KR100757428B1 - A sustain driving circuit for plasma display panel - Google Patents

Abstract

The present invention relates to a sustain driving circuit of a plasma display panel which can increase the efficiency of the driving circuit by reducing the freewheeling current that may occur at the end of the rising and falling sections of the sustain pulse. A first electrode energy recovery unit for recovering energy from the first electrode and supplying the recovered energy to the second electrode of the panel; A second electrode energy recovery unit for recovering energy from the second electrode and supplying the recovered energy to the first electrode; First switching means for supplying the energy recovered in said second electrode energy recovery part to said first electrode when it is turned on; And a second switching means for supplying the energy recovered to the first electrode energy recovery unit to the second electrode when conducting, thereby pre-willing that may occur when the rising and falling sections of the sustain pulse are completed. By reducing the current, the efficiency of the entire circuit can be improved, and the overall cost can be reduced by eliminating the clamping diode that used to pass the freewill current.

Description

Sustain driving circuit of plasma display panel {A SUSTAIN DRIVING CIRCUIT FOR PLASMA DISPLAY PANEL}

1 is an embodiment of a sustain driving circuit of a conventional plasma display panel.

FIG. 2 is a waveform diagram of sustain voltages applied to a panel in FIG. 1 and a diagram of resonance current waveforms of an inductor.

3 is a current flow chart (a) in section t0 and a current flow chart (b) in section t1 of FIG.

4 is an embodiment of a sustain driving circuit of the plasma display panel of the present invention;

Figure 5 is a waveform diagram of the resonant current and the sustain voltage applied to each electrode of the panel according to the present invention.

6A to 6E are flowcharts illustrating the operation and current of the switches for each section 1 to 6 of FIG.

FIG. 7 is a resonance current waveform diagram of a sustain voltage and an inductor applied to each electrode of the panel for the simulation result of the circuit shown in FIG.

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

110: Y electrode energy recovery unit 120: first switching means (Y_er_up)

210: Z electrode energy recovery unit 220: second switching means (Z_er_up)

C _Y , C _Z : Capacitor D3: First Diode

D4: 2nd diode L _Y , L _Z : Inductor

Y_er_dn, Y_sus_up, Y_sus_dn, Z_er_dn, Z_sus_up, Z_sus_dn: switching means

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sustain driving circuit of a plasma display panel. In particular, the present invention relates to a plasma capable of increasing the efficiency of the driving circuit by reducing the freewheeling current which may occur at the end of the rising and falling sections of the sustain pulse. It relates to a sustain drive circuit of a display panel.

Currently, an energy recovery driving circuit that can efficiently use electric power by recovering energy supplied to an electrode and supplying it to the electrode is used in the sustain circuit of the plasma display panel (PDP).

Figure 1 shows a sustain drive circuit of a conventional PDP, showing an energy recovery circuit, one inductor (L) and capacitor (Css) for recovering and supplying energy, and through the on / off by a switching control signal Four switching means (S1-S4) forming a path for supplying and recovering energy to the sustain electrode of the panel, two diodes (D1, D2) for preventing reverse current, and a sustain voltage and a ground voltage It consists of two clamping diodes (DC1, DC2) to prevent unwanted resonances that may occur.

FIG. 2 shows a sustain voltage waveform (a) and a resonance current waveform (b) of the inductor in the driving circuit shown in FIG. 1, and as shown in FIG. 2, the current flowing through the inductor by LC resonance while the sustain voltage rises and falls. You can see that looks like a sine wave.

As can be seen in FIG. 2, it can be seen that the resonant current waveform flowing through the inductor L is inverted in the resonant current polarity of the inductor at the end of the rising period of the sustain voltage and the end of the polling period.

The current generated by the polarity inversion is consumed by heat, not an energy source, which will be described with reference to FIG. 3.

FIG. 3A shows the current path during the t0 period of the resonance current waveform of the inductor shown in FIG. 2. When LC resonance is over and the sustain switch S3 is turned on in the rising period of the sustain pulse, the potential of the inductor L rises to Vs. Done. In the state where the switch S3 is on, that is, the sus_up operation state in which the sustain voltage is applied to the panel, the diode D1 and the switch S2 are off and the capacitors parasitic in the diode D1 and the switch S2 because the capacitor Css is charged by Vs / 2. A current path for charging Vs / 2 (not shown) occurs, and the generated current is a current flowing in the t0 section.

