KR100702053B1 - Plasma display panel device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display apparatus, comprising a driving unit for applying a driving waveform consisting of a reset signal and an address signal to a scan electrode and a sustain electrode during one subfield, and performing initialization of the plasma display panel and priming particles. When the still image is displayed, it is possible to improve the phenomenon of false discharge or splashing and to improve contrast.

Plasma Display Panel, Reset, Contrast

Description

 Plasma display panel device

1 is a view showing a structure of a plasma display panel according to the prior art;

2 is a view showing a plasma display panel driving waveform according to the prior art;

3A is a diagram showing a first embodiment of a plasma display panel drive waveform according to the present invention;

3B is a view showing a second embodiment of the plasma display panel driving waveform according to the present invention;

3C is a view showing a third embodiment of the plasma display panel drive waveform according to the present invention;

4A is a view showing a driving waveform for displaying a still image in the plasma display panel according to the present invention;

4B is a diagram illustrating a driving waveform for displaying a still image in the plasma display panel according to the present invention.

<Explanation of symbols on main parts of the drawings>

R: Reset signal A: Address signal

S: Sustain signal R_up: Setup reset signal

R_dn: set down reset signal R_pre: pre reset signal

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display apparatus. In particular, before a still image is displayed, a driving waveform consisting of only a reset signal and an address signal is applied to initialize each discharge cell of the plasma display panel, and supplying priming particles sufficiently to prevent misuse. The present invention relates to a plasma display device capable of preventing a transition from occurring.

1 is a diagram showing the structure of a conventional plasma display panel.

The plasma display panel is a display device in which a vacuum ultraviolet light (VUV) generated by discharging a gas inside the panel collides with a phosphor in the panel to generate light. The plasma display panel includes a front substrate 10 and a rear substrate 20.

In a typical plasma display panel, as shown in FIG. 1, the front substrate 10 includes a plurality of scan electrodes 11 and sustain electrodes 12 that are arranged in a stripe form to face the rear substrate 20. The dielectric layer 13 is laminated to cover the scan electrode and the sustain electrode to limit the discharge current during discharge and facilitate the generation of wall charges, and the dielectric protective layer 14 is formed of MgO to protect the dielectric layer.

In addition, the back substrate 20 is arranged in a stripe shape so as to be orthogonal to the scan electrode 11 and the sustain electrode 12 of the front substrate 10 so as to divide the entire screen into a plurality of cells together with the display electrode. An electrode 21, a dielectric layer 23 applied to the entire surface of the rear substrate to protect the address electrode and to perform electrical insulation, and a partition wall 22 formed in a stripe shape on the dielectric layer to form a discharge space; And a phosphor 24 which is printed and coated inside the discharge space formed by the barrier ribs and is excited by ultraviolet rays during the discharge of each cell to emit visible light.

The plasma display panel includes one frame for displaying a screen through discharge on a plurality of address electrodes 21 arranged in a column direction and a plurality of scan electrodes 11 and sustain electrodes 11 arranged in a row direction. Is driven by dividing into several subfields with different number of discharges.

Each of the subfields is divided into a reset period for initializing discharge cells, an address period for selecting discharge cells, and a sustain period for expressing gray levels according to the number of discharges in order to uniformly generate discharge.

As shown in FIG. 2, a reset signal R having a high high voltage is applied during the reset period to initialize a discharge cell, and the scan electrodes 11 and Y and the address electrodes 21 and X during an address period. Pulses are applied opposite to each other to generate address discharge to write data to the discharge cells.

During the sustain period, a sustain signal S is alternately applied to the scan electrodes 11 and Y and the sustain electrodes 12 and Z to generate a discharge, and the sustain discharges generated in each subfield are accumulated to express gray levels.

At this time, the reset signal R is applied to all the discharge cells regardless of the addressing of each cell in every subfield, and initialization is performed. When the reset signal is applied, reset discharge occurs. Therefore, even in the case of cells that are not addressed, fine light is emitted due to the reset discharge, so that the dark luminance of the plasma display panel cannot be lowered by a predetermined level or more.

Therefore, when a still image is displayed, a driving method of displaying a screen by applying only the address signal A and the sustain signal S, without applying the reset signal R, in order to lower the dark luminance of the plasma display panel. use.

However, in this case, if sufficient wall charges are not formed inside the discharge cell before the screen is displayed, or if priming particles that change into wall charges under low voltage are not formed, the discharge of sufficient brightness does not occur even if the sustain signal is applied during the sustain period. . If the discharge is not sufficiently generated during the sustain period, the brightness of the plasma display panel may not be sufficiently secured, and the contrast, which is the ratio between the brightness and the darkness, may not be sufficiently increased.

