KR100672858B1 - Method and apparatus for driving a plasma display panel - Google Patents

Abstract

SUMMARY OF THE INVENTION The present invention provides a method and apparatus for driving a plasma display panel for smoothly expressing gray scale expressions that are not purified by adjusting the number of sustain discharge waveforms of each susfield in the address / dielectric field separation driving method.

The driving method is to adjust the white balance and gamma of the screen data (R, G, B) in the data processing section 10, and then, in the APL calculation section 20 for a constant power consumption regardless of the brightness of the screen The output is adjusted according to the brightness of the output, and the output is converted to the data format conversion and driving circuit section 50 for driving the address electrode with the adjusted gray scale expression and the driving circuit section 40 for driving the X electrode and the Y electrode. A driving method for driving a plasma display panel, the method comprising: checking the number of fields and storing the first number of sustain data by the sustain number determining unit 31 according to a value less than or equal to the decimal point of the gray scale expression data output from the APL calculating unit 20 The sustain number is read from the unit 32 and the second sustain number data storage 33, and sustain discharge of adjacent fields with different sustain numbers.

Description

Method and apparatus for driving a plasma display panel

1 is a schematic block diagram for processing image data of R, G, and B of a conventional surface discharge AC plasma display panel;

2 is a schematic block diagram for processing image data of R, G, and B of a surface discharge AC plasma display panel according to an embodiment of the present invention;

<Description of the symbols for the main parts of the drawings>

10: data processing unit 20: APL calculation unit

30: Sustain number data generator 31: Field number check and sustain number determiner

32: first sustain number data storage unit 33: second sustain number data storage unit

40: drive circuit section 50: data format conversion and drive circuit section

The present invention relates to a method of driving a plasma display panel. More particularly, the number of sustain discharge waveforms of each subfield is adjusted by expressing a gray level by dividing one field (frame) into several subfields (subframes). The present invention relates to a method of driving a plasma display panel for smoothly expressing gradation expression that is not purified by the present invention, and an apparatus thereof.

In a conventional surface discharge AC plasma display panel, a front electrode group formed of an X electrode and a Y electrode is formed on a front substrate, and a dielectric layer is formed thereon. In addition, an address electrode is formed on an opposite rear substrate of the front substrate, a dielectric layer is formed thereon, and partition walls are formed to provide a constant discharge space filled with discharge gas therebetween. R, G, B fluorescent layers are formed.

The driving method applied to the plasma display panel configured as described above includes an address / oil dielectric separation method (disclosed in Japanese Patent Laid-Open Publication No. Hei 4-195188 (1992)) and an address / oil dielectric multiple method (Japanese Patent Number). 2,528,195), but mainly address / oil field separation method is applied, and the separation method uses one field (frame) for gray scale display, for example, from 1st to 1st. The subfields are divided into eighth subfields, and each subfield includes a reset period, an address period, a sustain discharge period, and each subfield is set with a specific sustain discharge period. The gradation of is displayed.

During the reset period of each subfield, all Y electrodes are first set to 0 V level, and at the same time, a front write pulse of high voltage (approximately 350 V) is applied to the X electrodes, regardless of the display state up to that point. Discharge is performed in all the cells. The address electrode potential at this time is about 100V. The wall charges are accumulated on the dielectric layers covering the X electrodes and the Y electrodes by the front surface discharge. That is, negative charges accumulate on the X electrode and positive charges accumulate on the Y electric pole. Next, the potentials of the X electrode and the address electrode become 0 V, so that the voltage of the wall charge itself exceeds the discharge start voltage in all cells, and discharge is started. The positive discharge neutralizes itself and the discharge ends. So-called self-erasing discharge. By this self-erasing discharge, the state of all the cells in the panel is made into a uniform state without wall charges, whereby the next address (write) discharge can be stabilized. It is also possible to optionally apply a gradually increasing priming erase pulse. This priming erase pulse further discharges the cells whose wall charges are not completely erased to initialize all the cells completely. Such an initialization process is an essential process for distinguishing each subfield when a gray level is expressed by dividing one field into a plurality of subfields.

