PURPOSE: To prevent the display irregularity of a display pattern from occurring by forming the data voltage of a simple matrix type liquid crystal display panel by a selection voltage, a non-selection voltage and an intermediate voltage and temporarily switching it to the intermediate voltage when the voltage is switched.
CONSTITUTION: The data voltage impressed on the data electrode 1 of the simple matrix type liquid crystal display panel 3 from a data driver 4 is formed by switching the selection voltage, the non-selection voltage and the intermediate voltage. Then, the device is driven by impressing the identical selection or non-selection voltage on of the electrodes 1 at the beginning of respective scanning terms and switching the voltage to the selection or the non-selection voltage after it is temporarily switched to the intermediate voltage when the selection or the non-selection voltage is impressed by a time width corresponding to gradation, next. Besides, it is driven by switching the voltage impressed on all of the electrodes 1 after it is temporarily switched to the intermediate voltage so as to make the end of the scanning term and the beginning of the next scanning term identical. Thus, the display irregularity by the display pattern and the display irregularity by a pulse voltage generated to a non-selection scanning electrode are prevented from occurring.
KANEKO YOSHIYA
MURAKAMI HIROSHI
