Studies Of IPS Liquid Crystal Display Mode

Liquid Crystal Display (LCDs) has been currently the dominant technique in the flat panel display (FPDs), for its availability for high resolution, full color and vedio graphic. However, its display performance needs further improving in several aspects, and among them its well-known narrow viewing angle is one of the most serious problems. The In-Plane-Switching (IPS) model has been recently proposed and believed to be one of the most promising method, but IPS model has some defects, such as high threshold voltage, shift color, slowly response time and low aperture ratio. This thesis will concentrate it study in the optimized design of the model and device aiming to improve the parameters as described above.The threshold voltage of common IPSLCD is very high, leading to higher power consumption and a more critical requirement for the thin film transistor (TFT). From the concept of asymmetric anchoring in this thesis, the asymmetric anchoring case were considered basing on elastic continuum theory of liquid crystal and using variational method. The analytical expressions of Freederick's transition threshold for IPS model were deduced. The effect of asymmetric weak anchoring to threshold voltage of IPSLCD were analyzed, the result expresses that the asymmetric weak anchoring can decrease the threshold voltage of IPSLCD.The color shift phenomenon is a serious drawback in IPSLCD model, the producing mechanism of color shift were analyzed in thesis, the One-Side-Rubbing Nematic-Twist IPS model and Arc-Electrode IPS model were proposed to suppress the color shift.We utilized the LC continuum theory and dynamics theory to analysis In-Plane-Switching liquid crystal model response time, and the monomer in liquid crystal can polymerize to form network by curing the UV light, the anchoring of polymer network can improve the fall response time of IPS model. A novel Two-Side-' Electrode IPS model were proposed in this thesis and we got the result that the fallresponse time was nearly to rise response time from the theory to the sample.The Cross-Talk problem of big capacity IPSLCD is same to TNLCD, the TFT method is a effective way to solve this problem, but the design of electrode and store capacity affected the aperture ratio and threshold voltage. In order to decreasing the threshold voltage and expanding the aperture ratio, we design the TFT-IPS electrode and novel store capacity, the liquid crystal parameter and device parameter were designed at the same time.