KR20070041901A - Apparatus of driving plasma display panel - Google Patents

Abstract

The present invention relates to a display panel driving apparatus for driving a display panel by controlling a connection between a power input terminal and a ground terminal to an electrode line by a switching element. The display panel driving apparatus according to the present invention drives a display panel in which discharge cells are formed in a region where a plurality of electrodes cross each other, and is connected between at least one of the electrodes and a ground terminal, and the electrode and the ground terminal. A switching element for controlling the connection between; And a current control element connected between the switching element and the ground terminal to control a current flowing from the electrode to the ground terminal. According to the present invention, by inserting a current control element between the switching element for controlling the connection of the electrode line and the ground terminal and the ground terminal, it is possible to reduce the EMI by controlling the current flowing from the electrode line through the ground terminal.

Description

Apparatus of driving plasma display panel

1 is a perspective view showing an internal structure of a three-electrode surface discharge plasma display panel to which a driving device of a display panel according to the present invention is applied.

FIG. 2 is a block diagram illustrating an apparatus for driving a plasma display panel for driving the plasma display panel of FIG. 1.

3 is a timing diagram illustrating a method of driving a plasma display panel in which a unit frame is configured by driving a plurality of subfields.

FIG. 4 is a timing diagram illustrating driving signals applied to respective electrode lines with respect to a subfield as a driving method of the plasma display panel driving apparatus according to the present invention.

FIG. 5 is a circuit diagram schematically illustrating an address driver of a driving apparatus of a plasma display panel using an inductor as a current control element between a switching element and a ground terminal according to an exemplary embodiment of the present invention.

FIG. 6 is a circuit diagram schematically illustrating an address driver of a driving device of a plasma display panel using a resistance between the switching element and the ground terminal as a current control element according to another exemplary embodiment of the present invention.

FIG. 7 is a circuit diagram schematically illustrating an address driver of a driving device of a plasma display panel using an inductor as a current control device between an electrode and a switching device according to another exemplary embodiment of the present invention.

FIG. 8 is a circuit diagram schematically illustrating an address driver of a driving apparatus of a plasma display panel using a resistance as an element for controlling current between an electrode and a switching element according to an exemplary embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

1: plasma display panel,

20: drive of the plasma display panel,

22: logic controller, 23: address driver,

24: X drive unit, 25: Y drive unit,

L5, L7: current control inductor, R6, R8: current control resistor,

X _{1 to} X _n : X electrode line, Y ₁ -Y _n : Y electrode line,

A ₁ ~A _m: address electrode lines, SF1~SF8: sub-field.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving device of a display panel, and more particularly, to a driving device of a display panel which drives a display panel by controlling a connection of a power input terminal and a ground terminal to an electrode line by a switching element.

As flat panel display devices, plasma display panels (PDPs), which are easy to manufacture large panels, have attracted attention. A plasma display panel is a display device that displays an image by using a discharge phenomenon. In general, a plasma display panel can be classified into a direct current type and an alternating current type according to the type of driving voltage. Due to the disadvantages, the development of the AC plasma display panel has been made a lot.

An AC plasma display panel includes a three-electrode AC surface discharge type plasma display panel having three electrodes and driven by an AC voltage. A typical three-electrode surface discharge type plasma display panel is composed of a multi-layered plate, which is spatially advantageous because it can provide a thinner, lighter, and wider screen than a conventional cathode ray tube (CRT).

The plasma display panel includes a plurality of display cells formed in a region where the sustain electrode and the address electrode cross each other, and one display cell includes three discharge cells (red, green, and blue), and discharges the discharge cells. The gray level of the image is expressed by adjusting the state.

In order to express the gray scale of the plasma display panel, one frame applied to the plasma display panel may be configured with eight subfields having different emission counts to express 256 gray scales. That is, in the case where the image is to be displayed with 256 gray levels, the frame period (16.67 ms) corresponding to 1/60 second is divided into eight subfields. Each of the sub-fields has a reset period, an address period, and a sustain discharge period, thereby driving the plasma display panel.

In the reset cycle, all discharge cells are initialized. In the next address period, scan pulses are sequentially applied to each of the Y electrodes, and data pulses synchronized with the scan pulses are applied to the address electrodes corresponding to the discharge cells to be displayed among the discharge cells, thereby displaying the discharges. Select the cell. In the subsequent sustain discharge cycle, sustain pulses are applied to the X electrode and the Y electrode so that the sustain discharge can occur only in the discharge cells to be displayed, thereby expressing the image.

