1. Field of the Invention
The present invention relates to a display having a display panel mounted there and a driving method of the display panel.
2. Description of the Related Art
Recently, a plasma display panel (hereafter, referred to as PDP) with a plurality of discharge cells arranged in matrix gains attention as a two-dimensional image display panel. The PDP is directly driven by a digital image signal and the number of the displayable brightness gradation is determined by the number of the bits of the pixel data for every pixel based on the digital image signal.
Subfield method is known as a gradation display method of the PDP. The subfield method features division of a display period into a plurality of sub-periods to drive each cell. In the subfield method, the display period of one field is divided into a plurality of subfields so to perform the light-emission drive on the PDP in every subfield. Each subfield includes an address period of setting a light-on mode or a light-off mode of each pixel depending on the pixel data and a light emission sustaining period for lighting on (emitting light) only the pixel in the light-on mode, for the period corresponding to the weight of the subfield. Namely, whether the discharge cell should emit light or not in each subfield is set in every subfield (address period), and only the discharge cell set at the light-on mode is made to emit light for only the period assigned to the subfield (light emission sustaining period). Thus, there occurs the case where a subfield in a light emitting state and a subfield in a light-off (non-light emitting) state exist in a mixed way, hence to visualize the intermediate gradation depending on the total sum of the light-emission periods of the respective subfields within one field.
Namely, one field in an image signal is divided into twelve subfields of SF1 to SF12 and the drive of the PDP is performed in each subfield. In this process, each subfield is formed by an address stage Wc for setting each discharge cell of the PDP at “light-on state” (namely, operative mode) according to an input image signal and “light-off state” (namely, non-operative mode) and a sustain stage Ic for making only the discharge cell in the “light-on state” emit light only for the period (the number of times) corresponding to the weight of each subfield. Here, a simultaneous reset stage Rc for initializing all the discharge cells of the PDP into the “light-on state” is executed only in the head subfield SF1, and an erase stage E is executed only in the last subfield SF12.
By sampling an image signal, for example, the pixel data for 8 bits can be obtained. The obtained pixel data is subjected to the multiple gradation processing and while keeping the current number of gradation levels, the number of the bits is reduced to 4 bits hence to generate the multiple gradation-processed pixel data PDs. The multiple gradation-processed pixel data PDs is converted into the pixel drive data GD consisting of first to twelfth bits, according to a conversion table, as shown in
In the simultaneous reset stage Rc of the subfield SF1, at first, the reset pulse RPx of negative polarity is applied to the row electrodes X1 to Xn. Simultaneously with the application of the reset pulse RPx, the reset pulse RPY of positive polarity is applied to the row electrodes Y1 to Y2. According to the application of the reset pulses RPx and RPy, all the discharge cells are discharged and reset, and each wall charge of the same predetermined amount is formed within each discharge cell. Thus, all the discharge cells are initialized into the “light-on state”.
In the address stage Wc of each subfield, pixel data pulses DP each having a voltage corresponding to a logical level of the pixel drive data bits DB1 to DB12. The pixel drive data bits DB1 to DB12 correspond to the first to the twelfth bits of the pixel drive data GD. For example, in the address stage Wc of the subfield SF1, at first, the pixel drive data bit DB1 is converted into a pixel data pulse having a voltage corresponding to its logical level. The number m of the pixel data pulses corresponding to the first line is defined as the pixel data pulse group DP11, the number m of the pixel data pulses corresponding to the second line is defined as the pixel data pulse group DP12, the number m of the pixel data pulses corresponding to the n-th line is defined as the pixel data pulse group DP1n, and each of the pixel data pulse groups DP11 to DP1n is sequentially applied to the column electrodes D1 to Dm.
Further, in the address stage Wc, at the same timing as each applying timing of the pixel data pulse group DP as mentioned above, a scanning pulse SP of negative polarity is sequentially applied to the column electrodes Y1 to Yn. In this process, only the discharge cell at an intersection of the row electrode having the scanning pulse SP applied and the column electrode having the pixel data pulse of high pressure applied, is discharged (selective-erase discharge) and the wall charge left within the discharge cell is selectively erased.
According to the selective-erase discharge, the discharge cell initialized into the “light-on state” in the simultaneous reset stage Rc is turned to the “light-off state”. While, the discharge cell where the selective-erase discharge does not occur is maintained in the initialized state, namely in the “light-on state” in the simultaneous reset stage Rc.
In the sustain stage IC of the respective subfields, as illustrated in
In this case, only the discharge cell where the wall discharge is still left, namely the discharge cell set at the “light-on state” in the above address stage Wc, is sustained every time the sustain pulses IPX and IPY are applied there. Accordingly, the discharge cell set at the “light-on state” sustains the light emission state accompanying the sustain discharge, for the number of the times assigned to each subfield as mentioned above.
