KR20050020529A - Apparatus and Method of Driving Plasma Display Panel - Google Patents

Abstract

The present invention relates to a driving apparatus for a plasma display panel that can reduce power consumption.

A driving apparatus of the plasma display panel according to the present invention includes: a subfield information calculating unit for extracting a highest gray value from data inputted thereto and extracting a subfield in which a sustain pulse is unnecessary in accordance with the extracted highest gray value; And a waveform generator for controlling the sustain pulse to be supplied during the sustain period of the other sustain field by the control of the subfield information calculating unit without supplying the sustain pulse during the sustain period of the subfield in which the sustain pulse is unnecessary.

Description

Driving apparatus and driving method of plasma display panel {Apparatus and Method of Driving Plasma Display Panel}

The present invention relates to a driving apparatus and a driving method of a plasma display panel, and more particularly, to a driving apparatus and a driving method of a plasma display panel to reduce power consumption.

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

1 and 2, the three-electrode AC surface discharge type PDP includes scan electrodes Y1 to Yn and sustain electrodes Z formed on the upper substrate 10, and addresses formed on the lower substrate 18. Electrodes X1 to Xm are provided.

The discharge cells 1 of the PDP are formed at the intersections of the scan electrodes Y1 to Yn, the sustain electrodes Z, and the address electrodes X1 to Xm.

Each of the scan electrodes Y1 to Yn and the sustain electrode Z includes a transparent electrode 12 and a metal bus electrode 11 having a line width smaller than that of the transparent electrode 12 and formed at one edge of the transparent electrode. The transparent electrode 12 is typically formed on the upper substrate 10 by indium tin oxide (ITO). The metal bus electrode 11 is formed of a metal on the transparent electrode 12 to reduce the voltage drop caused by the transparent electrode 12 having a high resistance. The upper dielectric layer 13 and the passivation layer 14 are stacked on the upper substrate 10 on which the scan electrodes Y1 to Yn and the sustain electrode Z are formed. On the upper dielectric layer 13, wall charges generated during plasma discharge are accumulated. The passivation layer 14 protects the electrodes Y1 to Yn and Z and the upper dielectric layer 13 from sputtering generated during plasma discharge and increases the emission efficiency of secondary electrons. As the protective film 14, magnesium oxide (MgO) is usually used.

The address electrodes X1 to Xm are formed on the lower substrate 18 in a direction crossing the scan electrodes Y1 to Yn and the sustain electrode Z. FIG. The lower dielectric layer 17 and the partition wall 15 are formed on the lower substrate 18. The phosphor layer 16 is formed on the surfaces of the lower dielectric layer 17 and the partition wall 15. The partition wall 15 is formed in a stripe or lattice shape to physically divide the discharge cells to block electrical and optical interference between neighboring discharge cells 1. The phosphor layer 16 is excited and emitted by ultraviolet rays generated during plasma discharge to generate visible light of any one of red, green, and blue.

An inert mixed gas such as He + Xe, Ne + Xe or He + Ne + Xe for discharging is injected into the discharge space of the discharge cells provided between the upper and lower substrates 10 and 18 and the partition wall 15.

The PDP is time-division-driven by dividing one frame into several subfields having different emission counts in order to realize gray levels 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 a reset period, 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.

3 is a view showing a driving apparatus of a conventional plasma display panel.

Referring to FIG. 3, a conventional driving apparatus of a PDP includes a gain adjusting unit 32, an error diffusion unit 33, and a subfield mapping unit connected between the first inverse gamma adjusting unit 31A and the data alignment unit 35. 34) and an APL calculation unit 36 connected between the second inverse gamma adjustment unit 31B and the waveform generator 37.

The first and second inverse gamma correction units 31A and 31B inversely gamma correct the digital video data RGB from the input line 30 to linearly convert luminance of the gray level of the image signal.

The gain adjusting unit 32 compensates the color temperature by adjusting the effective gain for each data of red, green, and blue.