In addition, even when a still image of a different pattern is displayed, when only the address signal A and the sustain signal S are applied to express gray scales, wall charges or priming particles are not sufficiently generated in the cells where the discharge is generated. Otherwise, even if the sustain signal is applied during the sustain period, no discharge occurs. On the contrary, in the case of a cell having a large number of wall charges or priming particles inside the discharge cell, even if the addressing does not occur, discharge occurs during the sustain period, and thus, misfiring occurs. .

That is, since the fine light is generated during the reset discharge, the dark grays are excited in the dark grays, making accurate color representation of the plasma display panel difficult. In order to prevent this and to increase the screen contrast, if a reset signal (R) is not applied when expressing still images, problems such as mis-discharge, flickering, and bright spots may occur, or when the screen is switched to another pattern, another screen may be displayed late. A problem occurs. In addition, when the screen is displayed by applying the reset signal R, sufficient contrast cannot be secured by the light generated during the reset discharge.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and activates the initialization of the plasma display panel and the generation of priming particles in a discharge cell by applying a driving waveform consisting of only a reset signal and an address signal before displaying a still image. The present invention provides a plasma display device capable of displaying a screen without mis-discharge without applying a reset signal when displaying a still image.

The plasma display device according to the present invention for solving the above problems is characterized in that it comprises a drive unit for applying a drive waveform consisting of a reset signal and an address signal to the scan electrode and the sustain electrode during one subfield.

Hereinafter, a plasma display device of the present invention will be described with reference to the accompanying drawings. 3A to 3C illustrate driving waveforms of the plasma display panel according to the present invention, and 4A to 4B illustrate driving waveforms for displaying still images in the plasma display panel according to the present invention.

The plasma display panel according to the present invention includes a module including a plurality of address electrodes X arranged in a column direction, a plurality of scan electrodes Y arranged in a row direction, and a sustain electrode Z. . The scan electrode is formed corresponding to each sustain electrode, and one end of the sustain electrode is connected to each other, and the same voltage is applied thereto.

The module is formed by bonding a front panel on which the scan electrode Y and the sustain electrode Z are alternately horizontally formed, and a rear panel on which the address electrode X is formed. The scan electrode, the sustain electrode and the address electrode are disposed to face each other with the discharge space interposed so as to vertically intersect, and the discharge space at the intersection of the scan electrode and the sustain electrode and the address electrode may form one basic discharge cell. Form.

The plasma display panel drives one frame by dividing one frame into one or more subfields SF having different discharge times in order to express gray scale. For example, when the screen is to be displayed with 256 levels of gray scale, 1 is displayed. One frame is displayed every / 60 seconds, and the frame is divided into 8 to 14 subfields.

The subfield SF includes a reset section in which a reset signal R is applied for initializing a discharge cell, an address section in which an address signal A for data writing is applied, and a sustain signal for displaying an image through sustain discharge. (S) is divided into a sustain period to which the reset period and the address period are the same for each subfield, and the length of the sustain period is set differently for each subfield.

The plasma display apparatus of the present invention includes a driver for applying a driving waveform consisting of a reset signal R and an address signal A during one subfield SF to initialize each of the discharge cells.

That is, as shown in FIG. 3A, when the driving waveform including only the reset signal R and the address signal A is applied to the plasma display panel by the driving unit before and after displaying the still image, each discharge cell is applied. Can be initialized.

The reset signal R includes a setup reset signal R_up in which a ramp type voltage increases and a set down reset signal R_dn in which a voltage decreases. The setup reset signal R_up is applied and a ground level voltage is applied to the address electrode X and the sustain electrode Z.

When the setup reset signal R_up is applied, positive charge is formed on the address electrode X and the sustain electrode Z, and negative charge is formed on the scan electrode Y. Subsequently, when the set down reset signal R_dn is applied, a voltage decrease occurs in the scan electrode Y, and a reset discharge is generated between the scan electrode and the sustain electrode. When the reset discharge occurs, the wall charges formed on the scan electrode and the sustain electrode are erased so that the wall charges in an amount sufficient to cause the address discharge are present in the discharge cell.

In addition, when reset discharge occurs during the reset period, priming particles are formed inside each discharge cell in addition to the wall charges. When a large number of priming particles are present in the discharge cells, the discharge is easily generated even when a low voltage is applied. Efficiency can be further increased.

