Fundamental Study of Ferroelectric Liquid Crystals for their Practical Use in Fast Displays

研究了SSFLC的态结构和态间的转换过程。使用频闪显微镜观察开关过程对澄清结构非常有用。在大多数情况下，当Sm A作为高温相存在时，细胞上半部分的导晶和下半部分的导晶以相反的方式在锥体上旋转；由于对称要求，中间不能连续运动的指导者突然跳跃，形成偏斜回路。以内部偏斜形成为特征的转换过程的发生不可避免地需要在边界表面选择性地预倾斜c -director。克拉克和拉格沃尔最初提出的更简单的转换过程，即所有董事都以同样的方式移动，这是相当例外的，尽管有时会发生。考虑到Clark等人的高分辨率X射线衍射研究，c指向选择性预倾斜的真正原因一定是近晶层的弯曲或扭结。有两种方式可以使层扭结，即<<<和>>>。迄今为止我们认为之字形缺陷线是由斜位修饰的位错，现在确定为层结的错误排列，如<<*>>>*<<<。这种识别成功地解释了锯齿线在切换过程中所发挥的特征。利用分光计与偏光显微镜相结合的方法，得到了SSFLC态的偏振透过率光谱。基于层弯曲或c指向选择性预倾斜，我们可以用4 × 4矩阵法近似地再现光谱。没有进行有关研究计划中所述倾斜角的实验，而是提出了一种测量粘度常数的高贵方法。在不以高温相存在的情况下，也进行了初步的研究。

The structure of SSFLC states and the switching processes among them have been studied. Observation of the switching processes using stroboscopic micrographs was very useful for clarifying the structure. In most cases where Sm A exists as a high temperature phase, directors in the upper half of a cell and those in the lower half rotate on a cone in the opposite sense; hence the director in the middle which cannot move continuously because of the symmetry requirement make a sudden jump, forming a disclination loop. Occurrence of the switching process characterized by the internal disclination formation inevitably requires selective pretilting of the C-directors at the bounding surfaces. The simpler switching process originally proposed by Clark and Lagerwall, where all directors move in the same sense, is rather exceptional, though sometimes occurs.Taking account of the high resolution X ray diffraction study by Clark et al., the real cause of the C-director selective pretilting must be the bending or kinking of the smectic layers. There are two ways in which the layers kink, i.e. <<< and >>>. Zigzag defect lines so far considered by us as dislocations decorated by disclinations are now identified as the misarrangement of the layer kinks, such as <<<*>>>*<<<. This identification successfully explains the characteristic features played by the zigzag lines during the switching processes.Polarized transmittance spectra of the SSFLC states have been obtained by combining a spectrometer with a polarizing microscope. Based on the layer bending or the C-director selective pretilting, we can nearly reproduce the spectra using the 4 x 4 matrix method. Experiments concerning the tilt angle described in the research proposal has not been performed, but instead a noble method has been proposed for measuring the viscosity constants. Preliminary studies have also been done in a case where Sm A does not exist as a high temperature phase.