The erase stage E is executed only in the last subfield SF12. In this erase stage E, an erase pulse AP of positive polarity is generated and applied to the respective column electrodes D1 to Dm. Further, simultaneously with the applying timing of the erase pulse AP, the erase pulse EP of negative polarity is generated and applied to the respective row electrodes Y1 to Yn. The simultaneous application of these erase pulses AP and EP causes the erase discharge in all the discharge cells in the PDP and extinguishes the wall charges left within all the discharge cells. According to the erase discharge, all the discharge cells in the PDP are turned to the “light-off state”.
In the drive method as mentioned above, only in one of the subfields, only the discharge cell in a light emission state in the proximate subfield is selectively erased in the address stage. Thus, starting from the head subfield, the number N (for example, 12) of the subfields are sequentially lit on, hence to display the N+1-level gradation (for example, 13-level gradation), and then, the gradation display depending on the brightness represented by an input image signal is realized according to the total sum of the sustain discharges in the respective subfields.
In the driving of the PDP, however, the reset discharge and the address discharge accompanied by the light emission not related to the display image should be generated, in addition to the sustain discharge serving for a display image. Accordingly, it has the defect of deteriorating the contrast of an image, especially, the dark contrast at a display time of an image indicating a dark scene.
In order to solve the above problem, an object of the present invention is to provide a display and a driving method of a display panel capable of improving the dark contrast.
A display according to the characteristic of the invention is the display for displaying an image according to pixel data of every pixel based on an input image signal, comprising: a display panel having a front substrate and a rear substrate arranged at opposite positions for interposing a discharge space therebetween; a plurality of pairs of row electrodes provided on an inner surface of the front substrate, a plurality of column electrodes arranged on an inner surface of the rear substrate in a way of intersecting with the pairs of row electrodes, and light-emission areas formed at each intersection of the row electrode pairs and the column electrodes, each of the light-emission areas consisting of a first discharge cell including a portion where the respective row electrodes in pair are opposed to each other with a first discharge gap in the discharge space and a second discharge cell including a portion where a light absorptive layer is provided on the front substrate's side and one row electrode of the row electrode pair and the other row electrode of the row electrode pair adjacent to the above row electrode pair are opposed to each other with a second discharge gap; and an address component for producing an address discharge within the second discharge cell selectively by applying a pixel data pulse based on the pixel data, to the respective column electrodes, while applying a scanning pulse to a row electrode having the longer distance to the first discharge cell, of the respective row electrodes within the second discharge cell, thereby setting the second discharge cell at a light-on state or a light-off state.
A driving method of a display panel according to the characteristic of the invention is the driving method for driving a display panel according to the pixel data of every pixel based on an input image signal, the display panel having: a front substrate and a rear substrate arranged at opposite positions for interposing a discharge space therebetween; a plurality of pairs of row electrodes provided on an inner surface of the front substrate; a plurality of column electrodes arranged on an inner surface of the rear substrate in a way of intersecting with the pairs of row electrodes; and light-emission areas formed at each intersection of the row electrode pairs and the column electrodes, each of the light-emission areas consisting of a first discharge cell including a portion where the respective row electrodes in pair are opposed to each other with a first discharge gap in the discharge space and a second discharge cell including a portion where a light absorptive layer is provided on the front substrate's side and one row electrode of the row electrode pair and the other row electrode of the row electrode pair adjacent to the above row electrode pair are opposed to each other with a second discharge gap, the method comprising: an address stage for producing an address discharge within the second discharge cell selectively by applying a pixel data pulse based on the pixel data, to the respective column electrodes, while applying a scanning pulse to a row electrode having the longer distance to the first discharge cell, of the respective row electrodes within the second discharge cell, thereby setting the second discharge cell at a light-on state or a light-off state; a priming expansion stage for expanding a discharge toward the first discharge cell to set the first discharge cell at a light-on state, by applying a priming pulse alternately to the respective row electrodes within the second discharge cell to cause a priming discharge only in the second discharge cell that is in the light-on state; and a sustain stage for repeatedly applying a sustain pulse alternately to the respective row electrodes within the first discharge cell to cause a sustain discharge only in the first discharge cell that is in the light-on state.
