Ferroelectric liquid-crystal display with wide range of working temperatures
AssigneeAventis Research & Technology Deutschland GmbH & Co.KG
InventorsAyako Takeichi, Barbara Hornung, Hans-Rolf Dübal
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Abstract
Ferroelectric liquid-crystal display having a broad operating temperature range. A ferroelectric liquid-crystal display containing a ferroelectric liquid-crystal mixture which is addressed with voltage pulses≧0.9 ms. The display according to the invention is particularly suitable for applications in which the length of the response time is not critical. Such displays can be operated with the same voltage over a broad temperature range; adjustment of the voltage as a function of temperature is not necessary. Examples of preferred applications are displays in chip cards, electronic price and display signs (shelf labels), PDAs (personal digital assistants) and pagers.
Claims9
A process for operating a FLC display containing a ferroelectric liquid crystal mixture, wherein the display is addressed with voltage pulses of an operating pulse width of longer than 10 milliseconds and wherein the spontaneous polarization at 25° C. is at least 20 nC cm−2 in order to decrease the temperature dependence of the threshold voltage of the display.
A process for improving the temperature dependence of the operating voltage of an FLC display, wherein the display is addressed with voltage pulses which are longer than 10 ms and wherein the spontaneous polarization at 25° C. is at least 20 nC cm−2.
Dependencies are inferred from the claim text.