液晶光學元件應用於立體顯示器之研究

Liquid crystal (LC)-based optical devices for 3D displays

李昭德(Chao-Te Lee)

指導教授 ： 林晃巖

國立臺灣大學/電機資訊學院/光電工程學研究所/博士(2012年)

https://doi.org/10.6342/NTU.2012.01833

摘要

本篇論文利用液晶光學元件應用於偏振眼鏡式與裸眼式3D立體顯示技術，以解決3D顯示器的漏光與左右眼相互干擾現象。
一般常見的液晶光學元件，可用於1.偏振光相位延遲與 2.折射率漸變而改變光的行進路徑。前者目的在於使單一偏振光改變其偏振型態，例如線偏振改圓偏振，或是偏振角度改變；後者在於使單一偏振方向的光，穿過折射率漸變的液晶元件，改變其行進路徑，進而形成發散或聚焦。以上兩種基本特性，我們在本篇論文應用在3D立體顯示器上，並討論其結果。
在偏振眼鏡式立體顯示技術方面，我們利用可固化式液晶做為圖形化相位延遲片與偏光片(patterned retarder and polarizer)，並將其製作於面板內部(in-cell)，使其達到無垂直視角限制之3D顯示系統。然而本質上，相位延遲片在不同入射角與不同入射波長的光會產生不同的相位延遲效果，因此我們利用雙軸式波片(biaxial waveplate)來達成寬頻與廣視角的圖形化偏光片。並且討論可能的設計情況適用於不同的液晶配向製程，包括單一配向層使用兩次曝光；和圖形化配向層(patterned alignment)。此研究目的在於提供無視角限制之大尺寸家庭劇院3D顯示器。
在裸眼式立體顯示器方面，我們利用藍相液晶(blue-phase liquid crystal)設計出可調式透鏡使用在產生非偏振光的顯示器，例如有機發光顯示器(OLED)。由於有機發光顯示器的色彩、亮度與低耗電性在小尺寸面板上有極佳的特性，但其產生非偏振光，因此需要非偏振光的可調性透鏡達成2D/3D切換功能。我們利用高介電係數之平坦層與多電極設計且最佳化透鏡相位圖案。此研究目的在於提供非偏振光之中小尺寸手持式3D顯示器。

關鍵字

相位延遲片 ； 偏振眼鏡式3D立體顯示器 ； 裸眼式3D立體顯示器 ； 2D/3D切換 ； 交互干擾 ； 藍相液晶 ； 可調式透鏡

並列摘要

This dissertation presents stereoscopic and autostereoscopic techniques based on liquid crystal (LC) devices, and the methods to achieve 3D effect and reduce crosstalk.
Basically, LC optical devices can be used as: 1. phase retardation device for a polarized light; and 2. gradient refractive index device to change the light propagation directions. The former is to change the polarization state of a polarized light. For example, the linear polarized state is changed to circular polarized state or vise versa. The later is used to change the optical path difference of a polarized light beam when passing through a LC device with gradient refractive index medium. So the light beam will become focused or divergent. We will discuss these two effects and apply them for 3D displays.
For stereoscopic displays using polarized glasses, we use polymerized LCs to fabricate in-cell patterned retarder and in-cell polarizer to achieve a very wide vertical viewing angle. However, the retardation plate has different phase differences throughout the entire wavelength range of visible light and different incident angles. Hence we use biaxial waveplates to accomplish broadband and wide-view patterned polarizers. Two kinds of fabrication processes for the patterned polarizers are considered: one is double exposure method for uniform alignment layer; the other is patterned alignment method. The final goal of this research is to offer unlimited viewing freedom for large-size or home theater 2D/3D LCDs.
For autostereoscopic displays, we employ blue-phase liquid crystal to design an adaptive focusing lens for unpolarized light based displays (ex: OLED). Due to OLED’s high performances of color, brightness and low power consumption, it has great potential for mobile displays. However it requires polarizer-free adaptive lens to generate 2D/3D switch ability. We use multi-electrode structure and high dielectric constant material to optimize the lens phase profile. The purpose of this research is to provide 2D/3D switchable lens for displays with unpolarized light source.

並列關鍵字

waveplate ； polarized glasses type 3D stereoscopic display ； autostereoscopic display ； 2D/3D switchability ； crosstalk ； blue-phase liquid crystal ； adaptive lens

參考文獻

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