When the address signal A is applied to the address electrode X and an address signal is also applied to the scan electrode Y opposite to the address electrode, when the data is written to the discharge cell, the sustain electrode ( As Z), a bias voltage of a constant voltage level is applied. When the bias voltage is applied to the sustain electrode, the voltage difference between the scan electrode Y and the sustain electrode Z is reduced, so that the address discharge between the address electrode and the scan electrode is stably performed and the cell to which the sustain discharge is to be selected is selected. However, in the present invention, since the sustain signal is not applied to each discharge cell, the bias voltage to the sustain electrode may not be applied during the address period.

The driving unit drives one or more frames including one or more subfields SF including only the reset signal R and the address signal A to initialize each of the discharge cells. In general, one frame includes eight or more subfields, whereas in the present invention, one frame may include only three to five subfields.

In addition, the driver applies the frame configured three or more times to initialize the plasma display panel. Since one frame period is approximately 16.7 ms, the plasma display panel may be initialized without inconvenience to the user since it is a very short time of less than 1 second even when the frame for initialization is applied 3 to 30 times.

In particular, since only the reset signal R and the address signal A are applied during the one subfield SF, no screen is displayed on the plasma display panel while the discharge cell is initialized by the driver. Since one frame time is very short, the user cannot detect this even if the initialization is performed by driving fewer than 30 frames.

As shown in FIG. 3B, the driving unit may be configured to further apply the pre-reset signal R_pre to the scan electrode Y before the reset signal R is applied, wherein the pre-reset signal has a negative polarity. It has a shape similar to the set down reset signal (R_dn).

When the pre-reset signal R_pre is applied to the scan electrode Y, a voltage of a predetermined level is applied to the sustain electrode Z. In this case, the voltage applied to the sustain electrode is the scan electrode or the sustain electrode during the sustain period. A voltage having the same magnitude as the sustain voltage Vs applied to the sustain electrode may be applied.

When the pre-reset signal R_pre is applied, charged priming particles are generated inside the discharge cell, and when the reset signal R is subsequently applied, a sufficient amount of wall charges can be generated, and weak discharge rather than strong discharge is generated. This can prevent the bright spots from flickering or blinking.

The pre-reset signal R_pre may be configured to be applied before the reset signal R is applied to every subfield SF. However, as shown in FIG. 3C, only the initial two to three subfields are provided. The pre-set signal may be applied to generate priming particles.

Since the wall reset is easily formed within the discharge cell and applied to perform the discharge cell initialization through the weak discharge, the pre-reset signal R_pre may apply the pre-reset signal to all subfields constituting one frame. There is no need.

In addition, the plasma display apparatus of the present invention may initialize the discharge cells by applying the driving waveform before and after the display of the still image. In order to display the still image, the image display unit may apply the driving waveform for displaying the still image. It is configured to include more.

The plasma display apparatus of the present invention applies a driving waveform composed of the reset signal R and the address signal A to initialize the discharge cells. Thus, the image driving unit is reset as shown in FIGS. 4A to 4B. Still images can be displayed without applying the signal R.

In the case of a still image, since all discharge cells always express the same gray level, discharge is continuously generated in a cell in which discharge occurs every frame, and discharge is not continuously generated in a cell in which discharge is not generated. Accordingly, the image driver may display the screen without mis-discharge by applying only the address signal A and the sustain signal S without initializing the discharge cell by applying a separate reset signal R. FIG.

In the discharge cell initialization, if the discharged cell in the previous frame is not discharged in the next frame or the cell in which the discharge is not generated in the previous frame is discharged in the next frame, the wall charge is excessively formed inside the discharge cell. This is done to prevent the occurrence of mis-discharge due to the lack or shortage.

However, in the case of a still image, each discharge cell represents the same gray level every frame, and thus, even when the discharge cell is not initialized by applying the reset signal R, erroneous discharge does not occur or bright spots or flashes do not occur.

That is, as shown in FIG. 4A, in the case of a cell in which one subfield SF is divided into an address period and a sustain period, and the discharge is performed, a cell generated in the discharge is selected by the address signal, and during the sustain period. The sustain discharge is generated by the applied sustain signal, and the screen is displayed.

The image driver writes data through address discharge by applying an address signal A to the scan electrode Y and the address electrode X during an address period. The image driver applies a bias voltage of a predetermined level to the sustain electrode Z during the address period to reduce the voltage difference between the scan electrode and the address electrode and the sustain electrode, thereby efficiently generating an address discharge between the scan electrode and the address electrode. Be sure to

During the sustain period, a sustain pulse is alternately applied to the scan electrode Y and the sustain electrode Z to generate a sustain discharge between the scan electrode and the sustain electrode, thereby displaying a screen.

