KR100456147B1 - Method and apparatus for controling an average picture level of plasma display panel - Google Patents

Abstract

The present invention relates to a method and an apparatus for controlling an average image level of a plasma display panel to minimize flicker and improve image quality.

The method and apparatus for controlling an average image level of a plasma display panel according to the present invention detects an average image level of a current frame, and adds or subtracts a predetermined correction value to the detected average image level to determine the number of sustain pulses.

Description

METHOD AND APPARATUS FOR CONTROLING AN AVERAGE PICTURE LEVEL OF PLASMA DISPLAY PANEL}

The present invention relates to a plasma display panel, and more particularly, to a method and apparatus for controlling an average image level of a plasma display panel to minimize flicker and to improve image quality.

The plasma display panel (hereinafter referred to as "PDP") displays an image using visible light generated from the phosphor when ultraviolet rays generated by gas discharge excite the phosphor. PDP is thinner and lighter than the cathode ray tube (CRT), which has been the dominant display device, and has the advantage of enabling high-definition / large screens.

The PDP is driven by dividing one frame into several subfields having different number of emission times in order to realize gray level of an image. Each subfield is divided into a reset period for uniformly generating a discharge, an address period for selecting a discharge cell, and a sustain period for implementing gray levels according to the number of discharges. For example, when the image is to be displayed with 256 gray levels, the frame period (16.67 ms) corresponding to 1/60 second is divided into eight subfields. In addition, each of the eight subfields is divided into an address period and a sustain period. Here, the reset period and the address period of each subfield are the same for each subfield, while the sustain period and the number of discharges thereof are 2 ⁿ (n = 0,1,2,3) in each subfield in proportion to the number of sustain pulses. , 4,5,6,7). As described above, since the sustain period is changed in each subfield, gray levels of an image can be realized.

However, since the brightness of PDP is determined according to the number of sustain pulses, if the total number of sustains is the same when the average brightness is dark and bright, various problems such as image quality deterioration, power consumption, and panel damage may occur. For example, when the number of sustain pulses is set low for all the input images, the contrast is reduced. In addition, when the number of sustain pulses is set to high for all input images, the brightness may be brighter and the contrast may be increased even in a dark image, but the panel may be damaged such as power consumption increases and the panel temperature increases. Therefore, it is necessary to appropriately adjust the total number of sustain pulses according to the average brightness of the input image. To this end, the conventional PDP driving apparatus includes a circuit for controlling an average picture level (hereinafter referred to as "APL").

However, in the conventional PDP, flicker occurs in a video due to a sudden change in the number of sustain pulses, thereby degrading the picture quality. The conventional APL control circuit detects an average luminance of video data, i.e., APL, in units of frames and adjusts the number of sustain pulses according to the detected APL step. Here, the number of sustain pulses is rapidly increased in the relatively low gradation range and decreased in the high gradation range as shown in FIG. Therefore, the number of sustain pulses changes abruptly at APL of a relatively low gradation range. In particular, the moving picture mainly has an APL of about 30, and the number of sustain pulses (ΔSUS) changes rapidly in the range of about 15 or more. When the number of sustain pulses changes abruptly in such a low gray scale range, flicker occurs because the luminance varies greatly from frame to frame.

In addition, in the conventional PDP, even when the APL step is minutely changed to 1 to 2 due to the quantization noise generated during the digitization of the analog video data, the number of sustain pulses is drastically changed to generate flicker.

Accordingly, it is an object of the present invention to provide a method and apparatus for controlling an average picture level of a PDP, which minimizes flicker and improves image quality.

1 is a graph showing a conventional average image level control method.

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

3 is a graph showing a method for controlling an average image level according to the present invention.

4 is a graph showing correction average image level and sustain pulse number information shown in Table 1. FIG.

FIG. 5 is a graph showing correction average image level and sustain pulse number information shown in Table 2. FIG.

FIG. 6 is a graph showing correction average image level and sustain pulse number information shown in Table 3. FIG.

FIG. 7 is a graph showing correction average image level and sustain pulse number information shown in Table 4. FIG.

8 is a flowchart illustrating a control procedure of an average image level control method of a plasma display panel according to a first exemplary embodiment of the present invention step by step.

