A study of the retardation variation with the driving voltage of the IPS mode cell

The retardation and the optic axis rotation dependence on the driving voltage have been evaluated quantitatively for the first time. The retardation begins to decrease when the driving voltage exceeds the critical voltage slightly. At the voltage of the maximum transmittance, the optic axis rotates by about 45 degrees and the retardation is reduced to about 80% of the original value. The transmittance calculated from the measured optic axis rotation and the retardation coincides with the measured voltage-transmittance characteristics. The change of the retardation has been confirmed by the transmission spectra. Theoretical calculations have been also executed and support the above results