Abstract:
A method for driving a PDP which can realize higher image quality and lower costs and a plasma display apparatus therefor are provided. A pulse having an interval during which a pulse voltage changes gradually and another interval during which the pulse voltage changes steeply is generated as a reset pulse applied for allowing a discharge cell of the PDP to reset-discharge. In this instance, in the interval during which the pulse voltage changes gradually, a voltage applied to the discharge cell is allowed to reach a minimum reset-discharge starting voltage.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The invention relates to a plasma display apparatus having a plasma display panel.  
           [0003]    2. Description of the Related Art  
           [0004]    In recent years, a thin type display device has been requested associated by the realization of a large screen of a display apparatus and various thin type display devices have been put into practical use. Attention is paid to a plasma display panel of an AC discharge type as one of the thin type display devices.  
           [0005]    [0005]FIG. 1 is a diagram showing a construction of a plasma display apparatus having a plasma display panel (designated as a PDP hereinafter).  
           [0006]    In FIG. 1, a PDP  10  comprises: m column electrodes D 1  to D m  ; and n row electrodes X 1  to X n  and n row electrodes Y 1  to Y n  which are arranged so as to cross the column electrodes, respectively. With respect to the row electrodes X 1  to X n  and the row electrodes Y 1  to Y n , first to nth display lines in the PDP  10  are constructed by pairs of row electrodes X i  (1≦i ≦n) and Y i  (1≦i ≦n). A discharge space filled with discharge gas is formed between the column electrode D and the row electrodes X and Y. The discharge space has a structure such that a discharge cell serving as a display pixel is formed at a crossing portion of each row electrode pair and the column electrode.  
           [0007]    Each discharge cell has only two states of “light emission” and “non-light emission” because a light emission is performed by using a discharge phenomenon. That is, only luminance of two gradations of the lowest luminance (non-light emitting state) and the highest luminance (light emitting state) is realized.  
           [0008]    A driving apparatus  100 , therefore, executes a gradation driving using a subfield method in order to allow the PDP  10  to realize a luminance display of a halftone corresponding to a supplied video signal. As subfield methods, there are a selective erasure address method and a selective write address method. According to the selective erasure address method, wall charges are previously formed in all discharge cells (all-resetting step Rc) and the wall charges in each discharge cell are selectively erased in response to an input video signal (pixel data writing step Wc). According to the selective write address method, wall charges in all discharge cells are previously extinguished (all-resetting step Rc) and the wall charges are selectively formed in each discharge cell in response to an input video signal (pixel data writing step Wc).  
           [0009]    In the subfield method, the supplied video signal is converted into pixel data of, for example, 4 bits corresponding to each pixel and one field is divided into four subfields SF 1  to SF 4  as shown in FIG. 2 in correspondence to each bit digit of the 4 bits. At this time, as shown in FIG. 2, the number of executing times of light emission corresponding to a weight of the pixel data bits is allocated to each of the subfields SF 1  to SF 4 . The discharge cells are light-emitted every subfield in accordance with a logic level of the pixel data bit corresponding to the subfield.  
           [0010]    [0010]FIG. 3 is a diagram showing various kinds of driving pulses which are applied to the row electrode pairs and the column electrodes of the PDP  10  in one subfield in order to drive the driving apparatus  100  by, for example, the selective erasure address method and showing timing for applying those pulses.  
           [0011]    First, in the all-resetting step Rc, the driving apparatus  100  applies a reset pulse RP x  of a negative polarity whose trailing change is mild and which is shown in FIG. 3 all at once to each of the row electrodes X 1  to X n . The driving apparatus  100 , further, applies a reset pulse RP y , of a positive polarity whose leading change is mild and which is shown in FIG. 3 all at once to each of the row electrodes Y 1  to Y n  simultaneously with the application of the reset pulse PR x . In accordance with the application of the reset pulses RP x  and RP y , all of the discharge cells of the PDP  10  are discharged for resetting. After termination of the reset discharge, wall charges of a predetermined amount are uniformly formed in each discharge cell and the formed wall charges are held.  
           [0012]    By the execution of the all-resetting step Rc, all of the discharge cells in the PDP  10  are initialized to a state where a light emission (sustaining discharge) is possible (hereinafter, referred to as a “light emitting cell” state) in a light emission sustaining step Ic, which will be explained hereinlater.  
           [0013]    In the pixel data writing step Wc, the driving apparatus  100  separates each bit of the pixel data of 4 bits in correspondence to each of the subfields SF 1  to SF 4  and generates a pixel data pulse having a pulse voltage according to a logic level of the bit. For example, in the pixel data writing step Wc of the subfield SF 1 , the driving apparatus  100  generates the pixel data pulse having the pulse voltage according to the logic level of the first bit of the pixel data. At this time, the driving apparatus  100  generates the pixel data pulse having the pulse voltage of a high voltage if the logic level of the first bit is equal to “1” and generates the pixel data pulse having the pulse voltage of a low voltage (0 volt) if the logic level of the first bit is equal to “0”. The driving apparatus  100  sequentially applies the pixel data pulses as pixel data pulse groups DP 1  to DP n  as many as each display line corresponding to each of the first to nth display lines to the column electrodes D 1  to D M  as shown in FIG. 3. The driving apparatus  100 , further, generates a scanning pulse SP of a negative polarity as shown in FIG. 3 synchronously with the applying timing of each of the pixel data pulse groups DP and sequentially applies the scanning pulse to the row electrodes Y 1  to Y n . At this time, a discharge (selective erasure discharge) is caused only in the discharge cell at the crossing portion of the display line to which the scanning pulse SP has been applied and the “column” to which the pixel data pulse of the high voltage has been applied. By the selective erasure discharge, the wall charges held in the discharge cell are extinguished. That is, the discharge cell is shifted to a state where the light emission (sustaining discharge) is impossible (hereinafter, referred to as a “non-light emitting cell” state) in the light emission sustaining step Ic, which will be explained hereinlater. The selective erasure discharge is not caused in the discharge cell to which the pixel data pulse of the low voltage has been applied although the scanning pulse SP was applied. That is, the discharge cell sustains the state where it has been initialized in the all-resetting step Rc, that is, the “light emitting cell” state.  
           [0014]    That is, according to the pixel data writing step Wc, each discharge cell of the PDP  10  is set to either the “light emitting cell” state or the “non-light emitting cell” state in accordance with the pixel data based on the input video signal.  