In addition, since a constant current is already built in the inductor L, a current flowing during the t0 period needs a pass for freewheeling, which is driven as shown in FIG. 3B. The clamping diode DC1 connected to the power supply Vs flows for a period t1. Here, the prewilling current flowing to the DC1 is consumed as heat while prefreezing itself rather than being used as another energy source or returning to the input power source.

Of course, at the end of the polling period, the pre-willing current flowing by inverting the polarity of the inductor also flows to the clamping diode DC2 and is consumed as heat.

Accordingly, the present invention has been made to solve the above-mentioned conventional problems, Y and Z electrode energy recovery unit connected to the two sustain electrodes (Y, Z) of the panel respectively to supply and recover energy to the panel, and conduction If necessary, by including the switching means for supplying the energy stored in the energy recovery portion of one electrode (Y) to the other electrode (Z), the pre-willing that can occur when the rising section and the falling section of the sustain pulse is completed Reducing the current has the effect of improving the efficiency of the entire circuit.

The present invention for achieving the above object is the first electrode energy recovery unit for recovering energy from the first electrode of the panel, and supplying the recovered energy to the second electrode of the panel; A second electrode energy recovery unit for recovering energy from the second electrode and supplying the recovered energy to the first electrode; First switching means for supplying the energy recovered in said second electrode energy recovery part to said first electrode when it is turned on; And a second switching means for supplying the energy recovered in the first electrode energy recovery unit to the second electrode when the conductive material is turned on.

The apparatus may further include a diode between the first electrode energy recovery unit and the first electrode to prevent the energy recovered in the first electrode energy recovery unit from being supplied to the first electrode.

The method may further include a diode between the second electrode energy recovery unit and the second electrode to prevent the energy recovered in the second electrode energy recovery unit from being supplied to the second electrode.

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

First, in describing the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

In addition, many specific details, such as specific processing flows, are set forth in the following description to provide a more general understanding of the invention, but are not limited thereto, and it is understood that the invention may be practiced without these specific details. It will be self-evident to those of ordinary knowledge in Esau.

In general, the sustain drive circuit of the PDP recovers energy from the sustain electrode of the panel (er_dn operation), and the energy recovery circuit operation and sustain drive voltage (sus_up operation) for supplying the recovered energy back to the sustain electrode (er_up operation), and A ground voltage (sus_dn operation) is applied to the panel. In order to perform the energy recovery circuit operation, LC resonance is used to recover the energy to the capacitor and the capacitor to store the recovered energy and to supply the recovered energy to the panel. An inductor is required for this purpose. In addition, an er_up switch for performing the er_up operation, an er_dn switch for performing the er_dn operation, a sus_up switch for performing the sus_up operation, and a sus_dn switch for performing the sus_dn operation are required.

The er_up operation performs an operation of applying energy charged in a capacitor included in the driving circuit to the sustain electrode of the panel through an inductor. The er_up switch is turned on to form a path connecting the capacitor, the inductor, and the panel.

When the energy charged in the capacitor is supplied to the panel, a sus_up operation for applying a sustain voltage to the panel is performed through a sustain driving power supply. The sus_up operation is for applying a voltage Vs of the sustain driving power supply to the sustain electrode of the panel. In this case, the sus_up switch is turned on to form a path between the sustain driving power supply and the panel.

When the sus_up operation is completed, the er_dn operation is performed. The er_dn operation performs an operation of charging energy supplied to the sustain electrode of the panel with a capacitor, and turns on the er_dn switch to form a path connecting the panel, the inductor, and the capacitor. do.

When the er_dn operation is completed, the sus_dn operation is performed. The sus_dn operation performs an operation for applying a ground voltage to the sustain electrode of the panel, and turns on the sus_dn switch to form a path between the ground and the panel.