9 is a flowchart showing step by step a control procedure of a method for controlling an average image level of a plasma display panel according to a second embodiment of the present invention.

FIG. 10 is a flowchart illustrating a subroutine 'A' in FIG. 9.

<Description of Symbols for Main Parts of Drawings>

2A, 2B: reverse gamma correction unit 4: gain control unit

6 error diffusion unit 8 subfield mapping unit

10: data alignment unit 12: APL detection unit

14: APL converter 16: memory

18: waveform generator 20: PDP

22: VSC

In order to achieve the above object, the method for controlling the average picture level of the PDP according to the first embodiment of the present invention comprises the steps of detecting the average picture level of the current frame, and adding or subtracting a predetermined correction value to the detected average picture level to sustain. Determining the number of pulses.

According to a second aspect of the present invention, there is provided a method for controlling an average picture level of a PDP, the method comprising: detecting an average picture level of a current frame; calculating a correction average picture level by calculating an index set in advance to the average picture level; Determining the number of sustain pulses by adding or subtracting a predetermined correction value to the average image level.

A method of controlling an average image level of a PDP according to the second embodiment of the present invention includes comparing the number of sustain pulses output in a previous frame with a corrected average image level calculated in a current frame, and comparing the sustain pulses output in a previous frame. Comparing the difference between the number and the correction average image level calculated in the current frame with a predetermined threshold; and the difference between the number of sustain pulses output in the previous frame and the correction average image level calculated in the current frame is larger than the threshold. In this case, the method may further include determining sustain pulse number information as a correction average image level value.

The method for controlling the average image level of the PDP according to the second embodiment of the present invention is applied to the corrected average image level when the difference between the number of sustain pulses output in the previous frame and the corrected average image level calculated in the current frame is within a threshold. The sustain pulse number information is determined by adding or subtracting a predetermined correction value.

A method of controlling an average image level of a PDP according to the second embodiment of the present invention includes comparing the number of sustain pulses output in a previous frame with a corrected average image level calculated in a current frame, and comparing the sustain pulses output in a previous frame. Comparing the difference between the number and the correction average image level calculated in the current frame with a predetermined reference value, and when the difference between the number of sustain pulses output in the previous frame and the correction average image level calculated in the current frame is larger than the reference value. And determining the sustain pulse number information by adding or subtracting a second correction value different from the correction value to the correction average image level.

The average image level control method of the PDP according to the second embodiment of the present invention corrects the corrected average image level when the difference between the number of sustain pulses output in the previous frame and the corrected average image level detected in the current frame is within a reference value. It is characterized in that the sustain pulse number information is determined by adding or subtracting a value.

An apparatus for controlling an average image level of a PDP according to a first embodiment of the present invention includes a detector for detecting an average image level of a current frame, and a pulse determination for determining the number of sustain pulses by adding or subtracting a predetermined correction value to the detected average image level. A part is provided.

The apparatus for controlling an average picture level of a PDP according to a second embodiment of the present invention includes a detector for detecting an average picture level of a current frame, a converter for calculating a corrected average picture level by calculating an index set in advance to the average picture level; And a pulse determination unit for determining the number of sustain pulses by adding or subtracting a predetermined correction value to the correction average image level.

The pulse determining unit determines the sustain pulse number information as the correction average image level value when the difference between the number of sustain pulses output in the previous frame and the correction average image level calculated in the current frame is larger than a predetermined threshold value. It is done.

When the difference between the number of sustain pulses output from the previous frame and the correction average image level of the current frame is within a threshold, the pulse determination unit adds or subtracts a predetermined correction value to the correction average image level to determine sustain pulse number information. It features.

When the difference between the number of sustain pulses output from the previous frame and the correction average image level calculated in the current frame is larger than a predetermined reference value, the pulse determination unit adds or subtracts a second correction value different from the correction average to the correction average image level. And determining the pulse number information.

The pulse determining unit determines the sustain pulse number information by adding or subtracting a correction value to the correction average image level when a difference between the number of sustain pulses output in the previous frame and the correction average image level detected in the current frame is within a reference value. It is done.

The pulse determining unit includes a lookup table in which the number of sustain pulses to which a correction value is added or subtracted is registered.

The pulse determiner may further include a memory configured to compare the corrected average image level stored in the lookup table and input from the converter to the number of sustain pulses output in the previous frame, and to output sustain pulse number information listed in the lookup table according to the comparison result. It is characterized by including.

