KR20050111187A - Apparatus for driving plasma display panel and plasma display panel comprising the same - Google Patents

Abstract

According to an aspect of the present invention, there is provided a driving apparatus of a plasma display panel, comprising: a subfield data converter configured to divide and drive one TV field into a plurality of subfields, and to convert input image data into subfield data; A subfield data summing unit for detecting a load ratio for each subfield; And a subfield weight adjusting unit for adjusting the luminance weight of the subfield data according to the load ratio for each subfield.

The conventional plasma display panel has a problem in that the line resistance of the panel is changed because the number of cells to be turned on for each subfield is not the same, thereby failing to achieve luminance corresponding to the original weight assigned to each subfield.

The plasma display panel of the present invention mitigates such image distortion by compensating for the luminance weights assigned to the subfields according to the subfield load rates.

Description

Apparatus for driving plasma display panel and plasma display panel comprising the same}

The present invention relates to a plasma display panel.

1 is a view showing the structure of a conventional three-electrode surface discharge plasma display panel.

Referring to FIG. 1, between the front and rear glass substrates 100 and 106 of a conventional surface discharge plasma display panel 1, address electrode lines A ₁ , A ₂ ,..., A _m , Dielectric layers 102 and 110, Y electrode lines Y ₁ , ..., Y _n , X electrode lines X ₁ , ..., X _n , fluorescent layer 112, barrier rib 114, and As a protective layer, the magnesium monoxide (MgO) layer 104 is provided, for example.

The address electrode lines A ₁ , A ₂ ,..., A _m are formed in a predetermined pattern on the front side of the rear glass substrate 106. The lower dielectric layer 110 is applied in front of the address electrode lines A ₁ , A ₂ ,..., A _m . In front of the lower dielectric layer 110, barrier ribs 114 are formed in a direction parallel to the address electrode lines A ₁ , A ₂ ,..., A _m . The partition walls 114 function to partition the discharge area of each display cell and to prevent optical interference between the display cells. The fluorescent layer 112 is formed between the partition walls 114.

The X electrode lines X ₁ , ..., X _n and the Y electrode lines Y ₁ , ..., Y _n are address electrode lines A ₁ , A ₂ , ..., A _m . It is formed in a predetermined pattern on the back of the front glass substrate 100 to be orthogonal to the. Each intersection sets a corresponding display cell. Each X electrode line (X ₁ , ..., X _n ) and each Y electrode line (Y ₁ , ..., Y _n ) are transparent electrode lines (X _na ) made of a transparent conductive material such as indium tin oxide (ITO). , Y _na ) and metal electrode lines X _nb and Y _nb for increasing conductivity may be formed. The front dielectric layer 102 is formed by applying the entire surface to the rear of the X electrode lines (X ₁ ,..., X _n ) and the Y electrode lines (Y ₁ ,..., Y _n ). A protective layer 104 for protecting the panel 1 from a strong electric field, for example, a magnesium monoxide (MgO) layer, is formed by applying a front surface to the back of the front dielectric layer 102. The plasma forming gas is sealed in the discharge space 108.

A driving scheme generally applied to such a plasma display panel is a method in which initialization, address, and display holding steps are sequentially performed in a unit sub-field. In the initialization step, the charge states of the display cells to be driven are made uniform. In the address step, the charge state of display cells to be selected and the charge state of display cells not to be selected are set. In the display holding step, display discharge is performed in the display cells to be selected. At this time, a plasma is formed from the plasma forming gas of the display cells performing display discharge, and the fluorescent layer 112 of the display cells is excited by ultraviolet radiation from the plasma to generate light.

2 illustrates a general driving device of the plasma display panel of FIG. 1.

