KR100458585B1 - A driving apparatus of plasma display panel and the method thereof - Google Patents

Abstract

The present invention relates to a driving apparatus for a plasma display panel and a driving method thereof. A driving device of a plasma display panel according to an aspect of the present invention is a driving device of a plasma display panel in which a panel capacitor is formed, including: a first power supply supplying a first voltage and one end connected in series between one end of the panel capacitor; A first driver including a second switching element, a third switching element connected in series between a contact point of the first and second switching elements, and a second power supply for supplying a second voltage; And fourth and fifth switching elements connected in series between a third power supply for supplying a third voltage and one end of the panel capacitor, and a fourth power supply for supplying a fourth voltage and a contact point of the fourth and fifth switching elements. And a second driver including a sixth switching element and a second inductor connected in series. Therefore, the present invention can use a low voltage withstand voltage switching element without using a separate external power supply or an additional circuit, so that the circuit can be easily implemented and the cost can be reduced.

Description

A driving device of a plasma display panel and a driving method thereof {A DRIVING APPARATUS OF PLASMA DISPLAY PANEL AND THE METHOD THEREOF}

The present invention relates to a driving apparatus for a plasma display panel and a driving method thereof.

In general, a plasma display panel (PDP) is a flat panel display device that displays characters or images by using plasma generated by gas discharge, and a matrix of tens to millions or more of pixels is matrixed according to its size. It is arranged in (matrix) form. In addition, the plasma display panel is classified into a direct current type (DC type) and an alternating current type (AC type) according to the shape of the driving voltage waveform applied and the structure of the discharge cell.

The structural difference between the direct current type and the alternating current type is that in the direct current type, the electrode is exposed to the discharge space as it is, so that the current flows in the discharge space while the voltage is applied. Therefore, in the case of direct current type, there is a disadvantage in that the resistance for current limitation must be made externally. On the other hand, in the case of the AC type, the dielectric layer covers the electrode so that the current is limited by the natural capacitive formation, and the life is longer than that of the DC type because the electrode is protected from the impact of ions during discharge. The memory characteristic, which is one of the important characteristics of the AC plasma display panel, also comes from the capacitive property of the dielectric layer covering the electrode.

In the light emission principle of the AC plasma display panel, a pulse type potential difference is formed between the common electrode (or the X electrode) and the scan electrode (or the Y electrode) to generate a discharge, and the vacuum ultraviolet rays generated in the discharge process are red (R). While being excited by the phosphors of green (G) and blue (B), each phosphor emits light by light combination.

In the AC plasma display panel, since the X and Y electrodes for the sustain discharge act as capacitive loads, capacitance is present on the X and Y electrodes, and in order to apply the waveform for the sustain discharge, reactive power other than the power for the discharge is required. This is necessary. A circuit for recovering and reusing such reactive power is called a sustain discharge circuit (or a power recovery circuit).

In the panel driving method using the X electrode and the Y electrode driving circuit, one frame includes n subfields, and one subfield includes a reset period, a scan period, a sustain period, and an erase period. It is composed.

In the reset period, all address electrodes A1 to Am and all sustain electrodes (or X electrodes) are kept at 0 V in the first half, and voltages which are equal to or lower than the discharge start voltage with respect to the sustain electrodes on all scan electrodes (or Y electrodes). A voltage exceeding the discharge start voltage is applied from the above, and a voltage equal to or lower than the discharge start voltage is applied to all the scan electrodes in the second half of the reset period. During the scan period, all scan electrodes are held at the scan voltage, a positive scan pulse voltage is applied to the address electrode corresponding to the discharge cell to be displayed on the first row of the addressing electrodes, and a scan pulse voltage (0 V is applied to the scan electrode of the first row). ) Are simultaneously applied to allow wall charge to accumulate. In the sustain period, a predetermined sustain pulse is applied to all the scan electrodes and the sustain electrodes so that sustain discharge occurs in a gray scale to be expressed in the discharge cells. In the erase period, a predetermined erase pulse is applied to all sustain electrodes to stop the sustain discharge.

Hereinafter, driving of the sustain discharge circuit of the conventional AC plasma display panel will be described.

1A and 1B are diagrams showing a conventional sustain discharge circuit and operation waveforms.