           [0015]    Subsequently, in the light emission sustaining step Ic, the driving apparatus  100  alternately and repetitively applies a sustaining pulse IP X  of a positive polarity and a sustaining pulse IP y  of a positive polarity to the row electrodes X 1  to X n  and the row electrodes Y 1  to Y n  as shown in FIG. 3. In one subfield, the number of times (period) of applying the sustaining pulses IP x  and IP y  is set in accordance with a weight of each subfield as shown in FIG. 2. Only the discharge cell in which the wall charges exist, namely, only the discharge cell in the “light emitting cell” state discharges for the sustaining light emission each time the sustaining pulses IP x  and IP Y  are applied. That is, only the discharge cell set to the “light emitting cell” state in the pixel data writing step Wc repeats the light emission associated by the sustaining discharge the number of times set in correspondence to the weight of each subfield as shown in FIG. 2 and sustains the light emitting state.  
           [0016]    The driving apparatus  100  executes the above operation every subfield. In this instance, a luminance of the halftone corresponding to the video signal is expressed by the total number (in one field) of light emissions associaed by the sustaining discharge caused in each subfield. That is, the image display corresponding to the video signal is performed by the light emission caused by the sustaining discharge.  
           [0017]    To perform the image display by using a discharge phenomenon, however, a discharge which causes a light emission that is not concerned with the display image has to be also caused. Particularly, since all of the discharge cells perform the light emission all at once by a reset discharge which is caused in the all-resetting step Rc, a problem such that a decrease in contrast appears typically when an image of a low luminance is displayed occurs. To prevent the problem, as shown in FIG. 3, each of the trailing change of the reset pulse RP x  which is applied to cause the reset discharge and the leading change of the reset pulse RP Y  which is also applied is set to be mild. Although the amount of light emission associated by the reset discharge consequently decreases, an amount of wall charges and priming particles which are formed also decreases. At this time, in order to form a desired amount of wall charges and priming particles, it is necessary to increase pulse voltages (VR, −VR) of the reset pulses (RP Y  and RP X ) and, further, widen a pulse width (T R ) of each of them. A driver of a high withstanding voltage, therefore, is used as a driver for generating the reset pulses, resulting in an increase in costs. Further, if the pulse width of the reset pulse is widened, since a time which is necessary for the all-resetting step Rc becomes long, a time which is necessary for the pixel data writing step Wc and the light emission sustaining step Ic has to be shortened by the duration corresponding to it. An erroneous discharge, however, occurs if the pulse width of each of the pixel data pulse and the scanning pulse SP is narrowed in order to shorten the time which is necessary for the pixel data writing step Wc. The luminance of the whole picture plane decreases if the number of executing times of the sustaining discharge is decreased in order to shorten the time which is necessary for the light emission sustaining step Ic. That is, a problem of deterioration of the picture quality is caused.  
         OBJECTS AND SUMMARY OF THE INVENTION  
         [0018]    The invention is made to overcome the above problems. An object of the invention is to provide a method for driving a PDP and a plasma display apparatus which can realize high picture quality and low costs.  
           [0019]    According to a fist aspect of the invention, we provide a method for driving a PDP in accordance with video signals, said PDP including a plurality of discharge cells arranged in a matrix form, each of said discharge cells working as a display pixel. The method comprises the steps of: applying a reset pulse to all of said discharge cells to cause all of said discharge cells to discharge for resetting all of said discharge cells; applying a scanning pulse to each of said discharge cells to cause each of said discharge cells to selective-discharge for selecting either of light-emission and non-light-emission modes for each of said discharge cells on the basis of pixel data corresponding to a video signal for each of said discharge cells; and applying a sustaining pulse to allow only the discharge cell in the light-emission mode to discharge for repeating light emission. The reset pulse comprises a first pulse voltage shift interval in which a pulse voltage changes gradually, reaches a minimum reset-discharge starting voltage, and exceeds the minimum reset-discharge starting voltage, and a second pulse voltage shift interval in which said pulse voltage changes steeply.  
           [0020]    According to a second aspect of the invention, we provides a method for driving a PDP in accordance with video signals, said PDP including a plurality of discharge cells arranged in a matrix form, each of said discharge cells working as a display pixel. The method comprises the steps of: applying a reset pulse to all of said discharge cells to cause all of said discharge cells to discharge for resetting all of said discharge cells; applying a scanning pulse to each of said discharge cells to cause each of said discharge cells to selective-discharge for selecting either of light-emission and non-light-emission modes for each of said discharge cells on the basis of pixel data corresponding to a video signal for each of said discharge cells; and applying a sustaining pulse to allow only the discharge cell in the light-emission mode to discharge for repeating light emission. The reset pulse comprises a first pulse voltage shift interval in which a pulse voltage changes steeply, and a second pulse voltage shift interval during which said pulse voltage changes gradually, reaches a minimum reset-discharge starting voltage, and exceeds the minimum reset-discharge starting voltage.  
           [0021]    According to a third aspect of the invention, we provide a method for driving a PDP in accordance with video signals, said PDP including a plurality of discharge cells arranged in a matrix form, each of said discharge cells working as a display pixel. The apparatus comprises the steps of: applying a reset pulse to all of said discharge cells to cause all of said discharge cells to discharge for resetting all of said discharge cells; applying a scanning pulse to each of said discharge cells to cause each of said discharge cells to selective-discharge for selecting either of light-emission and non-light-emission modes for each of said discharge cells on the basis of pixel data corresponding to a video signal for each of said discharge cells; and applying a sustaining pulse to allow only the discharge cell in the light-emission mode to discharge for repeating light emission. The reset pulse comprises a first pulse voltage shift interval during which a pulse voltage changes steeply, a second pulse voltage shift interval during which said pulse voltage changes gradually, reaches a minimum reset-discharge starting voltage, and exceeds the minimum reset-discharge starting voltage, and a third pulse voltage shift interval during which said pulse voltage changes steeply.  
           [0022]    According to a forth aspect of the invention, we provide an apparatus for driving a PDP in accordance with video signals, said PDP comprising a plurality of discharge cells arranged in a matrix form, each of said discharge cells working as a display pixel. The apparatus further comprises: a reset pulse generator for generating a reset pulse for causing each of said discharge cells to discharge and applying said reset pulse to all of said discharge cells, thereby resetting all of said discharge cells; a scanning pulse generator for generating a scanning pulse for causing each of said discharge cells to selective-discharge for selecting either of light-emission and non-light emission modes for each of said discharge cells in accordance with pixel data corresponding to a video signal for said each of discharge cells, and applying said scanning pulse to said each of discharge cells; and a sustaining pulse generator for generating a sustaining pulse to allow only the discharge cell in the light-emission mode to discharge for repeating light emission. The reset pulse comprises a first pulse voltage shift interval during which a pulse voltage changes gradually, reaches a minimum reset-discharge starting voltage, and exceeds said minimum reset-discharge starting voltage, and a second pulse voltage shift interval during which said pulse voltage changes steeply.  
