Patent ID: 8358255

Claim:
A plasma display device comprising: a plasma display panel having a plurality of discharge cells, each of the discharge cells including a display electrode pair that is formed of a scan electrode and a sustain electrode; a driving circuit for applying a driving voltage waveform to the display electrode pair and driving the plasma display panel; a current-flow accumulative time measuring circuit for measuring a accumulative time when the driving circuit drives the plasma display panel; and an image judging circuit for judging a property of an image to be displayed on the plasma display panel and outputting a judgment result, wherein the driving circuit varies the driving voltage waveform in response to the accumulative time, and controls a time interval for varying the driving voltage waveform in response to the judgment result of the image judging circuit, wherein the image judging circuit is configured by a still image judging circuit for judging whether the image to be displayed on the plasma display panel is a still image, and outputting the judgment result, and the driving circuit varies the driving voltage waveform in response to the accumulative time, and controls a time interval for varying the driving voltage waveform in response to a ratio of a display period of the still image to the accumulative time, and wherein the driving voltage waveform includes a gradually increasing ramp waveform voltage applied to the scan electrode, and the driving circuit decreases a time interval for varying maximum voltage of the ramp waveform voltage, as the ratio of the display period of the still image to the accumulative time increases.