Patent ID: 8179392

Claim:
A driving circuit for a liquid crystal display module having an array of liquid crystal cells connected to a common line, a plurality of gate lines and a plurality of signal lines, each gate line being arranged to selectively enable a respective set of the liquid crystal cells such that signal lines connected to respective liquid crystal cells of a set can be used to charge respective liquid crystal cells of that set when that set is enabled by the respective gate line, the driving circuit including: a common output configured to drive the common line with a common signal having selectively one of a first level and a second level; a plurality of gate outputs configured to drive the gate lines so as to selectively enable the respective sets of liquid crystal cells; and a plurality of signal outputs configured to charge liquid crystal cells with video signal levels varying between a minimum level and a maximum level wherein, when the common signal has the first level, the minimum level is the first level and the maximum level is the second level and, when the common signal has the second level, the minimum level is the second level and the maximum level is the first level; wherein the driving circuit further includes: a switch circuit configured to selectively drive at least some of the signal outputs with the maximum level; a monitor circuit configured to monitor the voltage on the at least some of the signal outputs and to control the switch circuit to cease driving the at least some of the signal outputs with the maximum level when the monitored voltage reaches a predetermined target value intermediate the minimum level and the maximum level; and a control circuit configured to pre-charge liquid crystal cells by operating the switch circuit for the at least some of the signal outputs prior to charging the liquid crystal cells according to video signals with said video signal levels.