The correction average image level is obtained by multiplying the average image level by an exponent.

The correction average image level is obtained by dividing an index by the average image level.

The correction value is smaller than the second correction value.

Other objects and features of the present invention in addition to the above object will become apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 2 to 10.

Referring to FIG. 2, a driving apparatus of a PDP according to an embodiment of the present invention includes a video signal control circuit (VSC) 22 to which a video signal is input, a VSC 22, Inverse gamma correction unit 2A, gain control unit 4, error diffusion unit 6, subfield mapping unit 8 and data alignment unit 10, and sustain pulses connected between PDP 20 A waveform generator 18 for supplying a timing control signal to the PDP 20, an inverse gamma correction unit 2B, an APL detector 12 connected between the VSC 22 and the waveform generator 18, An APL converter 14 and a memory 16 are provided.

The VSC 22 samples and digitizes the analog video signal according to the clock signal.

The inverse gamma correction units 2A and 2B inversely gamma correct the digital video signal from the VSC 22 to linearly convert the luminance value according to the gray value of the video signal.

The APL detector 12 detects the average luminance, that is, APL, on a frame-by-frame basis with respect to data input from the inverse gamma correction unit 2B. The APL detected from the APL detector 12 is divided into 256 steps from 0 to 255 according to the luminance value when the input video data is assumed to be 8 bits.

The APL converter 14 calculates the corrected APL (CAPL) by multiplying or dividing the APL detected by the APL detector 12 with the exponent IDX, and supplies the CAPL to the LUT 16. Here, the index IDX is selected from natural numbers.

The following look-up table (hereinafter referred to as "LUT") is stored in the memory 16. In the LUT stored in the memory 16, a preset correction value is registered in consideration of the relationship between the sustain pulse number information output in the previous frame Fn-1 and the correction APL (CAPL) calculated in the current frame Fn. The memory 16 compares the previous frame Fn-1 and the current frame Fn continuously input from the APL converter 14, and the corresponding sustain pulse number information (SUS) registered in the LUT according to the comparison result. ) Will be printed. This memory 16 is preferably selected as Epyrom (Erasable and Programmable ROM) to facilitate updating of the LUT.

The correction value listed in the LUT is added to the correction APL (CAPL) of the frame. Here, the correction value is the number of sustain pulses when the difference value between the sustain pulse number information output in the previous frame Fn-1 and the correction APL (CAPL) calculated in the current frame Fn is smaller than a preset threshold or reference value. It is set so that the fluctuation of information is not large. Further, the correction value is set to 0 when the sustain pulse number information output in the previous frame Fn-1 and the correction APL (CAPL) calculated in the current frame Fn are the same. Further, the correction value is the correction APL (current correction) of the current frame when the difference value between the sustain pulse number information output from the previous frame Fn-1 and the correction APL (CAPL) calculated in the current frame Fn is larger than a preset threshold. It is set to a value that is determined by CAPL).

The gain control section 4 amplifies the video data corrected by the inverse gamma correction section 2A by the effective gain.

The error diffusion unit 6 finely adjusts the luminance value by diffusing an error component to adjacent cells with respect to the data from the gain control unit 4. To this end, the error diffusion unit 6 divides the data into integer and fractional parts, and multiplies the fractional part by a Fly-Steinberg coefficient to spread error components in adjacent cells.

The subfield mapping unit 8 maps the data input from the error diffusion unit 6 to prestored subfields and supplies the data to the data alignment unit 10 for each subfield.

The data alignment unit 10 supplies the video data input from the subfield mapping unit 8 to a data driving integrated circuit (hereinafter referred to as "IC") of the PDP 20. The data driving IC is connected to the data electrodes of the PDP 20 to latch data input from the data alignment unit 10 by one horizontal line, and then supplies the latched data to the data electrodes in units of one horizontal period.

The waveform generator 18 generates a timing control signal in response to the sustain pulse number information SUS input from the memory 16, and supplies the timing control signal to the data driving IC, the scan driving IC, and the sustain driving IC. . The scan driver IC is connected to the scan electrodes of the PDP 20 orthogonal to the data electrodes and sequentially supplies scan pulses to the scan electrodes in response to a timing control signal input from the waveform generator 18, and then a sustain period. The sustain pulses are simultaneously supplied to the scan electrodes. The sustain driving IC supplies sustain pulses to the sustain electrodes formed on the PDP 20 to be in parallel with the scan electrodes and to be paired with the scan electrodes.

