Abstract
The applicability of the previously proposed method for measuring the rotational viscosity of nematic liquid crystals (NLCs) with negative dielectric anisotropy from transient current in homeotropic NLC cells has been examined. It is found that the shapes of transient current in NLCs with negative dielectric anisotropy are different from those with positive dielectric anisotropy and hence the method can not directly be applied to the analysis of the transient current of NLCs with negative dielectric anisotropy. Computer simulation shows that the transient current of NLCs with negative dielectric anisotropy is successfully reproduced by taking into account of flow effects. It is noted that the flow effects play a key role for faster electro-optic response in vertical alignment NLC displays.