Referring to the drawings, a typical driving device of the plasma display panel 1 includes an image processor 200, a controller 202, an address driver 206, an X driver 208, and a Y driver 204. The image processing unit 200 converts an external analog image signal into a digital signal, and internal image signals, for example, 8-bit red (R), green (G) and blue (B) image data, clock signals, vertical and horizontal, respectively. Generate synchronization signals. The controller 202 generates the driving control signals SA, SY, and SX according to the internal image signal from the image processor 200. The address driver 206 processes the address signal SA among the drive control signals SA, SY, and SX from the controller 202 to generate a display data signal, and generates the display data signal through the address electrode lines. To apply. The X driver 208 processes the X driving control signal SX among the driving control signals SA, SY, and SX from the controller 202 and applies the X driving control signal SX to the X electrode lines. The Y driver 204 processes the Y driving control signal SY among the driving control signals SA, SY, and SX from the controller 202 and applies the Y driving control signal SY to the Y electrode lines.

As a driving method of the plasma display panel 1 having the structure described above, an address-display separation driving method which is mainly used is disclosed in US Pat.

FIG. 3 illustrates a conventional address-display separation driving method for Y electrode lines as an example of the plasma display panel driving method of FIG. 1.

Referring to the drawings, a unit frame may be divided into a predetermined number, for example, eight subfields SF1, ..., SF8 to realize time division gray scale display. Each subfield SF1, ..., SF8 is divided into a reset section (not shown), an address section A1, ..., A8, and a sustain discharge section S1, ..., S8. do.

In each address section A1, ..., A8, a display data signal is applied to the address electrode lines AR1, AG1, ..., AGm, ABm in FIG. Scan pulses corresponding to..., Yn) are sequentially applied.

In each sustain discharge section S1, ..., S8, pulses for display discharge alternately in the Y electrode lines Y1, ..., Yn and the X electrode lines X1, ..., Xn. Is applied to cause display discharge in discharge cells in which wall charges are formed in the address periods A1, ..., A8.

The luminance of the plasma display panel is proportional to the number of sustain discharge pulses in the sustain discharge sections S1, ..., S8 occupied in the unit frame. When one frame forming one image is represented by eight subfields and 256 gray levels, each subfield is sequentially held at a ratio of 1, 2, 4, 8, 16, 32, 64, and 128 in order. The number of pulses can be assigned. In order to obtain luminance of 133 gray levels, cells may be addressed and sustained and discharged during the subfield 1 period, the subfield 3 period, and the subfield 8 period.

The number of sustain discharges allocated to each subfield may be variably determined according to the weights of the subfields according to the APC (Automatic Power Control) step. In addition, the number of sustain discharges allocated to each subfield is. Various modifications are possible in consideration of gamma characteristics or panel characteristics. For example, the gradation level assigned to subfield 4 may be lowered from 8 to 6, and the gradation level assigned to subfield 6 may be increased from 32 to 34. In addition, the number of subfields forming one frame can be variously modified according to design specifications.

FIG. 4 is a timing diagram for explaining an example of a driving signal of the panel shown in FIG. 1. The address electrode A, the common electrode X, and the scan electrode in one subfield SF in the ADS driving method of the AC PDP. The drive signal applied to (Y1 to Yn) is shown. Referring to FIG. 4, one subfield SF includes a reset period PR, an address period PA, and a sustain discharge period PS.

The reset period PR initializes the wall charge state of all cells by applying reset pulses to the scan lines of all groups and forcibly performing a write discharge. The reset period PR is performed before entering the address period PA, which is carried out over the entire screen, thus making it possible to create a wall distribution of wall charges with a fairly even and desired distribution. The cells initialized by the reset period PR have similar wall charge conditions in the cells. The address period PA is performed after the reset period PR is performed. At this time, in the address period PA, the bias voltage Ve is applied to the common electrode X, and the scan electrodes Y1 to Yn and the address electrodes A1 to Am are simultaneously turned on at the cell positions to be displayed. Select the display cell. After the address period PA is performed, the sustain pulse Vs is alternately applied to the common electrodes X and the scan electrodes Y1 to Yn to perform the sustain discharge period PS. During the sustain discharge period PS, a low level voltage VG is applied to the address electrodes A1 to Am. In PDP, the brightness is adjusted by the number of sustain discharge pulses. If the number of sustain discharge pulses in one subfield or one TV field is large, the luminance increases.