In the APL control method and apparatus according to the present invention, the reference APL vs. sustain number characteristic curve CREF and the reference characteristic curve CREF are multiplied by an index using the APL converter 14 and the memory 16 as shown in FIG. 3. The number of sustain pulses is gradually increased or decreased between the curves C2 (* IDX). In addition, the APL control method and apparatus according to the present invention uses the APL converter 14 and the LUT 16 to divide a reference APL vs. sustain number characteristic curve CREF and an index divided by the reference characteristic curve CREF. The number of sustain pulses is gradually increased or decreased between C1 (/ IDX)). As a result, the number of sustain pulses varies stepwise within a small natural number, for example, 2, unless the APL changes larger than a preset threshold. Detailed description thereof will be described later with reference to Tables 1 to 4 and FIGS. 4 to 7. In Tables 1 to 4 and Figs. 4 to 7, the index IDX multiplied by APL was set to '4'.

Tables 1 to 3 show an example of the method and apparatus for controlling the average image level of the PDP according to the first embodiment of the present invention, wherein the number of sustain pulses is the reference APL vs. the sustain number characteristic curve CREF and the reference characteristic curve ( CREF) is changed within '1' between the curve C2 (* IDX) multiplied by the exponent. Table 4 shows an example of the method and apparatus for controlling the average image level of the PDP according to the second embodiment of the present invention, wherein the number of sustain pulses is determined by the reference APL vs. the sustain number characteristic curve CREF and the reference characteristic curve CREF. It shows a change within '2' between the curve C2 (* IDX) multiplied by the exponent.

APL 50 51 50 50 50 51 51 51 51 51 52 52 62 52 51 50 49 CAPL 200 204 200 200 200 204 204 204 204 204 208 208 248 208 204 200 196 α One -One 0 0 One One One One 0 One One 42 -40 -One -One -One SUS 200 201 200 200 200 201 202 203 204 204 205 206 248 208 207 206 205

APL 50 51 51 50 50 49 50 49 48 48 48 48 48 48 48 48 47 CAPL 200 204 204 200 200 198 200 196 192 192 192 192 192 192 192 192 188 α One One -One -One -One One -One -One -One -One -One -One -One -One 0 -One SUS 200 201 202 201 200 199 200 199 198 197 196 195 194 193 192 192 191

APL 50 51 50 51 50 51 50 51 50 52 50 52 50 49 48 47 46 CAPL 200 204 200 204 200 204 200 204 200 208 200 208 200 196 192 188 184 α One -One One -One One -One One -One One -One One -One -One -One -One -One SUS 200 201 200 201 200 201 200 201 200 201 200 201 200 199 198 197 196

APL 50 53 53 53 53 50 50 50 54 54 54 52 51 54 51 50 49 CAPL 200 212 212 212 212 200 200 200 216 216 216 208 204 216 204 200 196 α 2 2 2 One -One -One -One 2 2 2 -One -One 2 -One -2 -2 SUS 200 202 204 206 207 206 205 204 206 208 210 209 208 210 209 207 205

In Tables 1 to 4, 'α' represents a correction value added to CAPL, and 'SUS' represents sustain pulse number information SUS output from the memory 16.

4 is a graph showing correction APL (CAPL) and sustain pulse number information (SUS) described in Table 1. FIG. FIG. 5 graphically shows correction APL (CAPL) and sustain pulse number information (SUS) shown in Table 2. FIG. FIG. 6 graphically shows correction APL (CAPL) and sustain pulse number information (SUS) shown in Table 3. FIG. 7 is a graph showing the correction APL (CAPL) and the sustain pulse number information (SUS) described in Table 4. FIG.

