KR100869797B1 - PlASMA DISPLAY AND CONTROLLING DEVICE, AND METHOD THEREOF - Google Patents

Abstract

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

To this end, the present invention provides a frame according to an input image signal in a plasma display device which is driven in a PAL method in which one frame is divided into two subfield groups of first and second groups having different weights and sequentially driven. If the subfield to be turned on to implement the gradation value is included in only the first group of the two groups, the timing of turning on the subfield is delayed, and if it is included only in the second group, the timing of turning on the subfield is advanced. As a result, a plasma display device driven by a PAL driving method, which prevents mis-discharge and performs a stable operation, is implemented.

PDP, PAL, subfield, and misfiring

Description

Plasma display device, control device thereof and driving method thereof {PlASMA DISPLAY AND CONTROLLING DEVICE, AND METHOD THEREOF}

1 is a diagram illustrating a subfield arrangement constituting one frame in a general PAL scheme.

2 is a view showing a change in luminance in one frame in the general PAL method.

FIG. 3 is a diagram illustrating a relationship between a previous frame and a next frame of turning on only a subfield included in one group in a general PAL scheme.

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

5 is a block diagram illustrating a controller of a plasma display panel according to an exemplary embodiment of the present invention.

6 is a table showing gray scale values when a subfield included in a first group is turned on according to an exemplary embodiment of the present invention.

FIG. 7 is a diagram illustrating subfield on timing adjustment of a subfield position adjusting unit when an image signal having a gray value shown in FIG. 6 is input, according to an exemplary embodiment of the present invention.

8 is a table showing gray scale values when a subfield included in a second group is turned on according to an exemplary embodiment of the present invention.

FIG. 9 is a diagram illustrating subfield on timing adjustment of a subfield position adjusting unit when an image signal having a gray scale value shown in FIG. 8 is input.

10 is a flowchart illustrating subfield on timing adjustment of a controller according to an embodiment of the present invention.

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

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

In general, NTSC (National Television System Committee) operating at 60Hz frequency has one frame time of 16.67ms (= 1 / 60sec), and PAL (Phase Alternate Line) operating at 50Hz frequency has 20ms (frame time). = 1/50 second).

In the case of long time of one frame like the PAL method, the human eye may feel that the screen is changed at 20 ms interval, which is the actual frame time, and this time interval is enough to be recognized by the human eye. Since it is a long time, it is actually recognized by the human eye in the form of blinking. That is, a flicker phenomenon occurs.

In order to prevent such a flicker phenomenon, one frame is divided into first and second groups, and weighted subfields are distributed to two groups.

1 is a diagram illustrating a subfield arrangement constituting one frame in a general PAL scheme.

As shown in FIG. 1, in a plasma display device driven by a conventional PAL method, one frame includes a first group and a second group, and subfields SF1, SF3, SF5, and SF7 are allocated to the first group. Subfields SF2, SF4, SF6, SF8 are allocated to the second group. The first and second groups are driven by being divided into a plurality of subfields having different luminance weights, and each of the subfields SF1 to SF8 includes an address period A1 to A8 and a sustain period S1 to S8. .

The address periods A1 to A8 are periods for selecting cells to be turned on and cells not to be turned on in the panel, and sustain periods S1 to S8 are periods for sustaining discharge of the cells to be turned on for a corresponding period to display an image. In this case, the lengths of the sustain periods S1 to S8 correspond to the weights of the subfields SF1 to SF8, and in FIG. 1, the lengths of the sustain periods S1 to S8 are respectively 1T, 2T, 4T, 8T, 16T, Assume 32T, 64T and 128T. Then, a reset period (not shown) for initializing the state of the discharge cells may be formed before the address periods A1 to A8.

Here, the gray level of the discharge cells is expressed by the sum of weights of the subfields in which the corresponding discharge cells are turned on among the eight subfields SF1 to SF8. Each of the subfields SF1 to SF8 is arranged in the order of the weight or in the reverse order of the size as shown in FIG.

In the PAL method shown in FIG. 1, since a large weighted subfield is distributed into two groups, the human eye actually feels that the screen changes at approximately 10 ms intervals, and this time interval is not well recognized by the human eye. Therefore, the flicker phenomenon can be reduced.

