KR20050006108A - A plasma display panel, a driving apparatus and a method of the plasma display panel - Google Patents

Abstract

PURPOSE: A plasma display panel and its driving apparatus and its driving method are provided to perform zero voltage switching without regard to parasitic component of an actual circuit. CONSTITUTION: The plasma display panel includes a panel having a plurality of first electrodes and a plurality of second electrodes and a panel capacitor formed by the first electrode and the second electrode. And a driver unit drives the first electrode and the second electrode. According to the driver unit, a sustain discharge unit(322) includes switches, and sustains a voltage of the first electrode or the second electrode to the first voltage or the second voltage. The first charge/discharge unit(324) changes the voltage of the first electrode. And the second charge/discharge unit(326) changes the voltage of the second electrode.

Description

Plasma display panel, driving device thereof and driving method thereof {A PLASMA DISPLAY PANEL, A DRIVING APPARATUS AND A METHOD OF THE PLASMA DISPLAY PANEL}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel (PDP), a driving apparatus and method thereof, and more particularly, to a power recovery circuit and a driving method thereof that directly contribute to plasma display light emission.

Recently, flat display devices such as liquid crystal displays (LCDs), field emission displays (FEDs), and PDPs have been actively developed. Among these flat panel display devices, PDPs have advantages of higher luminance and luminous efficiency and wider viewing angles than other flat panel display devices. Therefore, the PDP is in the spotlight as a display device to replace the conventional cathode ray tube (CRT) in a large display device of 40 inches or more.

PDPs are flat display devices that display characters or images using plasma generated by gas discharge, and dozens to millions or more of pixels are arranged in a matrix according to their size. Such PDPs are 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.

In the DC-type PDP, since the electrode is exposed to the discharge space as it is, the current flows in the discharge space while voltage is applied, and there is a disadvantage in that a resistance for current limitation must be made for this purpose. On the other hand, in the AC type PDP, the electrode covers the dielectric layer, so the current is limited by the formation of a natural capacitance component, and the electrode is protected from the impact of ions during discharge.

1 is a partial perspective view of an AC plasma display panel.

As shown in FIG. 1, the scan electrode 4 and the sustain electrode 5 covered with the dielectric layer 2 and the protective film 3 are arranged in parallel on the first glass substrate 1. A plurality of address electrodes 8 covered with the insulator layer 7 are provided on the second glass substrate 6. A partition 9 is formed on the insulator layer 7 between the address electrodes 8 in parallel with the address electrode 8. In addition, the phosphor 10 is formed on the surface of the insulator layer 7 and on both side surfaces of the partition wall 9. The first glass substrate 1 and the second glass substrate 6 have a discharge space 11 therebetween so that the scan electrode 4 and the address electrode 8 and the sustain electrode 5 and the address electrode 8 are orthogonal to each other. They are arranged to face each other. The discharge space at the intersection of the address electrode 8 and the pair of the scanning electrode 4 and the sustain electrode 5 forms a discharge cell 12.

2 shows an electrode arrangement diagram of the plasma display panel.

As shown in Fig. 2, the PDP electrode has a matrix structure of m x n. Specifically, the address electrodes A1 to Am are arranged in the column direction, and the scan electrodes Y1 to n rows in the row direction. Yn) and sustain electrodes X1 to Xn are arranged in a zigzag. The discharge cell 12 shown in FIG. 2 corresponds to the discharge cell 12 shown in FIG.

Generally, the driving method of the AC PDP is composed of a reset (initialization) period, a write (addressing) period, a sustain period, and an erase period.

The reset period is a period of initializing the state of each cell in order to smoothly perform an addressing operation on the cell, and the write period is a wall charge on a cell (addressed cell) that is turned on by selecting a cell that is turned on and a cell that is not turned on. This is the period during which the stacking operation is performed. The sustain period is a period in which discharge for actually displaying an image is performed on the addressed cell, and the erase period is a period in which the wall discharge of the cell is reduced to end the sustain discharge.

In the AC type PDP, the scan electrodes (hereinafter referred to as 'Y electrodes') and the sustain electrodes (hereinafter referred to as 'X electrodes') for sustaining discharge serve as capacitive loads. There is a capacitance with respect to the electrode, and reactive power is required in addition to the power for the discharge in order to apply the waveform for the sustain discharge. A circuit for recovering and reusing such reactive power is called a power recovery circuit (or sustain discharge circuit).

Hereinafter, a power recovery circuit of a conventional AC plasma display panel and a driving method thereof will be described.

3 and 4 show a conventional power recovery circuit and its operating waveforms.

As in the accompanying Figure 3, L.F. The power recovery circuits proposed by Weber (US Pat. Nos. 4,866,349 and 5,081,400) are power recovery circuits of an AC plasma display panel, and a driving circuit of an AC plasma display panel includes a power recovery circuit 10 of an X electrode and a Y electrode. The power recovery circuits 11 (not shown) are each configured identically. Hereinafter, a power recovery circuit for one electrode will be described for convenience.