Referring to Tables 1 to 3 and FIGS. 4 to 6, the method and the apparatus for controlling the average image level of the PDP according to the first embodiment of the present invention are output from the corrected APL (CAPL) calculated in the current frame and the previous frame. The sustain pulse number information SUS is compared. The method and apparatus for controlling an average picture level of a PDP according to the first embodiment of the present invention increases and decreases the correction APL (CAPL) value of the current frame by less than or equal to a preset threshold '8'. The sustain pulse number information SUS is output as a value obtained by adding or subtracting the correction value α '1' to the correction APL (CAPL). If the sustain pulse number information (SUS) output from the previous frame and the correction APL (CAPL) value calculated in the current frame are the same, the correction pulse (α) '0' is added to the correction APL (CAPL) of the current frame. The number information SUS is outputted.

The conventional APL method determines the number of sustain pulses by simply multiplying the APL value by an exponent, for example, '4', when increasing the number of sustain pulses at low gradation. Therefore, according to the conventional APL method, when the APL value is increased by 1 from '50' to '51' or decreases by 1 from '50' to '49', the number of sustain pulses at that time increases from '200' to '204'. Or decrease from '200' to '196'. That is, the conventional APL method simply calculates only the corrected APL value (CAPL) when increasing the number of sustain pulses at low gradations, and the number of sustain pulses is determined by the value. The number of sustain pulses varies. In contrast, the method and apparatus for controlling the average image level of the PDP according to the first embodiment of the present invention adds or subtracts '1' to the corrected APL (CAPL) value according to whether or not the APL changes. In the case of increasing by 1 to 51 'or decreasing by 1 from' 50 'to' 49 ', the number of sustain pulses is increased by 1 from' 200 'to' 201 'or by 1 from' 200 'to' 199 '.

In addition, the method and apparatus for controlling the average image level of the PDP according to the first embodiment of the present invention can be seen in Tables 1 and 4, and the sustain pulse number information (SUS) output from the previous frame and the correction calculated in the current frame. If the difference between APL (CAPL) is greater than the preset threshold value '8', the preset correction value α is output so that the sustain pulse number information is output as the correction APL (CAPL) value of the current frame. Added to. Here, the correction value α is calculated as (corrected APL value of the current frame-information on the number of sustain pulses output from the previous frame) and is registered in advance in the LUT. For example, as shown in Table 1 and FIG. 4, when the sustain pulse number information (SUS) output from the 12th frame is '206' and the correction APL (CAPL) of the 13th frame is rapidly increased to '248', The preset correction value α '42' is added to the correction APL (CAPL) of the 13th frame, and the sustain pulse number information SUS output from the 13th frame is '248'.

8 is a flowchart illustrating a control procedure of the average image level control method of the PDP according to the first embodiment of the present invention.

Referring to FIG. 8, the method for controlling the average image level of the PDP according to the first embodiment of the present invention first detects an average luminance of the current frame, that is, an APL (step S80). According to the method for controlling the average image level of the PDP, the corrected APL (CAPL) is calculated by multiplying the detected APL by an index (IDX), for example, '4' (Step S81). )) And the difference value Δn between the sustain pulse number information SUS (Fn-1) output in the previous frame is compared with the preset threshold value THR. (Steps S82 and S83) In step S83, the current frame When the difference value Δn between the correction APL (CAPL (Fn)) and the sustain pulse number information SUS (Fn-1) output in the previous frame is equal to or less than the preset threshold value THR, the first embodiment of the present invention The average image level control method of the PDP according to the embodiment includes the sustain pulse number information (SUS (Fn-1)) output from the previous frame and the beam of the current frame. In step S84, the sustain pulse number information SUS (Fn-1) output from the previous frame is equal to the correction APL (CAPL) value of the current frame. In this case, the sustain pulse number information SUS (Fn) of the current frame is determined by the correction APL (CAPL (Fn)) value of the current frame. (S85) In step S84, the sustain pulse number information (SUS) output from the previous frame. (Fn-1)) and the correction APL (CAPL) value of the current frame are not the same, the correction APL (CAPL) value of the current frame is larger than the sustain pulse number information (SUS (Fn-1)) output from the previous frame. (S86 and S88) In step S86, if it is determined that the correction APL (CAPL) value of the current frame is larger than the sustain pulse number information (SUS (Fn-1)) output from the previous frame, The sustain pulse number information SUS (Fn) of the current frame is obtained by adding a correction value '1' to the correction APL (CAPL (Fn)) of the current frame. If it is determined in step S88 that the correction APL (CAPL) value of the current frame is smaller than the sustain pulse number information SUS (Fn-1) output from the previous frame, the sustain of the current frame is determined. The pulse number information SUS (Fn) is determined as a value obtained by adding the correction value '-1' to the correction APL (CAPL (Fn)) of the current frame (step S89).