In the address period, scan pulses are sequentially applied to each of the sustain electrode lines, and data pulses synchronized with the scan pulses are applied to the address electrode lines forming discharge cells to be selected for display discharge with respect to the sustain electrode lines. Is approved.

Therefore, the voltage applied to each address electrode line has a repetitive rising portion and falling portion as the data pulse is applied. At this time, the address electrode line is connected to the power input terminal in the rising portion, and the source terminal of the switch is directly connected to the ground terminal in the falling portion.

That is, since the source terminal of the switch is directly connected to the ground terminal, there is a problem that EMI (Electro-magnetic Interference) due to current control cannot be reduced.

The present invention is to solve the above problems, by inserting a current control element between the switching element and the ground terminal for controlling the connection of the electrode line and the ground terminal, by controlling the current flowing through the ground terminal from the electrode line EMI It is an object of the present invention to provide a driving device of a display panel which can reduce the number.

A display panel driving apparatus according to the present invention for achieving the above object is to drive a display panel in which discharge cells are formed in a region where a plurality of electrodes intersect, between at least one of the electrodes and a ground terminal. A switching element connected to control a connection between the electrode and the ground terminal; And a current control element connected between the switching element and the ground terminal to control a current flowing from the electrode to the ground terminal.

It is preferable that the said current control element is an impedance element.

It is preferable that the said current control element is a resistance.

Preferably, the current control element is an inductor.

It is preferable that the said current control element is a bead.

The plurality of electrodes includes an address electrode, a Y electrode for causing an address discharge between the address electrode, and an X electrode for causing a sustain discharge between the Y electrode and the discharge cell for causing the address discharge. It is preferable that the electrode is an address electrode.

According to another aspect of the present invention, a display panel driving device drives a display panel in which discharge cells are formed in an area where a plurality of electrodes cross each other, and is connected between at least one of the electrodes and a ground terminal. A switching element for controlling a connection between the electrode and the ground terminal; And a current control element connected between the electrode and the switching element to control a current flowing from the electrode to the ground terminal.

According to the present invention, by inserting a current control element between the switching element for controlling the connection of the electrode line and the ground terminal and the ground terminal, it is possible to reduce the EMI by controlling the current flowing from the electrode line through the ground terminal.

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

1 is an internal perspective view showing the structure of a three-electrode surface discharge plasma display panel.

Referring to the drawings, between the front and rear glass substrates 10 and 13 of the surface discharge plasma display panel 1, the address electrode lines A _{R1 to} A _Bm , the dielectric layers 11 and 15, and the Y electrode line (Y ₁ to Y _n ), X electrode lines (X ₁ to X _n ), fluorescent layer 16, partition wall 17, and magnesium monoxide (MgO) layer 12 as a protective layer are provided.

The address electrode lines A _{R1 to} A _Bm are formed in a predetermined pattern on the front side of the rear glass substrate 13. The lower dielectric layer 15 is applied to the entire surface in front of the address electrode lines A _{R1 to} A _Bm . In front of the lower dielectric layer 15, barrier ribs 17 are formed in a direction parallel to the address electrode lines A _{R1 to} A _Bm . The partition walls 17 function to partition the discharge area of each discharge cell 14 and to prevent optical cross talk between the discharge cells 14. The fluorescent layer 16 is formed on the inner surface of the space formed between the lower dielectric layer 15 and the partition walls 17 formed on the rear glass substrate 13.

The X electrode lines X ₁ to X _n and the Y electrode lines Y ₁ to Y _n have a constant pattern on the rear side of the front glass substrate 10 to be orthogonal to the address electrode lines A _{R1 to} A _Bm . Is formed. Each intersection sets a corresponding discharge cell 14. Each X electrode line (X _{1 to} X _n ) and each Y electrode line (Y _{1 to} Y _n ) are combined with a transparent electrode line made of a transparent conductive material such as indium tin oxide (ITO) and a metal electrode line for increasing conductivity. Is formed. Here, the X electrode lines X ₁ to X _n become sustain electrodes in the respective discharge cells 14, and the Y electrode lines Y ₁ to Y _n correspond to scan electrodes in the respective discharge cells 14. And become an address electrode in the discharge cell 14 of each of the address electrode lines A _{R1 to} A _Bm .