The conventional power recovery circuit 10 includes a power recovery unit including two switches Sa and Sb, diodes D1 and D2, an inductor Lc, and a power recovery capacitor Cc, and two connected in series. The sustain discharge part comprised from the switches Sc and Sd is included.

A plasma display panel is connected to a contact between two switches Sc and Sd of the sustain discharge portion, and the plasma display panel is equivalently represented by a capacitor Cp.

The conventional power recovery circuit configured as described above is operated in four modes according to the switching operation of the switches Sa to Sd, as shown in FIG. 4, and is applied to the output voltage Vp and the inductor Lc according to the switching operation. The waveform of the flowing current I _{L is} shown, respectively.

In the initial state, immediately before the switch Sa is turned on, the switch Sd 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 sustain discharge voltage Vs so that an inrush current does not occur at the start of sustain discharge.

In the state where the voltage Vp at both ends of the panel is maintained at 0 V, when the time t0 is reached, the operation of Mode 1 in which the switch Sa is turned on and the switches Sb, Sc, and Sd are turned off It begins.

In the operation period t0 to t1 of the mode 1, the LC resonant circuit is formed in the path of the power recovery capacitor Cc, the switch Sa, the diode D1, the inductor Lc, and the plasma panel capacitor Cp. Therefore, as shown in FIG. 4, the current I _L flowing in the inductor Lc is half-waved by LC resonance, and the output voltage Vp of the panel gradually increases to almost maintain the discharge voltage Vs. do. At this time, almost no current flows through the inductor Lc when the output voltage Vp of the panel becomes the sustain discharge voltage Vs.

When mode 1 is completed, mode 2 is started in which switches Sa and Sc are turned on and switches Sb and Sd are 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 Sc to maintain the output voltage Vp of the panel. At this time, since the voltage across the switch Sc is ideally zero at t1, zero voltage switching is performed.

When mode 2 is completed while the discharge of the panel output voltage Vp is maintained, mode 3 starts when the switch Sb is turned on and the switches Sa, Sc, and Sd 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 D2, the switch S2, and the power recovery capacitor Cc is in the path to the LC resonance circuit is formed, the current in the inductor (Lc), as shown in Fig. 4 (I _L) flows to the output voltage (Vp) of the panel is decreased current in the inductor (Lc) in the t3 time (I _L) And the panel output voltage Vp becomes zero.

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

However, in the conventional power recovery circuit as described above, it is impossible for the switch constituting the circuit to switch zero voltage by the parasitic components of the actual circuit (parasitic resistance of the inductor, parasitic resistance of the capacitor and panel, conduction resistance of the switch), Accordingly, there is a problem that the switching loss is very large when the switch is turned on. That is, according to the conventional power recovery circuit, ideally, when one terminal of the panel capacitor is increased by the sustain discharge voltage (Vs), the magnetic energy stored in the inductor (Lc) is zero, so the panel is caused by the parasitic component of the actual circuit. If one terminal of the capacitor does not reach the sustain discharge voltage Vs, there is no voltage source to raise one terminal of the panel capacitor to the voltage Vs. Therefore, there is a problem in that the zero voltage switching of the actual switch Sc is impossible and the switching loss becomes very large when the switch is turned on.

In the conventional power recovery circuit, the power recovery capacitor Cc should always be charged by the voltage Vs / 2 immediately after the start of light emission, and at the start of the sustain discharge pulse in the state where the power recovery capacitor is not charged by Vs / 2. There is a problem in that a very large inrush current is generated and a protection circuit for limiting the inrush current is provided separately.

In addition, in the conventional power recovery circuit, the panel voltage rises or falls long, so that the panel discharge may occur in an energy recovery period (a panel voltage rises or falls). In this case, a drop of the panel voltage occurs to generate a sustain switch ( There is a problem that Sc) is hard switched, so that the switching loss is very large when the switch is turned on.

In order to solve such a problem, the technical problem to be achieved by the present invention is to provide a driving device and a driving method of the plasma display panel to enable the zero voltage switching in spite of the parasitic components of the actual circuit.

Another object of the present invention is to provide a driving apparatus and a driving method of the plasma display panel which can remove the inrush current at the start of the sustain discharge operation.

Another object of the present invention is to provide a driving apparatus and a driving method of a plasma display panel which shortens a rising or falling period of a panel voltage so that discharge can occur in a sustaining period.

1 is a partial perspective view of an AC plasma display panel.

2 is an electrode array diagram of a plasma display panel.

3 and 4 show a conventional power recovery circuit and its driving waveforms, respectively.

5 illustrates a plasma display panel according to an exemplary embodiment of the present invention.

6 is a view showing a power recovery circuit according to an embodiment of the present invention.