As shown in
Strip-shaped column electrodes D1 to Dm respectively extending in the vertical direction on the display screen are formed in the PDP 50. Further, strip-shaped row electrodes X2 to Xn and row electrodes Y1 to Yn respectively extending in the horizontal direction on the display screen are alternatively arranged in the PDP 50 in the order of the increasing number. Each pair of row electrodes, namely, a pair of the row electrodes (X2, Y2) to a pair of the row electrodes (Xn, Yn) corresponds to each of the first display line to the (n−1)-th display line. A pixel cell PC serving as a pixel is formed at each intersection of each display line and each column electrode D1 to Dm (the area surrounded by one-dotted chain line in
As illustrated in
The row electrodes Y each consisting of the transparent electrodes Ya and the bus electrode Yb and the row electrodes X each consisting of the transparent electrodes Xa and the bus electrode Xb are formed on the rear surface of a front glass substrate 10 serving as the display surface of the PDP 50, as shown in
The area surrounded by the first transversal wall 15A and the longitudinal wall 15C (the area surrounded by one-dotted chain line in
As shown in
Thus, each pixel cell of the pixel cells PC1,1 to PCn−1,m formed on the PDP 50 is formed by the display discharge cell C1 and the control discharge cell C2 whose discharge spaces communicating with each other.
The odd X electrode driver 51 applies various drive pulses (described later) to the row electrodes X3, X5, . . . , Xn−2 and Xn with the odd numbers (shown in
The drive controller 56 converts the input image signal into the pixel data of, for example, 8 bits, for showing the brightness level in each pixel, and then the error diffusion processing and the dither processing are performed on the pixel data. For example, in the error diffusion processing, at first the display data for the upper 6 bits of the pixel data is regarded as the display data and the remaining data for the lower 2 bits is regarded as the error data. Each weighted error data of the pixel data corresponding to the peripheral pixels is reflected in the above display data. According to the operation, the brightness for the lower 2 bits in the original pixel is represented by the peripheral pixels in a simulated way, and therefore, the display data for 6 bits less than 8 bits can represent the same brightness gradation as the pixel data for the above 8 bits. The dither processing is performed on the error diffusion processed pixel data of 6 bits obtained by this error diffusion processing. In the dither processing, a plurality of pixels adjacent to each other are regarded as the unit of one pixel, the dither coefficients having the different coefficients are respectively assigned and added to the error diffusion processed pixel data corresponding to each pixel within this unit, thereby obtaining the dither added pixel data. According to this addition of the dither coefficient, from the viewpoint of the above one pixel unit, it is possible to represent the brightness corresponding to 8 bits with only the upper 4 bits of the dither added pixel data. The drive controller 56 regards the upper 4 bits of the dither added pixel data as the multiple gradation pixel data PDs, and this is converted into the pixel drive data GD of 15 bits consisting of the first to the fifteenth bits according to the data conversion table as shown in
DB1: the first bits of the respective pixel drive data GD1,1 to GD(n−1),m
DB2: the second bits of the respective pixel drive data GD1,1 to GD(n−1),m
DB3: the third bits of the respective pixel drive data GD1,1 to GD(n−1),m
DB4: the fourth bits of the respective pixel drive data GD1,1 to GD(n−1),m
DB5: the fifth bits of the respective pixel drive data GD1,1 to GD(n−1),m
DB6: the sixth bits of the respective pixel drive data GD1,1 to GD(n−1),m
DB7: the seventh bits of the respective pixel drive GD1,1 to GD(n−1),m
DB8: the eighth bits of the respective pixel drive data GD1,1 to GD(n−1),m
DB9: the ninth bits of the respective pixel drive data GD1,1 to GD(n−1),m
DB10: the tenth bits of the respective pixel drive data GD1,1 to GD(n−1),m
DB11: the eleventh bits of the respective pixel drive data GD1,1 to GD(n−1),m
DB12: the twelfth bits of the respective pixel drive data GD1,1 to GD(n−1),m
DB13: the thirteenth bits of the respective pixel drive data GD1,1 to GD(n−1),m
DB14: the fourteenth bits of the respective pixel drive data GD1,1 to GD(n−1),m
DB15: the fifteenth bits of the respective pixel drive data GD1,1 to GD(n−1),m
The respective pixel drive data bit groups DB1 to DB15 correspond to the respective subfields SF1 to SF15 described later. The drive controller 56 supplies the pixel drive data bit group DB corresponding to the subfield, to the address driver 55 by every one display line (m), in every subfield SF1 to SF15.
Further, the drive controller 56 generates various timing signals to control the drive of the PDP 50 according to the light-emission drive sequence as shown in
In the light-emission drive sequence shown in
In the head subfield SF1, an odd row reset stage ROD, an odd row address stage WOOD, an even row reset stage REV, an even row address stage WEV, a priming expansion stage PI, a sustain stage I, and an erase stage E are sequentially performed. In the respective subfields SF2 to SF15, the address stage WO, the priming expansion stage PI, the sustain stage I, and the erase stage E are sequentially performed.
