KR20060127592A - Plasma display panel and driving method thereof - Google Patents

Abstract

A plasma display device and a driving method thereof are provided to improve the stability of an address discharge by omitting an address operation for a line with zero subfield data and using the residual time for the width extension of scan pulse and address voltage pulse. A method for driving images of each frame displayed on a plasma display device correspondingly to an input image signal, into plural subfields(SF1~SF8) and displaying the gray scale by combining luminance weighted values of plural subfields includes steps of: generating subfield data correspondingly to the input image signal; detecting a first line of which all subfield data are off, in the predetermined subfield on the basis of the subfield data; and executing an address operation for the rest lines except the detected first line.

Description

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

1 is a diagram illustrating a gray scale display method of a plasma display device.

2 illustrates an electrode arrangement diagram of a plasma display device according to an exemplary embodiment of the present invention.

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

4 is a block diagram schematically illustrating a configuration of a controller 400 according to an exemplary embodiment of the present invention.

5 is a diagram illustrating an example of an image input source according to an exemplary embodiment of the present invention.

The present invention relates to a plasma display device and a driving method thereof.

 Recently, the plasma display device has been in the spotlight as a flat panel display device because of the advantages of higher luminance and luminous efficiency and wider viewing angle than other display devices.

Plasma display devices are flat display devices that display characters or images using plasma generated by gas discharge, and dozens to millions of pixels are arranged in a matrix form according to their size.

On the other hand, ADS (Address Display Seperating) driving is widely used as a driving method of the plasma display device as described above.

 The ADS driving method basically consists of a reset period, an address period, and a sustain period.

In detail, one frame is divided into a plurality of sub-fields, and each of the subfields is divided into the reset period, the address period, and the sustain period. In general, 8 to 12 subfields form one frame and implement one image using the subfield having the above-described configuration as a basic unit.

As shown in FIG. 1, the plasma display device divides one frame (1TV field) into a plurality of subfields and performs time division control to implement gray scale. Each subfield consists of the reset period, address period, and sustain period described above. 1 illustrates a case where one frame is divided into eight subfields to implement 256 gray levels. Each subfield SF1-SF8 consists of a reset period (not shown), an address period A1-A8, and a sustain period S1-S8, and the sustain periods S1-S8 are light emission periods 1T, 2T. , 4T, ..., 128T) becomes 1: 2: 4: 8: 16: 32: 64: 128.

At this time, for example, in order to implement a gray scale of 3, the discharge cells are discharged in the subfield SF1 having the 1T emission period and the subfield SF2 having the 2T emission period so that the sum of the discharge periods is 3T. . In this manner, 256 grayscale images are displayed by combining subfields having different light emission periods.

However, in the method of displaying grayscales according to whether each subfield is turned on or off as described above, the luminance of light emitted actually is limited to a time period except a reset period and an address period according to the number of driving subfields, thereby lowering the luminance. This happens. In addition, when the sustain period is increased to increase the luminance and the address period is shortened, that is, when the scan pulse width is reduced, an address discharge failure occurs and a problem occurs.

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 for improving brightness and improving discharge stability.

The present invention determines whether data exists for each line using subfield data, and controls address operation for each line according to the determination result.

According to an aspect of the present invention, a method of driving a plasma display device divides an image of each frame displayed on a plasma display device into a plurality of subfields in correspondence to an input image signal, and combines the luminance weights of the plurality of subfields. A driving method of a plasma display device for displaying gray scales, the method comprising: generating subfield data in response to the input video signal and turning off all subfield data in a predetermined subfield based on the subfield data. Detecting one line and performing an address operation on the remaining lines except for the first line when the first line is detected in the detecting step.