In the plasma display panel, the more cells are discharged, the larger the line resistance of the scan electrode and the larger the voltage decrease. In a scan line with a large voltage reduction, even when the same sustain discharge pulse is applied, the intensity of the discharge is relatively weak, resulting in a decrease in the magnitude of the light output. Conversely, the fewer the cells to discharge, the smaller the line resistance and the lower the voltage. In a scan line with a small voltage reduction, even when the same sustain discharge pulse is applied, the intensity of the discharge becomes relatively large, resulting in a large light output.

Therefore, since the number of cells to be turned on for each subfield is not the same, there is a problem that the image is distorted without the luminance corresponding to the original weight assigned to each subfield.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a plasma display panel driving method and a plasma display panel capable of compensating for distortion of luminance according to a load ratio for each subfield.

According to an aspect of the present invention, there is provided a driving apparatus for a plasma display panel and a plasma display panel having the same. The driving apparatus divides one TV field into a plurality of subfields, and serves as an input image data. A subfield data converter for converting the field data into field data; A subfield data summing unit for detecting a load ratio for each subfield from the subfield data; And a subfield weight adjusting unit for adjusting the luminance weight of the subfield data according to the load ratio for each subfield.

The subfield weight adjusting unit may include: a weight gain table for allocating different gains according to the subfield load ratios; And a multiplier configured to multiply and output the luminance weight of the subfield data by the allocated gain.

The subfield weight adjusting unit may further include: a weight gain table for determining different gains by a function according to the load ratio for each subfield; And a multiplier configured to multiply and output the luminance weight of the subfield data by the allocated gain.

The subfield weight adjusting unit may adjust the luminance weight of the subfield data according to the load ratio of each subfield only when the load ratio of each subfield is equal to or less than a reference value.

The subfield weight adjusting unit may apply a gain less than 1 when the subfield weight ratio is smaller than a reference value, and apply a gain greater than 1 when the subfield weight ratio is larger than a reference value.

The subfield weight adjustment unit may include: a weight addition table for allocating different addition values according to the load ratio for each subfield; And an adder configured to add and output the luminance weight of the subfield data and the assigned addition value.

The subfield weight adjusting unit may include: a weight subtraction table for allocating different subtraction values according to the subfield load ratios; And a subtractor for subtracting the allocated subtracted value from the luminance weight of the subfield data and outputting the subtracted value.

According to another aspect of the present invention, there is provided a driving apparatus for a plasma display panel and a plasma display panel having the same, wherein one TV field is divided into a plurality of subfields to drive the input image data. A subfield data converter for converting the field data into field data; A subfield data summing unit for detecting a load ratio for each subfield from the subfield data and outputting the load ratio and an ID of the subfield; And a sub-field weight adjusting unit for adjusting the luminance weight of the subfield data according to the ID of the subfield.

The weight adjustment unit for each subfield includes: a plurality of weight gain tables for allocating different gains according to the load ratio for each subfield; A table selector which selects a corresponding weight gain table according to the subfield ID; And a multiplier configured to multiply and output a luminance weight of the subfield data by a gain allocated to a selected gain table.

The weight adjustment unit for each subfield may include: a plurality of weight gain tables for determining different gains by a function according to the load ratio for each subfield; A table selector which selects a corresponding weight gain table according to the subfield ID; And a weight calculator configured to multiply and output the luminance weight of the subfield data by the allocated gain.

The subfield weight adjusting unit may adjust the luminance weight of the subfield data according to the load ratio of each subfield only when the load ratio of each subfield is equal to or less than a reference value.

The subfield weight adjusting unit may apply a gain less than 1 when the load ratio for each subfield is smaller than a reference value, and apply a gain greater than 1 when the load ratio for each subfield is larger than a reference value.