As in the accompanying Figure 1a, L.F. The sustain discharge circuits proposed by Weber (US Pat. Nos. 4,866,349 and 5,081,400) are sustain discharge circuits (or power recovery circuits) of an AC plasma display panel, and a drive circuit of an AC plasma display panel is a sustain discharge circuit of an X electrode. 10 and the sustain discharge circuit 11 (not shown) of the Y electrode are constituted in the same manner. Hereinafter, the sustain discharge circuit for one electrode will be described for convenience.

The conventional sustain discharge circuit 10 includes a power recovery unit consisting of two switches S1 and S2, a diode D1 and D2, and a power recovery capacitor Cc, and two switches S3 and S4 connected in series. The sustain discharge unit includes a sustain discharge unit configured to be connected to an inductor Lc between the diodes D1 and D2 of the power recovery unit and the two switches S3 and S4 of the sustain discharge unit, and a capacitor of the plasma display panel. The load with Cp) is connected. At this time, the display of the parasitic elements is omitted.

The conventional sustain discharge circuit configured as described above is operated in four modes according to the switching sequence operation of the switches S1 to S4 as shown in FIG. 1B, and the output voltage Vp according to the switching sequence operation. ) And waveforms of the current IL flowing through the inductor Lc appear.

In the initial state, immediately before the switch S1 is turned on, the switch S4 is turned on so that the voltage Vp at both ends of the panel is maintained at 0V. At this time, the power recovery capacitor Cc is precharged with a voltage Vs / 2 equal to 1/2 of the externally applied voltage Vs so that an inrush current does not occur at the start of sustain discharge.

In this state in which the voltage Vp of both ends of the panel is maintained at 0 V, when the time t0 is reached, the mode 1 operation in which the switch S1 is turned on and the switches S2, S3, and S4 are turned off It begins.

In the operation period t0 to t1 of the mode 1, the LC resonant circuit is formed by the path of the power recovery capacitor Cc, the switch S1, the diode D1, the inductor Lc, and the plasma panel capacitor Cp. The current IL flows through the inductor Lc and the output voltage Vp of the panel increases.

At this time, as shown in FIG. 1B, the current IL flowing through the inductor Lc gradually decreases due to a parasitic resistance (not shown) and becomes 0 at time t1, and the output voltage Vp of the panel is applied to the external applied voltage ( Vs).

When mode 1 is completed, mode 2 begins, with switches S1 and S3 turned on and switches S2 and S4 turned off. In the operation period t1 to t2 of the mode 2, the externally applied voltage Vs flows directly to the panel capacitor Cp through the switch S3 to maintain the output voltage Vp of the panel.

When mode 2 is completed while the discharge of the output voltage Vp of the panel is maintained, mode 3 starts when the switch S2 is turned on and the switches S1, S3, and S4 are turned off.

In the operation period t2 to t3 of the mode 3, the path opposite to that of the mode 1, that is, the plasma panel capacitor Cp, the inductor Lc, the diode D1, the switch S2 and the power recovery capacitor Cc The LC resonant circuit is formed by the path of the current, and as shown in FIG. 2, the current IL flows through the inductor Lc, and the output voltage Vp of the panel decreases so that the current IL and the inductor Lc at time t3. The panel output voltage Vp is zero.

In the operation period t3 to t4 of the mode 4, the switches S2 and S4 are turned on, and the switches S1 and S3 are turned off to keep the panel output voltage Vp at 0V. In this state, when the switch S1 is turned on again, the cycle is repeated with the operation of the mode 1.

By the way, in the conventional sustain discharge circuit, the breakdown voltages of the switches S1 and S2 are the voltage Vs, and the breakdown voltages of the switches S3 and S4 are the voltage Vs. It is difficult to implement low-cost sustain discharge driving circuit because of the use of expensive switch elements.

Therefore, an object of the present invention is to provide a driving apparatus for a plasma display panel and a driving method thereof, which can be implemented using a low breakdown voltage element by reducing the breakdown voltage of a switching element.

1A and 1B are diagrams showing a conventional sustain discharge circuit and operation waveforms.

2A and 2B are diagrams showing the entire operation waveforms of the sustain discharge circuit according to the embodiment of the present invention.