In step S83, when the difference value Δn between the correction APL (CAPL (Fn)) of the current frame and the sustain pulse number information SUS (Fn-1) output in the previous frame is larger than the preset threshold value THR. In the average image level control method of the PDP according to the first embodiment of the present invention, the sustain pulse number information SUS (Fn) of the current frame is converted into a correction value APL (CAPL (Fn)) of the current frame. The corrected APL value of-is determined by adding or subtracting the sustain pulse number information (CAPL (Fn) -SUS (Fn_-1)) output from the previous frame (step S90).

Finally, the average image level control method of the PDP according to the first embodiment of the present invention outputs the sustain pulse number information SUS determined in steps S85, S87, S89 or S90 (step S91).

The method and apparatus for controlling the average image level of the PDP according to the second embodiment of the present invention sets a reference value in advance, and compares the sustain pulse number information (SUS) output from the previous frame with the correction APL (CAPL) of the current frame and the reference value. As a result, different correction values α are added to the correction APL (CAPL) of the current frame. As can be seen from Table 4 and FIG. 7, when the difference between the sustain pulse number information (SUS) output from the previous frame and the correction APL (CAPL) of the current frame changes below the reference value '8', the correction APL (CAPL) of the current frame is changed. Is added to or subtracted from the correction value α. On the contrary, when the difference value between the sustain pulse number information SUS output from the previous frame and the correction APL (CAPL) of the current frame exceeds the reference value '8', the correction value α is added to or corrected from the correction APL (CAPL) of the current frame. ) Is set to '2'. For example, in Tables 4 and 7, in each of the 2-4th frame, the 9-11th frame, the 14th frame, and the 16th-17th frame, the sustain pulse number information (SUS) output from the previous frame and the current frame are corrected. Since the difference value between APL (CAPL) exceeds the reference value '8', the correction value α'2 'is added to or subtracted from the correction APL (CAPL) of the current frame, and the sustain pulse information SUS changes by two. On the other hand, in each of the 5th to 8th frames, the 12th to 13th frames, and the 15th frame, the difference between the sustain pulse number information (SUS) output from the previous frame and the correction APL (CAPL) of the current frame is less than or equal to the reference value '8'. Therefore, the correction value α '1' is added to or subtracted from the correction APL (CAPL) of the current frame, and the sustain pulse information SUS changes by one.

9 and 10 are flowcharts showing the control procedure of the average image level control method of the PDP according to the second embodiment of the present invention.

9 and 10, the average image level control method of the PDP according to the second exemplary embodiment of the present invention first detects an average luminance of the current frame, that is, an APL. The average image level control method of the PDP according to the embodiment calculates a corrected APL (CAPL) by multiplying the detected APL by an index IDX, for example, '4' (step S101). The difference value Δn between CAPL (Fn)) and the sustain pulse number information SUS (Fn-1) output in the previous frame is compared with a preset reference value REF. (Steps S102 and S103) In step S103, When the difference value Δn between the correction APL (CAPL (Fn)) of the current frame and the sustain pulse number information SUS (Fn-1) output in the previous frame is equal to or less than the preset reference value REF, The average image level control method of the PDP according to the second embodiment includes the sustain pulse number information (SUS (Fn-1)) output from the previous frame and the current string. It is determined whether the frame is equal to the correction APL (CAPL). (Step S104) In step S104, the sustain pulse number information (SUS (Fn-1)) output from the previous frame and the correction APL (CAPL) value of the current frame. If this is the same, the sustain pulse number information SUS (Fn) of the current frame is determined by the correction APL (CAPL (Fn)) value of the current frame. (Step S105) In step S104, the sustain pulse number information output from the previous frame. If (SUS (Fn-1)) and the correction APL (CAPL) value of the current frame are not the same, the sustain pulse number information (SUS (Fn-1)) whose correction APL (CAPL) value of the current frame is output in the previous frame (S106 and S108) In step S106, it is determined that the correction APL (CAPL) value of the current frame is larger than the sustain pulse number information (SUS (Fn-1)) output from the previous frame. When the sustain pulse number information (SUS (Fn)) of the current frame is sent to the correction APL (CAPL (Fn)) Is determined by the value, the value "α1" added. (Step S87) Here, the correction value "α1" is set to be smaller than the correction value will be described later, α2 ', it may be set to' 1 'as shown in Table 4. In step S108, when it is determined that the correction APL (CAPL) value of the current frame is smaller than the sustain pulse number information SUS (Fn-1) output in the previous frame, the sustain pulse number information SUS (Fn) of the current frame. Is determined as a value obtained by adding the correction value '-α1' to the correction APL (CAPL (Fn)) of the current frame (step S109).

