Method for driving a plasma display panel

1. A method for driving a plasma display panel which displays a frame composed of a plurality of sub-fields which each have at least one sustain period and which has different weights of luminance, the method comprising:

applying plural kinds of sustain pulses having different voltage waveforms for at least one sustain period of a respective sub-field; and

adjusting a number of sustain pulses in each of the different voltage waveforms according to a weight of luminance said respective sub-field for said at least one sustain period, wherein

the plural kinds of sustain pulses bring light emissions that differ from one another.

2. The method of claim 1 , wherein the number of sustain pulses in each of the different voltage waveforms is changed in accordance with input luminance in order to perform gradation display.

3. The method of claim 2 , wherein the plural kinds of sustain pulses having different voltage waveforms are applied regularly and alternatively in a common sustain period.

4. The method of claim 2 , wherein the plural kinds of sustain pulses differ in ultimate electric potential, and a sustain pulse with a higher ultimate electric potential than another sustain pulse is applied in a latter phase of a sustain period.

5. The method of claim 2 , wherein the plural kinds of sustain pulses differ in ultimate electric potential, and a sustain pulse with a higher ultimate electric potential than another sustain pulse is applied in a middle phase of a sustain period, and the sustain pulse with a lower ultimate electric potential is applied in phases prior to and subsequent to the middle phase of the sustain period.

6. The method of claim 1 , wherein a constituent ratio of the plural kinds of sustain pulses having different voltage waveforms is changed in accordance with a display rate in a display screen.

7. A method for driving a plasma display panel which displays a frame having a plurality of sub-fields, the method comprising:

applying plural kinds of sustain pulses having different voltage waveforms for a sustain period of at least one sub-field; and

adjusting a number of sustain pulses in the different voltage waveforms according to a weight of luminance set for the at least one sustain period of the corresponding sub-field, wherein

one of the voltage waveforms of the sustain pulses is a step-like waveform.

8. The method of claim 7 , wherein the step-like waveform comprises a rectangular pulse and an offset voltage added to the rectangular pulse.

9. The method of claim 7 , wherein another voltage waveform of the sustain pulses is a rectangular pulse having a lower ultimate voltage than the sustain pulse of the step-like waveform.

10. The method of claim 7 , wherein at least one sustain pulse having the step-like waveform is applied in an initial phase of the sustain period, and another sustain pulse having a rectangular voltage waveform is applied in a subsequent phase in a common sustain period.

11. An apparatus comprising:

a sustain pulse application unit applying sustain pulses with different voltage waveforms for a sustain period of a sub-field of a frame; and

a sustain pulse adjustment unit adjusting a number of the sustain pulses in each of the voltage waveforms to achieve a weight of luminance for the sustain period of the sub-field, wherein

sustain pulses having different voltage waveforms bring different respective light emissions.

12. A method for driving a plasma display panel, comprising:

applying plural kinds of sustain pulses having different voltage waveforms for a sustain period of at least one sub-field, wherein

at least one sustain pulse having a step-like waveform is applied in an initial phase of the sustain period, and another sustain pulse having a rectangular voltage waveform is applied in a subsequent phase in a common sustain period.

13. A method for driving a plasma display panel which has a plurality of display electrodes to display on a screen, and a frame is composed of a plurality of sub-fields which have different weights of luminance, the method comprising:

applying plural kinds of sustain pulses to a display electrode for at least one sustain period of a respective sub-field; and

changing a constituent ratio of the plural kinds of sustain pulses applied for the at least one sustain period in accordance with a first display rate and a second display rate which is higher than the first display rate, and changing the number of the sustain pulses applied for the at least one sustain period in accordance with the first display rate and the second display rate.

14. The method of claim 13 , wherein the plural kinds of sustain pulses include a first kind of a sustain pulse and a second kind of sustain pulse which is different from the first kind of a sustain pulse.

15. The method of claim 14 , wherein a constituent ratio between the first kind of a sustain pulse and the second kind of a sustain pulse applied upon displaying the screen with the first display rate is different from a constituent ratio between the first kind of a sustain pulse and the second kind of a sustain pulse applied upon displaying the screen with the second display rate.

16. The method of claim 15 , wherein an ultimate electric potential of the first kind of a sustain pulse is higher than an ultimate electric potential of the second kind of a sustain pulse.