           [0023]    According to a fifth aspect of the invention, we provide an apparatus for driving a PDP in accordance with video signals, said PDP comprising a plurality of discharge cells arranged in a matrix form, each of said discharge cells working as display pixels. The apparatus further comprises: a reset pulse generator for generating a reset pulse for causing each of said discharge cells to discharge and applying said reset pulse to all of said discharge cells, thereby resetting all of said discharge cells; a scanning pulse generator for generating a scanning pulse for causing each of said discharge cells to selective-discharge for selecting either of light-emission and non-light emission modes for each of said discharge cells in accordance with pixel data corresponding to a video signal for said each of discharge cells, and applying said scanning pulse to said each of discharge cells; and a sustaining pulse generator for generating a sustaining pulse to allow only the discharge cell in the light-emission mode to discharge for repeating light emission. The reset pulse comprises a first pulse voltage shift interval during which a pulse voltage changes steeply, and a second pulse voltage shift interval during which said pulse voltage changes gradually, reaches a minimum reset-discharge starting voltage, and exceeds the minimum reset-discharge starting voltage.  
           [0024]    According to a sixth aspect of the invention, we provide an apparatus for driving a PDP in accordance with video signals, said PDP comprising a plurality of discharge cells arranged in a matrix form, each of said discharge cells working as a display pixel. The apparatus further comprises: a reset pulse generator for generating a reset pulse for causing each of said discharge cells to discharge and applying said reset pulse to all of said discharge cells, thereby resetting all of said discharge cells; a scanning pulse generator for generating a scanning pulse for causing each of said discharge cells to selective-discharge for selecting either of light-emission and non-light emission modes for each of said discharge cells in accordance with pixel data corresponding to a video signal for said each of discharge cells, and applying said scanning pulse to said each of discharge cells; and a sustaining pulse generator for generating a sustaining pulse to allow only the discharge cell in the light-emission mode to discharge for repeating light emission. The reset pulse comprises a first pulse voltage shift interval during which a pulse voltage changes steeply, a second pulse voltage shift interval during which said pulse voltage changes gradually, reaches a minimum reset-discharge starting voltage, and exceeds said minimum reset-discharge starting voltage, and a third pulse voltage shift interval during which the pulse voltage changes steeply.  
           [0025]    As mentioned above, according to the driving method of the PDP of the invention, the pulse comprising the interval where the pulse voltage is gradually shifted and the interval where it is steeply shifted is generated as a reset pulse which is applied for allowing the discharge cells of the PDP to be reset-discharged. In the invention, in the interval where the pulse voltage is gradually shifted, the pulse voltage is allowed to reach the minimum reset discharge starting voltage. Although the weak reset discharge of the low light emission luminance is, consequently, caused within the relatively short period of time, the applied voltage and the time which are necessary for forming the wall charges can be obtained.  
           [0026]    According to the invention, therefore, since the desired amount of wall charges can be formed in each discharge cell without needing to increase the pulse voltage and pulse width of the reset pulse, the relatively cheap driver of a low withstanding voltage can be used as a driver for generating the reset pulse. Further, since the pulse width of the reset pulse can be narrowed more than that of the conventional pulse, the time which is used for the pixel data writing step and the light emission sustaining step can be extended by the time corresponding to it and the high picture quality can be realized. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0027]    The aforementioned aspects and other features of the invention are explained in the following description, taken in connection with the accompanying drawing figures wherein:  
         [0028]    [0028]FIG. 1 is a diagram showing a schematic construction of a plasma display apparatus;  
         [0029]    [0029]FIG. 2 is a diagram showing an example of a light emission driving format;  
         [0030]    [0030]FIG. 3 is a diagram showing driving pulses which are applied to a PDP  10  in one subfield and timing for applying those pulses;  
         [0031]    [0031]FIG. 4 is a diagram showing a construction of a plasma display apparatus for driving a PDP by a driving method according to the invention;  
         [0032]    [0032]FIG. 5 is a diagram showing an example of a light emission driving format which is used in the plasma display apparatus shown in FIG. 4;  
         [0033]    [0033]FIG. 6 is a diagram showing an internal construction of an X-row electrode driver  7  and a Y-row electrode driver  8 ;  
         [0034]    [0034]FIG. 7 is a diagram showing various kinds of driving pulses which are generated in response to a switching signal SW by a selective erasure address method and timing for applying those pulses;  
         [0035]    [0035]FIG. 8 is a diagram showing driving pulses in an all-resetting step and a pixel data writing step by a selective write address method and timing for applying those pulses;  
         [0036]    [0036]FIG. 9 is a diagram showing waveforms of another embodiment of a reset pulse RP′; and  
         [0037]    [0037]FIG. 10 is a diagram showing waveforms of further another embodiment of the reset pulse RP′. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0038]    Preferred embodiments of the invention will be described in detail hereinbelow with reference to the drawings.  
         [0039]    [0039]FIG. 4 is a diagram showing a construction of a plasma display apparatus for driving a PDP by a driving method according to the invention.  
         [0040]    In FIG. 4, a PDP  10  as a PDP comprises: m column electrodes D 1  to D m ; and  n  row electrodes X 1  to X n  and n row electrodes Y 1  to Y n  which are arranged so as to cross the column electrodes, respectively. With respect to the row electrodes X 1  to X n  and the row electrodes Y 1  to Y n , the first to nth display lines in the PDP  10  are constructed by pairs of row electrodes X i  (1≦i ≦n) and Y i  (1≦i ≦n). A discharge space filled with discharge gas is formed between the column electrode D and the row electrodes X and Y. The discharge space has a structure such that a discharge cell serving as a display pixel is formed at each crossing portion of the row electrode pair and the column electrode including the discharge space. The discharge cells are arranged in a matrix form.  
         [0041]    An A/D converter  1  samples the supplied video signal and converts the sampled video signal to pixel data PD of  N  bits showing a luminance level of each pixel.  
         [0042]    The pixel data PD is sequentially written into a memory  3  in response to a write signal supplied from a drive control circuit  4 . After completion of the writing of the ( n×m ) pixel data PD of one frame, that is, the pixel data in a range from the pixel data PD 11  corresponding to the pixel of the first row and the first column to the pixel data PD nm  corresponding to the pixel of the nth row and the mth column, the following reading operation of the memory  3  is executed. First, the memory  3  captures the data of the first bit of each of the pixel data PD 11  to PD nm  as pixel driving data bits DB 1   11  to DB 1   nm  reads them out by every amount corresponding to one display line in accordance with a read address supplied from the drive control circuit  4 , and supplies them to an address driver  6 . The memory  3  subsequently captures the data of the second bit of each of the pixel data PD 11  to PD nm  as pixel driving data bits DB 2   11  to DB 2   nm , reads them out by every amount corresponding to one display line in accordance with the read address supplied from the drive control circuit  4 , and supplies them to the address driver  6 . In a manner similar to that mentioned above, the memory  3  captures the data of the third to Nth bits of each of the pixel data PD 11  to PD nm  as pixel driving data bits DB 3  to DB(N), reads them out every DB by every amount corresponding to one display line, and supplies them to the address driver  6 .  
