3-DIMENSIONAL SIMULATION OF THE ELECTRO-OPTICAL PROPERTIES OF IN-PLANE-SWITCHING LIQUID CRYSTAL DISPLAYS

초록

Recently, In-Plane-Switching Liquid Crystal Displays (IPS-LCDs) have attracted attention due to their potential as high performance displays with wide viewing angle. Because of their unique structure, however, IPS-LCDs inevitably reveal some disadvantages, such as high driving voltage, slow response time, and low opening ratio. In this paper, we optimized various design and material parameters for IPS-LCDs with 4-domain finger structure, most widely employed in the present, by 3-dimensionally simulating their electro-optical characteristics. The 3-diemnsional simulation is thought to be essential to the optimum design of IPS-LCDs, since they have a complex structure such as finger-type electrode patterning. To obtain the dynamic motion of the 3-dimensional director distribution of liquid crystals, we used Ericksen-Leslie equation and strain energy density represented by tensorial form for anisotropic elastic constants. Through the simulation, we obtained 3-dimensional potential and director distribution profiles within a pixel (Fig.1), and calculated the transmittance over the pixel using the profiles. We also investigated the effects of cell gap, space between pixel and common electrodes, and width of the electrode on driving voltage, response time, and opening ratio.