In FIG. 1, the change in luminance due to the arrangement of subfields forming one frame is illustrated in FIG. 2.

2 is a view showing a change in luminance in one frame in the general PAL method.

1 frame time shown in FIG. 2 is 20 ms, and the time allocated to the 1st group and the 2nd group, respectively, is 10 ms. In the first group and the second group, the subfields SF1, SF3, SF5, SF7 and the subfields SF2, SF4, SF6, SF8 are arranged in the order of the weights of the subfields, respectively. The brightness of is high.

FIG. 2A illustrates a case in which all of the subfields included in the first group and the second group are turned on. Meanwhile, the plasma display device may turn on only the subfields included in one of the first and second groups described above according to the gray level of the image to be displayed on the plasma display panel. 2 (c). FIG. 2B illustrates a case where only subfields included in the first group are turned on, and FIG. 2C illustrates a case where only subfields included in the second group are turned on.

FIG. 3 is a diagram illustrating a relationship between a previous frame and a next frame of a frame in which only subfields included in one group are turned on in a general PAL scheme.

3 (a) shows an image by turning on a subfield included in a first group and a second group together with a first frame and a third frame as shown in FIG. As shown in b), only the subfields included in the first group are displayed to represent an image. FIG. 3 (b) shows the image by turning on the subfields included in the first group and the second group for the first frame and the third frame, and the second frame as shown in FIG. 2 (c). The case where the image is represented by turning on only the subfields included in the diagram is illustrated.

In FIG. 3A, in the second frame, sustain discharge occurs only in the subfields corresponding to the first group, and sustain discharge does not occur in the subfields corresponding to the second group. In the sustain discharge in the first group of the third frame, there is a high possibility of occurrence of a false discharge. Similarly, even in the case shown in Fig. 3B, since the sustain discharge does not occur in the subfield corresponding to the first group of the second frame, the sustain discharge in the second group of the first frame, which is the previous frame, does not occur. Due to the difference in time, the possibility of occurrence of a false discharge during sustain discharge in the second group of the second frame is high, which is a problem.

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, a control device thereof, and a driving method thereof capable of preventing the occurrence of a false discharge.

In order to achieve the above technical problem, a driving method of a plasma display device according to an aspect of the present invention includes a first electrode and a second electrode, and a third electrode formed in a direction crossing the first electrode and the second electrode. According to the vertical synchronization signal of the second frequency lower than the first frequency, the first to the second frame is divided into two groups of a first group and a second group including a plurality of subfields having different weights; A driving method of a plasma display device for driving a three-electrode, comprising: (a) determining whether a subfield to be turned on to implement a gray level value for each frame according to an input image signal is included in both groups; (B) generating a subfield on timing control signal for controlling when the subfield is turned on according to the determination result; and (c) the subfill. And turning on the subfield according to the de-on timing control signal and repeating step (a) after the next frame.

In addition, the control device according to an aspect of the present invention, the first electrode and the second electrode and a third electrode formed in a direction crossing the first electrode and the second electrode, the second frequency lower than the first frequency Controls the driving circuit unit to drive the first to third electrodes so that one frame is divided into two groups of a first group and a second group including a plurality of subfields having different weights according to the vertical synchronization signal of the? A control device of a plasma display device applying a signal, the control device generating a subfield on timing control signal for adjusting an on-time of the subfield depending on whether an input subfield value is included in the two groups. A field position adjusting unit and the subfield value to be turned on to implement the gray level value for each frame according to the input video signal are transferred to the subfield position adjusting unit. And it includes in accordance with the subfield turn-on time control signal to control the on-time of the sub-field generating unit subfield data to pass to the driver circuit portion.

In addition, the plasma display device according to an aspect of the present invention, a plasma display panel including a first electrode, a second electrode and a third electrode formed in a direction crossing the first electrode and the second electrode, the input from the outside According to the vertical synchronization signal of the second frequency lower than the first frequency, one frame is divided into two groups, a first group and a second group including a plurality of subfields each including a reset period, an address period, and a sustain period. And a controller for generating a subfield on timing control signal that varies depending on whether one of the first and second groups includes a subfield to be turned on to implement a gray level value for each frame according to an input image signal. Driving the first to third electrodes according to a control to vary an on time point of the subfield according to the subfield on timing control signal; Includes a driving circuit section.

