A liquid crystal display device includes a drain drive circuit for driving drain signal lines of a liquid crystal display panel. The drain drive circuit receives a plurality of grey-scale reference voltages from an external circuit, interpolates a plurality of intermediate voltages between each pair of adjacent ones of the grey-scale reference voltages, selects voltages from the grey-scale reference voltages and the intermediate voltages, and applies the selected voltages to the drain signal lines. V0 is a grey-scale reference voltage corresponding to a minimum grey-scale level, Vm is a grey-scale reference voltage corresponding to a maximum grey-scale level, and Vi is a grey-scale reference voltage that is nearest to a voltage level (Vm+V0)/2. A number of intermediate voltages interpolated between V(i-1) and Vi is greater than both a number of intermediate voltages interpolated between V0 and V1, and a number of intermediate voltages interpolated between V(m-1) and Vm.