KR100786128B1 - Plasma display apparatus for removing image sticking, and image sticking removing methods using the same - Google Patents

Abstract

Disclosed are a method of removing a residual image during screen display of a plasma display device and a plasma display device for implementing the same. According to an aspect of the present invention, there is provided a method of removing a residual image in a plasma display apparatus, the method comprising: detecting an external input signal for initiating an afterimage removing mode, loading a pre-stored afterimage removing algorithm, and executing the afterimage removing algorithm upon detection; And the afterimage elimination algorithm is programmed to convert the driving waveform applied to the plasma display apparatus unit from the normal mode to the afterimage elimination mode for a predetermined period of time. Provide a removal method. According to the present invention, an afterimage removal method capable of directly removing an afterimage by a user's operation when an actual afterimage occurs and a plasma display apparatus having such an afterimage removal function can be provided.

Plasma display panel, PDP, afterimage, image sticking, burning image, drive waveform, afterimage removal mode, normal mode, mode switching

Description

Plasma display device having afterimage elimination method and afterimage elimination function {PLASMA DISPLAY APPARATUS FOR REMOVING IMAGE STICKING, AND IMAGE STICKING REMOVING METHODS USING THE SAME}

1 is an exploded perspective view showing the structure of a conventional three-electrode AC surface discharge type plasma display panel.

2 is a schematic diagram for explaining a process of generating an afterimage caused by phosphor deterioration.

3 is a block diagram showing a preferred configuration of a drive circuit for driving the plasma display device of the present invention.

4A to 4C are diagrams showing a drive waveform using an erase pulse as an example of a drive waveform for afterimage removal.

5A is a waveform diagram schematically showing a reset waveform applied to a reset section in a conventional driving waveform, and FIGS. 5B and 5C are waveform diagrams showing reset waveforms according to an exemplary embodiment of the present invention.

6 is a waveform diagram illustrating waveforms of a reset period according to another embodiment of the present invention.

7 is a flowchart illustrating an afterimage removal procedure performed in the plasma display apparatus of the present invention.

FIG. 8 conceptually illustrates how a user calls an OSD menu to execute the afterimage removal mode of the present invention with a remote controller.

9 is a procedure diagram conceptually illustrating an afterimage removal procedure when a user selects and operates a specific afterimage removal mode in a plurality of driving waveforms.

<Brief description of the symbols in the drawings>

10: plasma display panel

20: scan electrode driver 30: sustain electrode driver

40: data electrode driving unit 50: afterimage mode control unit

55 memory 60 control unit

100: plasma display device

110: plasma display device input means

120: OSD menu 200: remote control

The present invention relates to a plasma display device, and more particularly, to a method for removing the residual image during screen display of the plasma display device and a plasma display device for implementing the same.

The plasma display device or plasma display panel is a display device using a phenomenon in which visible light is generated when ultraviolet light generated by gas discharge excites a phosphor. Plasma display devices have the advantages of being thinner and lighter than the cathode ray tube (CRT) and enabling high-definition and large screens. In general, a plasma display panel includes a plurality of discharge cells arranged in a matrix form, and one discharge cell corresponds to one subpixel of a screen.

1 is an exploded perspective view showing the structure of a conventional three-electrode AC surface discharge type plasma display panel. Referring to FIG. 1, each discharge cell includes a scan electrode 2Y formed on the upper substrate 1, a sustain electrode 2Z, and an address electrode 2X formed on the lower substrate 9. The scan electrode 2Y and the sustain electrode 2Z are usually made of a transparent conductive film material such as patterned indium-tin oxide, and the like to reduce the voltage drop due to their high resistance characteristics. Bus electrodes 3 made of a metal such as chromium (Cr) are generally formed thereon.

The upper dielectric layer 4 and the protective film 5 are stacked on the upper substrate 1 on which the scan electrode 2Y and the sustain electrode 2Z are formed side by side. The protective film 5 is usually made of magnesium oxide (MgO) in order to prevent damage to the upper dielectric layer 4 by sputtering generated during plasma discharge and to improve emission efficiency of secondary electrons.