3 is a view showing the operation of the first mode of the sustain discharge circuit according to the embodiment of the present invention.

4 is a view showing the operation of the second mode of the sustain discharge circuit according to the embodiment of the present invention.

5 is a view showing the operation of the third mode of the sustain discharge circuit according to the embodiment of the present invention.

6 is a view showing the operation of the fourth mode of the sustain discharge circuit according to the embodiment of the present invention.

7 is a view showing the operation of the fifth mode of the sustain discharge circuit according to the embodiment of the present invention.

8 is a view showing the operation of the sixth mode of the sustain discharge circuit according to the embodiment of the present invention.

*** Description of the symbols for the main parts of the drawings ***

10: sustain discharge circuit of X electrode 11: sustain discharge circuit of Y electrode

100: first resonator 200: second resonator

300: panel

A driving device of a plasma display panel according to an aspect of the present invention for achieving the technical problem is a driving device of a plasma display panel in which a panel capacitor is formed, between a first power supply for supplying a first voltage and one end of the panel capacitor. A first and second switching elements connected in series, a third switching element and a first inductor connected in series between the contacts of the first and second switching elements and a second power supply for supplying a second voltage. 1 drive unit; And fourth and fifth switching elements connected in series between a third power supply for supplying a third voltage and one end of the panel capacitor, and a fourth power supply for supplying a fourth voltage and a contact point of the fourth and fifth switching elements. And a second driver including a sixth switching element and a second inductor connected in series.

In addition, the driving apparatus of the plasma display panel according to an aspect of the present invention further comprises first to fourth capacitors connected in series between the first power source and the third power source,

The second power source is formed by a voltage charged in the second to fourth capacitors connected in series, and the fourth power source is formed by a voltage charged in the fourth capacitor.

In addition, the first to fourth capacitors are characterized in that they have the same capacitance.

In addition, the first to sixth switching elements are characterized in that it has a body diode.

In addition, the driving device of the plasma display panel in which the panel capacitor according to another aspect of the present invention is formed,

And a first inductor, wherein the first inductor is electrically connected between the panel capacitor and a first power supply for supplying a first voltage to the terminal voltage of the panel capacitor using resonance of the panel capacitor and the first inductor. A first resonator configured to raise the voltage to a second voltage; And a second inductor, wherein the second inductor is electrically connected between the panel capacitor and a second power supply for supplying a third voltage, thereby utilizing the resonance of the panel capacitor and the second inductor to terminal of the panel capacitor. And a second resonator configured to raise the voltage to the fourth voltage.

In this case, the second resonator lowers the terminal voltage of the panel capacitor to the second voltage by using resonance of the first inductor and the panel capacitor.

The first resonator lowers the terminal voltage of the panel capacitor to a fifth voltage by using resonance of the second inductor and the panel capacitor.

When the terminal voltage of the panel capacitor rises to a fourth voltage, the second resonator electrically connects the panel capacitor to a third power supply for supplying the fourth voltage to maintain the terminal voltage of the panel capacitor at the fourth voltage. and,

When the terminal voltage of the panel capacitor is lowered to the fifth voltage, the first resonator electrically connects the panel capacitor to a fourth power supply for supplying a fifth voltage to maintain the terminal voltage of the panel capacitor at the fifth voltage. do.

Further, first to fourth capacitors are connected in series between the third power source and the fourth power source, the first power source is formed by a voltage charged in the fourth capacitor, and the second power source is connected in series. It is formed by the voltage charged in the connected second to fourth capacitor.

The second voltage may be substantially equal to half the difference between the fourth voltage and the fifth voltage.

In addition, a method of driving a plasma display panel in which a panel capacitor is formed according to an aspect of the present invention includes: a) a terminal of the panel capacitor using resonance of the panel capacitor and a first inductor electrically connected to one end of the panel capacitor; Raising the voltage to the first voltage; b) raising the terminal voltage of the panel capacitor to the second voltage by using the resonance of the panel capacitor and the second inductor electrically connected to one end of the panel capacitor while the terminal voltage of the panel capacitor is raised to the first voltage; ; c) lowering the terminal voltage of the panel capacitor from the second voltage to the first voltage by using resonance of the second inductor and the panel capacitor; And d) lowering a terminal voltage of the panel capacitor from the first voltage to a third voltage by using resonance of the first inductor and the panel capacitor.

