新型场序彩色液晶显示系统的设计与制备研究

In the past few years, thin film transistor liquid crystal display (TFT-LCD) technology has become one of the dominant technologies in display area. The traditional TFT-LCD encounters several difficulties, like slow response time leading to color break up effect of motion image, as well as low efficiency and high cost due to color filters, also the sub-pixel color generating structure limits the display resolution density. Field sequential color (FSC) display technology utilizes temporal color synthesis to generate full color. In an FSC display the backlight sequentially flashes R, G, and B, and the LCD panel is controlled to modulate the transmission of each pixel at each field. Thus, a FSC display does not need color filters and has the advantages of improving efficienty and resolution by at least three times and wider color gamut. The target response time for FSC display should be less than 1ms (240Hz frame frequency).The ferroelectric liquid crystal (FLC), which has the advantage of a fast response, has become one of the most promising candidates of the next generation FSC-LCD. However, research on the design/fabrication of FSC-FLCD device is still on its early stage, there are quite a few problems to be solved, such as alignment quality of ferroelectric liquid crystals, optimization of contrast ratio, and driving system desing, .etc. Therefore, we propose this project of "Research on design and fabrication of novel field sequential color display system", hopefully we can realize the implementation of FSC-FLCD devices research and fabrication. .

近年来，传统的液晶显示技术在高分辨率、低成本、低功耗等方面遇到了很大困难,而场序彩色显示技术采用新型全彩色合成方法，可以提高光学效率及像素密度三倍以上，扩大色域到120%NTSC，并且大大降低生产成本。场序彩色显示技术的实现对液晶器件的响应速度有很高的要求，例如若显示帧频为240Hz，液晶的响应时间要低于1毫秒。铁电液晶因具有快速响应的特性，在场序彩色显示领域有着很大的应用前景。然而，基于铁电液晶的场序彩色显示器件的设计制备研究尚处于初级阶段，许多科学难题有待攻克，诸如有效控制铁电液晶分子排布的表面取向层尚有缺陷，亮暗态对比度过低，有源矩阵驱动模块尚需设计开发等。鉴于此，我们提出“新型场序彩色液晶显示系统的设计与制备研究”项目，对铁电液晶光电模式进行分析研究，并采用非接触式光控取向技术，希望在综合解决上述问题基础上实现场序彩色显示器件的研究与制备。

基于铁电液晶的场序彩色显示器件尚处于研究初级阶段，铁电液晶无缺陷、有序性取向对对比度、响应时间、色域、视角等关键参数影响很大。在研究过程中，项目组建立铁电液晶DHF模式的物理模型，建立铁电液晶分子指向矢在外加电场下动态方程，得到铁电液晶螺旋结构随外加电场而产生的形变量及其对透过光束相位和偏振等参数的调控。在此基础上，总结此光电模式对取向层方位角、预倾角、锚定能等需求，利用光控取向技术，设计、制备及优化光控取向铁电液晶显示器件，为了提高铁电液晶盒在正交偏振片下的亮暗态对比度，系统研究了光控取向层与铁电液晶分子间相互作用及其对取向质量的影响。进一步针对DHF模式的对称V形光电响应特性，设计驱动电压幅度调控灰阶的显示方案，并采用三原色LED作为背光源与铁电液晶驱动信号同步，拓宽色域达130%NTSC。深入研究了背光源对光控取向层的取向质量退化方面的影响，并提出引入高分子掺杂偶氮染料作为复合型光控取向层，提高了铁电液晶器件的光稳定性及热稳定性，对铁电液晶盒进行了电荷残留等方面测试，达到商业应用标准。