The lower dielectric layer 8 and the partition wall 6 are formed on the lower substrate 9 on which the address electrode 2X is formed, and the phosphor 7 is coated on the surfaces of the lower dielectric layer 8 and the partition wall 6. The address electrode 2X is formed in a direction perpendicular to the scan electrode 2Y and the sustain electrode 2Z, and the partition wall 6 is formed in a direction parallel to the address electrode 2X to generate ultraviolet and visible light generated by discharge. This prevents leakage to adjacent discharge cells. The phosphor 7 is excited by ultraviolet rays generated during plasma discharge to generate visible light of any one of red (R), green (G), and blue (B). In the discharge space provided by the upper substrate 1, the lower substrate 9, and the partition wall 6, Ne + Xe, a penning gas, and the like for gas discharge are usually sealed.

In order to display a predetermined image on the plasma display panel having the above-described structure, a discharge cell to emit light by opposing discharge between the address electrode 2X and the scan electrode 2Y is selected (data writing), and then the scan electrode 2Y and Surface discharge between the sustain electrodes 2Z is generated to generate (sustain) a discharge in the selected discharge cell. By emitting the phosphor 7 by ultraviolet rays generated during the sustain discharge, visible light is emitted outside the cell. As a result, the discharge cells adjust the period during which the discharge is maintained to implement gray scale, and the plasma display panel in which the discharge cells are arranged in a matrix form can display an image.

In such a plasma display panel, as shown in FIG. 2, not only ultraviolet light (UV) but also a certain amount of charged particles can reach the phosphor 7 present in the discharge cell, thereby changing the state of the surface of the phosphor temporarily or permanently. That is, the degradation of the phosphor occurs. Accordingly, it is known that the surface state of the phosphor of the on-screen discharge cell is uneven, and an afterimage (Burning Image or Image Sticking) may occur. In particular, when the still image is continuously displayed on the whole or part of the screen, such an afterimage occurs.

Various methods have been proposed to solve this afterimage occurrence. In the related art, an afterimage problem is solved by setting an afterimage generation condition to a predetermined parameter and automatically performing the afterimage removal procedure when such a condition is established.

However, in the conventional method, the determination of whether the condition is established by a predetermined parameter is only an predicted value irrespective of whether or not an actual afterimage occurs. Therefore, there is a difference between whether or not an actual afterimage occurs. You cannot cope with the afterimage phenomenon which is not predicted at all.

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the prior art, an object of the present invention is to provide a plasma display device and a method for removing an afterimage used therein which allow a plasma display device to remove an afterimage generated on a screen by a user's request.

Also, an object of the present invention is to provide a plasma display device capable of removing an afterimage occurring on a screen by selecting various afterimage removal modes provided by a user, and an afterimage removal method used therefor.

According to an aspect of the present invention, there is provided a method of removing an afterimage in a plasma display device, the method including: sensing an external input signal for initiating an afterimage removal mode; Upon detection, loading a pre-stored afterimage removal algorithm; And executing the afterimage elimination algorithm, wherein the afterimage elimination algorithm is programmed to convert a driving waveform applied to the plasma display apparatus to a afterimage elimination mode for a predetermined period of time. The afterimage removal method performed in the plasma display device is provided.

In the method of the present invention, the driving waveform of the afterimage removal mode may include inserting an erase period including at least one erase pulse in at least one subfield in a predetermined frame. The driving waveform may include applying the reset waveform two or more times to the reset period of the at least one subfield in the afterimage removal mode or the at least one subfield in the afterimage removal mode. It may be to increase the reset voltage of the reset period of or to increase the slope of the ramp reset waveform in the reset period of the at least one subfield in the predetermined frame.

In the method of the present invention, the external input signal may be input through a remote controller, input through an OSD menu, or input through input means included in the plasma display apparatus.

In the method of the present invention, the driving waveform includes waveforms of a reset section, an address section, and a sustain section, and the driving waveform of the afterimage elimination mode is a waveform applied between the reset section or the sustain section, or between the sustain section and the reset section. It is preferable that the waveform is converted for the normal mode.

In addition, the present invention includes the steps of sensing the external input signal for the termination of the afterimage removal mode; And converting the driving waveform applied to the plasma display device from the afterimage removal mode to the normal mode.