The step b) includes maintaining the terminal voltage of the panel capacitor at the second voltage using a first power supply for supplying the second voltage;

Step d) includes maintaining a terminal voltage of the panel capacitor as the third voltage by using a second power supply for supplying the third voltage.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings the most preferred embodiment that can be easily carried out by those of ordinary skill in the art as follows.

2A is a diagram illustrating a sustain discharge circuit according to an embodiment of the present invention.

As shown in FIG. 2, the sustain discharge circuit according to an exemplary embodiment of the present invention includes a wall charge accumulated on each electrode according to driving signals of the resonator 100, the resonator 200, and the resonator 200, 100. And a panel 300 in which sustain discharge is performed to display a desired gray scale.

The resonator 100 includes three switches M1, M2, and M5 and an inductor L1. Each switch is a MOSFET, and further includes a body diode and an internal capacitor according to the MOSFET characteristics.

The resonator 200 is symmetrical with the resonator 100 based on the panel 300, and includes three switches M3, M4, and M6 and an inductor L2.

Hereinafter, with reference to the accompanying drawings, the operation of the sustain discharge circuit according to an embodiment of the present invention will be described in detail.

2B is a view showing an entire operation waveform of the sustain discharge circuit according to the embodiment of the present invention.

As shown in FIG. 2B, the operation of the sustain discharge circuit according to an exemplary embodiment of the present invention includes a mode 1 section t0 to t1 for charging the capacitor Cp of the panel 300 to a voltage Vs / 2, Mode 2 section t1 to t2 for charging capacitor Cp to voltage Vs, Mode 3 section t2 to t3 for maintaining capacitor Cp at high level (+ Vs) for sustain discharge, Mode 4 section (t3 ~ t4) for discharging capacitor Cp of panel 300 to voltage Vs / 2, mode 5 section (t4 ~ t5) for discharging capacitor Cp to 0, for sustain discharge It is divided into a mode 6 section (t5 ~ t6) for keeping the capacitor (Cp) at zero. To explain the situation of the initial state, it is assumed that the currents I _L1 and I _L2 of the inductor are 0 and the voltage Vp across the panel is 0 in the first mode 1 section t0 to t1.

The capacitances of the capacitors C1 to C4 are the same, and the voltages Vs / 4 are respectively charged in the capacitors C1 to C4.

3 is a diagram illustrating an operation in a mode 1 section of a sustain discharge circuit according to an exemplary embodiment of the present invention.

As shown in FIG. 3, when the switch M6 is turned on in the mode 1 section t0 to t1, the capacitor C4-the switch M6-the inductor L2-the body diode of the switch M3-the panel capacitor A resonance path is formed between Cp. At this time, the current I _L2 flowing through the inductor L2 is a resonant current caused by the inductor L2 and the panel capacitor Cp, and the voltage of the power recovery capacitor C4 maintains the voltage Vs / 4. Therefore, as shown in FIG. 2B, when the current I _L2 has a peak value, the voltage across the panel capacitor Cp rises to the voltage Vs / 4, and the current I _L2 flowing through the inductor _L2 . The voltage Vp at both ends of the panel becomes the voltage Vs / 2 at a time t1 at which t gradually decreases to zero.

Meanwhile, as shown in FIG. 4, when the mode 1 section ends and the switch M6 is disconnected at the time t1 in the mode 2 section t1 to t2 and the switch M2 is turned on, the capacitor C2-switch A resonance path is formed between the body diode-inductor L1-switch M2-panel capacitor Cp of M5. At this time, the current I _L1 flowing through the inductor L1 is a resonant current caused by the inductor L1 and the panel capacitor Cp, and the voltage of the power recovery capacitor C2 maintains the voltage (3Vs / 4). because there is time to have the current (I _L1) peak value as shown in 4b panel capacitor (Cp) and the voltage across the raised to the voltage (3Vs / 4), the current (I _L1), the time (t2 gradually decreases to be zero ), The voltage Vp at both ends of the panel becomes the voltage Vs.

Meanwhile, as shown in FIG. 5, when the switch M1 is turned on while the mode M section is finished and the switch M2 is turned on at the time t2 in the mode 3 section t2 to t3, the voltage of the panel is turned on. Vp is maintained at the voltage Vs applied from the outside.