2 is a block diagram illustrating a driving apparatus of a plasma display panel.

Referring to the drawing, the driving device 20 of the plasma display panel 1 includes an image processor 21, a logic controller 22, an address driver 23, an X driver 24, and a Y driver 25. . The image processor 21 converts an external analog image signal into a digital signal, and thus internal image signals, for example, 8-bit red (R), green (G), and blue (B) image data, clock signals, vertical and horizontal, respectively. Generate sync signals. The logic controller 22 generates driving control signals S _A , S _Y , and S _X according to an internal image signal from the image processor 21.

In this case, the driving unit such as the address driver 23, the X driver 24, and the Y driver 25 receives input from the driving control signals S _A , S _Y , and S _X , and generates respective driving signals. The applied driving signal to each of the electrode lines.

That is, the address driver 23 processes the address signal S _A among the drive control signals S _A , S _Y , and S _X from the logic controller 22 to generate a display data signal, and generates the displayed display. The data signal is applied to the address electrode lines. The X driver 24 processes the X driving control signal S _X from the driving control signals S _A , S _Y , and S _X from the logic controller 22 and applies the X driving control signal S _X to the X electrode lines. The Y driver 25 processes the Y driving control signal S _Y among the driving control signals S _A , S _Y , and S _X from the logic controller 22 and applies the Y driving control signal S _Y to the Y electrode lines.

Here, the address driver 23 may be connected between the power input terminal Va and the address electrode A _j as shown in FIGS. 5 to 8. The address driver 23 includes a first control switch S1, a second control switch S2, and current control elements L5, L7, R6, and R8. Detailed description thereof will be made in the description of FIGS. 5 to 8, and refer to this.

3 is a timing diagram illustrating a method of driving a plasma display panel in which a unit frame is configured by driving a plurality of subfields.

Referring to the drawing, the unit frame FR is divided into eight subfields SF1 to SF8 to realize time division gray scale display. Each subfield SF1 to SF8 is divided into reset periods R1 to R8, address periods A1 to A8, and sustain discharge periods S1 to S8.

The luminance of the plasma display panel is proportional to the length of the sustain discharge periods S1 to S8 occupied in the unit frame. The length of the sustain discharge cycles S1 to S8 occupied in the unit frame is 255T (T is the unit time). At this time, a time corresponding to 2 ⁿ is set in the sustain discharge period Sn of the nth subfield SFn. Accordingly, if the subfield to be displayed among the eight subfields is appropriately selected, 256 gray levels may be displayed including all zero (zero) grays not displayed in any of the subfields.

4 is a timing diagram illustrating driving signals applied to respective electrode lines with respect to a subfield as a driving method of the display panel driving apparatus according to the present invention.

In FIG. 4, reference numeral S _{AR1 ..ABm} denotes a driving signal applied to each address electrode line (A _R1 to A _Bm of FIG. 1), and S _{X1 ..Xn} denotes X electrode lines (X ₁ to X of FIG. 1). _n ), and S _Y1 to S _Yn indicate a drive signal applied to each Y electrode line (Y ₁ to Y _{n in} FIG. 1).

Referring to the drawings, in the reset period PR of the unit sub-field SF, first, the voltage applied to the X electrode lines X ₁ to X _n is converted from the ground voltage V _G to the second voltage V _S. For example, it continuously increases to 155 volts (V). Here, the ground voltage V _G is applied to the Y electrode lines Y ₁ to Y _n and the address electrode lines A _R1 to A _Bm . Accordingly, between the X electrode lines X ₁ to X _n and the Y electrode lines Y ₁ to Y _n , and the X electrode lines X ₁ to X _n and the address electrode lines A ₁ to A _A weak discharge occurs between _m ) and negative wall charges are formed around the X electrode lines X ₁ to X _n .