17. The method of claim 15 , wherein an electric potential at a rise part of the first kind of a sustain pulse is higher than an electric potential at a rise of the second kind of a sustain pulse.

18. The method of claim 15 , wherein the at least one sustain period has a period during which the first kind of a sustain pulse and the second kind of a sustain pulse are applied alternatively.

19. The method of claim 17 , wherein an initial phase of the at least one sustain period has a period during which the first kind of a sustain pulse is applied successively.

20. The method of claim 17 , wherein a final phase of the at least one sustain period hasa period during which the first kind of a sustain pulse is applied successively.

21. The method of claim 13 , wherein the plural kinds of sustain pulses include a first kind of a sustain pulse, a second kind of a sustain pulse which is different from the first kind of a sustain pulse, and a third kind of sustain pulse which is different from the first and second kinds of sustain pulses.

22. The method of claim 21 , wherein a constituent ratio among the first kind of a sustain pulse, the second kind of a sustain pulse and the third kind of a sustain pulse applied upon displaying the screen with the first display rate is different from a constituent ratio among the first kind of sustain pulse, the second kind of a sustain pulse and the third kind of a sustain pulse applied upon displaying the screen with the second display rate.

23. The method of claim 21 , wherein

an electric potential at a rise part of the first kind of a sustain pulse is higher than an electric potential at a rise part of the second kind of a sustain pulse, and

the electric potential at the rise part of the second kind of a sustain pulse is higher than an electric potential at a rise part of the third kind of a sustain pulse.

24. A method for driving a plasma display panel which has a plurality of display electrodes to display on a screen, and a frame is composed of a plurality of sub-fields which have different weights of luminance, the method comprising:

applying plural kinds of sustain pulses to a display electrode for at least one sustain period of a respective sub-field; and

differentiating a constituent ratio of the plural kinds of sustain pulses applied for the at least one sustain period upon displaying the screen with a first display rate from a constituent ratio of the plural kinds of sustain pulses applied for the at least one sustain period upon displaying the screen with a second display rate which is higher than the first display rate, and differentiating the number of teh sustain pulses applied for the at least one sustain period upon displaying the screen with the first display rate from the number of teh sustain pulses applied for the at least one sustain period upon displaying the screen with the second display rate.

25. The method of claim 24 , wherein the plural kinds of sustain pulses include a first kind of a sustain pulse and a second kind of a sustain pulse which is different from the first kind of a sustain pulse.

26. The method of claim 25 , wherein a constituent ratio between the first kind of a sustain pulse and the second kind of a sustain pulse applied upon displaying the screen with the first display rate is different from a constituent ratio between the first kind of a sustain pulse and the second kind of a sustain pulse applied upon displaying the screen with the second display rate.

27. The method of claim 25 , wherein an ultimate electric potential of the first kind of a sustain pulse is higher than an ultimate electric potential of the second kind of a sustain pulse.

28. The method of claim 25 , wherein an electric potential at a rise part of the first kind of a sustain pulse is higher than an electric potential at a rise part of teh second kind of a sustain pulse.

29. The method of claim 25 , wherein the at least one sustain period has a period during which the first kind of a sustain pulse and the second kind of a sustain pulse are applied alternatively.

30. The method of claim 28 , wherein an initial phase of the at least one sustain period has a period during which the first kind of a sustain pulse is applied successively.

31. The method of claim 28 , wherein a final phase of the at least one sustain period has a period during which the first kind of a sustain pulse is applied successively.

32. The method of claim 24 , wherein the plural kinds of sustain pulses include a first kind of a sustain pulse, a second kind of a sustain pulse which is different from the first kind of a sustain pulse, and a third kind of a sustain pulse which is different from the first and second kinds of sustain pulses.

33. The method of claim 32 , wherein a constituent ratio among the first kind of a sustain pulse, the secon kind of a sustain pulse and the third kind of a sustain pulse applied upon displaying the screen with the first display rate is different from a constituent ratio among the first kind of a sustain pulse, the second kind of a sustain pulse and the third kind of a sustain pilse applied upon displaying the screen with the second display rate.

34. The method of claim 32 , wherein

an electric potential at a rise part of the first kind of a sustain pulse is higher than an electric potential at a rise part of the second kind of a sustain pulse, and

the electric potential at a rise part of the second kind of a sustain pulse is higher than an electric potential at a rise part of the third kind of a sustain pulse.