7A to 7H are diagrams showing an operation mode of the power recovery circuit shown in FIG. 6, respectively.

8 is a diagram showing operation timings according to the first embodiment of the present invention.

9 is a view showing charge and discharge current of the inductor according to the first embodiment of the present invention.

Fig. 10 is a diagram showing operation timings according to the second embodiment of the present invention.

11 is a view showing charge and discharge current of the inductor according to the second embodiment of the present invention.

12 is a diagram showing operation timing according to the third embodiment of the present invention.

13 is a view showing charge and discharge current of the inductor according to the third embodiment of the present invention.

14 is a diagram showing a power recovery circuit according to a fourth embodiment of the present invention.

Fig. 15 shows an equivalent circuit of Mode 2 according to the embodiment of the present invention.

Driving apparatus for a plasma display panel according to an aspect of the present invention for achieving the above object is

A driving device of a plasma display panel including a plurality of scan electrodes and sustain electrodes paired with each other and arranged in a zigzag pattern, wherein a panel capacitor is formed between the scan electrodes and sustain electrodes.

First and second switches connected in series between a first voltage and a second voltage, the contacts being connected to one end of the panel capacitor, and connected in series between the first voltage and the second voltage and the contacts being connected to the panel. A sustain discharge unit including third and fourth switches connected to the other end of the capacitor, the sustain discharge unit maintaining a voltage of a terminal of the panel capacitor as the first voltage or the second voltage; First and second capacitors connected in series between the first voltage and the second voltage, fifth and sixth switches connected in parallel to the contacts between the first and second capacitors, respectively; A first charge / discharge unit including a first inductor connected to a contact point of a six switch and one end of the panel capacitor, wherein the first charge / discharge unit charges one end of the panel capacitor to the first voltage or discharges to the second voltage; And third and fourth capacitors connected in series between the first voltage and the second voltage, and seventh and eighth switches connected in parallel to the contacts between the third and fourth capacitors, respectively. And a second inductor connected to a contact point of an eighth switch and one end of the panel capacitor, and a second charge / discharge unit configured to charge or discharge the other end of the panel capacitor to the first voltage.

The driving method of the plasma display panel according to an aspect of the present invention used in such a driving apparatus is

A first step of conducting the second and third switches to maintain the voltage at one end and the other end of the panel capacitor at the second voltage and the first voltage, respectively; A second step of charging the first inductor and the second inductor by turning on the fifth and eighth switches while the second and third switches are turned on; A third step of turning off the second and third switches while the fifth and eighth switches are conductive to invert the polarities of the voltages at both ends of the panel capacitor; A fourth step of recovering energy stored in the first and second inductors by turning on the first and fourth switches while the fifth and eighth switches are in a conductive state; A fifth step of turning off the fifth and eighth switches while the first and fourth switches are in a conductive state to maintain one end and the other end of the panel capacitor at the first voltage and the second voltage, respectively. .

On the other hand, the driving device of the plasma display panel according to another feature of the present invention

A driving device of a plasma display panel including a plurality of scan electrodes and sustain electrodes paired with each other and arranged in a zigzag pattern, wherein a panel capacitor is formed between the scan electrodes and sustain electrodes.

First and second switches connected in series between a first voltage and a second voltage, the contacts being connected to one end of the panel capacitor, and connected in series between the first voltage and the second voltage and the contacts being connected to the panel. A sustain discharge unit including third and fourth switches connected to the other end of the capacitor, the sustain discharge unit maintaining a voltage of a terminal of the panel capacitor as the first voltage or the second voltage; Fifth and sixth switches connected in parallel to a first capacitor and a first variable voltage connected in series between the first voltage and the second voltage, and a contact point between the first capacitor and the first variable voltage, respectively; A first charging and discharging unit including a first inductor connected to the contacts of the fifth and sixth switches and one end of the panel capacitor, the first charging and discharging unit charging one end of the panel capacitor to the first voltage or discharging to the second voltage; And seventh and eighth switches connected in parallel to a contact between the second capacitor and the second variable voltage, the second capacitor, and the second variable voltage connected in series between the first voltage and the second voltage, respectively. And a second inductor connected to the contacts of the seventh and eighth switches and the other end of the panel capacitor, wherein the second charge / discharge unit charges the other end of the panel capacitor to the first voltage or discharges the second voltage to the second voltage. Include.

On the other hand, the driving device of the plasma display panel according to another aspect of the present invention

A driving device of a plasma display panel including a plurality of scan electrodes and sustain electrodes paired with each other and arranged in a zigzag pattern, wherein a panel capacitor is formed between the scan electrodes and sustain electrodes.