At first, in the odd row reset stage ROD of the subfield SF1, the odd Y electrode driver 53 generates a first reset pulse RPY1 of negative polarity falling and rising more gradually than the sustain pulse (described later) and simultaneously applies the above reset pulse to the respective odd row electrodes Y1, Y3, Y5, . . . , Yn of the PDP 50. At this time, the address driver 55 generates a reset pulse RPD of positive polarity and simultaneously applies the above reset pulse to the respective column electrodes D1 to Dn. In reply to the application of the first reset pulse RPY1 and the reset pulse RPD, first reset discharges (writing discharges) are produced within the control discharge cells C2 of the respective pixel cells PC1,1 to PC1,m, PC3,1 to PC3,m, . . . , PCn−2,1 to PCn−2,m belonging to the odd display lines. Namely, the first reset discharge is produced between the row electrode Y and the column electrode D within the control discharge cell C2, as shown in
As mentioned above, in the odd row reset stage ROD, all the wall charges are extinguished from the control discharge cells C2 of the respective pixel cells PC1,1 to PC1,m, PC3,1 to PC3,m, . . . , PCn−2,1 to PCn−2,m belonging to the odd display lines of the PDP 50 and all the pixel cells PCs belonging to the odd display lines are initialized into the light-off state.
In the odd row address stage WOOD of the subfield SF1, the odd Y electrode driver 53 sequentially applies the scanning pulse SP of negative polarity to the odd row electrodes Y1, Y3, Y5, . . . , Yn−2. At this time, the address driver 55 converts the corresponding data to the odd display lines, within the pixel drive data bit group DB1 corresponding to the subfield SF1, into the pixel data pulse DP having a pulse voltage depending on its logical level. For example, the address driver 55 converts the pixel drive data bit of the logical level 1 into the pixel data pulse DP of high voltage of positive polarity, while converting the pixel drive data bit of the logical level 0 into the pixel data pulse DP of low voltage (0 v). It applies the same pixel data pulse DP to the column electrodes D1 to Dm by every one display line (m) in synchronization with the applying timing of the scanning pulse SP. Namely, the address driver 55 converts the pixel drive data bits DB11,1 to DB11,m, DB13,1 to DB13,m, . . . , DB1n−2,1 to DB1n−2,m into the pixel data pulses DP1,1 to DP1,m DP3,1 to DP3,m, . . . , DPn−2,1 to DPn−2,m and applies these to the column electrodes D1 to Dm by every one display line.
At this time, the writing address discharge is produced between the column electrode D and the row electrode Y within the control discharge cell C2 of the pixel cell PC where the scanning pulse SP and the pixel data pulse DP of high voltage are applied, and the wall charge within the control discharge cell C2 is formed. While, the above-mentioned writing address discharge is not produced within the control discharge cell C2 of the pixel cell PC where the scanning pulse SP is applied but the pixel data pulse DP of high voltage is not applied, and therefore, the wall charge is not formed within the control discharge cell C2. At this time, the even X electrode driver 52 applies the voltage of the same polarity as the pixel data pulse DP to these even row electrodes X, so as not to produce each discharge by mistake between the bus electrodes Xb of the respective row electrodes X2, X4, X6, . . . , Xn−1 with the odd numbers attached and the column electrodes D.
As mentioned above, in the odd row address stage WOOD, the writing address discharge is selectively produced within the control discharge cell C2 of each pixel cell PC belonging to the odd display lines of the PDP 50, depending on the pixel drive data bit group DB 1 (the first bits of the pixel drive data GD shown in
In the even row reset stage REV of the subfield SF1, the even Y electrode driver 54 generates the first reset pulse RPY1 of negative polarity falling and rising more gradually than the sustain pulse (described later) and simultaneously applies the above reset pulse to the respective even row electrodes Y2, Y4, . . . , Yn−1 of the PDP 50. At this time, the address driver 55 generates the reset pulse RPD of positive polarity and simultaneously applies the above reset pulse to the respective column electrodes D1 to Dn. In reply to the application of the first reset pulse RPY1 and the reset pulse RPD, the first reset discharges (writing discharges) are produced within the control discharge cells C2 of the respective pixel cells PC2,1 to PC2,m, PC4,1 to PC4,m, . . . , PCn−1,1 to PCn−1,m belonging to the even display lines. Namely, the first reset discharge is produced between the row electrode Y and the column electrode D within the control discharge cell C2, as shown in
As mentioned above, in the even row reset stage REV, all the wall charges are extinguished from the control discharge cells C2 of the respective pixel cells PC2,1 to PC2,m, PC4,1 to PC4,m, . . . , PCn−1,1 to PCn−1,m belonging to the even display lines of the PDP 50 and all the pixel cells PCs belonging to the even display lines are initialized into the light-off state.