The error diffusion unit 33 finely adjusts the luminance value by diffusing the quantization error of the digital video data RGB input from the gain adjustment unit 32 into adjacent cells.

The subfield mapping unit 34 maps the data input from the error diffusion unit 33 to the subfield pattern stored in advance for each bit, and supplies the mapping data to the data alignment unit 35.

The data aligning unit 35 supplies digital video data input from the subfield mapping unit 34 to the data driving circuit of the panel 38. The data driving circuit is connected to the data electrodes of the panel 38 to latch data input from the data alignment unit 35 by one horizontal line, and then the latched data is addressed to the panel electrodes in one horizontal period. Will be supplied to

The APL calculator 36 calculates an average luminance, that is, an APL (Avarage Picture Level), in one screen unit with respect to the digital video data RGB input from the second inverse gamma correction unit 31B, and corresponds to the calculated APL. The sustain pulse number information is output.

The waveform generator 37 generates a timing control signal in response to the sustain pulse number information from the APL calculator 36, and supplies the timing control signal to a scan driving circuit and a sustain driving circuit (not shown). The scan driving circuit and the sustain driving circuit supply sustain pulses to the scan electrodes and the sustain electrodes of the panel 38 during the sustain period in response to the timing control signal input from the waveform generator 37.

In the conventional PDP, a sustain pulse calculated by APL is supplied to the discharge cells 1 regardless of data. Therefore, conventionally, the sustain pulse determined by the APL is also supplied to the subfield without data, so that unnecessary power consumption is wasted. For example, when full black is represented by the panel 38, sustain discharge does not occur in the discharge cells 1 of the panel 38. However, even in such a case, since a sustain pulse is supplied to each subfield in the PDP, unnecessary power is wasted. That is, in the conventional PDP, a large amount of power is consumed by supplying sustain pulses to subfields in which sustain discharges do not occur.

Accordingly, an object of the present invention is to provide a driving apparatus and a driving method of a plasma display panel which can reduce power consumption.

In order to achieve the above object, the driving apparatus of the plasma display panel of the present invention extracts the highest gray value from the data input to the subfield, and extracts a subfield in which the sustain pulse is unnecessary in response to the extracted highest gray value. An information calculator; And a waveform generator for controlling the sustain pulse to be supplied during the sustain period of the other sustain field by the control of the subfield information calculating unit without supplying the sustain pulse during the sustain period of the subfield in which the sustain pulse is unnecessary.

The subfield information calculating unit includes a maximum value calculating unit for calculating the highest grayscale value, and a lookup table for extracting a subfield in which a sustain pulse is unnecessary in correspondence with the highest grayscale value.

In the lookup table, subfields to which a sustain pulse is supplied and subfields in which a sustain pulse is unnecessary are stored in correspondence with the highest gray value.

The subfield information calculating unit extracts the highest gray level value in units of frames.

And an APL unit installed at the front end of the waveform generator to calculate the sustain pulse number information corresponding to the average luminance of the data input to the waveform generator and to supply the waveform to the waveform generator.

According to an aspect of the present invention, there is provided a method of driving a plasma display panel, the method including: extracting a highest gray value from input data; A second step of extracting a subfield in which a sustain pulse is unnecessary from among subfields in correspondence with the extracted highest gray value; And a third step of supplying the sustain pulse during the sustain period of the other sustain field without supplying the sustain pulse during the sustain period of the subfield in which the sustain pulse extracted in the second step is unnecessary.

In the first step, the highest gray level value is extracted in units of frames.

Other objects and features of the present invention in addition to the above objects 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. 4 to 6.

4 is a view showing a driving apparatus of a plasma display panel according to an embodiment of the present invention.

