标题: | 微光学液晶元件于裸眼式立体显示器之应用研究 Micro-optical Liquid Crystal Devices for Auto-stereoscopic 3D Display Applications |
作者: | 陈致维 Chen, Chih-Wei 黄乙白 Huang, Yi-Pai 光电工程研究所 |
关键字: | 液晶透镜;裸眼式立体显示器;Liquid Crystal Lens;Auto-stereoscopic 3D Display |
公开日期: | 2013 |
摘要: | 近年来,为了得到更真实的影像,已有许多专家及厂商投入裸眼式立体显示器的研究。目前多数裸眼式立体显示器皆使用固定式光学元件作为分光元件,但此种显示器仅能提供三维立体影像,无法提供传统高画质二维影像。此外,目前多数裸眼式立体显示器仅能显示低解析度三维立体影像也为一大缺点。因此,开发次世代可二维/三维切换显示,且具备显示高画质二维/三维影像显示器的发展便为本论文研究之课题。 在诸多光学元件中,可电控式液晶透镜具有电控变焦及体积小等优点,同时也可与现行面板制程相搭配制造,充分显示其应用于裸眼式立体显示器的优势。因此,利用液晶透镜取代传统固定式光学元件,除了可预期得到可二维/三维切换显示功能外,本论文更首次提出液晶透镜也具有扫描(或是移动)的功能,藉由循序切换电控方式,液晶透镜可表现出动态扫描的功能。将此动态扫描功能应用于立体显示器研究上,利用时间多工补偿空间多工所损失的资讯概念,预期可得到次世代高画质三维影像显示器。然而,液晶透镜目前仍有许多问题,如反应速度过慢、驱动电压高、较差的光学品质等等问题,都大大影响到液晶透镜应用于立体显示器之实用性。 本论文首先针对液晶透镜的问题进行改善,进而将研发之液晶透镜与面板搭配,最后做可二维/三维切换显示功能及动态扫描高画质立体显示器之验证。首先,我们针对液晶透镜不易精准控制问题,提出一多电极控制液晶透镜结构。藉由多电极之高控制自由度,可有效控制液晶层分布,提升透镜聚焦品质(光分布面积较传统液晶透镜小约35%)。在此阶段也改善操作电压需求(较传统液晶透镜约小50%),以及三维影像互扰问题(较传统液晶透镜约少60%)。第二阶段部分,我们更提出双向过电压驱动方式,可有效减少传统厚液晶透镜反应速度过慢问题,可将其反应时间大幅减少约75% (超过10秒降至约2秒)。我们更进一步提出突破性的多电极菲涅尔液晶透镜,在此架构下,液晶层厚度可被有效降低达到快速反应目的。而操作电压5伏特也远低于传统多电极液晶透镜的30伏特。藉由实作验证,多电极菲涅尔液晶透镜可在低于1秒的时间内快速有效聚焦;若搭配前述过电压驱动方式,反应时间可大大再减低至仅0.2秒,并且也展示出初步可扫描液晶透镜结果,此对液晶透镜研究领域为一大发展。 最后,我们将提出之多电极菲涅尔液晶透镜阵列实现于4寸及7寸的裸眼式立体显示器上,实现可快速二维/三维切换显示功能,以及验证动态扫描液晶透镜概念确实可有效补偿因空间多工而损失之影像资讯,达到未来高画质立体显示器之成果。相较于之前研究课题,本论文最大特点为首次提出液晶透镜不仅具可调控焦距功能,也可表现出动态扫描(移动)之功能。此动态扫描功能预期可被使用于多项应用,本论文则进一步将此动态扫描透镜概念应用于改善三维立体显示器影像品质的初期研究。 Since current high image quality displays are still two-dimensional (2D) displays, they cannot reproduce the images as real as the three-dimensional (3D) world. Thus, the advanced three-dimensional displays which can reconstruct the 3D scene from displays have been regarded as a critical technology for next generation displays. Many researchers have realized this interesting topic and have invested in developing 3D display technologies. The conventional auto-stereoscopic 3D displays utilize the fixed optical components to display 3D images that the displays cannot display the normal high quality 2D image. In addition, the current glasses-free 3D displays also suffer from the 3D image degradation issue. Therefore, developing the next generation 3D displays which can provide 2D/3D switchable function and high quality 3D image become the main subject in this dissertation. The Liquid Crystal Lens (LCLs) has unique features such as electronically tunable focal lengths without mechanical movement, as well as its compact volume. Moreover, the LCLs also has high potential for integrated manufacturing with current LCD industries. In this dissertation, we first propose that the LCLs not only performs the switch on/off function, it also performs the dynamic scanning function. Therefore, the LCLs could be a candidate for 3D applications, such as the 2D/3D switchable displays, and the temporal switching 3D displays. Nevertheless, the inferior optical performance, high driving voltage, and slow response of current LCLs make this device an impractical device for commercialization. In this dissertation, we first proposed the Multi-electrode Driving Liquid Crystal Lens (MeDLCLs), which can provide highly controlling-freedom in LCs distribution. Based on this proposed structure, the optical property of MeDLCLs could be improved (beam size reduced by 35% compare to conventional LCLs). Besides, the driving voltage and 3D crosstalk were also reduced by 50% and 60%, respectively. Second, we proposed the dual-directional overdriving method to reduce the response time of the thick LCLs by 75%. Following, we further proposed the superzone Fresnel LC lens (SFLCLs) in order to much more reduce the lens’ response time. Because the SFLCLs cell gap could be effectively reduced, that the response time of the SFLCLs finally could be decreased to 0.2sec with the overdriving method. In addition, the driving voltage of the SFLCLs was also suppressed to only 5 Vrms. We had also demonstrated the preliminary results on the first proposed fast scanning SFLCLs. Consequently, we not only dramatically improved the performance for the LCLs, but also broke though the current researches. Finally, this dissertation successfully established the fast response LCLs array on the 3D displays to demonstrate the fast 2D/3D switchable function, and to verify the most interesting topic, the temporally switching LCLs array technique for compensating the lost 3D image resolution of a spatial-multiplexed 3D display in a time-multiplexed manner. To the best of our knowledge, this is the first study on the temporally scanning LCLs technique and using this technique to approach future high quality 3D display. |
URI: | http://140.113.39.130/cdrfb3/record/nctu/#GT079615509 http://hdl.handle.net/11536/73424 |
显示于类别: | Thesis |