Study on optimized d/p of Bistable Chiral Tilted-Homeotropic Nematic Liquid Crystal Cells

• Main Authors: Che-li Lin, 林哲立
• Other Authors: Bau-Jy Liang
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/01171313805897295871

碩士 === 逢甲大學 === 電機工程所 === 95 === In recent years, bistable displays have been most prevalent, due to the function of memory access without imposing voltage, so as to decrease the displayed power consumption; such bistable displays are mostly applied to products which display the same image over a long period of time, such as e-books, cell phones, price tags, etc.; therefore, a variety of bistable related technologies have been developed. However, the main reasons that effect stability, contrast and response time are liquid crystal manufacturing material parameter and druve wavefront. The study aims at the research on BHN LC Cell to find the d/p (thickness-pitch ratio of liquid crystal cell) and pretilt angle through experimentation and dynamic simulation, and to see whether two steady states, the twisted state (T state) and the tiltedly homeotropic state (TH state) can be formed. we have successfully generated BHN LC Cells by applying wedge LC cell at different pretilt angles to observe and measure sampled bistable ranges. The bistability d/p range is tested by equilibrium and dynamic simulation. By way of dynamic simulation, we have found that the flow effect will have impact on bistable d/p range; in addition, by way of dynamic theory, we have analyzed the physical switch mechanism during both bistable and non-bistable d/p ranges. Discovers the best pretilt angle and d/p by the BHN LC wedge cell, manufacture BHN LC Cell in view of the actuation profile driving waveform (voltage, time), relaxation time with Optical measurement the angle of view (View angle), the contrast gradient discusses. Finally comparing the experiment and the simulation, we find the trend consistent with result