METHOD FOR CONTROLLING LIQUID CRYSTAL DISPLAY DEVICE, DRIVE ASSEMBLY FOR LIQUID CRYSTAL DISPLAY DEVICE, LIQUID CRYSTAL DISPLAY DEVICE AND ELECTRONIC APPLIANCE

摘要

PROBLEM TO BE SOLVED: To rapidly clear the charges accumulated in a liquid crystal layer and to prevent the deterioration of liquid crystals without depending on an individual device by electrically connecting the liquid crystal layer to a fixed potential when a power supply off is detected. SOLUTION: An off-sequence circuit 140 is a circuit for detecting the voltage drop of a power-supply voltage Vcc when the power source to be supplied to a liquid crystal display device turns off. The circuit causes the transition of the signal level of a signal PWR- and a signal PWR+ when the power-supply voltage Vcc falls to the threshold voltage Vth or below. A constant current circuit 150a connects supply lines of voltages V1, V6 among the plural voltage supply lines to which voltages of V0 to V7 are supplied from a DC-DC converter 130a to a grounding line according to the level transition of the signal PWR- or the signal PWR+. The grounding line exists at the grounding potential of the stable potential regardless of the on/off of the power source and is optimum as the fixed potential of the destination where the charges are removed from the liquid crystal layer. The constant current circuit 150a which supplies the grounding potential supplies the constant current.