臺灣博碩士論文加值系統

本篇論文主要目的為對光導管做一分析與研究，特別是為了應用於小尺寸分區場序列式液晶顯示器背光模組。場序式掃描為背光系統提供一種不需使用彩色濾光片及達到高效能高色彩飽和的方法。光源由光導管入光面射入，於其中傳撥，當全內反射條件不滿足時便會出射，其不滿足全內反射原因可能為光導管本身形狀或是光接觸到一些微結構時會改變原有行進方向。光導管的設計於背光的應用上有其應遵守的一些規範，除每一區塊的均勻度需有符合人眼所能接受的範圍，我們利用一光準直元件與光導管底部微結構控制出光發散角及分區間的漏光現象，以達到最後顯示的色彩無色偏現象。並經由模擬與實作來實現我們對於小尺寸分區場序式的背光設計。

The aim of this thesis is to analyze and investigate the light pipe principle, especially for that applied to the small size field-sequential color liquid crystal display. The field-sequential scanning backlight system has a lot of advantages such as high efficiency, high color gamut, and colorfilter-less. When the light coupled into the pipe, the ray propagates inside the pipe under a cone of aperture and then reflected outside the pipe by the micro structure deposited on the bottom or the shape of the pipe itself. The design of the pipe should have some criteria. For example, the non-uniformity should not be noticed by human eye and divergence angle should be well controlled. The light-collimating bars and the light pipes were adapted to manage the light illuminating angle and the light leakage into the other section in order to display the correct color on the panel. Through the simulation and experiment, a backlight for the small size field-sequential color liquid crystal display has been realized.

Table of Contents
Abstract (Chinese)
Abstract (English)
Table of Contents
Figure Caption

Chapter 1 Introduction ………………………1
1.1 Field-Sequential-Color Crystal Display (FSC LCD).…………3
1.2 Scanning Backlights Application to FSC LCD……5
1.3 Motivation and Objective of this Thesis………7
1.4 Organization of this Thesis………………7

Chapter 2 Principle of Illumination Light Pipes…8
2.1 Victor Form of Ray-Tracing Equation.………………………8
2.1.1 Refraction Law.8
2.1.2 Reflection Law9
2.2 Fresnel Reflection…………………10
2.2.1 Reflection Coefficients…………10
2.2.2 Typical Reflectance of Dielectric Media…11
2.2.3 Typical Reflectance of Metal…………………12
2.2.4 Reflectance of the Pipe-Air-Metal Interface.13
2.3 Radiometry and Photometry Quantities……15
2.3.1 Radiometry……15
2.3.2 Photometry…………………17
2.4 The Light Pipe Concept.……………………18
2.4.1 Variable Cross Section Light Pipe……………19
2.4.2 Refractive and Reflective Outcouplers……21

Chapter 3 Simulations and Discussions .……24
3.1 Introduction…24
3.2 Simulation Tool.………………24
3.3 Simulation Model of FSC LCD Backlight System.………………24
3.4 The Determination for the Type of the Micro Structure……27
3.5 Optimization of FSC LCD Backlight System………………………29
3.5.1 Optimization of the light-collimating bars29
3.5.2 Optimization of the linear light pipe…………30
3.6 Summary……………36

Chapter 4 Experimental Results and Discussion……37
4.1 Introduction…37
4.2 Light Source Properties………38
4.3 Micro-groove profiles.……………………39
4.4 Optical Performances…40
4.5 Summary…………43

Chapter 5 Conclusions ＆Future works 45

Reference……………………47

[1] K. K. Li, Illumination engine for a projection display using a tapered light pipe, U.S. Patent #6739726 (2004).
[2] N. Takahashi and S. Umemoto, Liquid crystal display apparatus having light pipe with reflective polarizer, U.S. Patent #6778235 (2004).
[3] E. Nestler, Light pipe for an optical mouse, U.S. Patent #4716287 (1987).
[4] S. Staley and S. W. Stout, Eject button for disk drive with light pipe, U.S. Patent #6717769 (2004).
[5] A. Gupta, J. Lee, and R. J. Koshel, Design of efficient lightpipes for illumination by an analytical approach, Appl. Opt. 40, 3640-3648 (2001).
[6] J. F. Van Derlofske and T. A. Hough, Analytical model of flux propagation in light-pipe systems, Opt. Engr. 43, 1503-1510 (2004).
[7] S. –C. Chu and J. –L. Chern, No-loss bent light pipe with an equiangular spiral, Opt. Lett. 30, 3006-3008(2005).
[8] Y. –K. Cheng and J. –L. Chern, Irradiance formations in hollow straight light pipes with square and circular shapes, J. Opt.Soc. Am. A23 427-434(2006).
[9] L. R. Daveport, A. Hough and J. Cassarly, Optimization for Efficient Angle-to-Area Conversion in Illumination Systems, Proc. of SPIE Vol. 5524 (2004).
[10] R. J. Koshel and A. Gupta, Characterization of lightpipes for efficient transfer of light, Proc. SPIE Vol. 5942 (2005).
[11] Fumiaki Yamada, Hajime Nakamura, Yoshitami Sakaguchi, Yoichi Taira, Sequential-color LCD based on OCB with an LED backlight, JSID, 10/1, 81-85 (2002).
[12] Kälil Käläntär, Tadashi Kishimoto, Kazuo Sekiya, Tetsuya Miyashita, Tatsuo Uchida, Yoshitami Sakaguchi, Yoichi Taira, Spatio-temporal scanning backlight mode for field-sequential-color opticallycompensated-bend liquid-crystal display, JSID, 14/2, 151-159 (2006).
[13] T. Uchida, et al., Color imaging and display system with field sequential OCB LCD, SID Digest, 13.2, 166-169 (2006)

[14] Juan Manuel Teijido, Conception and design of illumination light pipes, Ph.D. Thesis (University of Neuchâtel, 1999).
[15] Akihiro Funamoto and Shigeru Aoyama, LED backlight system with double-prism pattern, JSID, 14/11, 1045-1051. (2006)
[16] Kälil Käläntär, Modulation of viewing angle on an LCD surface through backlight optics, JSID, 11/4, 647-652 (2003)