In addition, to achieve the above technical problem, the present invention, in the afterimage removal method performed in the plasma display device, the step of sensing an external input signal for the start of the afterimage removal mode; Upon detection, loading a pre-stored afterimage elimination algorithm; And executing the afterimage elimination algorithm, wherein the afterimage elimination algorithm converts a driving waveform applied to the plasma display apparatus unit from a normal mode to an afterimage elimination mode for a predetermined period of time to drive the plasma display apparatus. Doing; And converting a driving waveform into a changed afterimage removal mode when the change signal of the afterimage mode is sensed to drive the plasma display apparatus. .

The afterimage removal algorithm and the afterimage removal method using the same of the present invention described above may be implemented as a computer-readable recording medium.

In addition, in order to achieve the above technical problem, the present invention provides a residual image removal algorithm for driving the plasma display apparatus by converting a driving waveform applied to the plasma display apparatus portion from a normal mode to an afterimage removal mode for a predetermined period of time. Stored memory means; A residual image mode controller configured to sense an external input signal for initiating an afterimage removal mode and to execute an afterimage removal algorithm stored in the memory means; A control unit interlocked with the afterimage control unit to generate a control signal for a driving waveform of the normal mode and the afterimage removal mode; And a driving unit controlled by the controller to drive the plasma display panel.

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

3 is a block diagram showing a preferred configuration of a drive circuit for driving the plasma display device of the present invention. In FIG. 3, illustrations that are not necessary in the description of the present invention are omitted. As shown in the related art, the plasma display apparatus 100 illustrated includes a plasma display panel 10 and a plurality of sustain electrodes Z ₁ , Z ₂ ,... Z _n formed in the panel 10. The sustain electrode driver 30 and the scan electrode driver 20 for driving the scan electrodes Y ₁ , Y ₂ , ... Y _n and the plurality of address electrodes X ₁ , X ₂ , ... X _n , respectively. ) And the data electrode driver 40. In addition, a control unit 60 for outputting a driving signal to each of the driving units 20, 30, and 40 according to the received image data is provided.

In the present invention, the afterimage mode control unit 50 is connected to the control unit 60. The afterimage mode control unit 50 controls the driving units 20, 30, and 40 by selecting an appropriate driving waveform in response to an operation command of an afterimage prevention mode input from the outside. In addition, the apparatus of the present invention may further include a memory 55 in which an afterimage elimination algorithm including data regarding a drive waveform in an afterimage removal mode is provided to provide an appropriate drive waveform to the controller 60.

In the drawing, the afterimage mode control unit 50 is shown as being separated from the control unit. However, this is merely expressed by dividing it into functional blocks for clarity and the afterimage mode control unit 50 and the control unit 60 are integrated. It may be implemented.

The afterimage mode controller, the controller, and the memory provide various driving waveforms to the driver to remove an afterimage, which will be described below.

An example of such an afterimage removal drive waveform is a drive waveform using an erase pulse as shown in FIGS. 4A to 4C.

First, referring to FIG. 4A, in the sustain period t1, after a sustain pulse is alternately applied to the scan electrode Y and the sustain electrode Z by the scan driver and the sustain driver, a last pulse is applied to the scan electrode Y. A sustain pulse is applied to maintain the discharge. Subsequently, in the erase period t2, a negative erase pulse is applied to the scan electrode Y for a period shorter than the pulse width of the sustain voltage, and at the same time, the erase pulse is applied to the Y electrode by the X electrode driver. A positive erase pulse of the same width as that of is applied to the address electrode (X). As such, the erase pulse applied to the erase period may forcibly release overcharge formed in a specific region, and thus, normal reset discharge may be performed in a subsequent reset period t3.

The erase method of FIG. 4B is as follows. After the sustain pulse is sequentially applied to the scan electrode Y and the sustain electrode Z in the sustain period t1, and the last sustain pulse is applied to the scan electrode, the scan electrode Y is shorter than the pulse width of the sustain voltage. A negative erase pulse is applied, and at the same time, a positive erase pulse having a width equal to the width of the erase pulse applied to the scan electrode Y is applied to the sustain electrode Z. According to this, the negative wall charges formed by the last sustain pulse of the scan electrode Y are pushed to the discharge space by the negative sweep pulse to the scan electrode, and the positive accumulated in the sustain electrode Z. The wall charge of is pushed into the discharge space by the positive erase pulse applied to the sustain electrode. The two wall charges pushed into the discharge space disappear through the strong discharge to prevent the accumulation of overcharge.