Next, in the address period, address discharge is sequentially performed in order to turn on / off the cells in accordance with the display data. First, a predetermined voltage (approximately 60 V) is applied to the X electrode, and a sequential scan pulse (approximately -160 V) is applied to the Y electrode, and at the same time, the address electrode corresponds to a cell causing sustain discharge, that is, a cell to be lit. An address pulse (approximately 60 V) is selectively applied to the address electrode, and discharge occurs between the address electrode and the Y electrode of the cell to be turned on, so that a positive wall charge capable of sustain discharge is accumulated. In addition, a predetermined voltage (about -60 V) is applied to the Y electrode to which the scan pulse is not applied so that discharge does not occur.

Thereafter, in the sustain discharge period, a sustain pulse (about 180 V) is applied to the Y electrode and the X electrode alternately to perform sustain discharge, thereby performing image display in one subfield. That is, in a cell in which wall charge is accumulated in an address period, discharge occurs because the voltage caused by the wall charge overlaps the sustain discharge pulse. However, in a cell in which wall charge is not accumulated in the address period, even if the sustain discharge pulse is applied, the discharge is not performed. By not generating, image display of one subfield can be performed. In addition, in order to avoid discharge between the address electrode and the X electrode or the Y electrode, a voltage of about 100 V is applied to the address electrode. In this " address / hold discharge separation method ", the luminance is determined by the length and duration of the sustain discharge period, that is, the number of sustain discharge pulses.

In the above-described address / sustain discharge period-separated write address method, one frame is divided into eight subfields, and in these subfields, the reset period and the address period each have a constant length, but the length of the sustain discharge period is 1: 2. The ratio is 4: 4: 8: 16: 32: 64: 128. Therefore, by selecting the subfield to be lit, the difference in luminance in 256 steps from 0 to 255 can be displayed (i.e., 256 gradations are displayed). In the specific time allocation, when the recording rate of the screen is 60 [Hz], one frame becomes 16.6 [ms] (1/60 [Hz]). When the number of sustain discharge cycles in one frame is 510, the number of sustain discharge cycles in each subfield is two cycles for the first subfield, four cycles for the second subfield, eight cycles for the third subfield, and the like. The four subfields are 16 cycles, the fifth subfield is 32 cycles, the sixth subfield is 64 cycles, the seventh subfield is 128 cycles, and the eighth subfield is 256 cycles. If the time of the sustain discharge cycle is 8 [ms], the total of one field is 4.08 [ms]. About 12 [ms] of the remainder is allocated to eight reset periods, address periods and rest periods. Therefore, when the reset period and the address period of each subfield are about 1.5 [ms], and 50 [ms] are required in the reset period of each address period, an address cycle takes 3 [ms] to drive a 500-line panel. Becomes

FIG. 1 is a schematic block diagram for processing the image data of R, G, and B described above. In FIG. 1, screen data R, G, and B are outputted from the A / V unit, and the output signal is input, and white balance and gamma adjustment is performed at the data processing unit 10. 20) adjusts the output according to the brightness of the screen for constant power consumption irrespective of the brightness of the screen, and the data format conversion and driving circuit section 50 and X for driving the address electrode with the gray level expression whose output is adjusted. It is output to the drive circuit part 40 via the sustain number data generation part 30 for driving an electrode and a Y electrode.

At this time, the gradation expression data output from the APL calculation unit 20 is converted to a value below the decimal point by the sustain number data generation unit 30 by rounding, etc. by the sustain number data generation unit 30, and the subfield and the sustain number. By determining and outputting to the driving circuit unit 40, the number of sustains corresponding to the gray scale expression data adjusted by the data processing unit 10 and the APL calculating unit 20 is outputted as it is from the sustain number data generating unit 30 as it is. The problem is that the value of is not properly represented.

 Accordingly, the present invention is to solve this problem, and in the address / dielectric field separation driving method, the plasma display panel is driven to smoothly express gray scale expression that is not purified by adjusting the number of sustain discharge waveforms of each susfield. It is an object to provide a method and an apparatus thereof.

