Plasma display panel driving method and plasma display device

A method for driving a plasma display panel that includes a plurality of discharge cells each of which is formed of a scan electrode, a sustain electrode, and a data electrode, wherein the plasma display panel is driven with a structure of one field formed of a plurality of subfields each of which includes an initializing period and an address period, and a sustain period, the method comprising the steps of:

• performing one of a forced initializing operation and a selective initializing operation in the initializing period, wherein the forced initializing operation generates initializing discharge in the discharge cells regardless of an operation in an immediately preceding subfield, and the selective initializing operation selectively generates initializing discharge only in a discharge cell that has undergone address discharge in the address period of an immediately preceding subfield;
• during the selective initializing operation, applying a first voltage to the sustain electrode and applying an up-ramp waveform voltage to the scan electrode for generating a first time discharge between the sustain electrode working as a negative electrode and the scan electrode working as a positive electrode, then applying a down-ramp waveform voltage to the scan electrode for generating a second time discharge between the scan electrode working as a negative electrode and the data electrode working as a positive electrode, then applying a positive rectangular waveform voltage to the scan electrode for generating a third time discharge between the sustain electrode working as a negative electrode and the scan electrode working as a positive electrode, and then applying a second voltage higher than the first voltage to the sustain electrode and applying a down-ramp waveform voltage to the scan electrode for generating a fourth time discharge between the scan electrode working as a negative electrode and the data electrode working as a positive electrode, and
• changing a time length of applying the positive rectangular waveform voltage to the scan electrode based on number of sustain pulses occurring in the sustain period of an immediately preceding subfield.