Referring to FIG. 4, the driving apparatus of the PDP of the present invention includes a gain adjusting unit 42, an error diffusion unit 43, and a subfield mapping unit connected between the first reverse gamma adjusting unit 41A and the data sorting unit 45. 44, an APL calculation unit 46 connected between the second inverse gamma adjustment unit 41B and the waveform generation unit 47, and a sub connected between the error diffusion unit 43 and the waveform generation unit 47. A field information calculation unit 49 is provided.

The first and second inverse gamma adjustment units 41A and 41B perform linear inverse gamma correction on the digital video data RGB from the input line 40 to linearly convert the luminance of the gray level of the image signal.

The gain adjusting unit 42 compensates the color temperature by adjusting the effective gain for each data of red, green, and blue.

The error diffusion unit 43 finely adjusts the luminance value by diffusing the quantization error of the digital video data RGB input from the gain adjustment unit 42 into adjacent cells.

The subfield mapping unit 44 maps the data input from the error diffusion unit 43 to the subfield pattern stored in advance for each bit, and supplies the mapping data to the data alignment unit 45.

The data aligning unit 45 supplies the digital video data input from the subfield mapping unit 44 to the data driving circuit of the panel 48. The data driving circuit is connected to the data electrodes of the panel 48 to latch data input from the data alignment unit 45 by one horizontal line, and then the latched data is addressed to the panel electrodes by one horizontal period. To feed.

The APL calculator 46 calculates an average luminance, that is, an average picture level (APL) in one screen unit, with respect to the digital video data RGB input from the second inverse gamma correction unit 41B and corresponds to the calculated APL. The sustain pulse number information is output.

The waveform generator 47 generates a timing control signal in response to the sustain pulse number information from the APL calculator 46, and supplies the timing control signal to a scan driving circuit and a sustain driving circuit (not shown). Here, the waveform generator 47 generates a timing control signal so that the sustain pulse is not supplied in the specific subfield under the control of the subfield information calculator 49. The scan driving circuit and the sustain driving circuit supply sustain pulses to the scan electrodes and the sustain electrodes of the panel 48 during the sustain period in response to the timing control signal input from the waveform generator 47.

The subfield information calculating unit 49 extracts data having the highest grayscale value among the data of one frame input from the error diffusion unit 43, and the subfield to which a sustain pulse is supplied corresponding to the grayscale value of the extracted data. And the subfield to which the sustain pulse is not supplied.

To this end, the subfield information calculator 49 includes a maximum value calculator 50 and a lookup table 52 as shown in FIG. 5. The maximum value calculator 50 sequentially receives one frame of data from the error diffusion unit 43 and extracts the maximum value of the gray level from the input data. In detail, the maximum calculator 50 sequentially receives one frame of data from the error diffusion unit 43. Here, the maximum value calculator 50 compares the maximum value of the gray level from the previously input data with the gray level of the currently input data, and sets the maximum value of the gray level for data having a larger gray level value. Then, the maximum value of the gray level is extracted within one frame while comparing the input data with the magnitude of the maximum value of the gray level.

The lookup table 52 extracts the subfield to be turned on (the subfield to which the subfield is supplied) and the subfield to be turned off (the subfield to which the subfield is not supplied) corresponding to the maximum value of the gradation. For example, when one frame includes eight subfields, the lookup table 52 is configured as shown in Table 1 below.

Gradation value Subfield Mapping Section 0 00000000 One 10000000 2 x1000000 3 x1000000 4 xx100000 5 1x100000 6 x1100000 7 xx100000 8 to 15 xxx10000 16 to 31 xxxx1000 32 to 63 xxxxx100 64-127 xxxxxx10 128 to 255 xxxxxxx1

In Table 1, "0" means a subfield to be turned off and "1" means a subfield to be turned on. And, "x" means a subfield to be turned on or off in response to the data. For example, if the maximum value of the gray level extracted by the maximum value calculating unit 50 is "79", the lookup table 52 sets the waveform generator 47 so that the sustain pulse is not supplied in the sustain period of the eighth subfield. To control. If the maximum value of the gray level extracted by the maximum value calculator 50 is "13", the waveform generator 47 is controlled so that the sustain pulse is not supplied in the sustain period of the fifth to eighth subfields.