The erase scheme of FIG. 4C can be described as follows. First, a sustain pulse is alternately applied to the scan electrode Y and the sustain electrode Z, and a last sustain pulse is applied to the scan electrode Y to maintain the discharge. Next, a positive erase pulse is applied to the sustain electrode Z for a period shorter than the pulse width of the sustain voltage, and at the same time, the scan electrode Y is maintained at the ground voltage, and the erase pulse of the sustain electrode Z is applied. After disappearing, a positive erase pulse is applied to the scan electrode Y for a period shorter than the pulse width of the sustain voltage.

By applying the last sustain pulse, negative wall charges are formed on the scan electrode Y and positive wall charges are formed on the sustain electrode Z, and then positive (+) is applied to the sustain electrode Y. ) Erase pulse pushes the positive wall charge of the sustain electrode into the discharge space, while the scan electrode (Y) is kept at ground level, so the negative wall charge is pushed out of the sustain electrode (Z). Coupling with positive charges causes a forced discharge. Since the positive (+) erase pulse is applied to the scan electrode (Y) for a period shorter than the pulse width of the sustain voltage, it pulls the negative charge to stop the discharge, and the negative wall suitable for the reset discharge in the next subfield. The charge can be maintained.

The erase operation by the waveform shown in FIG. 4D is as follows. First, the final sustain pulse is applied to the scan electrode (Y) to maintain the discharge, and then a positive erase pulse is applied to the sustain electrode, and the voltage of the erase pulse is gradually decreased to have a negative voltage. do. That is, after the last sustain pulse is applied to the scan electrode (Y), (-) wall charges are formed on the scan electrode (Y), and (+) wall charges are formed on the sustain electrode (Z), and then the sustain electrode (Z). A positive erasing pulse is applied to push out the positive wall charges around the Z electrode, and the positive charges are combined with the negative wall charges of the scan electrode maintaining the ground level. . Thereafter, the positive (+) erasing pulse of the sustain electrode is gradually decreased to reduce the amount of positive (+) wall charges that are pushed out of the Z electrode, and thus the negative (+) wall charge is generated because the (-) erasing pulse is applied. In this case, a condition suitable for the reset discharge in the next subfield is maintained.

Hereinafter, a driving waveform using reset waveform control will be described as another example of the afterimage removal driving waveform.

FIG. 5A is a diagram schematically illustrating a reset waveform applied to a reset section in a driving waveform in a conventional normal mode. As shown, the waveform is a ramp reset waveform that increases with a predetermined slope A from the first voltage V1 to the second voltage V2.

By increasing the slope A of the rising section of the ramp waveform shown in FIG. 5A or by increasing the second voltage V2, a stronger reset discharge may be generated, thereby eliminating the overcharge accumulated in a specific cell. The afterimage formed on the screen can be removed. FIG. 5B illustrates that the slope B of the rising section is increased compared to that of the waveform shown in FIG. 5A, and FIG. 5C illustrates a waveform in which the second voltage V2 is set larger than V _setup of FIG. 5A. .

As another method for controlling the waveform of the reset section, a method of applying two or more reset waveforms to the reset section may be used. FIG. 6 illustrates an example in which two reset waveforms having a ramp-up ramp and a ramp-down ramp are applied in the reset section to remove residual images.

In the above, various methods of removing afterimages applicable to the present invention have been described. However, the foregoing manners are merely embodiments for implementing the present invention, and the present invention is not limited thereto.

Hereinafter, the afterimage removal procedure performed in the above-described plasma display apparatus of the present invention will be described with reference to FIG. 7.

When the user calls the OSD menu through the menu button of the remote control or the display device, or selects the afterimage removal mode by operating the afterimage removal button provided on the remote control or the display device (S110), the afterimage elimination algorithm stored in the memory is loaded ( S112).