Hereinafter, configurations and operations of a plasma display panel driving apparatus and a plasma display panel according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In a plasma display panel in which one TV field is divided and driven into a plurality of subfields having predetermined luminance weights, the more cells are discharged, the larger the line resistance of the scan electrode and the larger the voltage decrease. In a scan line with a large voltage reduction, even when the same sustain discharge pulse is applied, the intensity of the discharge is relatively weak, resulting in a decrease in the magnitude of the light output. Conversely, the fewer the cells to discharge, the smaller the line resistance and the lower the voltage. In a scan line with a small voltage reduction, even when the same sustain discharge pulse is applied, the intensity of the discharge becomes relatively large, resulting in a large light output.

Therefore, since the number of cells that are turned on for each subfield is not the same, the image may be distorted without the luminance corresponding to the original weight assigned to each subfield.

As an example of such image distortion, quantization noise occurs. Quantization noise appears as anomalous brightness, for example, at the boundary between the gray levels of a cloud in an image representing a clouded sky. It looks like it's swarmed, so-called swarm noise, and it appears visually disgusting. This phenomenon occurs because the luminance of the subfield is different from the luminance by the weight originally assigned according to the number of cells to be turned on in the panel when the gray scale is expressed by subfield division.

5 is an example of a typical image in which quantization noise occurs. When an image is divided into an inner region (N + 1 gradation) and an outer region (N gradation), the luminance of the inner region (N + 1 gradation) is the outer luminance. One gradation is brighter than (N gradation).

FIG. 6 is a diagram for explaining the cause of quantization noise as distortion in the image of FIG. 5 when grayscale N = 14. SF1, SF2, SF3, and SF4 are subfields representing 1,2,4,8 gray levels, respectively.

5 and 6, N + 1 = 15 gray scales are displayed at the center and N = 14 gray scales are displayed at the periphery. N = 14 grayscales are represented by SF2, SF3, SF4, and N + 1 = 15 grayscales are represented by SF1, SF2, SF3, SF4.

Here, the horizontal line of the image is a scanning line, and in SF1, only the cells in the center portion (N + 1 = 15 area) of the image emit light. In SF2, SF3, and SF4, cells of all regions of the image emit light.

As the number of cells discharged in one scan line increases, the line resistance increases and the voltage decreases. In a scan line with a large voltage reduction, even when the same sustain discharge pulse is applied, the intensity of the discharge is relatively weak, resulting in a decrease in the magnitude of the light output. Conversely, the fewer the cells to discharge, the smaller the line resistance and the lower the voltage. In a scan line with a small voltage reduction, even when the same sustain discharge pulse is applied, the intensity of the discharge becomes relatively large, resulting in a large light output.

6, the cells of all the regions of the panel sustain discharge in SF2, SF3, SF4, so that the line resistance of the scan line becomes large, and thus the light output by the unit sustain discharge pulse becomes small.

On the other hand, in SF1, only the cells in the center portion (N + 1 = 15 area) of the panel sustain discharge, so that the line resistance of the scan line is small, and thus the magnitude of the light output by the unit sustain discharge pulse becomes large.

Referring to FIG. 6, according to the weight originally assigned to SF1, the light output of A should be generated, but in fact, the light output of A + e that is brighter than that is generated. The smaller the region of N + 1 = 15, the larger the error of this light output.

FIG. 7 is a diagram for explaining a cause of quantization noise as distortion in the image of FIG. 5 when grayscale N = 7. SF1, SF2, SF3, and SF4 are subfields representing 1,2,4,8 gray levels, respectively.

5 and 7, N + 1 = 8 grays are displayed at the center and N = 7 grays are displayed at the periphery. N = 7 gradations are represented by SF1, SF2, SF3, and N + 1 = 8 gradations are represented by SF4 only.

That is, in SF1, SF2, and SF3, only cells in the peripheral area of the panel (N = 7 area) sustain discharge. The area of N = 7 in one scan line is larger than the area of N + 1 = 8. Therefore, the line resistance of the scan line expressing only N = 7 gray scales becomes large, and thus the light output by the unit sustain discharge pulse becomes small.

On the other hand, in SF4, only the cells in the center portion (N + 1 = 8 area) of the panel sustain discharge, so that the line resistance of the scan line is reduced, and thus the magnitude of light output by the unit sustain discharge pulse is increased.