First and second switches connected in series between a first voltage and a second voltage, the contacts being connected to one end of the panel capacitor, and connected in series between the first voltage and the second voltage and the contacts being connected to the panel. A sustain discharge unit including third and fourth switches connected to the other end of the capacitor, the sustain discharge unit maintaining a voltage of a terminal of the panel capacitor as the first voltage or the second voltage; And first and second inductors electrically connected to one end and the other end of the panel capacitor, and boosting current while the voltage at both ends of the panel capacitor maintains the sustain discharge voltage. And a charge / discharge unit configured to store energy and change polarities of voltages across the panel capacitor using energy stored in the first and second inductors.

On the other hand, the plasma display panel according to the features of the present invention

A panel including a plurality of address electrodes and a plurality of scan electrodes and sustain electrodes crossing the address electrodes and arranged in a zigzag pair with each other, wherein a panel capacitor is formed between the scan electrodes and the sustain electrodes; A control unit for receiving an image signal from the outside and generating an address driving control signal and a sustain discharge signal; An address driver which receives the address drive control signal from the controller and applies a display data signal to the address electrode to select a discharge cell to be displayed; A scan / maintenance driving unit configured to receive a sustain discharge signal from the controller and perform sustain discharge for a selected discharge cell by alternately inputting a sustain discharge voltage to a scan electrode and a sustain electrode,

The scanning and holding drive unit

First and second switches connected in series between a first voltage and a second voltage, the contacts being connected to one end of the panel capacitor, and connected in series between the first voltage and the second voltage and the contacts being connected to the panel. A sustain discharge unit including third and fourth switches connected to the other end of the capacitor, the sustain discharge unit maintaining a voltage of a terminal of the panel capacitor as the first voltage or the second voltage; And first and second inductors electrically connected to one end and the other end of the panel capacitor, and boosting the current to a predetermined level for the next sustain discharge while the voltage at both ends of the panel capacitor maintains the sustain discharge voltage. And a charge / discharge unit configured to store energy in the first and second inductors, and to change polarities of voltages at both ends of the panel capacitor using energy stored in the first and second inductors.

On the other hand, the driving method of the plasma display panel according to another aspect of the present invention

A driving method of a plasma display panel including a plurality of scan electrodes and sustain electrodes paired with each other and arranged in a zigzag pattern, wherein a panel capacitor is formed between the scan electrodes and sustain electrodes.

While the voltage across the panel capacitor maintains the sustain discharge voltage of the first polarity, the current flowing through the first and second inductors electrically connected to one end and the other end of the panel capacitor is boosted to boost the first and second currents. A first step of storing energy in the inductor; A second step of changing the polarity of the voltage across the panel capacitor using energy stored in the first and second inductors; Recovering energy stored in the first inductor and the second inductor in a state where the voltage across the panel capacitor is changed to a sustain discharge voltage having a second polarity opposite to the first polarity; And a fourth step of maintaining the voltage across the panel capacitor to the sustain discharge voltage of the second polarity.

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

5 is a diagram illustrating a plasma display panel (PDP) according to an embodiment of the present invention.

As shown in FIG. 5, the PDP according to the embodiment of the present invention includes a plasma panel 100, an address driver 200, a scan / sustain driver 300, and a controller 400.

The plasma panel 100 includes a plurality of address electrodes A1 to Am arranged in a column direction, a plurality of scan electrodes Y1 to Yn arranged in a row direction, and a sustain electrode X1 to Xn. .

The address driver 200 receives an address drive control signal from the controller 200 and applies a display data signal for selecting a discharge cell to be displayed to each address electrode.

The scan / hold driver 300 receives a sustain discharge signal from the controller 200 and alternately inputs a sustain pulse voltage to the scan electrode and the sustain electrode to perform sustain discharge on the selected discharge cell.

The controller 400 receives an image signal from an external source, generates an address driving control signal and a sustain discharge signal, and applies the same to the address driver 200 and the scan and sustain driver 300, respectively.

The scan / maintenance driver 300 according to the embodiment of the present invention includes a power recovery circuit which is a circuit for recovering and reusing reactive power. The power recovery circuit 320 according to the first embodiment of the present invention is illustrated in FIG. Shown in

As shown in FIG. 6, the power recovery circuit 320 according to the embodiment of the present invention includes a sustain discharge unit 322, a Y electrode charge and discharge unit 324, and an X electrode charge and discharge unit 326.

The sustain discharge unit 322 includes four sustain switches Ys, Yg, Xs, and Xg each connected to a sustain discharge voltage Vs or a ground voltage, each of which has a MOSFET having a body diode. The voltages Vy and Vx of both terminals of the panel capacitor Cp maintain the sustain discharge voltage Vs or the ground voltage by the switching operation of these four switches.

