Characteristics of liquid crystal devices with improved response times

The response time and contrast are reported for a liquid crystal (LC) cell operated in the transmission mode. The cell yielded improved response times (e.g., of the order of 0.15 msec) that result from several features: (1) the LC material is a mixture of cholesteryl nonanoate, p-cyanophenyl p-butylbenzoate, and p-cyanophenyl p-heptylbenzoate in the weight ratio x:100:230, respectively; and (2) the cell is operated with the signal drive voltage superimposed on a low-frequency square-wave pedestal voltage. The influence of electrode surface treatment is discussed, and it is postulated that the rapid response time results from only the thin layer of LC material adjacent to the treated electrode surface.