Influence of Fringing Field on Single Cell Gap Transflective LCDs

• Main Authors: Mong-Hui Chou, 周孟輝
• Other Authors: Jy-Shan Hsu
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/51700130936993084328

碩士 === 中原大學 === 物理研究所 === 99 === We use the Coupling Capacitance type (CC type) method, which is adding a coupling capacitance between the transmissive and reflective part to induce a lower voltage in the reflective pixel electrode when we apply a voltage on the transmissive electrode. Thus, when light pass through the liquid crystal layer, the phase retardation of the light obtained in these two areas will be the same. The measurement, analysis and optimization of a CC type single-LC mode, single-cell-gap vertically aligned (VA) transflective LCD design will be discussed. 　　We adopted value (standard deviation of Gamma curve) to evaluate the image quality of LCD. The smaller the value, the better image quality of the LCD will exhibit, which is the consequence of the two matched Gamma curves of the transmissive and reflective areas. In the first part, we measured the  value of a CC type transflective LCD designed by using one-dimensional (1D) liquid crystal simulator. The value was smaller than we expected. Through some studies we realized that the disagreement was resulted from the Fringing-Field effect. Later, we used two-dimensional (2D) liquid crystal simulator (LCD Master) to confirm our analysis. 　　To optimize the design, we adjusted the values of the capacitance; reduce the length of the reflective electrode and even adding a proper voltage in the common electrode, that is, we modified it into a dual common & coupling capacitance design. The value of the VA transflective LCD was successfully reduced.