According to another aspect of the present invention, a plasma display device includes a plurality of first electrodes and a plurality of second electrodes, and a plurality of third electrodes formed to intersect the plurality of first and second electrodes. A frame is divided into a plurality of subfields, and each subfield is controlled to be divided into a reset period, an address period, and a sustain period, to generate subfield data corresponding to an input video signal, and to use the subfield data. A control unit for determining whether all subfield data of the entire line is off for each of the second electrode lines and outputting a control signal according to a determination result, and the first electrode, the second electrode, and the first electrode according to the control signal from the control unit. A driving unit for applying a driving signal to each of the three electrodes, wherein the control unit is configured to When the subfield data is all off, the address operation is performed only on the remaining lines except for the first line.

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.

2 shows an electrode array diagram of the plasma display device.

As shown in FIG. 2, the electrodes of the plasma display device are arranged in a matrix of m × n. Specifically, the address electrodes A1 to Am are arranged in the column direction and the n rows of scan electrodes in the row direction ( Y1-Yn and sustain electrodes X1-Xn are alternately arranged.

In general, the driving method of the AC plasma display device includes a reset period, an address period, and a sustain period.

The reset period is a period for initializing the state of each cell in order to perform an addressing operation smoothly on the cell, and the address period is sequentially scanned to the scan electrodes Y1-Yn to select cells that are turned on and cells that are not turned on. This is a period in which wall charges are accumulated by applying an address voltage pulse to a cell that is turned on when a pulse is applied. The sustain period is a period in which a discharge for actually displaying an image on a cell addressed in the address period by applying a sustain discharge pulse is performed.

Hereinafter, a plasma display device and a driving method thereof according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3 is a diagram illustrating a schematic configuration 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 includes a plasma panel 100, an address driver 200, a sustain driver 300, a sustain driver 500, and a controller 400.

The plasma panel 100 includes a plurality of address electrodes A1-Am arranged in the column direction and a plurality of scan electrodes Y1-Yn and sustain electrodes X1-Xn arranged alternately in the row direction. .

The address driver 200 receives an address drive control signal from the controller 400 and applies a display data signal (ie, an address voltage pulse) for selecting a discharge cell to be displayed to each address electrode A1-Am.

The scan driver 300 receives a scan electrode driving control signal from the controller 400 and applies a driving voltage to the scan electrode. The sustain driver 500 receives a sustain electrode driving control signal from the controller 400 and applies a driving voltage to the sustain electrode. At this time, the scan driver 300 and the sustain driver 500 which receive the control signal from the controller 400 respectively apply sustain discharge pulses to the scan electrodes Y1-Yn and sustain electrodes X1-Xn in the sustain period. Sustain discharge is applied to the selected discharge cells.

The controller 400 receives R, G, and B image signals and a synchronization signal from the outside, divides one frame into several subfields, and divides each subfield into a reset period, an address period, and a sustain period to drive the plasma display device. To control. The controller 400 supplies a control signal to the scan driver 300 and the sustain driver 500 to control the number of sustain discharge pulses in each sustain period of the subfield in one frame. Meanwhile, the control unit 400 according to an embodiment of the present invention refers to the subfield data generated for each subfield and determines whether there is no subfield data in the entire line for each scan electrode line. When there is a line in which no subfield data exists in the entire line, the address driver 200 and the scan driver may output a control signal that does not perform an address operation (that is, an operation of applying a scan pulse and an address voltage pulse) of the corresponding line. Send to 300.

Hereinafter, the control unit 400 will be described in detail with reference to FIG. 4.

4 is a block diagram schematically illustrating a configuration of a controller 400 of a plasma display device according to an exemplary embodiment of the present invention.

As shown in FIG. 4, the control unit 400 of the plasma display device according to an exemplary embodiment of the present invention may include an inverse gamma correction unit 410, an error diffusion unit 420, a subfield data generation unit 430, and a line data detection unit ( 440, a memory controller 450, an APC unit 460, a sustain pulse number generator 470, and a scan / sustain driving controller 480.

