24.2: Investigation of Flexoelectric Effect in Vertically‐Aligned In‐Plane‐Switching Mode by Low Frequency Driving

Abstract

Due to the inhomogeneous electric field, liquid crystal molecules reveal splay deformation in vertically-aligned in-plane-switching mode. The flexoelectric effect from the splay is confirmed by fast CCD images. We introduce a model to explain the mechanism of such phenomenon and to determine the sign of flexoelectric coefficient. Author Keywords VA-IPS; Flexoelectric effect 24.2 / C.-W. Lai SID 2014 DIGEST • 313

Investigation of response time of vertically aligned in-plane-switching LCD mode

“…It will take many cycles of switching polarities to stabilize the LC molecules. Another solid proof of Ton being influenced by flexoelectricity is the slowest Von of 9.25V which is very close to the voltage, 10V, which introduces the strongest flexoelectricity in [5]. …”

“…When more LC molecules attend deformation, the polarization field, Pf, induced by splay deformation (flexoelectricity) of our VA-IPS cell becomes larger. The direction of the polarization in our VA-IPS cells has been indicated to be pointing downwards [5]. Such polarization field will produce torques, f, which in Figure 8 is pointing out of the paper and the same as d-.…”

“…This may refer to something having influences upon the dynamics of the liquid crystal molecules other than dielectric torque. In [5], it's discovered that the splay deformation in VA-IPS causes strong flexoelectricity. This flexoelectricity is believed to be the major reason of the poor image sticking performance of the VA-IPS mode LCD.…”