KR20060001358A - Driving apparatus of plasma display panel - Google Patents

Abstract

An object of the present invention is to provide a driving device of a plasma display panel which replaces and supplies a bias voltage applied to a sustain electrode with a sustain discharge voltage.

In order to achieve the above object, the present invention provides a reset period for initializing all cells, an address period for selecting a cell to be turned on, and a sustain discharge in the selected cell. In the driving apparatus of the plasma display panel for applying a driving signal having a sustain discharge period,

An upper switch having one end connected to a power supply voltage terminal to which a sustain discharge voltage is applied;

One end is connected to the other end of the upper switch, the other end has a lower switch connected to the ground,

A drive device for a plasma display panel is provided, wherein a bias voltage is supplied to a sustain electrode by switching of an upper switch and a lower switch in an address period.

Description

Driving apparatus for plasma display panel {Driving apparatus of plasma display panel}

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

FIG. 2 shows a typical driving apparatus of the plasma display panel shown in FIG. 1.

3 is a timing diagram illustrating an example of a driving signal of the panel illustrated in FIG. 1.

4 is a view showing a drive device of the present invention.

5 is a view illustrating a signal flow for supplying a bias voltage according to the present invention using the driving apparatus of FIG. 4.

6 is a timing diagram for explaining a driving signal according to the present invention.

7 is a block diagram schematically illustrating a plasma display panel according to the present invention.

Explanation of symbols on main parts of drawing

1 ... plasma display panel, 100 ... front glass substrate,

102, 110, dielectric layer, 104 ... protective layer,

106 ... rear glass substrate, 108 ... discharge space,

112 fluorescent layer, 114 bulkhead,

A ₁ , A ₂ , ..., A _{m ...} address electrode line,

X ₁ , ..., X _n ... X electrode line, Y ₁ , ..., Y _n ... Y electrode line,

X _na , Y _na ... transparent electrode line, X _nb , Y _nb ... metal electrode line,

200 image processing unit, 202 logic control unit,

204 ... Y drive, 206 ... address drive,

208 ... X drive, Vs ... Dielectric potential voltage,

Vg ... ground voltage, Va ... address voltage,

Xs ... top field effect transistor, Xg ... bottom field effect transistor, Cp ... panel capacitor, 401 ... energy recovery circuit,

 403 ... X drive circuit, 700 ... power supply.

The present invention relates to a driving device of a plasma display panel, and more particularly, to a driving device of a plasma display panel in which a bias voltage supplied to a plasma display panel is replaced with a sustain discharge voltage.

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

Referring to FIG. 1, between the front and rear glass substrates 100 and 106 of a conventional surface discharge plasma display panel 1, the address electrode lines A ₁ ,. A ₂ , ..., A _m ), Dielectric layers 102 and 110, Y electrode lines Y ₁ , ..., Y _n , X electrode lines X ₁ , ..., X _n , fluorescent layer 112, barrier rib 114, and As a protective layer, the magnesium monoxide (MgO) layer 104 is provided, for example.

Address electrode lines A ₁ , A ₂ , ..., A _m ) is formed in a predetermined pattern on the front side of the rear glass substrate 106. The lower dielectric layer 110 includes the address electrode lines A ₁ ,. A ₂ , ..., A _m ) is applied to the front. In front of the lower dielectric layer 110, barrier ribs 114 may include address electrode lines A ₁ ,. A ₂ , ..., A _m ) is formed in a direction parallel to. The partition walls 114 function to partition a predetermined area of each display cell and to prevent optical interference between each display cell. The fluorescent layer 112 is formed between the partition walls 114.

The X electrode lines X ₁ ,..., X _n and the Y electrode lines Y ₁ , ..., Y _n are the address electrode lines A ₁ ,. A ₂ , ..., A _m ) is formed in a predetermined pattern on the back of the front glass substrate 100 to be orthogonal to each other. Each intersection sets a corresponding display cell. Each X electrode line (X ₁ , ..., X _n ) and each Y electrode line (Y ₁ , ..., Y _n ) are transparent electrode lines (X _na ) made of a transparent conductive material such as indium tin oxide (ITO). , Y _na ) and metal electrode lines X _nb and Y _nb for increasing conductivity may be formed. The front dielectric layer 102 is formed by applying the entire surface to the rear of the X electrode lines (X ₁ ,..., X _n ) and the Y electrode lines (Y ₁ ,..., Y _n ). A protective layer 104 for protecting the panel 1 from a strong electric field, for example, a magnesium monoxide (MgO) layer, is formed by applying a front surface to the back of the front dielectric layer 102. The plasma forming gas is sealed in the discharge space 108.