The inverse gamma correction unit 410 maps n-bit R, G, and B image input data, which is currently input image data, to an inverse gamma curve and corrects the m-bit (m≥n) image signal. In a typical plasma display panel, n is 8 and m is 10 or 12.

The error diffusion unit 420 is inversely gamma corrected by the inverse gamma correction unit 410 and error-diffuses the lower m-n bit image of the extended bit m image to surrounding pixels. Error diffusion is a method of displaying an image of a lower bit by separating an image of a lower bit to be diffused into adjacent pixels and a detailed description thereof is described in Korean Patent Laid-Open Publication No. 2002-0014766.

The subfield data generator 430 generates subfield data corresponding to the error spread data transmitted from the error spreader 420. That is, the subfield data generator 430 generates subfield data, which is information on whether each subfield corresponding to data input based on the luminance weight of each subfield, is turned on or off, and then the line data detector 440. To be sent). For example, the luminance weight of the subfield is 1 (SF1): 2 (SF2): 4 (SF3): 8 (SF4): 16 (SF5): 32 (SF6): 64 (SF7): 12 (SF8). In this case, the subfield data for gradation 3 is 11000000.

The line data detector 440 detects a line in which all of the subfield data in each subfield is off (that is, zero) by using the subfield data transferred from the subfield data generator 430. 5 is a diagram illustrating subfield data of all discharge cells in an arbitrary subfield. The line data detector 440 detects lines 1 and 4 in which all the subfield data are '0' when the subfield data is the same as in FIG. 5 in any subfield. In addition, the line data detector 400 transmits the information about the lines of which all of the subfield data is '0' to the memory controller 450 and the scan / sustain driving controller 480.

The memory controller 450 performs an addressing operation on the corresponding line (line 1 and line 4 in FIG. 5) by using information about a line in which all of the subfield data transferred from the line data detector 440 is '0'. The control signal not to be transmitted is transmitted to the address driver 200. That is, the memory controller 450 controls the application of the address data of the corresponding line to be omitted. Accordingly, the address driver 200 omits application of the address data of the corresponding line and applies the address data of the next line where the subfield data exists. do.

Automatic power control (APC) unit 460 detects the load rate using the image data output from the error diffusion unit 420, calculates the APC level according to the detected load rate, and generates the number of sustain pulses. The unit 470 calculates and outputs the number of sustain discharge pulses corresponding to the APC level calculated by the APC unit 460.

The scan / sustain driving control unit 480 uses the sustain discharge pulse number information output from the sustain pulse number generation unit 470 to provide a control signal for applying a sustain discharge pulse to the sustain period of each subfield. And to the holding driver 500, respectively.

On the other hand, the scan / maintenance drive control unit 480 uses the information on the line where all of the subfield data transferred from the line data detection unit 440 is '0' to the corresponding line (line 1 and line 4 in FIG. 5). In order to prevent the address operation from being performed, a scan pulse is not applied to the scan electrodes of the corresponding line. That is, the scan / maintenance drive control unit 480 omits the application of scan pulses to the scan electrodes of the lines where all of the subfield data is '0', and scan pulses to the scan electrodes of the line having the subfield data of at least one '1'. To be applied.

As described above, according to the exemplary embodiment of the present invention, the address period can be shortened by the time omitted by omitting the application of the scan pulse and the address data (i.e., the address voltage pulse) for the line in which all the subfield data is '0' in any subfield. have. Hereinafter, a method of using this shortened period of time to stabilize the discharge or improve the brightness will be described.

First, a method for securing discharge stability will be described. When the scan / sustain driving control unit 480 receives the information on the line of which all of the subfield data is '0' from the line data detection unit 440, as described above, the scan / sustain driving control unit 480 does not perform the address operation on the corresponding line. The rest of the lines except for the control to increase the scan pulse width applied to the scan electrode. In this way, when the scan pulse width is increased, address discharge can ensure stability. In this case, the memory controller 450 controls the address voltage pulse width to be increased in the application of the address voltage pulse to the remaining lines except for the corresponding line in response to the wider scan pulse width, thereby securing the stability of the address discharge.