Referring to FIG. 7, according to the weight originally assigned to SF8, the light output of A should be generated, but in fact, the light output of A + e which is brighter than that is generated. The smaller the region of N + 1 = 8, the greater the error of this light output.

8 is a view for explaining the basic concept of the present invention. In comparison with FIG. 7, the luminance weight assigned to SF4 is reduced by a predetermined value? Y. That is, according to the present invention, the luminance weight assigned to the subfield is adjusted according to the number of cells to be turned on, that is, the load ratio, so that the luminance corresponding to the originally assigned weight is actually displayed. That is, the basic concept of the present invention is to vary the luminance weight according to the load ratio in order to compensate for generating light output A + e larger than the luminance weight A assigned to the subfield when the load ratio is small. .

9 is a block diagram illustrating a plasma display panel driving apparatus according to an exemplary embodiment of the present invention. The subfield data converter 300, the subfield data adder 302, and the subfield weight adjuster 304 are shown in FIG. It is provided.

The subfield data converter 300 converts the input video data IN into the subfield data 306. For example, when one TV field is composed of SF1, SF2, ..., SF8 subfields having luminance weights of 1,2,4,8,16,32,64,128, the input image data IN is shown in Table 1 below. Is converted to subfield data 306, SF1, SF2, ..., SF8.

Input gradation SF1 (1) SF2 (2) SF3 (4) SF4 (8) SF5 (16) SF6 (32) SF7 (64) SF8 (128) 0 0 0 0 0 0 0 0 0 One One 0 0 0 0 0 0 0 2 0 One 0 0 0 0 0 0 ... ... ... ... ... ... ... ... ... 7 One One One 0 0 0 0 0 8 0 0 0 One 0 0 0 0 ... ... ... ... ... ... ... ... ... 31 One One One One One 0 0 0 32 0 0 0 0 0 One 0 0 ... ... ... ... ... ... ... ... ... 63 One One One One One One 0 0 64 0 0 0 0 0 0 One 0 ... ... ... ... ... ... ... ... ... 127 One One One One One One One 0 128 0 0 0 0 0 0 0 One

The subfield data summing unit 302 adds the number of cells whose subfield data is 1 in each subfield, and detects the load factor 308 for each subfield.

The load factor is the number of all cells having data of 1 in each subfield divided by the total resolution.

Considering the case where the display panel has N (line) x M (column) resolution, the load factor may be obtained as shown in Table 2 below.

Subfield SF1 SF2 SF3 SF4 SF5 SF6 SF7 SF8 Weight (W) One 2 4 8 16 32 64 128 Cell location Input data 0 × 0 5 One 0 One 0 0 0 0 0 0 × 1 15 One One One One 0 0 0 0 ... ... ... ... ... ... ... ... ... ... N × (M-1) 10 0 One 0 One 0 0 0 0 N × M 12 0 0 One One 0 0 0 0 SF _SUM by subfield 50% 40% 30% 25% 15% 10% 5% 3%

The subfield weight adjustment unit 304 adjusts the luminance weight of the subfield data 306 according to the load ratio 308 for each subfield.

FIG. 10 is a block diagram illustrating an exemplary embodiment of the subfield weight adjusting unit 304 of FIG. 9 and includes a weight gain table 310 and a multiplier 312.

The weight gain table 310 allocates different gains according to the load ratio IN1 for each subfield. The weight gain table 310 may be implemented, for example, as shown in Table 3 below.

Load rate (SF _SUM ) Gain (G) 50% 1.00 40% 0.95 30% 0.90 25% 0.85 20% 0.80 15% 0.75 10% 0.70  9% 0.65  8 % 0.60  7% 0.55  6% 0.50  5% 0.45  4 % 0.40  3% 0.35  2 % 0.30  One % 0.25

The multiplier 312 multiplies the original weight IN2 of the subfield data by the allocated gain 314 and outputs the weighted subfield data OUT.

In Table 3, if the load factor (SF _SUM ) is more than 50%, the gain (G) can be all assigned to 1. That is, the present invention may be implemented to adjust the luminance weight of the subfield data according to the load ratio of each subfield only when the load ratio of each subfield is less than or equal to the reference value.

