................ 20 2.5 Summary ............................................................................................................................. 23 CHAPTER THREE: DUAL PANEL FOR HIGH DYNAMIC RANGE DISPLAYS................. 25 3.1 Device configuration and working principles ..................................................................... 26 3.2 simulation and experimental results .................................................................................... 27 3.2.1 VT Curve ..................................................................................................................... 27 3.2.2 Contrast ratio ................................................................................................................ 28 3.2.3 Response time .............................................................................................................. 29 vii 3.2.4 Viewing angle .............................................................................................................. 30 3.3 Potential problems of the dual panel approach ................................................................... 31 3.4 Reducing the Moiré effect with polarization dependent scattering film ............................. 32 3.5 Summary ............................................................................................................................. 35 CHAPTER FOUR: QUANTUM DOT FOR WIDE COLOR GAMUT HIGH DYNAMIC RANGE DISPLAYS ................................................................................................................................... 37 4.1 Display system evaluation ................................................................................................... 39 4.2 Wide color gamut QD-enhanced LCD ................................................................................ 42 4.3 Wide color gamut RGB QLED ........................................................................................... 49 4.4 Discussions .......................................................................................................................... 52 4.4.1 Color Space selection ................................................................................................... 53 4.4.2 Angular performance of QD-LCD and RGB QLEDs.................................................. 54 4.4.3 Comparing QD-LCD with red and green phosphors embedded LCD ......................... 56 4.5 Summary ............................................................................................................................. 58 CHAPTER FIVE: ACHIEVING 12-BIT PERCEPTUAL QUANTIZER CURVE FOR HIGH DYNAMIC RANGE DISPLAY ................................................................................................... 59 5.1 Achieving 12-bit PQ curve: Driving the LC and LED separately ...................................... 60 5.2 Achieving 12-bit PQ curve: Driving the LC and LED simultaneously .............................. 64 5.3 Summary ............................................................................................................................. 69 viii CHAPTER SIX: REPRODUCE HIGH DYNAMIC RANGE CONTENTS BASED ON DISPLAY SPECIFICATIONS ....................................................................................................................... 70 6.1 Reproducing HDR content via HDR gamut mapping ......................................................... 70 6.2 HDR display setup .............................................................................................................. 74 6.3 The psychophysical experiment .......................................................................................... 76 6.4 Discussions .........................................................................................................................