That is, the lookup table 52 stores the subfields to be turned on and the subfields to be turned off corresponding to the subfield mapping pattern. The lookup table 52 extracts the subfield to be turned off by substituting the maximum value of one frame input to the subfield mapping pattern stored therein and does not supply a sustain pulse in the sustain period of the extracted subfield. To prevent it. In other words, the lookup table 52 controls such that the sustain pulse is not supplied in the subfield in which the sustain pulse is unnecessary in correspondence with the maximum value of the gray scale supplied from the maximum value calculator 50. As described above, the power consumption may be minimized by not supplying a sustain pulse during the sustain period of some subfields (or all subfields in full black) included in one frame corresponding to the subfield mapping pattern.

As described above, according to the driving apparatus and driving method of the plasma display panel according to the present invention, the maximum gray scale value is calculated in one frame, and the subfield in which the sustain pulse is unnecessary is corresponding to the gray scale value. In addition, power consumption can be minimized by not supplying the sustain pulse during the sustain period of the subfield in which the sustain pulse is unnecessary.

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.

1 is a plan view schematically showing a conventional plasma display panel.

2 is a perspective view showing in detail the structure of the cell shown in FIG.

3 is a block diagram showing a driving apparatus of a conventional plasma display panel.

4 is a block diagram showing a driving apparatus of a plasma display panel according to an embodiment of the present invention;

FIG. 5 is a block diagram illustrating in detail a subfield information calculator shown in FIG. 4; FIG.

Fig. 6 is a diagram showing an example of a gray scale value of data supplied to a panel.

<Description of Symbols for Main Parts of Drawings>

1: discharge cell 10: upper substrate

11 bus electrode 12 transparent electrode

13,17 dielectric layer 14 protective film

15 bulkhead 16: phosphor

18: lower substrate 30, 40: input line

31A, 31B, 41A, 41B: reverse gamma correction unit 32,42: gain adjustment unit

33,43: error diffusion unit 34,44: subfield mapping unit

35,45: data alignment unit 36,46: APL calculation unit

37,47: waveform generator 38,48: panel

49: subfield information calculating unit 50: maximum value calculating unit

52: Lookup Table

Claims (7)

A subfield information calculating unit for extracting a highest gray level value from data input to the self and extracting a subfield in which a sustain pulse is unnecessary in correspondence with the extracted highest gray level value; And a waveform generator for controlling a sustain pulse to be supplied during the sustain period of the other sustained field without supplying the sustain pulse during the sustain period of the subfield in which the sustain pulse is unnecessary under the control of the subfield information calculator. A driving device of the plasma display panel. The method of claim 1, The subfield information calculating unit A maximum value calculator for calculating the highest gray value; And a look-up table for extracting a subfield in which a sustain pulse is unnecessary in correspondence with the highest gray level value. The method of claim 2, And a subfield to which a sustain pulse is supplied and a subfield in which the sustain pulse is unnecessary are stored in the look-up table according to the highest gray value. The method of claim 1, And the subfield information calculating unit extracts the highest gray level value in units of frames. The method of claim 1, And an APL unit installed at the front end of the waveform generator to calculate the sustain pulse number information corresponding to the average luminance of the data input to the waveform generator and to supply the waveform to the waveform generator. Drive. A method of driving a plasma display panel in which one frame includes a plurality of subfields; Extracting a highest gray value from the input data; A second step of extracting a subfield in which a sustain pulse is unnecessary among the subfields in response to the extracted highest gray value; And a third step of supplying the sustain pulse during the sustain period of the other sustain field without supplying the sustain pulse during the sustain period of the subfield in which the sustain pulse extracted in the second step is unnecessary. A method of driving a plasma display panel. The method of claim 6, And in the first step, extracting the highest gray level value by one frame.