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 for simplicity of explanation, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is "connected" to another part, this includes not only "directly connected" but also "electrically connected" with another element in between. .

In addition, the term wall charge described herein refers to a charge formed close to each electrode on the cell's wall (eg, dielectric layer). Wall charges are not actually in contact with the electrodes themselves, but here they are described as “formed”, “accumulated” or “stacked” on the electrodes, where wall voltage refers to the potential difference formed on the wall of a cell by wall charges. In addition, when a part is said to "include" a certain component, which means that it may further include other components, except to exclude other components unless otherwise stated.

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

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

As shown in FIG. 4, a plasma display device according to an exemplary embodiment of the present invention includes a plasma display panel 100, a controller 200, an address electrode driver 300, a scan electrode driver 400, and a sustain electrode driver 500. ).

The plasma display panel 100 includes a plurality of address electrodes A1 to Am extending in the column direction, and a plurality of sustain electrodes X1 to Xn and scan electrodes Y1 to Yn extending in pairs in the row direction. Include. The sustain electrodes X1 to Xn are formed corresponding to the scan electrodes Y1 to Yn, and generally, one end thereof is commonly connected to each other. The plasma display panel 100 includes a substrate (not shown) on which the sustain electrodes X1 to Xn and the scan electrodes Y1 to Yn are arranged, and a substrate (not shown) on which the address electrodes A1 to Am are arranged. Is done. The two substrates are disposed to face each other with the discharge space therebetween so that the scan electrodes Y1 to Yn and the address electrodes A1 to Am and the sustain electrodes X1 to Xn and the address electrodes A1 to Am are orthogonal to each other. At this time, the discharge space at the intersection of the address electrodes A1 to Am, the sustain electrodes X1 to Xn, and the scan electrodes Y1 to Yn forms a discharge cell. The structure of the plasma display panel 100 is an example, and a panel having another structure to which the driving waveform described below may be applied may also be applied to the present invention.

The controller 200 receives an image signal from the outside and outputs an address electrode driving control signal Sa, a sustain electrode driving control signal Sx, and a scan electrode driving control signal Sy. The controller 200 divides and drives one frame into a plurality of subfields, and each subfield is composed of a reset period, an address period, and a sustain period.

The address electrode driver 300 receives an address electrode driving control signal Sa from the controller 200 and applies a display data signal for selecting a discharge cell to be displayed to each address electrode.

The scan electrode driver 400 receives the scan electrode driving control signal Sy from the controller 200 and applies a driving voltage to the scan electrode Y.

The sustain electrode driver 500 receives the sustain electrode driving control signal Sx from the controller 200 and applies a driving voltage to the sustain electrode X.

5 is a block diagram illustrating a controller of a plasma display panel according to an exemplary embodiment of the present invention.

As shown in FIG. 5, the control unit 200 of the plasma display panel according to an exemplary embodiment of the present invention includes a subfield data generator 220 and a subfield position adjuster 240.

The subfield data generator 220 subframes SF1, SF3, SF5, SF7 included in the first group and subfields SF2, SF4, SF6, SF8 included in the second group according to the gray level value for each frame. The control signal is transmitted to the scan electrode driver 400 and the sustain electrode driver 500 to turn ON.

The subfield data generator 220 transmits the subfield to be turned on to the subfield position adjuster 240, receives a subfield on timing control signal generated by the subfield position adjuster 240, and based on the received subfield on timing control signal, the subfield is generated based on the corresponding subfield. The control signal is transmitted to the scan electrode driver 400 and the sustain electrode driver 500 to turn on the field.

The subfield position adjusting unit 240 determines whether the plurality of subfields input from the subfield data generating unit 220 include the subfields of the first group and the subfields of the second group together or are included only in the first group. It is determined whether or not the fields SF1, SF3, SF5, SF7 or the subfields SF2, SF4, SF6, SF8 included only in the second group. According to the determination result, if the input subfield is a subfield included in the first group, the subfield position adjusting unit 240 generates a subfield on timing control signal that is turned on by a predetermined timing and vice versa. If the field is a subfield included in the second group, a subfield on timing control signal that is turned on first by the set timing is generated and reported to the subfield data generator 220. On the other hand, even when the plurality of input subfields together include the subfield of the first group and the subfield of the second group, the subfield position adjusting unit 240 generates the subfield on timing control signal. The subfield on time remains unchanged.