         [0043]    The drive control circuit  4  generates various switching signals for gradation-driving the PDP  10  in accordance with a light emission driving format shown in FIG. 5, and supplies them to the address driver  6 , an X-row electrode driver  7 , and a Y-row electrode driver  8 . For example, in the light emission driving format shown in FIG. 5, a display period of one field is divided into  N  subfields SF 1  to SF N . Each of the pixel data writing step Wc and the light emission sustaining step Ic as mentioned above is executed in each subfield. Further, the all-resetting step Rc is executed only in the head subfield SF 1 . An erasing step E for extinguishing the wall charges remaining in each discharge cell is executed only in the last subfield SFN.  
         [0044]    [0044]FIG. 6 is a diagram showing an internal construction of the X-row electrode driver  7  and Y-row electrode driver  8 .  
         [0045]    As shown in FIG. 6, the X-row electrode driver  7  comprises a reset pulse generating circuit RX for generating a reset pulse RP x ′, and a sustaining pulse generating circuit IX for generating the sustaining pulse IP X .  
         [0046]    The sustaining pulse generating circuit IX comprises: a DC power source B 1  for generating a DC voltage V S1 : switching devices S 1  to S 4 ; coils L 1  and L 2 ; diodes D 1  and D 2 ; and a capacitor C 1 . The switching device S 1  is turned on only for a period of time during which a switching signal SW 1  supplied from the drive control circuit  4  is at the logic level “1”, thereby allowing an electric potential on one end of the capacitor C 1  to be applied to the row electrode X through the coil L 1  and diode D 1 . The switching device S 2  is turned on only for a period of time during which a switching signal SW 2  supplied from the drive control circuit  4  is at the logic level “1”, thereby allowing the electric potential on the row electrode X to be applied to one end of the capacitor C 1  through the coil L 2  and diode D 2 . The switching device S 3  is turned on only for a period of time during which a switching signal SW 3  supplied from the drive control circuit  4  is at the logic level “1”, thereby allowing the voltage V S1  generated from the DC power source B 1  to be applied to the row electrode X. The switching device S 4  is turned on only for a period of time during which a switching signal SW 4  supplied from the drive control circuit  4  is at the logic level “1”, thereby connecting the row electrode X to the ground.  
         [0047]    The reset pulse generating circuit RX comprises: a DC power source B 2  for generating a DC voltage V R ′; switching devices S 7  and S 8 ; and resistors R 1  and R 2 . A resistance r 1  of the resistor R 1  is larger than a resistance r 2  of the resistor R 2 . A positive side terminal of the DC power source B 2  is connected to the ground and its negative side terminal is connected to each of the switching devices S 7  and S 8 . The switching device S 7  is turned on only for a period of time during which a switching signal SW 7  supplied from the drive control circuit  4  is at the logic level “1”, thereby allowing a voltage −V R ′ as a negative side terminal voltage of the DC power source B 2  to be applied to the row electrode X through the resistor R 1 . The switching device S 8  is turned on only for a period of time during which a switching signal SW 8  supplied from the drive control circuit  4  is at the logic level “1”, thereby allowing the voltage −V R ′ as a negative side terminal voltage of the DC power source B 2  to be applied to the row electrode X through the resistor R 2 .  
         [0048]    The Y-row electrode driver  8  comprises a reset pulse generating circuit RY for generating a reset pulse RP Y ′, a scanning pulse generating circuit SY for generating a scanning pulse SP, and a sustaining pulse generating circuit IY for generating the sustaining pulse IP Y .  
         [0049]    The reset pulse generating circuit RY comprises: a DC power source B 4  for generating the DC voltage V R ′; switching devices S 15  to S 17 ; and resistors R 3  and R 4 . A resistance value r 1  of the resistor R 3  is larger than a resistance value r 2  of the resistor R 4 . A negative side terminal of the DC power source B 4  is connected to the ground, and its positive side terminal is connected to each of the switching devices S 16  and S 17 . The switching device S 16  is turned on only for a period of time during which a switching signal SW 16  supplied from the drive control circuit  4  is at the logic level “1”, thereby allowing the voltage V R ′ as a positive side terminal voltage of the DC power source B 4  to be applied onto a line  20  through the resistor R 3 . The switching device S 17  is turned on only for a period of time during which a switching signal SW 17  supplied from the drive control circuit  4  is at the logic level “1”, thereby allowing the voltage V R ′ as a positive side terminal voltage of the DC power source B 4  to be applied onto the line  20  through the resistor R 4 . The switching device S 15  is turned on only for a period of time during which a switching signal SW 15  supplied from the drive control circuit  4  is at the logic level “1”, thereby allowing the line  20  to be connected to a line  12 , which will be explained hereinlater.  
         [0050]    The sustaining pulse generating circuit IY comprises: a DC power source B 3  for generating the DC voltage V S1 ; switching devices S 11  to S 14 ; coils L 3  and L 4 ; diodes D 3  and D 4 ; and a capacitor C 2 . The switching device S 11  is turned on only for a period of time during which a switching signal SW 11  supplied from the drive control circuit  4  is at the logic level “1”, thereby allowing an electric potential on one end of the capacitor C 2  to be applied onto the line  12  through the coil L 3  and diode D 3 . The switching device S 12  is turned on only for a period of time during which a switching signal SW 12  supplied from the drive control circuit  4  is at the logic level “1”, thereby allowing the electric potential on the line  12  to be applied to one end of the capacitor C 2  through the coil L 4  and diode D 4 . The switching device S 13  is turned on only for a period of time during which a switching signal SW 13  supplied from the drive control circuit  4  is at the logic level “1”, thereby allowing the voltage V S1  generated from the DC power source B 3  to be applied onto the line  12 . The switching device S 14  is turned on only for a period of time during which a switching signal SW 14  supplied from the drive control circuit  4  is at the logic level “1”, thereby connecting the line  12  to the ground.  