In step S103, when the difference value Δn between the correction APL (CAPL (Fn)) of the current frame and the sustain pulse number information SUS (Fn-1) output from the previous frame is larger than the preset threshold THR In the method of controlling the average image level of the PDP according to the second embodiment of the present invention, the correction APL (CAPL (Fn)) of the current frame and the sustain pulse number information (SUS (Fn) output from the previous frame are branched to 'A'. -1)) will be compared again. First, it is determined whether or not the same information is obtained between the sustain pulse number information SUS (Fn-1) output from the previous frame and the correction APL (CAPL) of the current frame. (Step S110) In step S110, the sustain pulse output from the previous frame is determined. If the number information (SUS (Fn-1)) is equal to the correction APL (CAPL) value of the current frame, the sustain pulse number information (SUS (Fn)) of the current frame is the correction APL (CAPL (Fn)) value of the current frame. (Step S111) If the sustain pulse number information (SUS (Fn-1)) output from the previous frame and the correction APL (CAPL) value of the current frame are not the same in step S110, the correction APL (CAPL) of the current frame is determined. ) Value is larger or smaller than the sustain pulse number information SUS (Fn-1) output in the previous frame. (Steps S112 and S114) In step S112, the correction APL (CAPL) value of the current frame If it is determined to be larger than the sustain pulse number information (SUS (Fn-1)) output from the frame, the sustain of the current frame The tain pulse number information SUS (Fn) is determined as a value obtained by adding the correction value 'α2' to the correction APL (CAPL (Fn)) of the current frame (step S87). It can be set to '2' as shown. In step S114, if it is determined that the correction APL (CAPL) value of the current frame is smaller than the sustain pulse number information SUS (Fn-1) output from the previous frame, the sustain pulse number information SUS (Fn) of the current frame. Is determined as a value obtained by adding the correction value '-α2' to the correction APL (CAPL (Fn)) of the current frame (step S115).

Finally, the average image level control method of the PDP according to the second embodiment of the present invention outputs the sustain pulse number information (SUS) determined in steps S105, S107, S109, S111, S113 or S115. (Step S116)

8, 9 and 10 are implemented as a LUT in which the sustain pulse number information is set in advance so that the variation in the number of sustain pulses is not large in every frame. In addition, the PDP according to the first embodiment of the present invention The average image level control method may be implemented by a logic operation circuit that calculates sustain pulse number information in real time by performing a logical operation on the algorithms of FIGS. 8, 9, and 10.

Meanwhile, in the method of controlling an average image level of a PDP according to an embodiment of the present invention, the correction APL (CAPL) is calculated by multiplying the APL detected in the current frame by the exponent IDX through FIGS. 8, 9, and 10. It may be calculated by dividing the index IDX by the APL detected in the frame.

In addition, the method and apparatus for controlling the average image level of the PDP according to an embodiment of the present invention determines the number of sustain pulses by adding or subtracting the correction value α to the APL detected in the current frame without converting the APL detected in the current frame. It may be.