The Y electrode charge / discharge unit 324 increases or decreases the voltage Vp between both ends of the power recovery capacitors Cyer1 and Cyer2 and the panel capacitor Cp connected in series between the sustain discharge voltage Vs and the ground voltage. To the energy recovery switches Yr and Yf connected in parallel with the contacts between the capacitors Cyer1 and Cyer2, and the inductor L1 formed between the contacts between the switches Yr and Yf and the panel capacitor Cp. do. In addition, the Y electrode charging and discharging unit 324 according to the embodiment of the present invention is connected to the switches (Yr, Yf), respectively, and sets the current path supplied to the panel capacitor Cp and the current path recovered from the panel capacitor ( Dy1, Dy2) may be further included. The Y electrode charge / discharge unit 324 charges the Y electrode terminal of the panel capacitor to the sustain discharge voltage (Vs) or discharges to the ground voltage.

The X electrode charge / discharge unit 326 increases or decreases the voltage Vp between both ends of the power recovery capacitors Cxer1 and Cxer2 and the panel capacitor Cp connected in series between the sustain discharge voltage Vs and the ground voltage. Energy recovery switches Xr and Xf connected in parallel with the contacts between the capacitors Cxer1 and Cxer2, and an inductor L2 formed between the contacts between the switches Xr and Xf and the panel capacitor Cp. do. In addition, the X electrode charging and discharging unit 326 according to an embodiment of the present invention is connected to the switches (Xr, Xf), respectively, and sets a current path supplied to the panel capacitor Cp and a current path recovered from the panel capacitor ( Dx1, Dx2) may be further included. The X electrode charging and discharging unit 326 serves to charge the X electrode terminal of the panel capacitor to the sustain discharge voltage (Vs) or to discharge the ground voltage.

Next, a driving method of the plasma display panel according to the first embodiment of the present invention will be described with reference to FIGS. 7A to 7H and 8.

7A to 7H are diagrams showing a current path in each mode according to the first embodiment of the present invention, and FIG. 8 is a diagram showing an operation timing diagram according to the first embodiment of the present invention.

In the first embodiment of the present invention, the switches (Yg, Xs) are turned on before the mode 1 starts, the voltages of Cyer1 = V1, Cyer2 = V2, Cxer1 = V3, Cxer2 = V4 are charged, and L1 = L2. Assume = L

① Mode 1 (t0-t1)-see Fig. 7A

In the mode 1 section, the switches Yr and Xf are turned on while the switches Yg and Xs are turned on. When the switch Yr of the Y electrode charge / discharge unit 324 is turned on while the switches Yg and Xs are turned on, the capacitor Cyer2-the switch Yr-the inductor L1-as shown in Fig. 7A. The current path is formed by the switch Yg. In addition, when the switch Xf of the X electrode charge / discharge unit 326 is turned on, a current path is formed by the switch Xs-inductor L2-switch Xf-capacitor Cxer2. Therefore, as shown in FIG. 8, in the mode 1 section, the current IL1 and the current IL2 flowing in the inductor L1 and the inductor L2 increase linearly with slopes of V2 / L and V4 / L, respectively. In addition, magnetic energy is accumulated in the inductor L1 and the inductor L2.

② Mode 2 (t1-t2)-see Fig. 7B

In the mode 2 section t1 to t2, the switches Xs and Yg are blocked while the switches Yr and Xf are turned on. Then, as shown in Fig. 7B, a current path is formed by the capacitor Cyer2-the switch Yr-the inductor L1-the panel capacitor Cp-the inductor L2-the switch Xf-the capacitor Cxer2. do. At this time, as shown in Fig. 8, the resonant current due to the panel capacitance flows through L1 and L2, and the voltage Vp at both ends of the panel capacitor is changed from -Vs to Vs. That is, in the mode 2 section, the voltage Vy of the Y electrode terminal of the panel capacitor Cp rises from the ground voltage to the discharge holding voltage Vs, and the voltage Vx of the X electrode terminal of the panel capacitor Cp discharges. Since the sustain voltage Vs drops to the ground voltage, the voltage Vp at both ends of the panel capacitor changes its polarity from -Vs to Vs.

③ Mode 3 (t2-t3)-see FIG. 7C

In mode 3, while the switches Yr and Xf are turned on, the switches Ys and Xg are turned on.

At t = t2, when the voltage Vy becomes Vs, the sustain discharge voltage, and the voltage Vx becomes the ground voltage, the body diodes of the switches (Ys, Xg) become conductive. At this time, as shown in Fig. 8, when the switches Ys and Xg are conducted, the voltage between the drain and the source of the switches Ys and Xg is conducted at zero voltage, that is, the switches Ys and Xg are zero. Because of the voltage switching, no turn-on switching losses of the switches (Ys, Xg) occur. According to the embodiment of the present invention, since energy is stored in the inductor L1 ideally even when the voltage of the Y electrode of the panel capacitor reaches the sustain discharge voltage Vs, the parasitic component of the circuit, etc. Even in this case, the voltage stored in the inductor L1 may increase the voltage of the Y electrode of the panel capacitor to Vs, the sustain discharge voltage. Therefore, even when the switch Ys has a parasitic component of the circuit, zero voltage switching can be performed.