         [0051]    The scanning pulse generating circuit SY is actually provided for each of the row electrodes Y 1  to Y n . The scanning pulse generating circuit SY comprises: a DC power source B 5  for generating a DC voltage V h ; switching devices S 21  and S 22 ; and diodes D 5  and D 6 . The switching device S 21  is turned on only for a period of time during which a switching signal SW 21  supplied from the drive control circuit  4  is at the logic level “1”, thereby allowing a positive side terminal of the DC power source B 5  to be connected to the row electrode Y and a cathode terminal of the diode D 6 , respectively. The switching device S 22  is turned on only for a period of time during which a switching signal SW 22  supplied from the drive control circuit  4  is at the logic level “1”, thereby allowing a negative side terminal of the DC power source B 5  to be connected to the row electrode Y and an anode terminal of the diode D 5 , respectively.  
         [0052]    [0052]FIG. 7 shows various driving pulses which are applied to the PDP  10  and their applying timing in the case where in the subfield SF 1  shown in FIG. 5, the address driver  6 , X-row electrode driver  7 , and Y-row electrode driver  8  use a selective erasure address method.  
         [0053]    In the all-resetting step Rc, the drive control circuit  4  supplies the switching signals SW 7  and SW 8  which change as shown in FIG. 7 to the reset pulse generating circuit RX. That is, first, the drive control circuit  4  maintains supplying the switching signal SW 7  at the logic level “1” and the switching signal SW 8  at the logic level “0” to the reset pulse generating circuit RX for a time of 20 [μsec] or longer (a first pulse voltage shift interval Ta). Only the switching device S 7  between the switching devices S 7  and S 8  is, thus, turned on, and the voltage −V R ′ as a negative side terminal voltage of the DC power source B 2  is applied to the row electrode X through the resistor R 1 . At this time, since a load capacitance C 0  exists between the row electrodes X and Y, the voltage on the row electrode X gradually drops as shown in FIG. 7. That is, in the first pulse voltage shift interval Ta, after the elapse of a time of about 20 [μsec] after the voltage on the row electrode X started to gradually drop, the pulse voltage reaches a voltage (−V MIN &gt;−V R ′) of ½ of a minimum reset discharge starting voltage V MIN  and falls below the minimum reset discharge starting voltage. At this time, the drive control circuit  4  switches the switching signal SW 7  to the logic level “0” and switches the switching signal SW 8  to the logic level “ 1 ,” (a second pulse voltage shift interval Tb). Only the switching device S 8  between the switching devices S 7  and S 8  is, thus, turned on, and the voltage −V R ′ as a negative side terminal voltage of the DC power source B 2  is applied to the row electrode X through the resistor R 2 . At this time, since the resistance value r 2  of the resistor R 2  is smaller than the resistance value r 1  of the resistor R 1 , the voltage steeply drops and reaches the voltage −V R ′ as shown in FIG. 7.  
         [0054]    By the above operation, the X-row electrode driver  7  applies the reset pulse RP X ′ of the negative polarity having the waveform as shown in FIG. 7 all at once to each of the row electrodes X 1  to X n . That is, as shown in FIG. 7, first, the X-row electrode driver  7  applies the reset pulse RP X ′ to the row electrodes X 1  to X n . The reset pulse RP X ′ has a voltage which gradually drops, reaches the voltage of ½ of the minimum reset discharge starting voltage −V MIN  and falls below the minimum reset discharge starting voltage −V MIN  during the first pulse voltage shift interval Ta, and then steeply drops and reaches the pulse voltage −V R ′ during the second pulse voltage shift interval Tb. In the all-resetting step Rc, a period of time until the pixel data writing step Wc is started after the second pulse voltage shift interval Tb becomes a shift interval Tr.  
         [0055]    Further, in the all-resetting step Rc, the drive control circuit  4  supplies the switching signal SW 21  at the logic level “1” and the switching signal SW 22  at the logic level “0” to the scanning pulse generating circuit SY. The switching device S 21  is, thus, turned on and the electric potential on the line  20  is applied to the row electrode Y. Further, in the all-resetting step Rc, the drive control circuit  4  supplies the switching signals SW 16  and SW 17 , which change as shown in FIG. 7, to the reset pulse generating circuit RY. That is, first, the drive control circuit  4  maintains supplying the switching signal SW 16  at the logic level “1” and the switching signal SW 17  at the logic level “0” to the reset pulse generating circuit RY for a time of 20 [μsec] or longer (the first pulse voltage shift interval Ta). Only the switching device S 16  between the switching devices S 16  and S 17  is, thus, turned on and the voltage V R ′ as a positive side terminal voltage of the DC power source B 4  is applied to the row electrode Y through the resistor R 3  and line  20 . At this time, since the load capacitance C 0  exists between the row electrodes X and Y, the voltage on the row electrode Y gradually rises as shown in FIG. 7. That is, in the first pulse voltage shift interval Ta, after the elapse of a time of about 20 [μsec] after the voltage on the row electrode Y started to rise, the pulse voltage reaches a voltage of ½ of a minimum reset discharge starting voltage V MIN  (V MIN &lt;VR R ′), and increases above the voltage of ½ of a minimum reset discharge starting voltage V MIN . At this time, the drive control circuit  4  switches the switching signal SW 16  to the logic level “0” and switches the switching signal SW 17  to the logic level “1” (the second pulse voltage shift interval Tb). Only the switching device S 17  between the switching devices S 16  and S 17  is, thus, turned on and the voltage V R ′ as a positive side terminal voltage of the DC power source B 4  is applied to the row electrode Y through the resistor R 4  and line  20 . Since the resistance value r 2  of the resistor R 4  is smaller than the resistance value r 1  of the resistor R 3 , the voltage steeply rises more than that of the first pulse voltage shift interval Ta, and reaches the voltage V R ′ as shown in FIG. 7.  
         [0056]    By the above operation, the Y-row electrode driver  8  applies the reset pulse RP Y ′ of the positive polarity having the waveform as shown in FIG. 7 all at once to each of the row electrodes Y 1  to Y n  simultaneously with the application of the reset pulse RP X ′. That is, as shown in FIG. 7, first, the Y-row electrode driver  8  applies the reset pulse RP Y ′ to the row electrodes Y 1  to Y n . The reset pulse RP Y ′ has a voltage which gradually rises, reaches the voltage of ½ of the minimum reset discharge starting voltage V MIN , and increases above the voltage of ½ of the minimum reset discharge starting voltage V MIN  during the first pulse voltage shift interval Ta), and then steeply rises and reaches the voltage V R ′ during the second pulse voltage shift interval Tb.  
