KR100542524B1 - Plasma display device and driving method thereof - Google Patents

Abstract

The present invention provides a plasma display device and a driving method thereof, which receives image data input from the outside, generates subfield data, and calculates a load ratio for each subfield. At least one subfield weight having a load ratio equal to or greater than a reference value is distributed and determined in a dummy subfield, and the subfield data is regenerated according to the determined subfield weight and output as an address electrode driving signal. In this way, the linearity of the luminance can be maintained by distributing the weight of the subfield where the load ratio is concentrated to obtain the desired luminance.

PDP, discharge, lamp, pulse, picture quality, subfield

Description

Plasma display device and driving method thereof {PLASMA DISPLAY DEVICE AND DRIVING METHOD THEREOF}

1 is a view showing an example in which a conventional quantization noise occurs.

2 is a diagram illustrating a conventional display screen for each subfield.

3 is a configuration diagram of a plasma display device according to an exemplary embodiment of the present invention.

4 is a configuration diagram of the controller of FIG. 3.

5 is a view showing a subfield weight structure of the prior art and the embodiment of the present invention.

6 is a diagram illustrating a display screen for each subfield of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display device, and more particularly, to a subfield realization method of a plasma display device.

In order to express gray scales, the plasma display device divides one frame into a plurality of subfields and expresses gray scales by varying the specific gravity of the sustain discharge period for each subfield.

In the plasma display device, when a large number of cells are turned on at the same time, that is, when the screen display area becomes large, the amount of current flowing decreases little by little. In fact, the luminance when the screen display area is the lowest is when the screen display area is the highest. About 20% higher.

For example, when a screen having 64 gray levels and 65 gray levels as shown in FIG. 1 is to be displayed, converting image data into subfield data converts them as shown in FIG.

Referring to FIG. 2, the 64th gradation converted subfield data becomes 00000010 and the 65th gradation converted subfield data becomes 10000010. At this time, since the display area has a large display area and a large load factor, the unit sustained light emission luminance (luminance per sustain pulse) of the subfield is small. In addition, since the area representing one gray scale has a small display area and a small load factor, the unit sustained light emission luminance is larger than the area representing 64 gray scales. That is, the unit sustained light emission luminance is relatively large because the load ratio of the first subfield is small, and the unit sustained light emission luminance is relatively small because the load ratio of the eighth subfield is large.

For this reason, theoretically, the luminance difference between 64 and 65 gradations should be one gradation difference, but in practice, the difference between the load ratios and the four to five gradations or more, which differs from the one or more gradations, is different, and linearity of gradation is not maintained. I can't.

SUMMARY OF THE INVENTION The present invention has been made in an effort to solve the above-described problems of the related art, and to provide a plasma display device and a driving method thereof in which the linearity of gray levels is maintained even when the load ratio is changed in the plasma display device.

A plasma display device according to another aspect of the present invention for solving the technical problem,

A plasma panel including a plurality of address electrodes, a plurality of scan electrodes, and a sustain electrode;

Receives a video signal input from outside to generate subfield data, calculates a load ratio for each subfield, determines a rank, distributes at least one subfield weight to a dummy subfield, and outputs it as an address driving signal. A control unit;

And an address electrode driver for applying a corresponding voltage to the address electrode of the plasma display panel according to the address driving signal output from the controller.

The driving method of the plasma display device according to another aspect of the present invention for solving this problem,

Receiving image data input from the outside and generating the subfield data;

Calculating a load ratio for each subfield;

Determining by distributing at least one subfield weight whose load ratio is equal to or greater than a reference value to dummy subfields;

Regenerating subfield data according to the determined subfield weight and outputting the subfield data as an address driving signal.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention. Like parts are designated by like reference numerals throughout the specification.

3 is a configuration diagram of a plasma display device according to an exemplary embodiment of the present invention.

Referring to FIG. 3, a plasma display device according to an exemplary embodiment of the present invention may include a plasma display panel 100, a controller 200, an address electrode driver 300, and a scan electrode driver (hereinafter referred to as a “Y electrode driver”). 400 and a sustain electrode driver (hereinafter referred to as an 'X electrode driver') 500.