In addition, in Table 3, when the load factor (SF _SUM ) is 50% or more, the gain (G) may be assigned a gain greater than one. That is, when the sub-field by the load factor (SF _SUM), the reference value is smaller than (e. G. 50%) is larger than the load by applying a small gain greater than 1, and the sub-fields (SF _SUM) the reference value (e.g. 50%) is greater than 1 Big gains can be applied.

Regarding the subfield data of Table 2, the subfield data by the weight (W × G) adjusted by multiplying the gain G according to the load ratio SF _SUM of Table 3 is shown in Table 4 below.

Subfield SF1 SF2 SF3 SF4 SF5 SF6 SF7 SF8 Weight (W) One 2 4 8 16 32 64 128 Cell location Input data 0 × 0 5 One 0 One 0 0 0 0 0 0 × 1 15 One One One One 0 0 0 0 ... ... ... ... ... ... ... ... ... ... N × (M-1) 10 0 One 0 One 0 0 0 0 N × M 12 0 0 One One 0 0 0 0 SF _SUM by subfield 50% 40% 30% 25% 15% 10% 5% 3% Allocated Gain (G) 1.00 0.95 0.90 0.85 0.75 0.70 0.45 0.35 Adjusted weights (W × G) One 0.8 1.2 7 12 22 29 45

In the above description, it has been exemplified that the subfield weight adjustment unit 304 allocates the gain of the luminance weight according to the load ratio for each subfield by the table shown in Table 3.

The subfield weight adjusting unit 304 may also determine different gains G by a function according to the load ratio SF _{SUM for} each subfield. That is, the gain G may be implemented to be determined as shown in Equations 1 and 2, for example.

Specifically, the function of Equation 1 is implemented in the form of Equation 2 below.

Here, the gain offset G1 and the proportional coefficient α may be appropriately selected according to the characteristics of the plasma display panel. In addition, although Equation 2 exemplifies the gain G as the first function according to the load factor SF _SUM , the gain G may be determined by various types of functions according to the characteristics of the plasma display panel.

FIG. 11 is a block diagram illustrating another exemplary embodiment of the subfield weight adjusting unit 304 of FIG. 9 and includes a weight adding table 310 and an adder 322.

The weight addition table 310 allocates different addition values 324 according to the load ratio IN1 for each subfield. The adder 322 adds and outputs the luminance weight IN2 of the subfield data and the assigned addition value.

FIG. 12 is a block diagram illustrating another exemplary embodiment of the subfield weight adjusting unit 304 of FIG. 9 and includes a weight subtraction table 330 and a subtractor 332.

The weight subtraction table 330 allocates different subtraction values 334 according to the load ratio IN1 for each subfield. The subtractor 332 subtracts the subtracted value 334 from the luminance weight value IN2 of the subfield data and outputs the result.

FIG. 13 is a block diagram illustrating a plasma display panel driving apparatus according to another exemplary embodiment of the present invention. ).

The subfield data converter 400 converts the input image data IN into the subfield data 406.

Subfield data summation unit 402 detects a load ratio per subfield (SF _SUM), and outputs the ID (SF _ID) of the load factor (SF _SUM) and the sub-fields.

The subfield weight adjusting unit 404 adjusts the luminance weight 406 of the subfield data according to the subfield load ratio SF _SUM and the subfield ID SF _ID .

FIG. 14 is a block diagram illustrating an exemplary embodiment of the weight adjustment unit 404 for each subfield of FIG. 13, and includes a plurality of weight gain tables 410-1. And a weight calculator 414.

The plurality of weight gain tables 410-1 to 410-n allocate different gains according to the load factor SF _SUM for each subfield. The plurality of weight gain tables 410-1 ... 410-n may be implemented, for example, as shown in Table 5 below.