Since each discharge cell expresses the same gray level every frame while the same pattern is displayed, if the discharge cell is initialized before the screen display as described above, each still cell does not need to be initialized by applying a reset signal R thereafter. The screen may be displayed by performing address discharge and sustain discharge through wall charges and priming particles formed in the discharge cells.

In particular, when the reset signal R is not applied when displaying a still image, fine light is not generated by the reset discharge. Therefore, since the darkness of the off-cell that does not generate discharge becomes 0 cd / cm 2, a contrast of ∞: 1 relative to the brightness can be secured.

In this case, as illustrated in FIG. 4B, the image driver may be configured to further apply a set down reset signal R_dn before applying the address signal A and the sustain signal S. FIG.

In the display of still images, the cells in which the discharge is generated express the same gray level every frame, but the sustain discharge is not made the same for all subfields for each subfield SF constituting one frame.

That is, since discharge occurs in one subfield SF and no discharge occurs in one subfield with respect to one cell, the set down reset signal R_dn is applied to a cell in which a discharge occurs in a previous subfield. By stabilizing the wall charge and priming particles formed inside the discharge cell.

The cell in which the discharge is generated in the previous subfield SF does not need to initialize the discharge cell by applying a high voltage to generate a strong reset discharge as shown in the setup reset signal R_up, but is accumulated inside the cell by the discharge. It is necessary to clean up the disturbed wall charge or priming particles.

Therefore, the image driver applies the set down reset signal R_dn before applying the address signal A in every subfield, and stably rearranges the wall charge or priming particles formed in the cell, thereby discharging each discharge cell every frame. It is possible to achieve stable image quality by maintaining constant brightness at all times.

In particular, since the reset discharge does not occur inside the discharge cell only by the set down reset signal R_dn, in the case of the off-cell that is not turned on, the dark brightness is maintained at 0 cd / cm 2 and thus does not affect the contrast.

The driving unit applies the driving waveform consisting of the reset signal R and the address signal A only before displaying the still image to initialize the discharge cell or displays the driving waveform only after displaying one still image. The driving waveform may be applied to a pre- / post-display mode of the still image to initialize the plasma display panel.

Therefore, when displaying the still image without applying the reset signal R, if the discharge cell initialization is performed before or after the display of the still image, the reset discharge does not occur while displaying the still image. Contrast is secured and the screen can be displayed without bright spots, blinks, or misdischarges without applying a reset signal to each subfield SF.

In addition, even when the still image is displayed by applying all of the reset signal R, the address signal A, and the sustain signal S, if the initializing of the discharge cells is performed before or after the still image display, the discharge is weak. Will occur. That is, sufficient priming particles are formed inside the discharge cell, so that the screen is displayed by weak discharge when displaying the screen, thereby improving image quality when displaying still images.

As described above, the plasma display device according to the present invention has been described with reference to the illustrated drawings. However, the present invention is not limited by the embodiments and drawings disclosed herein, and is provided to those skilled in the art within the scope of the technical idea of the present invention. Application is possible.

The plasma display device according to the present invention configured as described above applies a driving waveform consisting of only a reset signal and an address signal before displaying a still image to activate the initialization of the plasma display panel and generation of priming particles in the discharge cell, thereby generating a reset signal. Still images can be displayed without mis-discharge without authorization.

Furthermore, since the discharge cells do not need to be initialized when the still image is displayed and reset discharge does not occur, there is an effect of improving the contrast and improving the bright point.

Claims (9)

If still images are displayed, And a driving unit for applying a driving waveform consisting of only a reset signal and an address signal to at least one subfield to a scan electrode and a sustain electrode. The method of claim 1, And the driving unit applies a negative pre-reset signal to the scan electrode before applying the reset signal. The method of claim 1, And the driver applies a predetermined level of voltage to the sustain electrode before applying the reset signal. delete The method of claim 1, And the driving unit applies the driving waveform before the still image is displayed. The method of claim 1, And the driving unit applies the driving waveform before one still image is displayed and before another still image is displayed. The method of claim 1, And the driving unit applies the driving waveform to both before and after one still image is displayed. The method according to any one of claims 5 to 7, The plasma display apparatus may further include an image driver configured to apply, to the scan electrode, a driving waveform including only a set down reset signal and an address signal and a sustain signal to one or more subfields when the still image is displayed. Plasma display device. The method according to any one of claims 5 to 7, The plasma display apparatus may further include an image driver configured to apply, to a scan electrode, a driving waveform including only an address signal and a sustain signal to one or more subfields when the still image is displayed.

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