In the even row address stage WOEV of the subfield SF1, the even Y electrode driver 54 sequentially applies the scanning pulse SP of negative polarity to the even row electrodes Y2, Y4, . . . , Yn−1. In this case, the address driver 55 converts the corresponding data to the even display lines, within the pixel drive data bit group DB1 corresponding to the subfield SF1, into the pixel data pulse DP having a pulse voltage depending on its logical level. For example, the address driver 55 converts the pixel drive data bit of the logical level 1 into the pixel data pulse DP of high voltage of positive polarity, while converting the pixel drive data bit of the logical level 0 into the pixel data pulse DP of low voltage (0 v). It applies the same pixel data pulse DP to the column electrodes D1 to Dm by every one display line (m) in synchronization with the applying timing of the scanning pulse SP. Namely, the address driver 55 converts the pixel drive data bits DB12,1 to DB12,m, DB14,1 to DB14,m, . . . , DB1n−1,1 to DB1n−1,m into the pixel data pulses DP2,1 to DP2,m, DP4,1 to DP4,m, . . . , DPn−1,1 to DPn−1,m and applies these to the column electrodes D1 to Dm by every one display line. At this time, the writing address discharge is produced between the column electrode D and the row electrode Y within the control discharge cell C2 of the pixel cell PC where the scanning pulse SP and the pixel data pulse DP of high voltage are applied, and the wall charge is formed within the control discharge cell C2. While, the above-mentioned writing address discharge is not produced within the control discharge cell C2 of the pixel cell PC where the scanning pulse SP is applied but the pixel data pulse DP of high voltage is not applied, and therefore, the wall charge is not formed within the control discharge cell C2. In this case, the odd X electrode driver 51 applies the voltage of the same polarity as the pixel data pulse DP, to these odd row electrodes X, so as not to produce each discharge by mistake between the respective bus electrodes Xb of the respective row electrodes X3, X5, . . . , Xn with the odd numbers attached and the respective column electrodes D.
As mentioned above, in the even row address stage WOEV, the wall charges are produced within the control discharge cells C2 of the respective pixel cells PCs belonging to the even display lines of the PDP 50, selectively depending on the pixel drive data bit group DB1 (the first bits of the pixel drive data GD shown in
In the address stage WO of each of the subfields SF2 to SF15, the odd Y electrode driver 53 and the even X electrode driver 54 sequentially apply the scanning pulse SP of negative polarity to the respective row electrodes Y1, Y2, Y3, . . . , Yn−1, as shown in
As mentioned above, in the address stage WO, the wall charge is formed within the control discharge cell C2 of the pixel cell PC, selectively depending on the logical level of the j-th bit of the pixel drive data GD corresponding to the subfield SF(j) to which the address stage WO belongs. Thus, the respective pixel cells PCs of the PDP 50 are set at a provisional light-on state (the wall charge exists within the control discharge cell C2) or the light-off state (no wall charge exists within the control discharge cell C2).
In the priming expansion stage PI of each of the subfields SF1 to SF15, the odd Y electrode driver 53 continuously and repeatedly applies the priming pulse PPYO of positive polarity to the odd row electrodes Y1, Y3, . . . , Yn, as shown in
As mentioned above, by producing the priming discharge repeatedly in the control discharge cell C2 set at the temporarily light-on state, in the odd row address stage WOOD, the even row address stage WOEV, or the address stage WO, the discharge is gradually expanded toward the display discharge cell C1, in the priming expansion stage PI. Owing to the discharge expansion, the wall charge is formed within the display discharge cell C1, and the pixel cell PC to which this display discharge cell C1 belong is set at the light-on state. While, in the above-mentioned various address stages, the priming discharge never occurs in the control discharge cell C2 set at the light-off state. Accordingly, since the wall charge is not formed within the display discharge cell C1 communicating with the control discharge cell C2, the pixel cell PC is set at the light-off state.
In the sustain stage I of each of the subfields SF1 to SF15, the odd Y electrode driver 53 applies the sustain pulse IPYO of positive polarity to the respective odd row electrodes Y1, Y3, Y5′, . . . , Yn, repeatedly for the number of the times assigned to the subfield to which the sustain stage I belongs, as shown in
As mentioned above, in the sustain stage I, only the pixel cell PC set at the light-on state is repeatedly made to emit light for the number of the times assigned to each subfield.
In the erase stage E of each of the subfields SF1 to SF15, the odd X electrode driver 51, the even X electrode driver 52, the odd Y electrode driver 53, the even Y electrode driver 54, and the address driver 55 apply the erase pulse of positive polarity to all the row electrodes X and Y, as shown in
Thus, in the erase stage E, by producing the erase discharge only in the control discharge cell C2 where the wall charge is left, the state of the charge generation within all the control discharge cells C2 is initialized into a uniform state.