Load factor by subfield (SF _SUM ) SF1 gain (G, SF1) ... SF8 gain (G, SF8) 50% 1.00 ... 1.00 40% 0.96 ... 0.95 30% 0.92 ... 0.90 25% 0.88 ... 0.85 20% 0.84 ... 0.80 15% 0.80 ... 0.75 10% 0.76 ... 0.70  9% 0.72 ... 0.65  8 % 0.68 ... 0.60  7% 0.64 ... 0.55  6% 0.60 ... 0.50  5% 0.56 ... 0.45  4 % 0.52 ... 0.40  3% 0.48 ... 0.35  2 % 0.44 ... 0.30  One % 0.40 ... 0.25

The table selector 412 selects a corresponding weight gain table according to the subfield ID SF _ID .

The weight calculator 414 multiplies the original luminance weight IN of the subfield data by a gain allocated to the selected gain table and outputs the weighted subfield data OUT.

In Table 5, if the load factor (SF _SUM ) is more than 50%, the gain (G) can be all assigned to 1. That is, the present invention may be implemented to adjust the luminance weight of the subfield data according to the load ratio of each subfield only when the load ratio of each subfield is less than or equal to the reference value.

In addition, in Table 3, when the load factor (SF _SUM ) is 50% or more, the gain (G) may be assigned a gain greater than one. That is, when the sub-field by the load factor (SF _SUM), the reference value is smaller than (e. G. 50%) is larger than the load by applying a small gain greater than 1, and the sub-fields (SF _SUM) the reference value (e.g. 50%) is greater than 1 Big gains can be applied.

In the above description, it has been exemplified that the subfield weight adjusting unit 404 allocates the gain of the luminance weight according to the load ratio for each subfield by the table shown in Table 3.

The weight adjustment unit 404 for each subfield may also determine different gains G by a function according to the load ratio SF _{SUM for} each subfield. That is, the gain G may be implemented to be determined as shown in Equations 3 and 4, for example.

Specifically, the function of Equation 3 is implemented in the form of Equation 4 below.

Here, the gain offsets G1 ... G8 and the proportional coefficients α ₁ ... α _{8 for} each subfield SF1... SF8 may be appropriately selected according to the characteristics of the plasma display panel. In addition, although Equation 4 exemplifies the gain G as the first function according to the load factor SF _SUM , the gain G may be determined by various types of functions according to the characteristics of the plasma display panel.

On the other hand, the plasma display device according to the present invention, for example, has a structure of FIG. 1 and includes a driving device as shown in FIG. Here, the above-described driving device may be provided in the plasma display panel of the present invention and implemented as an integrated circuit, for example, in the logic controller 202 of FIG. 2.

The best embodiments have been disclosed in the drawings and specification above. Although specific terms have been used herein, they are used only for the purpose of describing the present invention and are not used to limit the scope of the present invention as defined in the meaning or claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

As described above, the plasma display panel of the present invention adjusts the luminance weight assigned to the subfields according to the load ratio for each subfield.

The conventional plasma display panel has a problem in that the line resistance of the panel is changed because the number of cells to be turned on for each subfield is not the same, thereby failing to achieve luminance corresponding to the original weight assigned to each subfield.

The plasma display panel of the present invention mitigates such image distortion by compensating for the luminance weights assigned to the subfields according to the subfield load rates.

The invention is not limited to the examples described above and represented in the drawings. Those skilled in the art taught by the above-described embodiments, many modifications to the above-described embodiments are possible by substitution, erasure, merging, etc. within the scope and object of the present invention described in the following claims.

1 is a view showing the structure of a conventional three-electrode surface discharge plasma display panel.

FIG. 2 shows a typical driving apparatus of the plasma display panel shown in FIG. 1.

FIG. 3 shows a conventional address-display separation driving method for Y electrode lines as an example of the plasma display panel driving method of FIG. 1.

FIG. 4 is a timing diagram for explaining an example of a drive signal of the panel shown in FIG. 1.

5 is an example of a typical image in which distortion of luminance occurs according to a load ratio for each subfield.

FIG. 6 is a diagram for explaining a cause of distortion in the image of FIG. 5 when grayscale N = 14.