A driving scheme generally applied to such a plasma display panel is a method in which initialization, address, and display holding steps are sequentially performed in a unit sub-field. In the initialization step, the state of charge of the display cells to be driven becomes uniform. In the address step, the charge state of display cells to be selected and the charge state of display cells not to be selected are set. In the display holding step, display discharge is performed in selected display cells. At this time, a plasma is formed from the plasma forming gas of the display cells performing display discharge, and the fluorescent layer 112 of the display cells is excited by ultraviolet radiation from the plasma to generate light.

2 illustrates a general driving device of the plasma display panel of FIG. 1.

Referring to the drawings, a typical driving apparatus of the plasma display panel 1 includes an image processor 200, a logic controller 202, an address driver 206, an X driver 208, and a Y driver. The image processing unit 200 converts an external analog image signal into a digital signal, and internal image signals such as 8-bit red (R), green (G), and blue (B) image data, clock signals, vertical and Generate horizontal sync signals. The address driver 206 processes the address drive control signal SA from the logic controller 202 to generate a display data signal, and applies the generated display data signal to the address electrode lines. The X driver 208 processes the X drive control signal SX from the logic controller 202 and applies it to the X electrode lines. The Y driver 204 processes and applies the Y drive control signal SY from the logic controller 202 to the Y electrode lines.

As a driving method of the plasma display panel 1 having the above-described structure, an address-display separation driving method mainly used is disclosed in US Pat. No. 5,541,618.

FIG. 3 is a timing diagram illustrating an example of a driving signal of the panel shown in FIG. 1 and applied to the address electrode A, the sustain electrode X, and the scan electrodes Y1 to Yn in one subfield SF. The drive signal to be displayed. One subfield SF includes a reset period PR, an address period PA, and a sustain discharge period PS.

The reset period PR applies a reset pulse to all of the scan lines of all groups and forcibly performs a write discharge, thereby initializing the wall charge states of all cells. In the address period PA, the bias voltage Vb is applied to the sustain electrode X, and the display cells are turned on simultaneously by turning on the scan electrodes Y1 to Yn and the address electrodes A1 to Am at the cell positions to be displayed. Choose. After the address period PA is performed, the sustain pulse Vs is alternately applied to the sustain electrodes X and the scan electrodes Y1 to Yn to perform the sustain discharge period PS. During the sustain discharge period PS, a low level voltage Vg is applied to the address electrodes A1 to Am. In PDP, the brightness is adjusted by the number of sustain discharge pulses. If the number of sustain discharge pulses in one subfield or one TV field is large, the luminance increases.

In the X driver 208 shown in FIG. 2, a switching unit for supplying the bias voltage Vb to the sustain electrode X is used, and a switch circuit using the sustain discharge voltage Vs is also used to supply the sustain pulse. Doing. Conventionally, by further including a switch circuit for supplying the bias voltage Vb to the sustain electrode X in the X driver 208, the manufacturing cost of the plasma display panel is thereby increased.

In order to solve the above problems, an object of the present invention is to provide a driving device of a plasma display panel in which a bias voltage applied to a sustain electrode is replaced with a sustain discharge voltage.

In order to achieve the above object, the present invention provides a reset period for initializing all cells, an address period for selecting a cell to be turned on, and a sustain period for the address electrode, sustain electrode, and scan electrode. A driving apparatus of a plasma display panel for applying a driving signal having a sustain discharge period in which discharge is performed,

An upper switch having one end connected to a power supply voltage terminal to which a sustain discharge voltage is applied;

One end is connected to the other end of the upper switch, the other end has a lower switch connected to the ground,

A drive device for a plasma display panel is provided, wherein a bias voltage is supplied to a sustain electrode by switching of an upper switch and a lower switch in an address period.