         [0057]    In accordance with the application of the reset pulses RP X ′ and RP Y ′, in all of the discharge cells of the PDP  10 , a weak reset discharge is intermittently caused at timing when an electric potential difference between the row electrodes X and Y serving as a pair exceeds the minimum reset discharge starting voltage V MIN  (−V MIN ), so that priming particles are generated. By maintaining applying a voltage near the voltage V R  (−V R ) in the second pulse voltage shift interval Tb for a predetermined period, a predetermined amount of wall charges are formed in each discharge cell. That is, by applying the minimum voltage (V MIN , −V MIN ) which can cause the reset discharge to the discharge cells in the first pulse voltage shift interval Ta, the reset discharge of a low light emission luminance is caused. In the second pulse voltage shift interval Tb, the voltage to be applied to the discharge cells is immediately raised to the voltage V R ′ (decreased to the voltage −V R ′) at which the wall charges can be formed, and continuous application of the voltage is maintained. Therefore, the predetermined amount of wall charges is formed in a short period of time.  
         [0058]    By the execution of the all-resetting step Rc, all of the discharge cells in the PDP  10  are initialized to the “light emitting cell” state where the light emission (sustaining discharge) is possible in the light emission sustaining step Ic, which will be explained hereinlater.  
         [0059]    In the case of using the selective write address method, as shown in FIG. 8, in the shift interval Tr, an erasing pulse EP whose polarity is opposite to that of the reset pulse RP X ′ and which is a short pulse is applied all at once to all of the row electrodes X 1  to X n , thereby causing the discharge. By the generation of the discharge, the wall charges in all of the discharge cells are extinguished, and all of the discharge cells are initialized to the “non-light emitting” state.  
         [0060]    Referring to FIG. 7 again, in the pixel data writing step Wc, the address driver  6  generates the pixel data pulse having the pulse voltage according to the pixel driving data bits DB supplied from the memory  3 . In the subfield SF 1 , in response to each of the pixel driving data bits DB 1   11  to DB 1   nm , the address driver  6  generates the pixel data pulse which is set to the high voltage when the logic level of the data bit is equal to “ 1 ,” and the low voltage (0 volt) when the logic level of the data bit is equal to “0”. The address driver  6  sequentially applies the pixel data pulse groups DP 1  to DP n , obtained by grouping the pixel data pulses every display line, to the column electrodes D 1  to D m  as shown in FIG. 7.  
         [0061]    During the above period of time, as shown in FIG. 7, the drive control circuit  4  sequentially supplies the switching signal SW 21  at the logic level “0” and the switching signal SW 22  at the logic level “1” to each of the scanning pulse generating circuit SY corresponding to each of the row electrodes Y 1  to Y n  synchronously with the applying timing of each of the pixel data pulse groups DP 1  to DP n . At this time, in the scanning pulse generating circuit SY to which the switching signals SW 21  and SW 22  are supplied, the switching device S 22  is turned on and the switching device S 21  is turned off. The scanning pulse SP of a negative polarity having a voltage −V h  as shown in FIG. 7 is, thus, applied onto the row electrode Y corresponding to the scanning pulse generating circuit SY. At this time, a discharge (selective erasure discharge) is caused only in the discharge cell at the crossing portion of the display line to which the scanning pulse SP is applied, and the “column” to which the pixel data pulse of the high voltage has been applied. By the selective erasure discharge, the wall charges held in the discharge cell are extinguished, and the discharge cell is shifted to the “non-light emitting cell” state where the light emission (sustaining discharge) cannot be performed in the light emission sustaining step Ic, which will be explained hereinlater. The selective erasure discharge is not caused in the discharge cell to which the pixel data pulse of the low voltage has been applied although the scanning pulse SP was applied. The discharge cell, therefore, sustains the state where it was initialized in the all-resetting step Rc, that is, the “light emitting cell” state.  
         [0062]    In the case of using the selective write address method, when the scanning pulse SP of the negative polarity is applied in the pixel data writing step Wc, a discharge (selective write discharge) is caused only in the discharge cell at the crossing portion of the display line to which the scanning pulse SP is applied and the “column” to which the pixel data pulse of the high voltage is applied. By the selective write discharge, the wall charges are induced in the discharge cell. The discharge cell is set to the “light emitting cell” which can perform the light emission (sustaining discharge) in the light emission sustaining step Ic, which will be explained hereinlater. The selective write discharge is not caused in the discharge cell to which the pixel data pulse of the low voltage is applied although the scanning pulse SP was applied. The discharge cell sustains the state where it was initialized in the all-resetting step Rc, that is, a state where there is no wall charge, and is set to the “non-light emitting cell”.  
         [0063]    That is, by the pixel data writing step Wc, even in the case of using either the selective erasure address method or the selective write address method, each of the discharge cells of the PDP  10  is set to either the “light emitting cell” state or the “non-light emitting cell” state in accordance with the pixel data based on the input video signal.  
         [0064]    Subsequently, in the light emission sustaining step Ic, the drive control circuit  4  supplies each of the switching signals SW 1  to SW 4 , which change as shown in FIG. 7, to the sustaining pulse generating circuit IX. Only the switching device S 1  is first turned on by the above switching signals SW 1  to SW 4 , and a current associated by the charges accumulated in the capacitor C 1  flows into the discharge cell through the coil L 1 , diode D 1 , and row electrode X. The voltage on the row electrode X, thus, rises gradually as shown in FIG. 7. Subsequently, only the switching device S 3  is turned on, and the voltage V S1  generated from the DC power source B 1  is immediately applied to the row electrode X. The voltage on the row electrode X, therefore, becomes the voltage V S1  as shown in FIG. 7. Only the switching device S 2  is subsequently turned on, and the current which is caused by the charges accumulated in the load capacitor C 0  between the row electrodes X and Y flows into the capacitor C 1  through the coil L 2  and diode D 2 . The voltage on the row electrode X drops gradually as shown in FIG. 7. By repetitively executing the above operation as shown in FIG. 7, the sustaining pulse generating circuit IX repetitively applies the sustaining pulse IP X  having the waveform as shown in FIG. 7 onto the row electrode X.  
         [0065]    Further, in the light emission sustaining step Ic, the drive control circuit  4  supplies each of the switching signals SW 11  to SW 14  which change as shown in FIG. 7 to the sustaining pulse generating circuit IY. By the switching signals SW 11  to SW 14 , only the switching device S 11  is first turned on. The current associated by the charges accumulated in the capacitor C 2 , therefore, flows into the discharge cell through the coil L 3 , diode D 3 , line  12 , switching device S 15 , line  20 , switching device S 21 , and row electrode Y. The voltage on the row electrode Y rises gradually as shown in FIG. 7. Subsequently, only the switching device S 13  is turned on, and the voltage V S1  generated from the DC power source B 3  is applied to the row electrode Y through the line  12 , switching device S 15 , line  20 , and switching device S 21 . The voltage on the row electrode Y becomes the voltage V S1  as shown in FIG. 7. Subsequently, only the switching device S 12  is turned on and the current associated by the charges accumulated in the capacitor C 0  between the row electrodes X and Y flows into the capacitor C 2  through the row electrode Y, switching device S 21 , line  20 , switching device S 15 , coil L 4 , and diode D 4 . The voltage on the row electrode Y decreases gradually as shown in FIG. 7. By repetitively executing the operation as mentioned above as shown in FIG. 7, the sustaining pulse generating circuit IY repetitively applies the sustaining pulse IP Y  having the waveform as shown in FIG. 7 to the row electrode Y.  