In order to achieve the above object, a method of driving a plasma display panel according to an exemplary embodiment of the present invention includes adjusting white balance and gamma of screen data in a data processing unit, and then performing constant power regardless of the brightness of the screen in the APL calculation unit. The output is adjusted according to the brightness of the screen for consumption, and the output is converted to the data type conversion and driving circuit unit for driving the address electrode and the driving circuit unit for driving the X electrode and the Y electrode with the adjusted gray scale expression. A driving method for driving a display panel, comprising: storing the first sustain number data storage unit and the second sustain number data by the field number check and the sustain number determiner according to the value of the decimal point of the gray scale expression data output from the APL calculator; Reading sustain number from the negative part and sustaining discharge of adjacent fields with different sustain number It features.

In addition, the present invention, the data processing unit for adjusting the white balance and gamma by receiving the screen data, APL calculation unit for adjusting the output according to the brightness of the screen for constant power consumption irrespective of the brightness of the screen, A driving apparatus for a plasma display panel comprising a data format conversion and driving circuit portion for driving an address electrode with a gray scale expression whose output is adjusted, and a driving circuit portion for driving an X electrode and a Y electrode: an APL calculator A first sustain number data storage unit and a second sustain number data storage unit for storing a sustain number corresponding to an adjacent integer value according to a value less than or equal to the decimal point of the gray scale expression data output from the second sustain number data storage unit; And reading the sustain number from the first sustain number data storage unit and the second sustain number data storage unit according to a value less than or equal to the decimal point of the gray scale expression data output from the APL calculator, and outputting different sustain numbers to the driving circuit unit. The present invention provides a driving apparatus for a plasma display panel comprising a field number check and a sustain number determiner for sustain discharge of adjacent fields.

When the value below the decimal point of the gradation expression data is 0.3 to 0.7, the value of the sustain number of the second sustain number data storage unit is stored as large as the value corresponding to the gradation expression data 1 than the first sustain number data storage unit, thereby storing By expressing the gradation expression data 0.5 by the combination, an image can be expressed more smoothly.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

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

As shown in FIG. 2, in the data processing unit 10 to which the screen data R, G, and B are input, white balance and gamma adjustment of the screen data R, G, and B are performed. 20, and the APL calculator 20 adjusts the output of the gray scale expression data according to the brightness of the screen for constant power consumption regardless of the brightness of the screen. The gray scale expression data whose output is adjusted is output to the data format conversion and driving circuit section 50 for driving the address electrode, and to the field number check and the sustain number determination section 31, and the field number check and the sustain. The number and sustain number are determined by the number determining unit 31 to drive the X electrode and the Y electrode through the driving circuit unit 40.                     

The above-described screen data R, G, and B convert analog R, G, and B signals into digital data of N bits (e.g., each 8 bits of RG B in 256 grayscales) based on a predetermined sampling clock. The video data of one field is reconstructed into a plurality of subfields (for example, eight subfields) and output for gradation processing on the converted digital data.

On the other hand, in the first sustain number data storage unit 32 and the second sustain number data storage unit 33, a sustain corresponding to an adjacent integer value according to a value less than or equal to the decimal point of the gray scale expression data output from the APL calculator 20 is provided. The number is stored.

In this way, the number of fields is checked to read the sustain number from the first sustain number data storage unit 32 and the second sustain number data storage unit 33 storing different sustain numbers, and to maintain and discharge adjacent fields with different sustain numbers. The sustain number determining unit 31 is configured.

Thus, as the driving apparatus of the plasma display panel of the present invention is configured, when the value is less than or equal to the decimal point of the gradation expression data output from the APL calculator 20, the first sustain number data storage unit 32 is corresponding to the value less than or equal to the decimal point. ) And one sustain number data are read from one of the second sustain number data storages 33 to form one field, and the other is different from the first sustain number data storage 32 and the second sustain number data storage 33. By reading out the sustain number from one to form an adjacent field, the adjacent fields are sustained and discharged with different sustain numbers according to values below the decimal point of the gray scale expression data output from the APL calculation unit 20.                     