According to another aspect of the present invention, the upper switch and the lower switch switching of the upper switch is turned on, the lower switch may be turned off.

According to another feature of the present invention, both the upper switch and the lower switch may be a field effect transistor.

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

4 is a view showing a drive device of the present invention.

Referring to the drawings, FIG. 4 is a view showing the X driving device 208. The X driving device 208 is largely divided into an energy recovery circuit 401 and an X driving circuit 403.

The X driving circuit 403 includes an upper switch having one end connected to a power supply voltage terminal to which the sustain discharge voltage Vs is applied, and one end connected to the other end of the upper switch, and the other end having a lower switch Xg connected to ground. .

Both the upper and lower switches can be field effect transistors (FETs). Therefore, a power supply voltage terminal to which the sustain discharge voltage Vs is applied is connected to the drain terminal of the upper field effect transistor Xs, and a control signal for operating the upper field effect transistor Xs is input to the gate terminal. To the drain terminal of the lower field effect transistor Xg is connected. The source terminal of the lower field effect transistor Xg is connected to ground, and a control signal for operating the lower field effect transistor Xg is input to the gate terminal. The source terminal of the upper field effect transistor Xs and the drain terminal of the lower field effect transistor Xg are connected to one end of the panel capacitor Cp, and the other end of the panel capacitor Cp is connected to ground.

The energy recovery circuit 401 recovers and stores the charges remaining in the panel capacitor Cp at the end of the application of the sustain discharge voltage Vs in the sustain discharge period (PS in FIG. 3), and applies the sustain discharge voltage Vs. It serves to supply the recovered energy to the panel capacitor (Cp) at the time.

Referring to the operation, immediately before the sustain discharge voltage Vs is applied, the first switching element Xr is turned on to supply charges charged in the energy storage capacitor Cxerc to the panel capacitor Cp, and for energy storage. When the voltage supplied from the capacitor Cxerc reaches its maximum value, the upper field effect transistor Xs is turned on to rise to the sustain discharge voltage Vs and supplied to the panel capacitor Cp, and the application of the sustain discharge voltage Vs Upon termination, the second switching element Xf is turned on to collect the charges remaining in the panel capacitor Cp and store the charges in the energy storage capacitor Cxerc.

An object of the present invention is to replace the bias voltage applied to the sustain electrode X in the address period PA with the sustain discharge voltage Vs applied in the sustain discharge period. That is, the separate switching unit for supplying the bias voltage in the conventional X driver 208 is removed, and instead, the bias voltage is supplied through the switching unit supplying the sustain discharge voltage Vs. Therefore, the bias voltage is supplied to the operation of the X driving circuit 403. In this manner, the circuit of the X driver 208 can be simplified, and the manufacturing cost of the plasma display panel can be reduced.

5 is a view illustrating a signal flow for supplying a bias voltage according to the present invention using the driving apparatus of FIG. 4.

Referring to the operation of applying the sustain discharge voltage Vs as the bias voltage in the address period (PA of FIG. 3), the upper field effect transistor Xs connected to the power supply voltage terminal to which the sustain discharge voltage Vs is applied is turned on. In this case, the lower field effect transistor Xg may be turned off. Therefore, the sustain discharge voltage VS is applied to the panel capacitor Cp via the upper field effect transistor Xs.

6 is a timing diagram for explaining a driving signal according to the present invention.

Referring to FIGS. 4 and 6, a driving signal is applied to the address electrode, the sustain electrode, and the scan electrode to drive the plasma display panel, and accordingly, the plasma display panel is discharged by discharge in the discharge cells constituting the pixel. The image is displayed on the screen.

The drive signal has a reset period PR, an address period PA, and a sustain discharge period PS. First, in the reset period PR, initialization discharge is performed on all cells to generate an even wall charge distribution in the discharge cells. To this end, a ground voltage is applied to the address electrode A, and a rising ramp signal and a falling ramp signal are applied to the scan electrode Y. A bias voltage is applied to the sustain electrode X when the falling ramp signal is applied. Initialization discharge is performed centering on the weak discharge due to the potential difference between the scan electrode and the sustain electrode.