The Next, Y electrode lines (Y ₁ ~ Y _n) voltage to the second voltage applied to the (V _S), for example, the third voltage (V _SET than the second voltage (V _S) from 155 volt (V) The maximum voltage (V _SET + V _S ), which is as high as), continues to rise to, for example, 355 volts (V). Here, the ground voltage V _G is applied to the X electrode lines X ₁ to X _n and the address electrode lines A _R1 to A _Bm . Accordingly, a weak discharge occurs between the Y electrode lines Y ₁ to Y _n and the X electrode lines X ₁ to X _n , while the Y electrode lines Y ₁ to Y _n and the address electrode lines are formed. Weak discharge occurs between (A _R1 and A _Bm ).

Next, while the voltage applied to the X electrode lines X ₁ to X _n is maintained at the second voltage V _S , the voltage applied to the Y electrode lines Y ₁ to Y _n is second. It continues to fall from voltage V _S to ground voltage V _G. Here, the ground voltage V _G is applied to the address electrode lines A _R1 to A _Bm .

Leads in the address period (PA), the address is applied to a display data signal of the address pulse to the electrode line, the second voltage (V _S) lower fourth voltage (V _SCAN) to bias the Y-electrode line than the (Y ₁ As the scan signals of the scan pulses of the ground voltage V _G are sequentially applied to ˜Y _n ), smooth addressing may be performed.

At this time, the display data signal applied to each of the address electrode lines A _R1 to A _{Bm is} supplied with the positive address voltage V _A when the discharge cell is selected and the ground voltage V _G when the discharge cell is not selected. Accordingly, when the display data signal of the positive address voltage V _A is applied while the scan pulse of the ground voltage V _G is applied, wall charges are formed by the address discharge in the corresponding discharge cell. Wall charges do not form. In addition, the second voltage V _S is applied to the X electrode lines X ₁ to X _{n for} more accurate and efficient address discharge.

To this end, a pulse-shaped voltage is repeatedly applied to the address electrode, and the address electrode and the ground terminal are connected to the pulse voltage, thereby causing rapid current change. Therefore, by inserting the current control element shown in Figures 5 to 8 according to the present invention between the electrode and the ground terminal to control the rapid current change, it is possible to reduce or control the generation of EMI.

In the sustain discharge period PS, the display sustain pulse of the second voltage V _S is alternately applied to all the Y electrode lines Y ₁ to Y _n and the X electrode lines X ₁ to X _n . In the corresponding address period PA, a discharge for maintaining the display is generated in discharge cells in which wall charges are formed.

To this end, a pulse type voltage is repeatedly applied to the sustain electrodes (the X electrode and the Y electrode), and the sustain electrode and the ground terminal are connected to the pulse voltage, thereby causing rapid current change. Therefore, by inserting the current control element shown in Figures 5 to 8 according to the present invention between the electrode and the ground terminal to control the rapid current change, it is possible to reduce or control the generation of EMI.

FIG. 5 is a circuit diagram schematically illustrating an address driver of a driving apparatus of a plasma display panel using an inductor as a current control element between a switching element and a ground terminal according to an exemplary embodiment of the present invention. FIG. 6 is a circuit diagram schematically illustrating an address driver of a driving device of a plasma display panel using a resistance between the switching element and the ground terminal as a current control element according to another exemplary embodiment of the present invention.

FIG. 7 is a circuit diagram schematically illustrating an address driver of a driving device of a plasma display panel using an inductor as a current control device between an electrode and a switching device according to another exemplary embodiment of the present invention. FIG. 8 is a circuit diagram schematically illustrating an address driver of a driving apparatus of a plasma display panel using a resistance as an element for controlling current between an electrode and a switching element according to an exemplary embodiment of the present invention.

Referring to the drawings, the driving apparatus of the plasma display panel drives a display panel in which discharge cells are formed in an area where a plurality of electrodes intersect, at least one of the electrodes A _j and a ground terminal GND. A switching element S2 connected therebetween to control a connection between the electrode A _j and a ground terminal GND; And current control elements L5, L7, R6, and R8 connected between the switching element S2 and the ground terminal GND to control a current flowing from the electrode A _j to the ground terminal GND. Characterized in that.

As shown in FIG. 2, the driving apparatus of the plasma display panel includes an image processor 21, a logic controller 22, an address driver 23, an X driver 24, and a Y driver 25. In this case, the address driver 23 may be connected between the power input terminal Va and the address electrode A _j .