Here, when the driving operations as shown in
Here, in the plasma display shown in
As shown in
By forming the discharge gap g within the control discharge cell C2 at a position near the display discharge cell C1, as shown in
In the above embodiment, although the case of adopting the method of selectively forming the wall charge within each pixel cell PC in the address stage, what is called, the selective-write address method, has been described, the selective-erase address method for selectively erasing the wall charge formed on each pixel cell PC may be adopted.
In the driving operation based on the selective-erase address method, the drive controller 56 converts the input image signal into the pixel data of, for example, 8 bits, for showing the brightness level in each pixel, and then the error diffusion processing and the dither processing are performed on the pixel data. The drive controller 56 converts the pixel data of 8 bits into the multiple gradation pixel data PDs of 4 bits by the error diffusion processing and the dither processing, and further converts the multiple gradation pixel data PDs into the pixel drive data GD of 15 bits according to the data conversion table shown in
In the light-emission drive sequence shown in
In the head subfield SF1, the odd row reset stage ROD, the odd row address stage WIOD, the even row reset stage REV, the even row address stage WIEV, a selective-erase auxiliary stage CA, the priming expansion stage PI, the sustain stage I, and an charge transition stage MR are sequentially performed. In the respective subfields SF2 to SF15, the address stage W1, the selective-erase auxiliary stage CA, the priming expansion stage PI, the sustain stage I, and the charge transition stage MR are sequentially performed. In the last subfield SF15, the erase stage (not illustrated) is performed just after the charge transition stage MR.
At first, in the odd row reset stage ROD of the subfield SF1, the odd Y electrode driver 53 generates the first reset pulse RPY1 of negative polarity falling and rising more gradually than the sustain pulse (described later) and simultaneously applies the above reset pulse to the respective odd row electrodes Y1, Y3, Y5, . . . , Yn of the PDP 50. At this time, the address driver 55 generates the reset pulse RPD of positive polarity and simultaneously applies the above reset pulse to the respective column electrodes D1 to Dn. In reply to the application of the first reset pulse RPY1 and the reset pulse RPD, the first reset discharges (writing discharge) are produced in the control discharge cells C2 of the respective pixel cells PC1,1 to PC1,m, PC3,1 to PC3,m, . . . , PCn−2,1 to PCn−2,m belonging to the odd display lines. Namely, the first reset discharge is produced between the row electrode Y and the column electrode D within the control discharge cell C2, as shown in
As mentioned above, in the odd row reset stage ROD, the first and the second reset discharges are produced within the control discharge cells C2 of all the pixel cells PCs belonging to the odd display lines of the PDP 50, hence to form the wall discharges within the control discharge cells C2 belonging to the odd display lines.
In the odd row address stage WIOD of the subfield SF1, the odd Y electrode driver 53 sequentially applies the scanning pulse SP of negative polarity to the odd row electrodes Y1, Y3, Y5, . . . , Yn−2 of the PDP 50. At this time, the address driver 55 converts the corresponding data to the odd display lines, within the pixel drive data bit group DB1 corresponding to the subfield SF1, into the pixel data pulse DP having a pulse voltage depending on its logical level. For example, the address driver 55 converts the pixel drive data bit of the logical level 1 into the pixel data pulse DP of high voltage of positive polarity, while converting the pixel drive data bit of the logical level 0 into the pixel data pulse DP of low voltage (0 v). It applies the same pixel data pulse DP to the column electrodes D1 to Dm by every one display line (m) in synchronization with the applying timing of the scanning pulse SP. Namely, the address driver 55 converts the pixel drive data bits DB11 to DB11,m, DB13,1 to DB13,m, . . . , DB1n−2,1 to DB1n−2,m into the pixel data pulses DP1,1 to DP11,m, DP3,1 to DP3,m, . . . , DPn−2,1 to DPn−2,m and applies these to the column electrodes D1 to Dm by every one display line.
At this time, the erasing address discharge is produced between the column electrode D and the row electrode Y within the control discharge cell C2 of the pixel cell PC where the scanning pulse SP and the pixel data pulse DP of high voltage are applied, and the wall charge formed within the control discharge cell C2 is extinguished. While, the above-mentioned erasing address discharge is not produced within the control discharge cell C2 of the pixel cell PC where the scanning pulse SP is applied but the pixel data pulse DP of high voltage is not applied, and therefore, the wall charge is left within the control discharge cell C2.