         [0066]    That is, in the light emission sustaining step Ic, each of the X-row electrode driver  7  and the Y-row electrode driver  8  alternately repeats applying the sustaining pulse IP X  of the positive polarity and the sustaining pulse IP y  of the positive polarity as shown in FIG. 7 to the row electrodes X 1  to X n  and the row electrodes Y 1  to Y n . At this time, only the discharge cell in which the wall charges exist, that is, only the discharge cell in the “light emitting cell” state repeats a discharge (sustaining discharge) each time one of the sustaining pulses IP X  and IP Y  is applied. Therefore, the discharge cell repeats the light emission due to the discharge.  
         [0067]    As mentioned above, only the discharge cell in which the wall charges formed by the reset discharge in the all-resetting step Rc remain without being erased even in the pixel data writing step Wc repeats light emission, and forms a display image in the light emission sustaining step Ic.  
         [0068]    At this time, according to the invention, the reset pulses RP X ′ and RP Y ′ having the waveforms as shown in FIG. 7 are formed in order to cause the reset discharge in the all-resetting step Rc.  
         [0069]    That is, in the first pulse voltage shift interval Ta in the reset pulses RP X ′ (RP Y ′), the voltage to be applied between the paired row electrodes X and Y is gradually dropped (raised) until it exceeds the minimum reset discharge starting voltage −V MIN  (V MIN ) which can cause the reset discharge, thereby intermittently causing the reset discharge of low light emission luminance. In the next second pulse voltage shift interval Tb, the voltage is steeply dropped (raised), thereby shifting the voltage to a value near the lowest voltage −V R ′ (voltage V R ′) which can form the wall charges. By maintaining applying the voltage, the formation of a desired amount of wall charges is promoted.  
         [0070]    The desired amount of wall charges, consequently, can be formed even if the pulse width and voltage are set to be smaller than those of the conventional reset pulse RP having the waveform as shown in FIG. 3.  
         [0071]    As waveforms of the reset pulses RP X ′ and RP Y ′, a similar effect can be obtained even if waveforms shown in FIG. 9 are used in place of those shown in FIG. 7.  
         [0072]    In order to generate the reset pulses RP X ′ and RP Y ′ having the waveforms as shown in FIG. 9, the drive control circuit  4  supplies the switching signals SW 7  and SW 8  which change as shown in FIG. 9 to the reset pulse generating circuit RX. That is, the drive control circuit  4  first supplies the switching signal SW 7  at the logic level “0” and the switching signal SW 8  at the logic level “1” to the reset pulse generating circuit RX (the first pulse voltage shift interval Ta). Only the switching device S 8  between the switching devices S 7  and S 8  is, then, turned on, thereby allowing the voltage −V R ′ as a negative side terminal voltage of the DC power source B 2  to be applied to the row electrode X through the resistor R 2 . At this time, although the load capacitance C 0  exists between the row electrodes X and Y, the voltage on the row electrode X steeply drops as shown in FIG. 9, since the resistor R 2  has the relatively low resistance value as mentioned above. Before the voltage on the row electrode X decreases below the voltage of ½ of the minimum reset discharge starting voltage −V MIN , the drive control circuit  4  switches the switching signal SW 7  to the logic level “1”, switches the switching signal SW 8  to the logic level “0”, and sustains those states for a time of 20 [μsec] or longer (the second pulse voltage shift interval Tb). Only the switching device S 7  between the switching devices S 7  and S 8  is, thus, turned on in the second pulse voltage shift interval Tb, thereby allowing the voltage −V R ′ as a negative side terminal voltage of the DC power source B 2  to be applied to the row electrode X through the resistor R 1 . Since the resistor R 1  has a higher resistance value than that of the resistor R 2  as mentioned above, the voltage on the row electrode X gradually drops as shown in FIG. 9 below the voltage of ½ of the minimum reset discharge starting voltage −V MIN , and reaches the voltage −V R ′.  
         [0073]    Further, in the all-resetting step Rc shown in FIG. 9, the drive control circuit  4  supplies the switching signals SW 16  and SW 17  which change as shown in FIG. 9 to the reset pulse generating circuit RY. That is, the drive control circuit  4  first supplies the switching signal SW 16  at the logic level “0” and the switching signal SW 17  at the logic level “1” to the reset pulse generating circuit RY (the first pulse voltage shift interval Ta). Only the switching device S 17  between the switching devices S 16  and S 17  is, thus, turned on, thereby allowing the voltage V R ′ as a positive side terminal voltage of the DC power source B 4  to be applied to the row electrode Y through the resistor R 4 , line  20 , and switching device S 21 . At this time, although the load capacitance C 0  exists between the row electrodes X and Y, the voltage on the row electrode Y steeply rises as shown in FIG. 9, since the resistor R 4  has the relatively low resistance value as mentioned above. Before the voltage on the row electrode Y rises above the voltage of ½ of the minimum reset discharge starting voltage V MIN , the drive control circuit  4  switches the switching signal SW 16  to the logic level “1”, switches the switching signal SW 17  to the logic level “0”, and sustains those states for a time of 20 [μsec] or longer (the second pulse voltage shift interval Tb). Only the switching device S 16  between the switching devices S 16  and S 17  is, thus, turned on in the second pulse voltage shift interval Tb, thereby allowing the voltage V R ′ as a positive side terminal voltage of the DC power source B 4  to be applied to the row electrode Y through the resistor R 3 , line  20 , and switching device S 21 . At this time, since the resistor R 3  has a higher resistance value than that of the resistor R 4  as mentioned above, the voltage on the row electrode Y gradually rises as shown in FIG. 9 above the voltage of ½ of the minimum reset discharge starting voltage V MIN , and reaches the voltage V R ′. In the all-resetting step Rc, a period of time from the end of second pulse voltage shift interval Tb to the start of the pixel data writing step Wc is the shift interval Tr.  
         [0074]    In accordance with the application of the reset pulses RP X ′ and RP Y ′ as shown in FIG. 9, in all of the discharge cells of the PDP  10 , in the second pulse voltage shift interval Tb, a weak reset discharge is intermittently caused at the time when the voltage applied between the row electrodes X and Y exceeds the minimum reset discharge starting voltage V MIN  (−V MIN ). By maintaining applying a voltage near the voltage V R  (−V R ) in the second pulse voltage shift interval Tb for a predetermined period of time, a predetermined amount of wall charges are formed in each discharge cell.  