At this time, a voltage equal to the difference (3Vs / 4) between the voltage Vs of the panel capacitor Cp and the voltage Vs / 4 of the capacitor C4 at both ends of the switch M3 by the body diode of the switch M6. The voltage (3Vs / 4) is applied to both ends of the switch M5 by the body diode of the switch M2. In addition, if the characteristics of the switch M3 and the switch M4 are the same, the voltage Vs / 2 is applied to both ends of the switch M4.

In addition, since the switch M5 and the switch M6 are turned off and no current flows through the inductor L1 and the inductor L2 in the mode 3 section, the inductor current I _L1 and the inductor current I _L2 as shown in FIG. 2B. ) Becomes 0, and the mode 3 section ends when the switch M1 is blocked at time t3.

On the other hand, when the switch M5 is turned on as shown in FIG. 6 at the time t3 in the mode 4 section t3 to t4, the panel capacitor Cp-the body diode of the switch M2-the inductor L1- A resonant path is formed by the switch M5-capacitor C2. In the inductor L1, the resonance current I _L1 caused by the inductor L1 and the panel capacitor Cp flows in the direction of the arrow, and energy is recovered along this path.

At this time, the absolute value of the resonant current I _L1 gradually increases to a peak value and then gradually decreases as shown in FIG. 2B. When the absolute value of the resonant current I _L1 has a peak value, the voltage at both ends of the panel is increased. (Vp) decreases to voltage (3Vs / 4), and at time t4 at which the absolute value of resonant current I _L1 gradually decreases to zero, the voltage Vp at both ends of the panel is equal to voltage (Vs / 2). do. At this time, if the switch M5 is blocked at time t4, the mode 4 section ends.

Meanwhile, when the switch M6 and the switch M3 are conducted as shown in FIG. 7A at the time t4 in the mode 5 section t4 to t5, the panel capacitor Cp-switch M3-inductor L2 )-A resonant path is formed in the body diode of the switch M6-the capacitor C4 so that the resonant current I _L2 flows in the inductor L2 by the inductor L2 and the panel capacitor Cp in the direction of the arrow. Energy recovery occurs along the path. The breakdown voltage applied to the switch M6 at time t4 is the voltage Vs / 4, and the breakdown voltage applied to the switch M4 is the voltage Vs / 2.

At this time, the absolute value of the resonant current I _L2 gradually increases to a peak value and then gradually decreases as shown in FIG. 7B. When the absolute value of the resonant current I _L2 has a peak value, the voltage at both ends of the panel is increased. The voltage Vp decreases to the voltage Vs / 4, and the voltage Vp at both ends of the panel becomes zero at a time t5 at which the absolute value of the resonance current I _L2 gradually decreases to zero. At this time, if the switch M6 is blocked at time t5, the mode 5 section ends.

On the other hand, after the end of the mode 5 section, when the switch M4 is turned on as shown in FIG. 8A while the switch M3 is turned on, the voltage Vp across the panel is maintained at zero. In addition, in the mode 6 section, the voltage (3Vs / 4) is applied to both ends of the switch M2 by the body diode of the switch M5, and the voltage Vs / 4 is applied to both ends of the switch M6. In addition, if the characteristics of the switch M1 and the switch M2 are the same, the voltage Vs / 2 is applied to both ends of the switch M1.

In addition, since the switch M5 and the switch M6 are turned off and no current flows through the inductor L1 and the inductor L2 in the mode 6 section, the inductor current I _L1 and the inductor current I _L2 as shown in FIG. 8B. ) Becomes 0, and at time t6, when switch M4 is cut off and switch M6 is turned on, mode 1 is repeated again.

As described above, according to the exemplary embodiment of the present invention, the maximum voltages applied to both ends when the switches M1 to M6 are turned off are Vs / 2, 3Vs / 4, 3Vs / 4, Vs / 2, and Vs / 4, respectively. , Vs / 4. Therefore, as the switches M1 to M6, transistors having breakdown voltages of Vs / 2, 3Vs / 4, 3Vs / 4, Vs / 2, Vs / 4 and Vs / 4 can be used.