8 is a diagram illustrating a state in which a user calls the OSD menu 120 with the remote controller 200. In FIG. 8, when the user selects the “afterimage removal mode START” command in the OSD menu through the operation of the remote controller 200, the afterimage mode controller 50 described with reference to FIG. 3 loads the afterimage removal algorithm from the memory 55. . The afterimage mode controller 50 operates the controller 60 to convert the driving waveform from the normal mode to the afterimage removal mode (S114). The converted driving waveform is transferred to the driving units 20, 30, and 40 to drive the display panel. Although FIG. 8 illustrates the start operation of the afterimage removal mode using the OSD menu, the afterimage removal mode by the input button 110 or the button of the remote controller 200 provided in the device 100 is directly replaced. It is also possible to operate.

In the present invention, the converted driving waveform may be supplied to the driving unit for a predetermined period. Of course, the converted driving waveform may drive the display panel until there is a separate " stop image removal mode " command from the user. FIG. 7 shows a procedure for a method of removing an afterimage when a driving waveform is driven for a predetermined frame and an active end command of a user can be input. That is, the afterimage mode controller 50 determines whether the preset period has ended from the time when the driving waveform is started (S118), and if the user does not select the end of the afterimage removal mode when the period is not terminated, the determination result is determined. (S120).

The afterimage mode control unit 50 instructs the control unit 60 to convert the driving waveform to the normal mode when a preset period ends or the end of the afterimage removal mode is selected by the user, and the control unit converts the driving waveform to the normal mode. In operation S122, the driving units 20, 30, and 40 drive the panel by driving waveforms in a normal mode (S124).

As the driving waveform in the procedure of the present invention described with reference to FIG. 7, any one of the driving waveforms described above with reference to FIGS. 4A to 4B, 5A to 5C, and other methods may be used. However, the afterimage removal method of the present invention may provide these drive waveforms in the form of a selectable afterimage removal mode to be selected by the user.

9 is a procedure diagram conceptually illustrating an afterimage removal procedure when a user selects and operates a specific afterimage removal mode in a plurality of driving waveforms.

9, when the user selects any one of the provided afterimage removal modes (S210), the afterimage removal algorithm is loaded (S212), and the driving waveform is converted into the selected afterimage removal mode (S214). The panel is driven by the driving waveform (S216). The above process is similar to that described in connection with FIG.

At this time, the afterimage mode control unit 50 determines whether there is a request for changing the afterimage removal mode by the user (S218), and when there is a request for changing the afterimage removal mode, converts the driving waveform to the changed afterimage removal mode ( S220, the panel is driven in the changed afterimage removal mode (S222).

When there is no mode change, the afterimage mode control unit 50 determines whether a preset period has expired in the operation of the afterimage removal mode (S224) and whether a command for ending the afterimage removal mode is input from the user (S226). If any one of these is true, the driving waveform is converted to the normal mode (S228), and the panel is driven in the normal mode (S230).

The above procedure allows the user to select any one of the plurality of afterimage removal modes and to change the afterimage removal mode during the progress of the afterimage removal mode, thereby to the afterimage removal mode of the drive waveform suitable for the removal of the current image. It has the advantage of being able to remove afterimages.

It will be appreciated by those skilled in the art that some or all of the afterimage removal algorithm and the afterimage removal method described with reference to FIGS. 7 and 9 in the above-described embodiments may be implemented as a computer-readable recording medium. There will be.

In addition, the preferred embodiments of the present invention described above are merely illustrative of the present invention, and the present invention may be variously modified from these examples and may take various forms. Therefore, the invention should not be construed as limited to the particular forms mentioned in the description, but includes all modifications, equivalents, and substitutions within the spirit and scope of the invention as defined by the appended claims. It should be understood that.

According to the present invention, an afterimage removal method capable of directly removing an afterimage by a user's operation when an actual afterimage occurs and a plasma display apparatus having such an afterimage removal function can be provided. As a result, when strong image retention occurs as a result of displaying specific image data such as a logo or a still image, it is possible to promptly remove the user by arbitrary adjustment.

