臺灣博碩士論文加值系統

近年來透明顯示器普遍被認為是下一世代的新型顯示器，因為它可同時看到環境景物時顯示虛擬資訊，成為鏈結虛擬資訊與現實世界的橋梁。因此在智慧窗戶、智慧型手機、戶外廣告看板、車用窗戶、擴增實境甚至是大樓建築等皆有與透明顯示器整合的潛力，可依消費者的需求提供娛樂、導航、廣告、教育等等互動式的體驗，使效能提高。
目前已有許多技術可做到同時呈現背景與顯示資訊如攝相機式、電濕潤式、全像投影式、有機發光二極體、側光源偏振片式、半反穿式、反射式以及散射式等等。這些技術各自有優缺點，但都無法同時做到有高穿透率透明態以及相容主動式驅動電路設計的低操作電壓，使透明顯示器的應用產生限制。而有團隊利用聚合物網絡型液晶搭配側向光源製作透明顯示器，由於聚合物網絡液晶的散射性質可取代偏振片以及快速反應時間特性可使用色序法取代彩色濾波片，使透明態穿透率達80%以上。而側向的散射路徑長可使較薄的液晶層厚度即有較高的對比度，使操作電壓下降可整合至主動式驅動，使透明顯示器有較好的應用。
而本研究論文基於此側向散射技術並深入瞭解入射光與散射光的偏振相依機制、不同材料選擇以及討論聚合物濃度及曝光強度對光電特性的影響，進而優化元件的光電特性。我們做出操作電壓13伏特、反應時間1.8毫秒、對比度30.4、透明態80%的側向散射元件能符合色序法以及主動式驅動的電壓設計。並且討論未來應用於顯示器上材料電壓保持率與光源準直性的問題，我們認為此技術未來在透明顯示器、擴增實境上皆有相當大的潛力。

In recent years, see-through display captures much attention as next-generation displays, because it can have virtual image and background view at the same time. Therefore, transparent displays have the potential for integrating with smart windows, smart phones, outdoor advertising billboards, vehicular head-up windows, augmented reality and even building outlook. It also can provide interactive experience of entertainment, navigation, advertising, education according to the demand of consumers.
At present, there are many technologies that can simultaneously display background and information, but they both can’t achieve transparent state with high transmittance and low operating voltage required for active matrix driving circuit design. They limit the development and application of transparent display. However, some groups used polymer network liquid crystals to develop transparent displays with edge-light sources. The scattering property of polymer network liquid crystals can replace polarizer, and color sequential method replace color filters due to fast response time. Therefore, based on the two properties, the transparent state with the transmittance more than 80% is expected to be achieved. In addition, longer lateral scattering paths allow the thin cell gap of liquid crystal still have a high contrast, so that the operating voltage can be reduced to make the devices integrated with the active matrix driving.
Based on this edge-light scattering method, we continue to study the polarization dependence mechanism of incident light and scattered light, material selection, and the influence of polymer structure on electric-optical characteristics, and finally optimizes devices. In this research, we achieve excellent electro-optical properties: operating voltage is 13V, response time is about 2.1ms, the contrast ratio is about 30, and transmittance of transparent state is nearly 80%, which can apply to the color sequential method and the active matrix driving. We discuss the voltage holding rate of material and the collimation of the light source for the future application of the display. We believe this technology has considerable potential in the future for transparent displays and augmented reality.

論文審定書 i
致謝 ii
摘要 iii
Abstract iv
目錄 v
圖目錄 viii
表目錄 xi
第一章 緒論 1
第二章 液晶簡介 2
2-1 液晶起源 2
2-2 液晶分類 2
2-3 液晶的物理特性 4
2-3.1 秩序性參數 4
2-3.2 光學與介電係數異向性 5
2-3.3 黏滯係數異向性 8
2-3.4 彈性係數異向性與連續彈性理論 9
第三章 透明顯示器介紹 10
3-1 透明顯示器技術 10
3-1.1 攝相機式 10
3-1.2 電濕潤式 11
3-1.3 全像投影 12
3-1.4 有機發光二極體 13
3-2 液晶透明顯示器 14
3-2.1 偏振片式 14
3-2.2 半反穿式 14
3-2.3 膽固醇液晶散射粒子點式 15
3-2.4 聚合物網絡液晶散射式 16
3-2.5 前述技術討論 17
3-2.6 側向散射式 18
3-3 研究動機 21
第四章 實驗製程與量測系統介紹 25
4-1 材料介紹 25
4-1.1 液晶材料 25
4-2.2 高分子聚合物單體 26
4-2.3 光起始劑 26
4-2 樣品製作 26
4-3 量測系統介紹 28
4-3.1 偏振光學顯微鏡 28
4-3.2 側向耦合光源光路 29
第五章 實驗結果與討論 33
5-1 不同液晶模態討論 33
5-2 入射光及散射光偏振相依性 34
5-2.1 入射光與液晶排列關係 34
5-2.2 散射光偏振相依性 35
5-2.3 入射光偏振相依性 39
5-2.4 不同液晶模態驗證 40
5-3 材料匹配性 44
5-4 聚合物結構討論 45
5-4.1 曝光強度與聚合物濃度 45
5-4.2 週期結構干涉曝光 53
5-5 市售顯示器應用 54
5-5.1 電壓保持率 54
5-5.2 光源凖直性 56
第六章 結論與未來展望 59
參考文獻 60

[1]M. Tomioka, S. Ikeda, and K. Sato, "Pseudo-transparent tablet based on 3D feature tracking," in Proceedings of the 5th Augmented Human International Conference, 2014, p. 52.