In mode 3, as shown in FIG. 8, while the voltage Vp across the panel maintains the voltage (+ Vs), the current IL1 flowing in the inductor L1 of the Y electrode charge / discharge unit 324 is the capacitor Cyer1. The path of the body diode-power source Vs of the switch (Yr) -inductor (L1) -switch (Ys) has a slope of -V1 / L and decreases linearly to zero. That is, energy stored in the inductor L1 is recovered to the capacitor Cyer1 through the body diode of the switch Ys. In addition, the current IL2 flowing in the inductor L2 of the X electrode charge / discharge unit 326 is -V4 through the path of the body diode-inductor L2-switch Xf-capacitor Cxer2 of the switch Xg. It has a slope of / L and decreases linearly to zero. That is, the energy stored in the inductor L2 is recovered to the capacitor Cxer2 through the switch Xf.

Here, the currents IL1 and IL2 flowing through the inductors L1 and L2 having negative values mean that the current flows in a direction opposite to the reference direction.

④ Mode 4 (t3-t4)-see Figure 7D

In the mode 4 section, the switches Yr and Xf are cut off while the switches Ys and Xg are turned on, and the voltage Vp across the panel is maintained at the sustain discharge voltage (+ Vs).

During mode 4, the voltage Vy of the Y electrode of the panel capacitor maintains Vs, and the voltage Vx of the X electrode of the panel capacitor maintains the ground voltage. Therefore, the voltage Vp between the capacitors of the panel is + Vs. Keeps the panel to emit light.

⑤ Mode 5 (t4-t5)-see Fig. 7E

In the mode 5 section, the switches Yf and Xr are turned on while the switches Ys and Xg are turned on. When the switch Yf of the Y electrode charge / discharge unit 324 is conducted while the switches Ys and Xg are conducted, the current path is made to the switch Ys-inductor L1-switch Yf-capacitor Cyer2. Is formed. Further, when the switch Xr of the X electrode charging and charging unit 326 is turned on, a current path is formed by the capacitor Cxer2-the switch Xr-the inductor L2-the switch Xg as shown in FIG. 7E. . Therefore, as shown in FIG. 8, the current IL1 and the current IL2 flowing in the inductor L1 and the inductor L2 in the mode 5 section are linear with slopes of -V4 / L and -V2 / L, respectively. The magnetic energy is accumulated in the inductor L1 and the inductor L2.

⑥ Mode 6 (t5-t6)-see Figure 7F

In the mode 6 section t5 to t6, the switches Ys and Xg are blocked while the switches Xr and Yf are turned on. Then, as shown in FIG. 7F, a current path is formed by the capacitor Cxer2-the switch Xr-the inductor L2-the panel capacitor Cp-the inductor L1-the switch Yf-the capacitor Cyer2. do. At this time, as shown in FIG. 8, a resonant current flows due to the panel capacitance through L1 and L2, and the voltage Vp at both ends of the panel capacitor is changed from Vs to -Vs. That is, in the mode 6 section, the voltage Vx of the X electrode terminal of the panel capacitor Cp increases from the ground voltage to the discharge holding voltage Vs, and the voltage Vy of the Y electrode terminal of the panel capacitor Cp discharges. Since the voltage drops from the sustain voltage Vs to the ground voltage, the voltage Vp at both ends of the panel capacitor changes its polarity from Vs to -Vs.

⑦ Mode 7 (t6-t7)-see Fig. 7G

In mode 7, the switches Xs and Yg are turned on while the switches Xr and Yf are turned on.

When t = t6, when the voltage Vx becomes Vs, the sustain discharge voltage, and the voltage Vy becomes the ground voltage, the body diodes of the switches (Xs, Yg) become conductive. At this time, as shown in Fig. 8, when the switches Xs and Yg are conducted, the voltages between the drain and the source of the switches Xs and Yg are conducted at zero voltage, that is, the switches Xs and Yg are zero. Because of the voltage switching, no turn-on switching losses of the switches (Xs, Yg) occur.

In mode 7, the current IL1 flowing in the inductor L1 of the Y-electrode charge / discharge unit 324 is switched Yg while the voltage Vp across the panel maintains the voltage (-Vs) as shown in FIG. With a slope of V2 / L through the path of the body diode-inductor (L1) -switch (Yf) -capacitor (Cyer2), it linearly increases to zero. In other words, the energy stored in the inductor L1 is recovered to the capacitor Cyer2 through the switch Yf. In addition, the current IL2 flowing in the inductor L2 of the X electrode charge / discharge unit 326 is the body diode-power source Vs of the capacitor Cxer1-switch Xr-inductor L2-switch Xs. It has a slope of V3 / L with the path of and increases linearly to zero. That is, the energy stored in the inductor L2 is recovered to the capacitor Cxer1 through the body diode of the switch Xs.

