Development of extremely low power reflective color liquid crystal display with high brightness

实现本研究目标的关键是尽可能提高反射光水平。为此，进行了以下调查，并达到了目标。从亮度和对比度两个方面对各种液晶显示方式进行了理论和实验研究。结果表明，相变主客模式（PCGH-mode）最适合于反射型液晶显示器（LCD）。阐明了pcgh模式的最佳设计条件。研究了微彩色滤光片的透射光谱。阐明了微滤光片考虑单色和混合色的明度、色相和色度的最佳光谱设计理念。研究了反射器表面粗糙度与其反射性能的关系，明确了表面粗糙度的最佳设计条件。此外，还建立了光加工粗糙表面的方法。研究了在特定方向上获得均匀反射性且无干涉色的粗糙度图案设计的适宜条件。在此基础上，利用薄膜晶体管成功地制作了具有有源矩阵驱动的彩色反射液晶显示器。该显示器是第一个具有足够亮度的反射式彩色显示器。

A key to achieve the target of this research was to increase reflected light level as high as possible. For this purpose, the following investigation has been made and the target has been achieved.1. Various liquid crystal display mode was theoretically and experimentally studied in the term of braghtness and contrast. It was found from the results that phase change type guest-host mede (PCGH-mode) was most suitable for the reflective type liquid crystal display (LCD). The optimum design condition for the PCGH-mode was also clarified.2. Transmittance spectrum of micro-color filter was investigated. It was clarified that the optimum design concept for the spectrum considering lightness, hue and chroma of individual and mixed color for the micro-color filters.3. Relation between surface roughness of the reflector and its reflective property was investigated and the optimum design condition of the roughmess was clarified. In addition, method to fabricate the rough surface by photo-process was established. Suitable condition for designing the roughness pattern to obtain uniform reflective property without interference color in the specific direction was investigated.Based on the results mentioned above, the reflective color LCD with active matrix driver using thin film transistor was successfully made. The fabricated display was a first reflective color display with sufficient brightness.