Patent ID: 7142178

Claim:
A modulator, comprising: a modulation circuit for generating modulation signals based on inputted luminance data and for outputting the modulation signals to a plurality of image display elements, each of which is driven by a potential difference between a selection potential applied within a predetermined time period by a selection circuit and the modulation signal, wherein the image display elements are matrix-wired by a plurality of row wirings and a plurality of column wirings, the selection circuit selects the row wiring for the predetermined time period by line sequential scan, and one modulation signal is outputted to one of the column wirings in the predetermined time, the modulation signal has a waveform which is a combination of a plurality of unit pulses, the unit pulses having an identical width and n kinds of peak values A1 to An, with n being an integer greater than 1, and A1<. . . <An, and the unit pulses are combined in such a way that the plurality of unit pulses forming the waveform are continuously arranged without an interval, that maximal peak value portions of the waveform of the modulation signal are dispersed, and that a rising portion and a falling portion of the waveform have a stair-step-like shape.