         [0075]    According to the reset pulses RP X ′ and RP Y ′ shown in FIG. 9, by steeply changing the pulse voltage in the first pulse voltage shift interval Ta, a time which elapses until the voltage applied between the row electrodes X and Y reaches the minimum reset discharge starting voltage V MIN  (−V MIN ) is set to be shorter than that of the reset pulse shown in FIG. 7. In the embodiment, as shown in FIGS. 7 and 9, a voltage shift state of the reset pulse RP′ is switched at two stages in the all-resetting step Rc. It can be also similarly switched at three stages as shown in FIG. 10.  
         [0076]    In order to generate the reset pulses RP X ′ and RP Y ′ having waveforms as shown in FIG. 10, the drive control circuit  4  supplies the switching signals SW 7  and SW 8  which change as shown in FIG. 10 to the reset pulse generating circuit RX. That is, the drive control circuit  4  first supplies the switching signal SW 7  at the logic level “0” and the switching signal SW 8  at the logic level “1” to the reset pulse generating circuit RX (the first pulse voltage shift interval Ta). Only the switching device S 8  between the switching devices S 7  and S 8  is, thus, turned on, thereby allowing the voltage −V R ′ as a negative side terminal voltage of the DC power source B 2  to be applied to the row electrode X through the resistor R 2 . At this time, although the load capacitance C 0  exists between the row electrodes X and Y, since the resistor R 2  has the relatively low resistance value as mentioned above, the voltage on the row electrode X steeply drops as shown in FIG. 10. When the voltage on the row electrode X decreases to a value lower than the voltage of ½ of the minimum reset discharge starting voltage −V MIN , the drive control circuit  4  switches the switching signal SW 7  to the logic level “1”, switches the switching signal SW 8  to the logic level “0”, and sustains those states for a time of 20 [μsec] or longer (the second pulse voltage shift interval Tb). Only the switching device S 7  between the switching devices S 7  and S 8  is, thus, turned on in the second pulse voltage shift interval Tb, thereby allowing the voltage −V R ′ as a negative side terminal voltage of the DC power source B 2  to be applied to the row electrode X through the resistor R 1 . At this time, since the resistor R 1  has a higher resistance value than that of the resistor R 2  as mentioned above, the voltage on the row electrode X gradually drops as shown in FIG. 10 to a value lower than the voltage of ½ of the minimum reset discharge starting voltage −V MIN . Subsequently, the drive control circuit  4  again switches the switching signal SW 7  to the logic level “0” and switches the switching signal SW 8  to the logic level “1” (a third pulse voltage shift interval Tc). Only the switching device S 8  is, thus, turned on again, thereby allowing the voltage −V R ′ as a negative side terminal voltage of the DC power source B 2  to be applied to the row electrode X through the resistor R 2 . The voltage on the row electrode X, therefore, steeply drops as shown in FIG. 10 and reaches the voltage −V R ′.  
         [0077]    Further, in the all-resetting step Rc shown in FIG. 10, the drive control circuit  4  supplies the switching signals SW 16  and SW 17  which change as shown in FIG. 10 to the reset pulse generating circuit RY. That is, the drive control circuit  4  first supplies the switching signal SW 16  at the logic level “0” and the switching signal SW 17  at the logic level “1” to the reset pulse generating circuit RY (the first pulse voltage shift interval Ta). Only the switching device S 17  between the switching devices S 16  and S 17  is, thus, turned on, thereby allowing the voltage V R ′ as a positive side terminal voltage of the DC power source B 4  to be applied to the row electrode Y through the resistor R 4 , line  20 , and switching device S 21 . At ythis time, although the load capacitance C 0  exists between the row electrodes X and Y, since the resistor R 4  has the relatively low resistance value as mentioned above, the voltage on the row electrode Y steeply rises as shown in FIG. 10. When the voltage on the row electrode Y rises to a value near the voltage of ½ of the minimum reset discharge starting voltage V MIN , the drive control circuit  4  switches the switching signal SW 16  to the logic level “1”, switches the switching signal SW 17  to the logic level “0”, and sustains those states for a time of 20 [μsec] or longer (the second pulse voltage shift interval Tb). Only the switching device S 16  between the switching devices S 16  and S 17  is, therefore, turned on, thereby allowing the voltage VR′ as a positive side terminal voltage of the DC power source B 4  to be applied to the row electrode Y through the resistor R 3 , line  20 , and switching device S 21 . At this time, since the resistor R 3  has a higher resistance value than that of the resistor R 4  as mentioned above, the voltage on the row electrode Y gradually rises as shown in FIG. 10. Subsequently, the drive control circuit  4  again switches the switching signal SW 16  to the logic level “0” and switches the switching signal SW 17  to the logic level “1” (the third pulse voltage shift interval Tc). Only the switching device S 17  is, thus, turned on again, thereby allowing the voltage V R ′ as a positive side terminal voltage of the DC power source B 4  to be applied to the row electrode Y through the resistor R 4 . The voltage on the row electrode Y, therefore, steeply rises as shown in FIG. 10 and reaches the voltage V R ′. In the all-resetting step Rc, a period of time from the end of the third pulse voltage shift interval Tc to the start of the pixel data writing step Wc becomes the shift interval Tr.  
         [0078]    That is, in the reset pulses RP X ′ and RP Y ′ shown in FIG. 10, the voltage which is applied between the row electrodes X and Y serving as a pair steeply drops (rises) until timing just before it reaches the minimum reset discharge starting voltage −V MIN  (V MIN ) (the first pulse voltage shift interval Ta). After that, the voltage gradually drops (rises), and the state is sustained for a predetermined time (20 [μsec]) or longer (the second pulse voltage shift interval Tb). At this time, in the second pulse voltage shift interval Tb, since the voltage which is applied between the row electrodes X and Y gradually exceeds the minimum reset discharge starting voltage −V MIN  (V MIN ), a weak reset discharge is intermittently caused. After that, the voltage steeply drops (rises) again, and the voltage is shifted to the lowest voltage −V R ′ (voltage V R ′) at which the wall charges can be formed (the third pulse voltage shift interval Tc).  
         [0079]    It is understood that the foregoing description and accompanying drawings set forth the preferred embodiments of the invention at the present time. Various modifications, additions and alternative designs will, of course, become apparent to those skilled in the art in light of the foregoing teachings without departing from the spirit and scope of the disclosed invention. Thus, it should be appreciated that the invention is not limited to the disclosed embodiments but may be practiced within the full scope of the appended claims.  
         [0080]    This application is based on Japanese patent applications Nos. 2000-370988 and 2001-155217 which are hereby incorporated by reference.