⑧ Mode 8 (t7-t8)-see Fig. 7H

In the mode 8 section, the switches Xr and Yf are blocked while the switches Xs and Yg are turned on, and the voltage Vp across the panel is maintained at the sustain discharge voltage (-Vs).

During mode 8, the voltage Vx of the X electrode of the panel capacitor maintains Vs, and the voltage Vy of the Y electrode of the panel capacitor maintains the ground voltage. Therefore, the voltage across the capacitor of the panel maintains -Vs. The panel will emit light.

According to the first embodiment of the present invention described above, boosting the inductor current for energy recovery in Mode 1 and Mode 5 before changing the polarity of the panel capacitor Cp, and in the Mode 2 and Mode 6 panel capacitor By using the boosted current (energy) to change the polarity of, the terminals of the panel capacitor can be raised to the discharge holding voltage (Vs) or lowered to the ground voltage regardless of the power recovery rate. Therefore, according to the first embodiment of the present invention, zero voltage switching of the switch may be achieved by using a boosted current in the inductor.

On the other hand, the power recovery circuit according to the embodiment of the present invention shown in Figure 6 adjusts the section where the gate signal of the energy recovery switch (Yr, Yf, Xr, Xf) and the sustain switch (Ys, Yg, Xs, Xg) overlap Thus, the voltage levels of the energy recovery capacitors Cyer1, Cyer2, Cxer1, and Cxer2 can be adjusted.

That is, as in the first embodiment of the present invention shown in Fig. 8, the gate on signal of the sustain switches Ys, Xg; Xs, Yg overlaps with the gate on signal of the energy recovery switches Yr, Yf, Xr, and Yf. If the intervals are the same, as shown in Fig. 9, the charge / discharge currents of the capacitor Cyer2 and the capacitor Cxer2 are the same, so that the voltages V2 and V4 of the capacitors Cyer2 and Cxer2 are maintained at Vs / 2. Therefore, according to the first embodiment of the present invention, V1 = V2 = V3 = V4 = Vs / 2.

On the other hand, as in the second embodiment of the present invention shown in Fig. 10, the switch (Yf, Xf) is a section in which the gate signals of the energy recovery switches (Yr, Xr) and the sustain switches (Ys, Yg, Xs, Xg) overlap. If the gate signals of the sustain switches Ys, Yg, Xs, and Xg are longer than the overlapping period, as shown in FIG. 11, the discharge current of the capacitors Cyer2 and Cxer2 becomes larger than the charging current, so that the capacitors Cyer2, The voltages V2 and V4 at both ends of Cxer2 become smaller than Vs / 2.

On the contrary, as in the third embodiment shown in Fig. 12, the sections in which the gate signals of the energy recovery switches Yr and Xr and the sustain switches Ys, Yg, Xs and Xg overlap with each other are switched to the switches Yf and Xf. If the gate signals of (Ys, Yg, Xs, Xg) are made shorter than the overlapping section, as shown in FIG. Both voltages V2 and V4 become larger than Vs / 2.

The drive timing diagrams according to the second and third embodiments of the present invention shown in Figs. 10 and 12, respectively, use the same circuit as the power recovery circuit shown in Fig. 6, except that only the drive timing of the switch is different. . In addition, since the operation description of the power recovery circuit according to the second and third embodiments of the present invention can be easily understood by those skilled in the art from the previous description with reference to FIGS.

Thus, unlike the conventional circuit shown in Fig. 3, the power recovery circuit shown in Fig. 6 exists only as a voltage source for boosting the current of the voltage of the energy recovery capacitor, and keeps the voltage value at Vs / 2. The advantage is that there is no need.

On the other hand, the power recovery circuit according to the embodiment of the present invention shown in Figure 6 adjusts the section where the gate signal of the energy recovery switch (Yr, Yf, Xr, Xf) and the sustain switch (Ys, Yg, Xs, Xg) overlap By adjusting the voltage level of the energy recovery capacitor (Cyer1, Cyer2, Cxer1, Cxer2), the voltage level can be adjusted in the following manner.

14 is a diagram showing a power recovery circuit 340 according to a fourth embodiment of the present invention. As shown in Fig. 14, the power recovery circuit according to the fourth embodiment of the present invention includes a sustain discharge unit 342, a Y electrode charge and discharge unit 344, and an X electrode charge and discharge unit 346.

The sustain discharge unit 342, the Y electrode charge / discharge unit 344, and the X electrode charge / discharge unit 346 shown in FIG. 14 are the sustain discharge unit 322, the Y electrode charge / discharge unit 324, and the X electrode charge / discharge unit shown in FIG. The components and operations of 326 are almost the same, except that the capacitors Cyer2 and Cxer2 are replaced with the variable voltages Vyer2 and Vxer 2.