The plasma display panel 100 includes a plurality of address electrodes A1-Am arranged in a column direction, a plurality of sustain electrodes (hereinafter referred to as 'X electrodes') (X1-Xn) and scans arranged in a row direction. Electrodes (hereinafter referred to as 'Y electrodes') Y1-Yn. The X electrodes X1-Xn are formed corresponding to the respective Y electrodes Y1-Yn, and generally have one end connected in common to each other. The plasma display panel 100 includes a glass substrate (not shown) in which the X and Y electrodes X1-Xn and Y1-Yn are arranged, and a glass substrate (not shown) in which the address electrodes A1-Am are arranged. Is done. The two glass substrates are disposed to face each other with the discharge space therebetween so that the Y electrodes Y1-Yn and the address electrodes A1-Am and the X electrodes X1-Xn and the address electrodes A1-Am are orthogonal to each other. At this time, the discharge space at the intersection of the address electrodes A1-Am and the X and Y electrodes X1-Xn and Y1-Yn forms a discharge cell. The controller 200 receives an image signal from the outside and outputs an address electrode driving signal, an X electrode driving signal, and a Y electrode driving signal. The controller 200 divides and drives one frame into a plurality of subfields, and each subfield includes a reset period, an addressing period, and a sustain period. In particular, the controller 200 receives an externally input image signal, generates the subfield data, calculates a load ratio for each subfield, determines a ranking, and distributes at least one subfield weight to a dummy subfield to determine the ranking. And output as an address drive signal.

The address electrode driver 300 receives an address electrode driving signal from the controller 200 and applies a display data signal for selecting a discharge cell to be displayed to each address electrode A1-Am. The X electrode driver 500 receives an X electrode driving signal from the controller 200 and applies a driving voltage to the X electrodes X1 to Xn. The Y electrode driver 400 receives the Y electrode driving signal from the controller 200 and applies a driving voltage to the Y electrodes Y1-Yn.

4 is a detailed view of the controller of FIG. 3.

Referring to FIG. 4, the control unit 200 includes a gamma correction unit, a subfield data generation unit, a subfield arranging unit, a load factor detector for each subfield, a major subfield determination unit, a subfield weight determination unit, and a subfield data regeneration unit. Include.

The gamma correction unit 210 gamma corrects an image signal and outputs the gamma correction. The subfield data generation unit 220 generates and outputs subfield data from the image signal output from the gamma correction unit 210. The load rate detector 240 for each subfield calculates and outputs a load rate of each subfield from the subfield data. The major subfield determination unit 250 determines the subfields to overlap with the dummy subfields by ranking them in large order as the load ratio of the subfields becomes more than the reference value. On the other hand, if there is no major subfield, the major subfield determination unit 250 outputs the subfield data to the subfield arranging unit 230 as it is. Then, the subfield weight determination unit 260 determines the weight of the subfield again including the dummy subfield weight, and the subfield data regeneration unit 270 generates the subfield data again according to the new subfield weight. Output Thereafter, the subfield arranging unit 230 rearranges the subfield data in a matrix form and outputs the subfield data to the address electrode driver 300.

The operation of the plasma display device according to the embodiment of the present invention having such a configuration will now be described in detail.

First, the gamma correction unit 210 of the controller 200 receives an image signal input from the outside and corrects and outputs a gamma value according to the characteristics of the plasma display panel. Then, the subfield data generator 220 generates and outputs subfield data from the image signal output from the gamma correction unit 210.

Then, the load ratio detector 240 for each subfield calculates and outputs the load ratio of each subfield from the subfield data, and the major subfield determination unit 250 ranks the orders in large order while the load ratio of the subfields is greater than or equal to the reference value. Determine the subfield to overlap the dummy subfield. On the other hand, if there is no major subfield, the major subfield determination unit 250 outputs the subfield data to the subfield arranging unit 230 as it is.

Then, the subfield weight determination unit 260 determines the weight of the subfield again including the dummy subfield weight, and the subfield data regeneration unit 270 generates the subfield data again according to the new subfield weight. Output

According to an exemplary embodiment of the present invention, in order to minimize grayscale nonlinearity generated in a specific grayscale, at least one subfield having the same weight is made (Subfield Redundancy) so that the load ratio concentrated in one subfield is changed to another subfield. Dispersion to minimize gradation nonlinearity. At this time, the reference value for determining the concentration degree of the load ratio is determined by an experiment. The load ratio reference value of the subfield to be distributed is set according to the experiment result, and the load ratio is distributed to subfields having a load ratio equal to or greater than the reference value.