As mentioned above, in the odd row address stage WIOD, the erasing address discharge is selectively produced within the control discharge cell C2 of each pixel cell PC belonging to the odd display lines of the PDP 50, depending on the pixel drive data bit group DB1 (the first bits of the pixel drive data GD shown in
In the even row reset stage REV of the subfield SF1, the even Y electrode driver 54 generates the first reset pulse RPY1 of negative polarity falling and rising more gradually than the sustain pulse (described later) and simultaneously applies the above reset pulse to the respective even row electrodes Y2, Y4, . . . , Yn−1 of the PDP 50. At this time, the address driver 55 generates the reset pulse RPD of positive polarity and simultaneously applies the above reset pulse to the respective column electrodes D1 to Dn. In reply to the application of the first reset pulse RPY1 and the reset pulse RPD, the first reset discharges (writing discharges) are produced in the control discharge cells C2 of the respective pixel cells PC2,1 to PC2,m, PC4,1 to PC4,m, . . . , PCn−1,1 to PCn−1,m belonging to the even display lines. Namely, the first reset discharge is produced between the row electrode Y and the column electrode D within the control discharge cell C2, as shown in
As mentioned above, in the even row reset stage REV, the first and second reset discharges are produced within the control discharge cells C2 of all the respective pixel cells PCs belonging to the even display lines of the PDP 50, hence to form the wall charges within the control discharge cells C2 belonging to the even display lines.
In the even row address stage WIEV of the subfield SF1, the even Y electrode driver 54 sequentially applies the scanning pulse SP of negative polarity to the even row electrodes Y2, Y4, . . . , Yn−1. At this time, the address driver 55 converts the corresponding data to the even display lines, within the pixel drive data bit group DB1 corresponding to the subfield SF1, into the pixel data pulse DP having a pulse voltage depending on its logical level. For example, the address driver 55 converts the pixel drive data bit of the logical level 1 into the pixel data pulse DP of high voltage of positive polarity, while converting the pixel drive data bit of the logical level 0 into the pixel data pulse DP of low voltage (0 v). It applies the same pixel data pulse DP to the column electrodes D1 to Dm by every one display line (m) in synchronization with the applying timing of the scanning pulse SP. Namely, the address driver 55 converts the pixel drive data bits DB12,1 to DB12,m, DB14,1 to DB14,m, . . . , DB1n−1,1 to DB1n−1,m corresponding to the even display lines into the pixel data pulses DP2,1 to DP2,m, DP4,1 to DP4,m, . . . , DPn−1,1 to DPn−1,m and applies these to the column electrodes D1 to Dm by every one display line. At this time, the erasing address discharge is produced between the column electrode D and the row electrode Y within the control discharge cell C2 of the pixel cell PC where the scanning pulse SP and the pixel data pulse DP of high voltage are applied, and the wall charge within the control discharge cell C2 is extinguished. While, the above-mentioned erasing address discharge is not produced within the control discharge cell C2 of the pixel cell PC where the scanning pulse SP is applied but the pixel data pulse DP of high voltage is not applied, and therefore, the wall charge is left within the control discharge cell C2.
As mentioned above, in the even row address stage WIEV, the erasing address discharge is selectively produced within the control discharge cell C2 of each pixel cell PC belonging to the even display lines of the PDP 50, depending on the pixel drive data bit group DB1 (the first bits of the pixel drive data GD shown in
In the address stage W1 of each of the subfields SF2 to SF15, the odd Y electrode driver 53 and the even X electrode driver 54 sequentially apply the scanning pulse SP of negative polarity to the respective row electrodes Y1, Y2, Y3, . . . , Yn−1, as shown in
As mentioned above, in the address stage W1 of each of the subfields SF2 to SF15, the wall charges existing within the control discharge cells C2 of the respective pixel cells PCs are selectively extinguished, depending on the logical level of the j-th bit of the pixel drive data GD corresponding to the subfield SF(j) to which the the address stage W1 belongs. Thus, the respective pixel cells PCs of the PDP 50 are set at the temporarily light-on state (the wall charge exists within the control discharge cell C2) or the light-off state (no wall charge exists within the control discharge cell C2).
In the selective-erase auxiliary stage CA of each of the subfields SF1 to SF15, the odd X electrode driver 51, the even X electrode driver 52, the odd Y electrode driver 53, and the even Y electrode driver 54 apply a cancel pulse CP of positive polarity to all the row electrodes X2 to Xn and Y1 to Yn, as shown in
In the selective-erase auxiliary stage CA, by applying the cancel pulse CP of positive polarity to both the row electrodes X and Y, the erase discharge is produced only in the control discharge cell C2 that is in the incorrect state of electrical charge, as shown in
In the priming expansion stage PI of each of the subfields SF2 to SF15, the even X electrode driver 52 applies the priming pulse PPXE of positive polarity to the even row electrodes X2, X4, . . . , Xn−1, as shown in
As mentioned above, by producing the priming discharge repeatedly in the control discharge cell C2 set at the temporarily light-on state, in the address stages (WIOD, WIEV, WI), the discharge is gradually expanded toward the display discharge cell C1, through the interstice r, in the priming expansion stage PI. Owing to the discharge expansion, the wall charge is formed within the display discharge cell C1, and the pixel cell PC including this display discharge cell C1 is set at the light-on state. While, since the wall charge is not formed within the display discharge cell C1 communicating with the control discharge cell C2 where the priming discharge has not been produced, the pixel cell PC maintains the light-off state.