Next, a method of improving the luminance will be described. The scan / maintenance drive control unit 480 increases the number of sustain discharge pulses by using the spare time generated by not performing the address operation of the corresponding line. That is, when the scan / sustain driving control unit 480 receives the information about the line of which all of the subfield data is '0' from the line data detection unit 440, the scan / maintenance driving control unit 480 reduces the amount of time that is generated by omitting the address operation of the corresponding line. Control to increase the number of sustain discharge pulses. For example, in FIG. 5, the scan driver 300 and the sustain driver may further include a control signal to further apply the number of sustain pulses in the sustain period by using the spare time generated by not performing the address operation on the lines 1 and 4. 500) respectively.

Therefore, the spare time generated by not performing the address operation as described above may be used to increase the other scan pulse width and the address voltage pulse width, thereby improving margin during address discharge and improving discharge stability.

In addition, the luminance of the plasma display device can be improved by using the spare time generated by not performing the address operation as described above to add the number of sustain pulses.

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 present invention, the address operation is omitted for a line where all of the subfield data is '0', thereby improving address discharge stability by using the spare time to increase the scan pulse and the address voltage pulse width. have. In addition, the luminance can be improved by using the spare time to increase the number of sustain discharge pulses.

Claims (8)

A driving method of a plasma display device in which an image of each frame displayed on a plasma display device in response to an input video signal is divided into a plurality of subfields, and a gray level is displayed by combining luminance weights of the plurality of subfields. Generating subfield data corresponding to the input video signal; Detecting a first line in which a subfield is all off in a predetermined subfield based on the subfield data; And And when the first line is detected in the detecting step, performing an address operation on the remaining lines except for the first line. The method of claim 1, And a scan pulse width applied for an address operation when the first line is detected is wider than a width of a scan pulse applied for an address operation when the first line is not detected. The method of claim 1, And a period allocated for the address operation of the first line to increase the number of sustain discharge pulses when the first line is detected. The method of claim 2, A width of an address voltage pulse applied for an address operation when the first line is detected. A method of driving a plasma display device having a width greater than a width of an address voltage pulse applied for an address operation when the first line is not detected. A plasma display panel including a plurality of first electrodes and a plurality of second electrodes, and a plurality of third electrodes formed to intersect the plurality of first electrodes and the second electrodes; A frame is divided into a plurality of subfields, each subfield is controlled to be divided into a reset period, an address period, and a sustain period, the subfield data corresponding to the input video signal is generated, and the subfield data is used. A control unit which determines whether all subfield data of the entire line is off for each of the second electrode lines and outputs a control signal according to a determination result; And A driving unit configured to apply driving signals to the first electrode, the second electrode, and the third electrode according to the control signal from the controller, And the control unit performs an address operation on only the remaining lines except for the first line when the subfield data of the entire first predetermined line of the second electrode is all off. The method of claim 5, The control unit A subfield data generator for generating subfield data corresponding to an input video signal; A line data detector for detecting a line in which all of the subfield data in each subfield is off by using the subfield data transferred from the subfield data generator; A memory controller configured to output a control signal to prevent an addressing operation on a corresponding line using information on a line in which all of the subfield data transferred from the line data detection unit are off; A sustain pulse number generator for calculating and outputting a sustain discharge pulse number according to a load ratio of the input image signal; And A scan / maintenance drive control unit which transmits a control signal for applying a sustain discharge pulse to a sustain period of each subfield by using the sustain discharge pulse number information output from the sustain pulse number generator; Plasma display device comprising a. The method of claim 6, And when the first line in which the subfield data is all off is detected by the memory controller, an address operation is performed on the remaining lines except for the first line. The method of claim 7, wherein And a scan pulse width applied for an address operation when the first line is detected is wider than a width of a scan pulse applied for an address operation when the first line is not detected.

Images