The power recovery circuit according to the fourth embodiment of the present invention shown in FIG. 14 fixes a section in which the energy recovery switches Yr, Yf, Xr, and Xf overlap with the gate signals of the sustain switches Ys, Yg, Xs, and Xg. In the state in which the gate on signal of the sustain switches Ys, Xg; The charge and discharge current of the capacitor can be adjusted by adjusting the voltage values of Vyer2 and Vxer2).

On the other hand, according to an embodiment of the present invention, the time required for the polarity inversion in mode 2 and mode ( ) Can be obtained as

First, the time required for polarity reversal ( The circuit state in mode 2 is modeled as shown in FIG. It is assumed here that L1 = L2 = L and V2 = V4 = V. At the initial condition t = t1, the inductor current IL and the voltage across the panel capacitor Vp are Ipk and Vs, respectively.

Here, Ipk is as Equation 1 below.

.

Based on this equivalent circuit, the time required for polarity reversal ( ) Is obtained from Equation 2 below.

here, to be.

As can be seen from Equation 2, according to the embodiment of the present invention, the polarity inversion time can be obtained by setting the inductor and the power recovery capacitor value. Therefore, according to an embodiment of the present invention, by appropriately selecting the inductance and the power recovery capacitance, the rise and fall time of the panel voltage can be shortened so that the panel can discharge in the discharge maintenance section except for the rise and fall of the panel voltage. Can be.

As mentioned above, although the Example of this invention was described, this invention is not limited only to the above-mentioned Example, A various other deformation | transformation and a change are possible.

For example, the power recovery circuit of the embodiment of the present invention uses a driving circuit of a plasma display panel as an example, but can also be used as a power recovery circuit of an element having another capacitive load.

As described above, the present invention enables zero voltage switching in spite of the parasitic component of the circuit, and prevents inrush current at the start of the sustain discharge operation. In addition, the present invention can shorten the rise and fall time of the panel voltage without increasing the current flowing through the driving element so that the panel can perform the discharge in the maintenance section except for the rise and fall of the panel voltage. Since the input voltage is divided and charged to the energy recovery capacitor when the circuit operation is started, a voltage of the internal voltage of the energy recovery switch is divided and applied at the initial startup, so that a switch having a low breakdown voltage can be used, thereby reducing costs and increasing efficiency. have.

Claims (3)

A panel including a plurality of first electrodes and a plurality of second electrodes, the panel capacitor being formed by the first electrode and the second electrode, and It includes a drive unit for driving the first electrode and the second electrode, The driving unit, First and second switches connected in series between a first voltage and a second voltage, the contacts being connected to the first electrode, and connected in series between the first voltage and the second voltage, the contact being connected to the second A sustain discharge unit including third and fourth switches connected to electrodes, the sustain discharge unit maintaining a voltage of the first electrode or the second electrode at the first voltage or the second voltage; First and second capacitors connected in series between the first voltage and the second voltage, fifth and sixth switches connected in parallel to the contacts between the first and second capacitors, respectively; A first charging and discharging unit including a first inductor connected between a contact of a sixth switch and the first electrode and changing a voltage of the first electrode; And Third and fourth capacitors connected in series between the first voltage and the second voltage, and seventh and eighth switches connected in parallel to the contacts between the third and fourth capacitors, respectively; A second charging and discharging unit including a second inductor connected between a contact of the eighth switch and the second electrode and changing a voltage of the second electrode Plasma display panel comprising a. A panel including a plurality of first electrodes and a plurality of second electrodes, the panel capacitor being formed by the first electrode and the second electrode, and It includes a drive unit for driving the first electrode and the second electrode, The driving unit, First and second switches connected in series between a first voltage and a second voltage, the contacts being connected to the first electrode, and connected in series between the first voltage and the second voltage, the contact being connected to the second A sustain discharge unit including third and fourth switches connected to electrodes, the sustain discharge unit maintaining a voltage of the first electrode or the second electrode at the first voltage or the second voltage; Fifth and sixth switches connected in parallel to a first capacitor and a first variable voltage connected in series between the first voltage and the second voltage, and a contact point between the first capacitor and the first variable voltage, respectively; A first charging and discharging unit including a first inductor connected between the contacts of the fifth and sixth switches and the first electrode, and changing a voltage of the first electrode; And A seventh and eighth switch connected in parallel to a contact between the second capacitor and the second variable voltage, the second capacitor and the second variable voltage connected in series between the first voltage and the second voltage, respectively A second charge / discharge unit including a second inductor connected between the contacts of the seventh and eighth switches and the second electrode, and changing a voltage of the second electrode Plasma display panel comprising a. The method according to claim 1 or 2, The first and second charging and discharging units inject current into the first and second inductors while the voltage of the first electrode or the second electrode is substantially maintained at the first voltage or the second voltage, And a voltage of the first electrode or the second electrode is changed by using current and resonance injected into the first and second inductors.