As described above, the method and apparatus for controlling the average image level of the PDP according to the present invention detects the APL in the current frame, multiplies or divides the detected APL by an exponent, and calculates the corrected APL, According to the result of the comparison of the number of sustain pulses output, the number of sustain pulses is determined by adding a correction value set so that the variation of the number of sustain pulses between frames is not large. In addition, the method and apparatus for controlling the average image level of the PDP according to the present invention provides a gradation representation when the difference between the APL detected in the current frame and the number of sustain pulses output in the previous frame exceeds a predetermined threshold. The correction APL value determines the number of sustain pulses. In addition, the method and apparatus for controlling the average image level of the PDP according to the present invention compares a difference value between the correction APL of the current frame and the number of sustain pulses output from the previous frame with a predetermined reference value and displays different correction values according to the comparison result. The number of sustain pulses is determined by adding or subtracting the frame correction APL. As a result, the method and apparatus for controlling the average image level of the PDP according to the present invention can suppress the change in the number of sustain pulses to be large, thereby minimizing the flicker and improving the image quality.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (20)

delete Detecting an average image level of the current frame; Calculating a corrected average image level by calculating a predetermined index to the average image level; And determining a number of sustain pulses by adding or subtracting a predetermined correction value to the corrected average image level. The method of claim 2, And said corrected average image level is obtained by multiplying said index by said detected average image level. The method of claim 2, And the corrected average image level is obtained by dividing the index by the detected average image level. The method of claim 2, Comparing the number of sustain pulses output in the previous frame with the corrected average image level calculated in the current frame; Comparing a difference value between the number of sustain pulses output in the previous frame and the corrected average image level calculated in the current frame with a predetermined threshold value; And determining the sustain pulse number information as the corrected average image level value when the difference between the number of sustain pulses output in the previous frame and the corrected average image level calculated in the current frame is greater than the threshold value. An average image level control method for a plasma display panel. The method of claim 5, wherein When the difference between the number of sustain pulses output from the previous frame and the correction average image level calculated in the current frame is within the threshold, a predetermined correction value is added to or subtracted from the correction average image level to determine sustain pulse number information. An average image level control method for a plasma display panel. The method of claim 2, Comparing the number of sustain pulses output in the previous frame with the corrected average image level calculated in the current frame; Comparing a difference value between the number of sustain pulses output in the previous frame and the corrected average image level calculated in the current frame with a predetermined reference value; When the difference between the number of sustain pulses output from the previous frame and the correction average image level calculated in the current frame is larger than the reference value, a second correction value different from the correction value is added to or subtracted from the correction average image level. Determining the number information; and controlling the average image level of the plasma display panel. The method of claim 7, wherein Determining the sustain pulse number information by adding or subtracting the correction value to the correction average image level when the difference between the number of sustain pulses output from the previous frame and the correction average image level detected in the current frame is within the reference value. An average image level control method for a plasma display panel. The method of claim 7, wherein And the correction value is smaller than the second correction value. delete A detector for detecting an average image level of the current frame; A converter which calculates a corrected average image level by calculating a predetermined index to the average image level; And a pulse determination unit which determines a number of sustain pulses by adding or subtracting a predetermined correction value to the correction average image level. The method of claim 11, And said corrected average image level is obtained by multiplying said index by said detected average image level. The method of claim 11, And the corrected average image level is obtained by dividing the index by the detected average image level. The method of claim 11, The pulse determining unit may convert the sustain pulse number information to the corrected average image level value when the difference between the number of sustain pulses output from the previous frame and the corrected average image level calculated in the current frame is greater than a predetermined threshold value. And an average image level control device for the plasma display panel. The method of claim 14, The pulse determining unit adds or subtracts a predetermined correction value to the correction average image level when the difference between the number of sustain pulses output from the previous frame and the correction average image level of the current frame is within the threshold value. And an average image level control device of the plasma display panel. The method of claim 11, The pulse determining unit may determine a second correction value different from the correction value when the difference between the number of sustain pulses output from the previous frame and the correction average image level calculated in the current frame is greater than a predetermined reference value. And determining the sustain pulse number information in addition to and in response to the average image level control apparatus of the plasma display panel. The method of claim 16, The pulse determining unit adds or subtracts the correction value to the corrected average image level when the difference between the number of sustain pulses output from the previous frame and the corrected average image level detected in the current frame is within the reference value. And an average image level control device of the plasma display panel. The method of claim 16, And the correction value is smaller than the second correction value. The method of claim 16, And the pulse determination unit includes a look-up table in which the number of sustain pulses to which the correction value is added or subtracted is registered. The method of claim 19, The pulse determiner compares the corrected average image level stored in the lookup table and input from the converter with the number of sustain pulses output in the previous frame, and outputs sustain pulse number information listed in the lookup table according to the comparison result. An apparatus for controlling an average image level of a plasma display panel, further comprising a memory.