In fact, when the screen shown in FIG. 1 is applied to the subfield weight structure of the embodiment of the present invention, it may be applied as shown in FIG. Referring to FIG. 5, there are three types of 000000100, 000000010, and 000000001 of 64 gray level subfield converted data. In FIG. 5, the weights of the subfields concentrated according to the subfield weights are distributed to the dummy subfields, but two gray levels can be implemented. In FIG. 5, the overlapping weight is 64, but this may vary according to the load factor of the screen.

FIG. 6 illustrates an example in which the load ratio is distributed to the added subfield by adding a subfield having the same weight as the subfield in which the load ratio is concentrated using the dummy subfield of FIG. 5 having the above structure. As described above, the display method as shown in FIG. 6 can solve the problem of gray scale formation that occurs when the screen ratio shown in FIG. 1 is applied in the manner shown in FIG.

Subsequently, the subfield array unit 230 rearranges the subfield data in a matrix form and outputs the subfield data to the address electrode driver 300, and the address electrode driver 300 responds to the address electrode driving signal received from the controller 200. The voltage is then applied to the address electrode.

Meanwhile, the controller 200 calculates the load ratio of the gamma corrected image signal to generate and output the X electrode driving signal and the Y electrode driving signal with the sustain number corresponding to the current load ratio, and the X electrode driving unit 500 controls the controller ( The X electrode driving signal is received from the 200 and a driving voltage is applied to the X electrodes X1 to Xn. The Y electrode driver 400 receives the Y electrode driving signal from the controller 200 and applies a driving voltage to the Y electrodes Y1-Yn.

As a result, image data is displayed on the plasma display panel 100.

In the above process, the dummy subfields are described as one, but may be two or three or more as necessary.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

As described above, according to the exemplary embodiment of the present invention, the linearity of luminance may be maintained by dispersing the weight of the subfield in which the load factor is concentrated in the plasma display panel to obtain a desired luminance.

Claims (8)

A plasma panel including a plurality of address electrodes, a plurality of scan electrodes, and a sustain electrode; Receives a video signal input from outside to generate subfield data, calculates a load ratio for each subfield, determines a rank, distributes at least one subfield weight to a dummy subfield, and outputs it as an address driving signal. A control unit; And an address electrode driver for applying a corresponding voltage to the address electrode of the plasma display panel according to an address driving signal output from the controller. The method of claim 1, And the dummy subfield is at least one subfield or more. delete The method of claim 2, And an address electrode driving signal is generated from the subfield data when the load ratio of the subfield is equal to or less than a reference value. The method of claim 1, The control unit, A subfield data generator for generating and outputting subfield data of the video signal; A load rate detector for each subfield that calculates and outputs a load rate of each subfield from the subfield data; A major subfield determination unit for determining a major subfield to be overlapped with the dummy subfield by ranking in a large order as the load ratio is greater than or equal to a reference value, and outputting the subfield data as it is if there is no major subfield; A subfield weight determination unit that determines the weight of the subfield again including the dummy subfield weight; A subfield data regenerator for regenerating and outputting subfield data according to the subfield weight determined by the subfield weight determiner; And a subfield array unit for rearranging the subfield data output from the major subfield determiner or the subfield data regenerator in a matrix form and outputting the subfield data to the address electrode driver. A first step of receiving externally input image data and generating the subfield data; Calculating a load ratio for each of the subfields; A third step of distributing and determining at least one subfield weight having a load ratio equal to or greater than a reference value by being distributed in a dummy subfield; And reproducing subfield data according to the determined subfield weight and outputting the subfield data as an address electrode driving signal. The method of claim 6, And the third step generates an address electrode driving signal from the subfield data generated in the first step if the load ratio of all subfields is equal to or less than a reference value. The method according to claim 6 or 7, In the third step, the subfield weight is determined to reduce the load ratio of at least one subfield that is equal to or greater than a reference value.

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