[2]Y. S. Ku, S. W. Kuo, Y. H. Tsai, P. P. Cheng, J. L. Chen, K. W. Lan, et al., "62.4: The Structure and Manufacturing Process of Large Area Transparent Electrowetting Display," in SID Symposium Digest of Technical Papers, 2012, pp. 850-852.
[3]H. Takahashi and S. Hirooka, "Stereoscopic see-through retinal projection head-mounted display," in Stereoscopic displays and applications XIX, 2008, p. 68031N.
[4]A. Georgiou, J. Christmas, J. Moore, A. Jeziorska-Chapman, A. Davey, N. Collings, et al., "Liquid crystal over silicon device characteristics for holographic projection of high-definition television images," Applied optics, vol. 47, pp. 4793-4803, 2008.
[5]K. Hong, J. Yeom, C. Jang, G. Li, J. Hong, and B. Lee, "Two-dimensional and three-dimensional transparent screens based on lens-array holographic optical elements," Optics express, vol. 22, pp. 14363-14374, 2014.
[6]K. Hong, J. Yeom, C. Jang, J. Hong, and B. Lee, "Full-color lens-array holographic optical element for three-dimensional optical see-through augmented reality," Optics letters, vol. 39, pp. 127-130, 2014.
[7]G. Li, D. Lee, Y. Jeong, J. Cho, and B. Lee, "Holographic display for see-through augmented reality using mirror-lens holographic optical element," Optics letters, vol. 41, pp. 2486-2489, 2016.
[8]M. Kashiwabara, K. Hanawa, R. Asaki, I. Kobori, R. Matsuura, H. Yamada, et al., "29.5 L: Late‐News paper: Advanced AM‐OLED display based on white emitter with microcavity structure," in SID Symposium Digest of Technical Papers, 2004, pp. 1017-1019.
[9]S. H. K. Park, C. S. Hwang, J. I. Lee, S. M. Chung, Y. S. Yang, L. M. Do, et al., "4.3: Transparent ZnO Thin Film Transistor Array for the Application of Transparent AM‐OLED Display," in SID Symposium Digest of Technical Papers, 2006, pp. 25-28.
[10]S. H. K. Park, M. Ryu, C. S. Hwang, S. Yang, C. Byun, J. I. Lee, et al., "42.3: Transparent ZnO thin film transistor for the application of high aperture ratio bottom emission AM‐OLED display," in SID Symposium Digest of Technical Papers, 2008, pp. 629-632.
[11]S. K. Park, M. Ryu, S. Yang, C. Byun, C. Hwang, K. I. Cho, et al., "18.1: Invited Paper: Oxide TFT Driving Transparent AMOLED," in SID Symposium Digest of Technical Papers, 2010, pp. 245-248.
[12]J. Chung, J. Lee, J. Choi, C. Park, J. Ha, H. Chung, et al., "11.4: Transparent AMOLED Display Based on Bottom Emission Structure," in SID Symposium Digest of Technical Papers, 2010, pp. 148-151.
[13]Y. Park, D. Kang, S. Kim, T. Han, J. Yoo, and M. Lim, "Paper No 5.3: Simulation of Visual Quality for Transparent OLED Display," in SID Symposium Digest of Technical Papers, 2013, pp. 156-159.
[14]C.-C. Li, H.-Y. Tseng, H.-C. Liao, H.-M. Chen, T. Hsieh, S.-A. Lin, et al., "Enhanced image quality of OLED transparent display by cholesteric liquid crystal back-panel," Optics Express, vol. 25, pp. 29199-29206, 2017.
[15]C. H. Lin, W. B. Lo, K. H. Liu, C. Y. Liu, J. K. Lu, and N. Sugiura, "P‐144L: Late‐News Poster: Novel Transparent LCD with Tunable Transparency," in SID Symposium Digest of Technical Papers, 2012, pp. 1159-1162.
[16]H. Hua and C. Gao, "A polarized head-mounted projective display," in Proceedings of the 4th IEEE/ACM International Symposium on Mixed and Augmented Reality, 2005, pp. 32-35.
[17]O. Bimber, L. M. Encarnaçáo, and D. Schmalstieg, "Augmented Reality with Back‐Projection Systems using Transflective Surfaces," in Computer Graphics Forum, 2000, pp. 161-168.
