Optical response of helix‐free FLC: Continuous gray scale, fastest response, and lowest control voltage

Abstract

AbstractElectro‐optical response of a display cells with novel helix‐free FLC (differently, compensated helix ferroelectric—CHF) is considered. Predominance of the shear viscosity in the soliton mode of FLC director reorientation leads to weakening the temperature dependence of the response time. Increasing the electric field frequency expands this temperature interval, and it is 15°C… 45°C for the frequency about 3 kHz at ±1.5 V in a display cell with FLC viscosity of 0.7 P. Increasing the rotational viscosity up to 1.0 P provides the increase of speed ability due to Maxwell's nature of energy dissipation. The optical response time of 24 µs and light modulation frequency of 7 kHz were achieved at the amplitude of control voltage pulses ±1.5 V.Thus, like NLC based cells, the experimental samples of CHF based display cells at the same (or even lower) value of voltage and electric field tension (1–2 V/µm) show the continuous gray scale and hysteresis‐free modulation characteristic (up to 5 kHz) but can provide 40–50 times (!) higher speed. These break‐through results characterize CHF as the most high‐speed materials for future 3D displays and displays using field sequential color technique, including FLCoS and TFT addressed, as well as displays with new functional properties.