In the sustain stage I of each of the subfields SF2 to SF15, the odd Y electrode driver 53 applies the sustain pulse IPYO of positive polarity to the respective odd row electrodes Y1, Y3, Y5, . . . , Yn, repeatedly for the number of the times assigned to the subfield belonging to the sustain stage I, as shown in
As mentioned above, in the sustain stage I, only the pixel cell PC set at the light-on state in the proximate address stages (WIOD, WIEv, WI) is repeatedly made to emit light for the number of the times assigned to the subfield.
In the charge transition stage MR of each of the subfields SF1 to SF15, the odd Y electrode driver 53 continuously and repeatedly applies the charge transition pulse MPYO of positive polarity to the odd row electrodes Y1, Y3, . . . , Yn. In the charge transition stage MR, the odd X electrode driver 51 continuously and repeatedly applies the charge transition pulse MPXO of positive polarity to the odd row electrodes X3, X5, . . . , Xn at the same timing as the charge transition pulse MPYO. In the charge transition stage MR, the even X electrode driver 52 applies the charge transition pulse MPXE of positive polarity to the even row electrodes X2, X4, . . . , Xn−1 and the even Y electrode driver 54 applies the charge transition pulse MPYE of positive polarity to the even row electrodes Y2, Y4, . . . , Yn−1 at the same timing as the above charge transition pulse MPXE. Every time the charge transition pulse MPXO, MPYO, MPXE, or PMYE is applied, the discharge is produced within the control discharge cell C2 of the pixel cell PC where the sustain discharge has been produced in the proximate sustain stage I. According to the discharge, the wall charge produced in the display discharge cell C1 paired with the control discharge cell C2 is moved to the control discharge cell C2 through the interstice r, as shown in
Thus, in the charge transition stage MR, by discharging the control discharge cell C2 of the pixel PC where the sustain discharge has been produced in the proximate sustain stage I, the wall charge having been formed within the display discharge cell C1 is moved to the control discharge cell C2.
In the erase stage E of the last subfield SF15, the odd X electrode driver 51, the even X electrode driver 52, the odd Y electrode driver 53, the even Y electrode driver 54, and the address driver 55 apply the erase pulse of positive polarity to all the row electrodes X and Y (not illustrated). In reply to the application of the erase pulse, the erase discharges are produced within all the control discharge cells C2 where the wall charges are left, hence to erase the wall charges.
According to the driving operations using the selective-erase address method as shown in
According to the above-mentioned driving operation, the brightness corresponding to the total sum of the discharges produced in the period of one field is visible. Namely, according to the 16 types of light-emission drive patterns corresponding to the first to the sixteenth gradation drivings as shown in
In this case, even in the driving operation by using the selective-erase address method as mentioned above, the sustain discharge related to the display image is produced in the display discharge cell C1, while the reset discharge, the priming discharge, and the address discharge accompanied by the light emission not related to the display image are produced in the control discharge cell C2. Accordingly, since the discharge light accompanying the reset discharge, the priming discharge, and the address discharge is blocked by the augmentative dielectric layer 12 formed only in the control discharge cell C2, it is possible to enhance the contrast, especially, the dark contrast of the display image.
Even in the driving operation using the selective erasing address method, the priming discharge is produced between the transparent electrodes Xa and Ya within the control discharge cell C2, and the reset discharge and the address discharge are produced between the column electrode D and the transparent electrode Ya. Since the priming discharge is produced at a position near the display discharge cell C1 paired with the control discharge cell C2, the discharge can be easily expanded from the control discharge cell C2 to the display discharge cell C1. While, since the reset discharge and the address discharge are produced at a position farther away from the display discharge cell C1 paired with the control discharge cell C2 than the place where the priming discharge is produced, the flow amount of the ultraviolet ray accompanying the reset discharge and the address discharge, into the display discharge cell C1 is reduced, thereby suppressing the decrease in the dark contrast.
This application is based on Japanese Patent Application No. 2002-292850 which is herein incorporated by reference.
Number | Date | Country | Kind |
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2002-292850 | Oct 2002 | JP | national |
Number | Name | Date | Kind |
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6603263 | Hashimoto et al. | Aug 2003 | B1 |
6608611 | Lim | Aug 2003 | B1 |
Number | Date | Country |
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1397979 | Feb 2003 | CN |
1405829 | Mar 2003 | CN |
11-297211 | Oct 1999 | JP |
2001-154630 | Jun 2001 | JP |
Number | Date | Country | |
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20040104685 A1 | Jun 2004 | US |