In addition, according to the exemplary embodiments of the present invention, afterimage removal is performed by adding a new waveform between the reset section, the sustain section, or the two sections instead of the waveform of the address section of the driving waveform. There is no fear that the screen will stop displaying.

In addition, according to an embodiment of the present invention, it is possible to present a plurality of afterimage removal modes having different afterimage removal effects to a user, and to allow a user to find an afterimage removal mode suitable for the removal of a current image.

Claims (17)

In the afterimage removal method performed in the plasma display device, Sensing an external input signal for initiating an afterimage removal mode; Upon detection, loading a pre-stored afterimage elimination algorithm; And Executing the afterimage elimination algorithm, The afterimage elimination algorithm is programmed to convert the driving waveform applied to the plasma display apparatus for a predetermined period of time from the normal mode to the afterimage elimination mode, In the afterimage elimination mode, the driving waveform inserts an erase period including at least one erase pulse into at least one subfield in a predetermined frame, and resets the voltage or the slope of the subfield to a reset period of the subfield, which is higher than that in the normal mode. In which the waveform is applied two or more times Afterimage removal method performed in the plasma display device characterized in that. delete delete delete delete The method of claim 1, The external input signal is a residual image removal method performed in the plasma display device, characterized in that the input via a remote control. The method of claim 1, And the external input signal is input through an OSD menu. The method of claim 1, And the external input signal is an input through an input means provided in the plasma display apparatus.  The method of claim 1, The driving waveform may include waveforms of a reset period, an address period, and a sustain period, and the driving waveform of the afterimage removal mode may include a waveform applied between the reset period and the sustain period, or between the sustain period and the reset period. An afterimage removal method performed in a plasma display device, characterized in that converted to a waveform. The method of claim 1, Sensing an external input signal for terminating the afterimage removal mode; And And converting a driving waveform applied to the plasma display device from an afterimage removing mode to a normal mode. In the afterimage removal method performed in the plasma display device, Sensing an external input signal for initiating an afterimage removal mode; Upon detection, loading a pre-stored afterimage elimination algorithm; And Executing the afterimage elimination algorithm, The afterimage removal algorithm, Driving the plasma display apparatus by converting a driving waveform applied to the plasma display apparatus for a predetermined period from a normal mode to an afterimage removing mode; And Converting a driving waveform into a changed afterimage removal mode when the change signal of the afterimage removal mode is detected, and driving the plasma display apparatus; In the afterimage elimination mode, the driving waveform inserts an erase period including at least one erase pulse into at least one subfield in a predetermined frame, and resets the voltage or the slope of the subfield to a reset period of the subfield, which is higher than that in the normal mode. In which the waveform is applied two or more times Afterimage removal method performed in the plasma display device characterized in that. A recording medium mounted on a memory means of a plasma display device, in which a computer readable program for performing the method according to any one of claims 1 to 11 is recorded. Memory means for storing an afterimage removal algorithm for driving the plasma display device by converting a driving waveform applied to the plasma display device for a predetermined period from a normal mode to an afterimage removal mode; A residual image mode controller configured to sense an external input signal for initiating an afterimage removal mode and to execute an afterimage removal algorithm stored in the memory means; A control unit interlocked with the afterimage control unit to generate a control signal for a driving waveform of the normal mode and the afterimage removal mode; And A driving unit controlled by the controller to drive a plasma display panel, In the afterimage elimination mode, the driving waveform inserts an erase period including at least one erase pulse into at least one subfield in a predetermined frame, and resets the voltage or the slope of the subfield to a reset period of the subfield, which is higher than that in the normal mode. In which the waveform is applied two or more times Plasma display device characterized in that. The method of claim 13, And a remote controller having a selection button to allow the user to select the afterimage removal mode. The method of claim 13, And an OSD display means for providing an OSD menu for the user to select the afterimage removal mode. The method of claim 13, And an input means for allowing a user to select the afterimage removal mode. The method of claim 13, The driving waveform by the driving unit includes waveforms of a reset section, an address section, and a sustain section, and the driving waveform of the afterimage elimination mode is a waveform applied between the reset section or the sustain section, or between the sustain section and the reset section. And the waveform of the normal mode is converted.

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