Hereinafter, the operation of the subfield position adjusting unit shown in FIG. 5 and the on time point of the subfield controlled accordingly will be described with reference to FIGS. 6 to 9.

FIG. 6 is a table showing gray scale values when a subfield included in a first group is turned on according to an exemplary embodiment of the present invention, and FIG. 7 is a table illustrating subfield positions when an image signal having gray scale values shown in FIG. 6 is input. It is a figure which shows the subfield on timing adjustment of an adjustment part.

The gray scale values shown in FIG. 6 represent the gray scale values corresponding to the second frame among the first to third frames illustrated in FIG. 7, and the gray scale values 1, 4, 5, 16, 17, 20, It is assumed that the video signal having 21) is a gray level value that is turned on in the second frame.

As shown in FIG. 7, the subfield data generator 220 informs the subfield position adjuster 240 of the subfields SF1, SF3, SF5 that are turned on, and the subfield position adjuster 240 inputs the input subfield. Since the field is a subfield included only in the first group, the on time of the subfield is delayed by the set timing.

FIG. 8 is a table showing gray scale values when a subfield included in a second group is turned on according to an exemplary embodiment of the present invention, and FIG. 9 is a table illustrating subfield positions when an image signal having gray scale values shown in FIG. 8 is input. It is a figure which shows the subfield on timing adjustment of an adjustment part.

The gray scale values shown in FIG. 8 represent the gray scale values corresponding to the second frame among the first to third frames shown in FIG. 9, and the gray scale values 2, 8, 10, 32, 34, 40, Assume that a video signal having 42) is a gray level value that is turned on in a second frame.

As shown in FIG. 9, the subfield data generator 220 informs the subfield position adjuster 240 of the subfields SF2, SF4, SF6 that are turned on, and the subfield position adjuster 240 inputs the input subfield. Since the field is a subfield included only in the second group, the on time of the subfield is advanced by the set timing.

10 is a flowchart illustrating subfield on timing adjustment of a controller according to an embodiment of the present invention.

First, the subfield data generator 220 receiving the video signal initializes the frame number N (S602). At this time, initializing the frame number N to "1" is an example, and may be replaced with one that may represent a numerical value in combination with another natural number, a decimal number, or a specific character such as an alphabet. Meanwhile, the initialization of step S602 may be performed to adjust the subfield on timing from the first frame generated by the control unit 200 using the input image signal while the plasma display device is turned on in the standby state. In addition, when the number of frames set as the input of the continuous video signal exceeds a predetermined value, the subfield data generator 220 may be set to perform initialization.

In operation S602, the initialized subfield data generation unit 220 transmits a subfield value to be turned on according to the grayscale value to be displayed as a frame according to the input image signal to the subfield position adjusting unit 240, and the sub The field position adjusting unit 240 determines whether the input subfield value includes the subfield of the first group and the subfield of the second group (S604).

As a result of the determination in step S604, when the gray level value of the corresponding frame is expressed by only the subfield included in only one of the first and second groups, the subfield position adjusting unit 240 includes the input subfield value in the first group. It is determined whether or not the corresponding subfield is present (S606).

As a result of the determination in step S606, if the input subfield value is a subfield included in the first group, the subfield position adjusting unit 240 generates a subfield on timing control signal to delay the onfield of the subfield by a predetermined time. The subfield data generation unit 220 reports the result (S608). On the other hand, if the input subfield value is not a subfield included in the first group, the subfield position adjusting unit 240 regards this as a subfield included in the second group and advances the on-field timing of the subfield by a set time. Generates a subfield on timing control signal and reports it to the subfield data generator 220 (S610).

Meanwhile, in step S606, it may be set to determine whether the subfield value is a subfield included in the second group, and in this case, it should be set to replace steps S608 and S610.