[18]Z. Luo, F. Peng, H. Chen, M. Hu, J. Li, Z. An, et al., "Fast-response liquid crystals for high image quality wearable displays," Optical Materials Express, vol. 5, pp. 603-610, 2015.
[19]K. Y. Chen, Y. W. Li, K. H. Fan‐Chiang, H. C. Kuo, and H. C. Tsai, "P‐181L: Late‐News Poster: Color Sequential Front‐Lit LCOS for Wearable Displays," in SID Symposium Digest of Technical Papers, 2015, pp. 1737-1740.
[20]A. Yamamoto, Y. Yanai, M. Nagai, R. Suzuki, and Y. Ito, "16‐3: A Novel Transparent Screen Using Cholesteric Liquid Crystal Dots," in SID Symposium Digest of Technical Papers, 2016, pp. 185-188.
[21]E. Satoh, Y. Asaoka, K. Deguchi, I. Ihara, K. Minoura, S. Fujiwara, et al., "80.2: 60‐inch Highly Transparent See‐through Active Matrix Display without Polarizers," in SID Symposium Digest of Technical Papers, 2010, pp. 1192-1195.
[22]K. Okuyama, T. Nakahara, Y. Numata, T. Nakamura, M. Mizuno, H. Sugiyama, et al., "79‐4L: Late‐News Paper: Highly Transparent LCD using New Scattering‐type Liquid Crystal with Field Sequential Color Edge Light," in SID Symposium Digest of Technical Papers, 2017, pp. 1166-1169.
[23]X. Zhou, G. Qin, L. Wang, Z. Chen, X. Xu, Y. Dong, et al., "Full color waveguide liquid crystal display," Optics letters, vol. 42, pp. 3706-3709, 2017.
[24]D.-K. Yang, Fundamentals of liquid crystal devices: John Wiley & Sons, 2014.
[25]A. Moheghi, H. Nemati, and D.-K. Yang, "Polarizing light waveguide plate from polymer stabilized liquid crystals," Optical Materials Express, vol. 5, pp. 1217-1223, 2015.
[26]A. Moheghi, G. Qin, and D.-K. Yang, "Stable polarizing light waveguide plate for edgelit liquid crystal displays," Optical Materials Express, vol. 6, pp. 429-435, 2016.
[27]Y. Fung, D.-K. Yang, S. Ying, L.-C. Chien, S. Zumer, and J. Doane, "Polymer networks formed in liquid crystals," Liquid Crystals, vol. 19, pp. 797-801, 1995.
[28]R.-Q. Ma and D.-K. Yang, "Freedericksz transition in polymer-stabilized nematic liquid crystals," Physical Review E, vol. 61, p. 1567, 2000.
[29]I. Dierking, "Polymer network–stabilized liquid crystals," Advanced Materials, vol. 12, pp. 167-181, 2000.
[30]D. Broer, G. P. Crawford, and S. Zumer, Cross-linked liquid crystalline systems: from rigid polymer networks to elastomers: CRC press, 2011.
[31]D.-K. Yang, Y. Cui, H. Nemati, X. Zhou, and A. Moheghi, "Modeling aligning effect of polymer network in polymer stabilized nematic liquid crystals," Journal of Applied Physics, vol. 114, p. 243515, 2013.
[32]J. Sun and S. T. Wu, "Recent advances in polymer network liquid crystal spatial light modulators," Journal of Polymer Science Part B: Polymer Physics, vol. 52, pp. 183-192, 2014.
[33]H. Clark, C. Bozler, S. Berry, R. Reich, P. Bos, V. Finnemeyer, et al., "Liquid crystal uncooled thermal imager development," in Infrared Sensors, Devices, and Applications VI, 2016, p. 99740E.
[34]Y. Zhang, F. C. Lin, and E. H. Langendijk, "A field‐sequential‐color display with a local‐primary‐desaturation backlight scheme," Journal of the Society for Information Display, vol. 19, pp. 258-264, 2011.
[35]J. Heo, J.-W. Huh, and T.-H. Yoon, "Fast-switching initially-transparent liquid crystal light shutter with crossed patterned electrodes," AIP Advances, vol. 5, p. 047118, 2015.
[36]H. Lu, Y. Chu, S. Jing, G. Zhang, J. Hu, G. Lv, et al., "Characterisation and effect of polymer network deformation in reverse-mode polymer-stabilised cholesteric texture," Liquid Crystals, vol. 44, pp. 437-443, 2017.
[37]J. Moon, Y. Shul, H. Han, S. Hong, Y. Choi, and H. Kim, "A study on UV-curable adhesives for optical pick-up: I. Photo-initiator effects," International journal of adhesion and adhesives, vol. 25, pp. 301-312, 2005.
[38]B.-J. Liang, D.-G. Liu, W.-Y. Shie, W.-L. Tsai, P.-F. Hsu, and R.-F. Louh, "Effects of nanoscaled tin-doped indium oxide on liquid crystals against electrostatic discharge," Crystals, vol. 3, pp. 530-553, 2013.