Next, in the address period, address discharge for selecting a cell to be turned on is performed. Scanning electrodes Y1, Y2, ..., Yn The scan signals having the negative scan voltage Vscan are applied to each scan electrode line with time, and the address electrodes A1, A2, ..., Am are applied. ), A display data signal having an address voltage Va is applied to select the corresponding display cell. At this time, a positive bias voltage is applied to the sustain electrodes X1, X2, ..., Xn so as to smoothly perform the address discharge in the cells to be turned on, and to prevent erroneous discharges from occurring in the cells that will not be turned on. The address discharge is mainly caused by the potential difference between the scan electrode Y and the address electrode A, thereby accumulating wall charges in the discharge cell.

Next, in the sustain discharge period PS, sustain discharge is performed in the discharge cells selected in the address period PA. For this purpose, a sustain pulse having a sustain discharge voltage is alternately applied to the scan electrode Y and the sustain electrode X. The sustain discharge is generated by the potential difference between the scan electrode Y and the sustain electrode X, and also uses the wall charges accumulated inside the discharge cell in the address period PA. Therefore, the sustain discharge voltage Vs may be applied at a voltage lower than the discharge start voltage.

 In general, the bias voltage is lower than the sustain discharge voltage, but in the driving apparatus of the present invention, by removing the switching unit applying the bias voltage to simplify the circuit and reduce the cost of the driving apparatus of the plasma display panel in accordance with the present invention. The sustain discharge voltage Vs is applied as a bias voltage through a switching unit that applies a voltage.

7 is a block diagram schematically illustrating a plasma display panel according to the present invention.

Referring to the description, the image processing unit 200 receives an external production signal and processes the signal to output an internal image signal. The logic controller 202 receives the internal image signal and performs an X driving control signal SX, a Y driving control signal SY, and an address driving control signal SA through a gamma correction and an automatic power control (APC) step. Output Each driver 204, 206, or 208 receives respective drive control signals SY, SA, and SX and outputs each drive signal to the panel.

In particular with respect to the present invention, the X driver can simply implement the circuit by removing the switching unit for supplying the bias voltage.

The power supply unit 700 supplies the control voltage Vc and the ground voltage Vg to the image processor 200 and the logic controller 202, and the sustain discharge voltage Vs and the final rise voltage to the Y driver 204. Vset, the final falling voltage Vnf, the scan voltage Vscan, and the ground voltage Vg are supplied, and the address driver 206 is supplied with the address voltage Va and the ground voltage Vg. In relation to the present invention, since the X driver 208 uses the sustain discharge voltage Vs instead of the bias voltage, the power supply 700 supplies the sustain discharge voltage Vs and the ground voltage (Vs) to the X driver 208. It is enough to supply Vg).

In a plasma display panel driven with a high voltage, the power supply 700 must supply various high voltages, thereby increasing costs and complicated circuits. However, in connection with the present invention, by using the sustain discharge voltage Vs as a bias voltage by simplifying the circuit of the X driver 208, the power supply 700 may also be more easily implemented.

According to the present invention as described above, the following effects can be obtained.

First, since the switching part for supplying the bias voltage in the X driving part can be removed, the circuit can be simplified and the cost can be reduced.

Secondly, there is no need to supply a conventional bias voltage in the power supply, resulting in the effect of simplifying the power supply and reducing costs.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (3)

A plasma display for applying a drive signal having a reset period for initializing all cells, an address period for selecting a cell to be turned on, and a sustain discharge period for sustain discharge in the selected cell, to the address electrode, the sustain electrode, and the scan electrode. In the driving device of the panel,  An upper switch having one end connected to a power supply voltage terminal to which a sustain discharge voltage is applied; One end is connected to the other end of the upper switch, the other end has a lower switch connected to the ground, And in the address period, a bias voltage is supplied to the sustain electrode by switching between the upper switch and the lower switch. The method of claim 1, wherein the switching of the upper switch and the lower switch, And the upper switch is turned on and the lower switch is turned off. The method of claim 2, wherein the upper switch and the lower switch is A driving device of a plasma display panel, wherein all of them are field effect transistors.

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