As a result of the determination in step S604, when the subfield included in the first group of the frame and the subfield included in the second group are to be turned on together, the subfield position adjusting unit 240 selects the corresponding subfield without changing the on time. A subfield on timing control signal for turning on is generated and reported to the subfield data generation unit 220. Meanwhile, the subfield data generator 220 receiving the subfield on timing control signal through steps S604, S608, or S610 may turn on the scan electrode driver 400 and the sustain electrode driver so that the corresponding subfield is turned on when the subfield is changed. The control signal is transmitted to 500 (S612).

 In operation S612, the subfield data generator 220 determining the on-time of the corresponding frame and transmitting the control signal increases the number of frames (S614) and performs the next frame after operation S604.

Although the 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, within a frame divided into two groups of the first and second groups having different weights, only the subfields included in one group are prevented from being discharged due to turning on stably. The plasma display device may be implemented.

Claims (12)

A driving method of a plasma display device which sequentially drives one frame into a first subfield group and a second subfield group each having a plurality of subfields, (a) Whether one of the first subfield group and the second subfield group is included in one or more subfields to be turned on in order to implement a gray level value for each frame according to an input video signal; Determining; (b) generating a subfield on timing control signal for controlling a time point at which the subfield to be turned on is turned on according to the determination result; And (c) turning on the subfield at an on time point corresponding to the subfield on timing control signal; Method of driving a plasma display device comprising a. The method of claim 1, In step (b), As a result of the determination of step (a), If all the subfields to be turned on are subfields included only in the first subfield group, generating the subfield on timing control signal for delaying an on time point of the subfield to be turned on for a set time; . The method of claim 1, In step (b), As a result of the determination of step (a), If all the subfields to be turned on are subfields included only in the second subfield group, the subfield on timing control signal for generating the subfield on timing control signal which advances an on time point of the subfield to be turned on by a predetermined time is generated. . The method of claim 1, In step (b), As a result of the determination of step (a), When the first subfield group and the second subfield group each include the subfield to be turned on, the plasma display device generates the subfield on timing control signal that does not change the on-time of the subfield to be turned on. Driving method. A control apparatus of a plasma display device which sequentially drives one frame into a first subfield group and a second subfield group each having a plurality of subfields according to a vertical synchronization signal having a first frequency. A subfield position adjusting unit configured to generate a subfield on timing control signal for adjusting an on-time of the subfield according to whether one or more input subfield values are included in the two subfield groups; And The subfield value to be turned on to realize the gray level value for each frame according to the input image signal is transmitted to the subfield position adjusting unit, and the on time of the subfield is adjusted according to the subfield on timing control signal. Subfield data generator to transfer to the field position adjuster Control device comprising a. The method of claim 5, The subfield on timing control signal is If all the subfields to be turned on are included only in the first subfield group, the on time delay is delayed, and when all the subfields to be turned on are included only in the second subfield group, a timing adjustment signal for advancing the on time point. Control device. The method of claim 5, The subfield on timing control signal is And if the first subfield group and the second subfield group each include the subfield to be turned on, the on point of time is not changed. The method of claim 5, And the first frequency is a vertical synchronization frequency of a phase alternate line (PAL). A plasma display panel including a first electrode, a second electrode, and a third electrode formed in a direction crossing the first electrode and the second electrode; According to the vertical synchronization signal of the first frequency input from the outside, one frame is sequentially divided into a first subfield group and a second subfield group each including a plurality of subfields, and each frame is sequentially driven according to the input image signal. A control unit for generating a subfield on timing control signal that varies depending on whether the subfield to be turned on to implement the gray value is included in the first subfield group and the second subfield group; And A driving circuit unit driving the first to third electrodes under the control of the controller to vary the on-time of the subfield according to the subfield on timing control signal Plasma display device comprising a. The method of claim 9, The subfield on timing control signal is If all the subfields to be turned on are included only in the first subfield group, the on time delay is delayed, and when all the subfields to be turned on are included only in the second subfield group, a timing adjustment signal for advancing the on time point. Plasma display device. The method of claim 9, The subfield on timing control signal is And if the first subfield group and the second subfield group each include the subfield to be turned on, the on-view point is not changed. The method of claim 9, And the first frequency is a vertical synchronization frequency of a phase alternate line (PAL).

Images