The address driver 23 includes a first control switch S1, a second control switch S2, and current control elements L5, L7, R6, and R8. The first control switch (S1) is controlled as to whether the power supply Va to the power input terminal (Va) and the address electrode (A _j) is connected between an address electrode (A _j) from the power input terminal (Va). The second control switch (S2) is connected between the address electrode (A _j) and the ground terminal (GND), and controls the connection or the ground terminal (GND) of the address electrode (A _j).

The current control elements L5, L7, R6, and R8 may be disposed between the address electrode A _j and the second control switch S2 (FIGS. 5 and 6), or the second control switch S2 and the ground terminal GND. 7 and 8) to control abrupt current flow, thereby reducing or controlling EMI generation. That is, EMI is usually represented by the amount of change in the current per hour. In this case, when the address electrode A _j and the ground terminal GND are directly connected by the current control elements L5, L7, R6, and R8. It is possible to control the rapid flow of current that can flow, thereby reducing or controlling the EMI that may be caused by a sudden current change.

In particular, when a voltage is applied to the address electrode A _j in the form of a pulse, a sudden current change may occur at the lower portion of the pulse voltage, but the current control elements L5, L7, R6, By R8), such abrupt current flow can be limited to reduce EMI generation.

The current control elements L5 and R6 may be connected between the second control switch S2 and the ground terminal GND, as shown in FIGS. 5 and 6. In another embodiment, the current control elements L7 and R8 may be connected between the address electrode A _j and the second control switch S2 as shown in FIGS. 7 and 8.

The current control element is preferably an impedance element (L5, L7, R6, R8) for controlling the rapid current flow. In this case, the current control element may be an inductor (L5, L7) as in the embodiment shown in Figures 5 and 7, as another embodiment, the resistance as in the embodiment shown in Figures 6 and 8 (R6, R8) can be.

In addition, as another embodiment, the current control element may be mainly used for suppressing high frequency, and an inductor having a ferrite core having a good permeability, that is, a bead may be used.

In the present embodiment, the present invention has been described mainly with reference to an embodiment in which an element for controlling current is inserted between the address electrode and the ground terminal to reduce or control EMI. However, the present invention is not limited thereto. That is, the ground terminal and the electrode are connected to each other, it is also applicable to the X electrode and the Y electrode of Figure 1, the voltage of the pulse form having a falling portion flowing current rapidly through the ground terminal.

The plasma display panel, its driving device, and the driving method shown in FIGS. 1 to 4 are just one embodiment to which the driving method of the plasma display panel according to the present invention can be applied, and various other plasma display panels and its driving method. Applicable to the device and the driving method.

According to the display panel driving apparatus according to the present invention, by inserting a current control element between the switching element for controlling the connection of the electrode line and the ground terminal and the ground terminal, controlling the current flowing from the electrode line through the ground terminal to reduce the EMI You can.

Although the present invention has been described with reference to one embodiment shown in the accompanying drawings, it is merely an example, and those skilled in the art may realize various modifications and equivalent other embodiments therefrom. I can understand. Accordingly, the true scope of protection of the invention should be defined only by the appended claims.

Claims (9)

To drive a display panel in which discharge cells are formed in an area where a plurality of electrodes cross each other. A switching element connected between at least one of the electrodes and a ground terminal to control a connection between the electrode and the ground terminal; And And a current control element connected between the switching element and the ground terminal to control a current flowing from the electrode to the ground terminal. The method of claim 1, And the current control element is an impedance element. The method of claim 1, And the current control element is a resistor. The method of claim 1, And the current control element is an inductor. The method of claim 1, And the current control element is a bead. The method of claim 1, The plurality of electrodes includes an address electrode, a Y electrode for causing an address discharge between the address electrode, and an X electrode for causing a sustain discharge between the Y electrode and the discharge cell for causing the address discharge. , And the electrode is an address electrode. To drive a display panel in which discharge cells are formed in an area where a plurality of electrodes cross each other. A switching element connected between at least one of the electrodes and a ground terminal to control a connection between the electrode and the ground terminal; And And a current control element connected between the electrode and the switching element to control a current flowing from the electrode to the ground terminal. The method of claim 7, wherein And the current control element is an impedance element. The method of claim 7, wherein The plurality of electrodes includes an address electrode, a Y electrode for causing an address discharge between the address electrode, and an X electrode for causing a sustain discharge between the Y electrode and the discharge cell for causing the address discharge. , And the electrode is an address electrode.

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