The drawings and detailed description of the invention are merely exemplary of the invention, which are used for the purpose of illustrating the invention only and are not intended to limit the scope of the invention as defined in the appended claims or claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

As described above, according to the present invention, the breakdown voltage of the switch was reduced by charging and discharging the voltage of the panel capacitor in two steps with two resonators. Therefore, a low voltage switching device can be used even without a separate external power supply or an additional circuit, thereby facilitating circuit implementation and reducing costs.

Claims (11)

In a driving device of a plasma display panel in which a panel capacitor is formed, First and second switching elements connected in series between a first power supply for supplying a first voltage and one end of the panel capacitor, and a contact between the first and second switching devices and a second power supply for supplying a second voltage. A first driver including a third switching element and a first inductor connected in series; And Between the fourth and fifth switching elements connected in series between the third power supply for supplying a third voltage and one end of the panel capacitor, between the contacts of the fourth and fifth switching elements and the fourth power supply for supplying a fourth voltage. A second driver including a sixth switching element and a second inductor connected in series Driving device of the plasma display panel comprising a. The method of claim 1, Further comprising first to fourth capacitors connected in series between the first power source and the third power source, And the second power source is formed by a voltage charged in the second to fourth capacitors connected in series, and the fourth power source is formed by a voltage charged in the fourth capacitor. The method of claim 1, And the first to fourth capacitors have the same capacitance. The method of claim 1, And the first to sixth switching elements have a body diode. In a driving device of a plasma display panel in which a panel capacitor is formed, And a first inductor, wherein the first inductor is electrically connected between the panel capacitor and a first power supply for supplying a first voltage to the terminal voltage of the panel capacitor using resonance of the panel capacitor and the first inductor. A first resonator configured to raise the voltage to a second voltage; And And a second inductor, wherein the second inductor is electrically connected between the panel capacitor and a second power supply for supplying a third voltage to the terminal voltage of the panel capacitor using resonance of the panel capacitor and the second inductor. Second resonator to raise the voltage to the fourth voltage Driving device of the plasma display panel comprising a. The method of claim 5, The second resonator unit, Lowering the terminal voltage of the panel capacitor to the second voltage by using resonance of the first inductor and the panel capacitor; The first resonator, A terminal voltage of the panel capacitor is lowered to a fifth voltage by using resonance of the second inductor and the panel capacitor. Driving device of plasma display panel. The method of claim 6, The second resonator unit, When the terminal voltage of the panel capacitor rises to the fourth voltage, the panel capacitor is electrically connected to a third power supply for supplying the fourth voltage to maintain the terminal voltage of the panel capacitor at the fourth voltage. The first resonator, When the terminal voltage of the panel capacitor is lowered to the fifth voltage, the panel capacitor is electrically connected to a fourth power supply for supplying a fifth voltage to maintain the terminal voltage of the panel capacitor at the fifth voltage. Driving device of plasma display panel. The method of claim 5, First to fourth capacitors are connected in series between the third power source and the fourth power source. The first power source is formed by a voltage charged in the fourth capacitor, and the second power source is formed by a voltage charged in the second to fourth capacitors connected in series. Driving device of plasma display panel. The method of claim 5, And the second voltage is substantially half the difference between the fourth voltage and the fifth voltage. In the method of driving a plasma display panel in which a panel capacitor is formed, a) raising a terminal voltage of the panel capacitor to a first voltage by using a resonance of the panel capacitor and a first inductor electrically connected to one end of the panel capacitor; b) raising the terminal voltage of the panel capacitor to the second voltage by using the resonance of the panel capacitor and the second inductor electrically connected to one end of the panel capacitor while the terminal voltage of the panel capacitor is raised to the first voltage; ; c) lowering the terminal voltage of the panel capacitor from the second voltage to the first voltage by using resonance of the second inductor and the panel capacitor; And d) lowering the terminal voltage of the panel capacitor from the first voltage to a third voltage by using resonance of the first inductor and the panel capacitor; Method of driving a plasma display panel comprising a. The method of claim 10, The step b) includes maintaining the terminal voltage of the panel capacitor at the second voltage using a first power supply for supplying the second voltage; The step d) includes maintaining the terminal voltage of the panel capacitor as the third voltage by using a second power supply for supplying the third voltage. A method of driving a plasma display panel.