Liquid crystal display having clock-controlled disconnection

摘要

Liquid crystal displays are driven by a driver circuit, usually using a multiplex method. For generating the driver signals a multiplicity of different voltage levels is necessary which are generated by voltage multiplier circuits. The driver circuit and the voltage multiplier circuit are connected to a clock generator to ensure, inter alia, a regular polarity change-over at the electrodes of the liquid crystal display. To protect the liquid crystals from being loaded with a direct current, for example in the case of a failure of the clock generator, according to the invention there is provided a means which switches off the driver stage when the difference between the basis voltage level and a voltage level generated by the voltage multiplier circuit falls below a predetermined value.