A liquid-crystal display system includes a data driver, a scan driver, a liquid-crystal panel, a line memory (204 in FIG. 2) in which input display data (101) for representing any of display-ON, display-OFF and halftone every pixel are stored for, at least, one line, and a halftone pattern generator (200) by which liquid-crystal display data (106) to be applied to the data driver are generated using the contents of the line memory and the input display data. The halftone pattern generator generates ON data in response to the input display data representing the display-ON of the pixel; it generates OFF data in response to the input display data representing the display-OFF of the pixel; and it generates the ON data and the OFF data alternately in successive frames as halftone data in response to the input display data representing the halftone display of the pixel, and it also compares the input display data of a pertinent line and those of a preceding line every line so as to invert a phase of changing-over the ON data and the OFF data in accordance with a result of the comparison. Since the number of ON pixels (or pixels for either of first and second data) for the halftone display is substantially equalized every frame, flickering can be reduced irrespective of display patterns.