FIG. 7 is a diagram for explaining a cause of distortion in the image of FIG. 5 when grayscale N = 7.

8 is a view for explaining the basic concept of the present invention.

9 is a block diagram illustrating a plasma display panel driving apparatus according to an exemplary embodiment of the present invention.

FIG. 10 is a block diagram illustrating an exemplary embodiment of the subfield weight adjusting unit of FIG. 9.

FIG. 11 is a block diagram illustrating another exemplary embodiment of the subfield weight adjusting unit of FIG. 9.

FIG. 12 is a block diagram illustrating another exemplary embodiment of the subfield weight adjusting unit of FIG. 9.

13 is a block diagram illustrating a plasma display panel driving apparatus according to another exemplary embodiment of the present invention.

FIG. 14 is a block diagram illustrating an exemplary embodiment of a weight adjustment unit for each subfield of FIG. 13.

Claims (13)

An apparatus for driving a plasma display panel by dividing one TV field into a plurality of subfields, A subfield data converter for converting input image data into subfield data; A subfield data summing unit for detecting a load ratio for each subfield from the subfield data; And And a subfield weight adjusting unit for adjusting the luminance weight of the subfield data according to the load ratio for each subfield. The method of claim 1, wherein the subfield weight adjustment unit, A weight gain table for allocating different gains according to the load ratio for each subfield; And And a multiplier configured to multiply and output the luminance weight of the subfield data by the allocated gain. The method of claim 1, wherein the subfield weight adjustment unit, A weight gain table for determining different gains by a function according to the load ratio for each subfield; And And a multiplier configured to multiply and output the luminance weight of the subfield data by the allocated gain. The method of claim 2 or 3, wherein the subfield weight adjustment unit, And the luminance weight of the subfield data is adjusted according to the load ratio for each subfield only when the load ratio for each subfield is equal to or less than a reference value. The method of claim 2 or 3, wherein the subfield weight adjustment unit, When the load ratio for each subfield is smaller than the reference value, a gain less than 1 is applied. And a gain greater than one when the load ratio for each subfield is greater than a reference value. The method of claim 1, wherein the subfield weight adjustment unit, A weight addition table for allocating different addition values according to the load ratios of the subfields; And And an adder which adds the luminance weight of the subfield data and the assigned addition value to output the sum. The method of claim 1, wherein the subfield weight adjustment unit, A weight subtraction table for allocating different subtraction values according to the load ratios for each subfield; And And a subtractor for subtracting the assigned subtracted value from the luminance weight of the subfield data and outputting the subtracted data. An apparatus for driving a plasma display panel by dividing one TV field into a plurality of subfields, A subfield data converter for converting input image data into subfield data; A subfield data summing unit for detecting a load ratio for each subfield from the subfield data and outputting the load ratio and an ID of the subfield; And And a sub-field weight adjusting unit for adjusting a luminance weight of the sub-field data according to the sub-field load ratio and the ID of the sub-field. The method of claim 8, wherein the weight adjustment unit for each subfield, A plurality of weight gain tables for allocating different gains according to the load ratio for each subfield; A table selector which selects a corresponding weight gain table according to the subfield ID; And And a multiplier for multiplying and outputting a luminance weight of the subfield data and a gain allocated to a selected gain table. The method of claim 8, wherein the weight adjustment unit for each subfield, A plurality of weight gain tables for determining different gains by a function according to the load ratio for each subfield; A table selector which selects a corresponding weight gain table according to the subfield ID; And And a weight calculator configured to multiply and output the luminance weight of the subfield data by the allocated gain. The method of claim 9 or 10, wherein the subfield weight adjustment unit, And the luminance weight of the subfield data is adjusted according to the load ratio for each subfield only when the load ratio for each subfield is equal to or less than a reference value. The method of claim 9 or 10, wherein the subfield weight adjustment unit, When the load ratio for each subfield is smaller than the reference value, a gain less than 1 is applied. And a gain greater than one when the load ratio for each subfield is greater than a reference value. A plasma display panel comprising the driving device of any one of claims 1 to 12.