For example, when the value below the decimal point of the gray scale expression data output from the APL calculation unit 20 is between 0.3 and 0.7, the number of sustains of the second sustain number data storage unit 33 is determined by the first sustain number data storage unit ( By storing a value larger than the value corresponding to the gray scale expression data 1 than 32), the adjacent fields are sustained and discharged differently from each other by the value corresponding to the gray scale expression data 1. As such, since the adjacent fields are differently expressed in gray scale, 0.5 gray scale expression data 0.5 can be expressed by a combination of adjacent fields on average, so that a value below the decimal point of the gray scale data can be expressed on an average of 0.3 to 0.7. Will be.

Therefore, it is possible to express gray scales in a range not expressed in the related art, and thus it is possible to prevent specific degradation that is apparent to the naked eye in gray scales which are not expressed or gray scales before and after the gray scales to be expressed.

That is, when the unnumbered sustain number is forcibly purified due to the APL step, gamma, and white balance adjustment, and the luminance difference of the gray level is visually observed depending on the number of sustains and the number of sustained subfields between the front and back fields. In the APL step, gamma, and white balance, two or more different sustain numbers are defined and changed for each field, thereby reducing the appearance of the luminance difference. In this way, if the number of sustains that are not integer is rounded for each field by calculating the number of rounds for each field, the number of original sustains that is not integer is expressed on average.

In addition, it is also possible to obtain the desired sustain number on average by varying the unsaturated sustain number for each field.If the gray level expression is not smooth due to the difference in the sustain number between the front and rear gray levels, the value of the sustain number is changed. By driving each field, the gradation expression can be made smooth.

 According to the configuration and operation of the plasma display panel driving method and the apparatus according to the embodiment of the present invention described above, the number of sustains not purified by sustain discharge of the adjacent fields by varying the number of sustains according to the gray scale expression data below the decimal point Since the desired sustain number can be taken on average, the desired gradation can be expressed and the gradation expression can be excellent, and the discontinuity expression of the gradation due to the difference between the front and the rear spectral can be reduced.

Claims (4)

After adjusting the white balance and gamma of the screen data (R, G, B) in the data processing unit 10, the APL calculator 20 outputs the screen data according to the brightness of the screen for a constant power consumption regardless of the brightness of the screen. To the data type conversion and driving circuit unit 50 for driving the address electrode and the driving circuit unit 40 for driving the X electrode and the Y electrode with the adjusted gray scale expression. In the driving method for driving: The first number of sustain data storage unit 32 and the second number of sustain data storage unit are checked by the number of fields check and the number of sustain determination unit 31 according to the value below the decimal point of the gray scale expression data output from the APL calculator 20. A method of driving a plasma display panel, characterized in that the sustain number is read out from (33) to sustain discharge the adjacent fields with different sustain numbers. 2. The gray scale expression data 1 according to claim 1, wherein the number of sustains of the second sustain number data storage unit 33 is less than that of the first sustain number data storage unit 32 when the value below the decimal point of the gray scale expression data is 0.3 to 0.7. A method of driving a plasma display panel comprising storing a value as large as a value corresponding to and expressing the gradation expression data 0.5 by a combination of adjacent fields. Data processing unit 10 for inputting screen data (R, G, B) for white balance and gamma adjustment, and APL for adjusting output according to screen brightness for constant power consumption regardless of screen brightness And a calculation unit 20, a data format conversion and driving circuit unit 50 for driving the address electrode with the gray scale expression whose output is adjusted, and a driving circuit unit 40 for driving the X electrode and the Y electrode. In the driving device of the plasma display panel is: A first sustain number data storage unit 32 and a second sustain number data storage unit 33 for storing a sustain number corresponding to an adjacent integer value according to a value below a decimal point of the gray scale expression data output from the APL calculation unit 20 ); And The sustain number is read from the first sustain number data storage unit 32 and the second sustain number data storage unit 33 according to a value less than or equal to the decimal point of the gray scale expression data output from the APL calculation unit 20 to perform different sustain. And a field number check and a sustain number determiner (31) for outputting the number to the drive circuit (40) to sustain discharge the adjacent fields. The sustain number of the second sustain number data storage unit 33 is higher than that of the first sustain number data storage unit 32 when the value below the decimal point of the gray scale expression data is 0.3 to 0.7. And a value as large as a corresponding value is stored.

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