The present invention is to improve the overall efficiency of the sustain drive circuit for performing the above operation, to recover energy from each sustain electrode (Y, Z electrode) of the panel and to supply the recovered energy to the other sustain electrode And a switching means for supplying the energy stored in the electrode (for example, Y electrode) energy recovery unit to another electrode (for example, Z electrode) of the panel when conducting. When the rising interval of the corresponding electrode is completed, the energy stored in the energy recovery unit of the corresponding electrode is supplied to another electrode to reduce the pre-willing current that may occur when the rising interval and the sustaining period of the sustain pulse are completed. The point is to improve the efficiency of the entire circuit.

Each of the electrodes, for example, the Y electrode energy recovery unit, is connected in series with a capacitor, an inductor, and a switch for recovering energy from the panel, and the Y electrode energy recovery unit is recovered between the Y electrode energy recovery unit and the Y electrode of the panel. A diode for preventing energy from being supplied to the Y electrode should be provided, and one side of a switching means (for example, a Z_er_up switch) for applying energy stored in the Y electrode energy recovery unit to the Z electrode may recover the Y electrode energy. It is connected to the contact of the negative and the diode (for example, the first diode) and the other side is connected to the Z electrode of the panel. That is, one side of the switching means (for example, the Y_er_up switch) for applying the energy stored in the Z electrode energy recovery unit to the Y electrode has energy from the Z electrode energy recovery unit and the Z electrode energy recovery unit to the Z electrode of the panel. It is connected to the contact of the diode (for example, the second diode) to prevent the supply, the other side is connected to the Y electrode of the panel.

The energy stored in the Y electrode energy recovery unit is supplied to the Z electrode of the panel by turning on the Z_er_up switch when the polling period of the Y electrode sustain pulse is completed, and conversely, the energy stored in the Z electrode energy recovery unit is stored in the Z electrode sustain pulse. When the polling interval of is completed, the Y_er_up switch is turned on and supplied to the Y electrode of the panel.

4 shows an embodiment of the sustain drive circuit of the PDP according to the present invention, as shown in FIG. 110, a Z electrode energy recovery unit 210 for recovering energy from the Z electrode of the panel and supplying the recovered energy to the Y electrode, and the energy stored in the Y electrode energy recovery unit 110 is Y. The first diode D3 for preventing the supply of the electrode and the second diode D4 for preventing the energy stored in the Z electrode energy recovery unit 210 from being supplied to the Z electrode. The first switching means (Y_er_up switch) 120 for supplying the energy stored in the Z electrode energy recovery unit 210 to the Y electrode and the energy stored in the Y electrode energy recovery unit 110 are supplied to the Z electrode. And comprising a second switching means (Z_er_up switch) 220.

In addition, switching means for applying a sustain driving voltage (Vs) and a ground voltage to each electrode of the panel are configured, respectively. The configuration includes a Y_sus_up switch located between the Y electrode of the panel and the sustain driving power supply (Vs), A Z_sus_up switch located between a Z electrode and a sustain driving power supply, a Y_sus_dn switch located between the Y electrode and ground, and a Z_sus_dn switch located between the Z electrode and ground.

Each of the electrodes Y and Z energy recovery units 110 and 210 has a capacitor C _Y and C _Z having one side grounded for charging energy, an inductor L _Y and L _Z , and a switching means Y_er_dn switch, Z_er_dn switch) is connected in series, and the positions of the inductor and the switching means can be changed. That is, it is configured in the order of a capacitor, an inductor, a switching means, or in the order of a capacitor, a switching means, an inductor.

The first switching means 120 is turned on (conducted) when the rising period of the sustain pulse applied to the Z electrode is completed, that is, when the ground voltage is applied to the Z electrode, and the second switching means ( 220 is turned on when the ground voltage is applied to the Z electrode, which is the point at which the rising interval of the sustain pulse applied to the Y electrode is completed.

Figure 5 shows the sustain pulse waveform of each electrode and the resonant current waveform of the inductor provided in each electrode energy recovery unit according to the present invention, the inductor (L _Y , As can be seen from the resonance current waveform of L _Z ), when the energy is recovered from the corresponding electrode energy recovery unit, the recovered energy is immediately supplied to another electrode. That is, the Y-electrode energy recovery unit recovers energy during the polling period of the sustain pulse applied to the Y electrode, and supplies the recovered energy to the end of the polling period (rising period of the sustain pulse applied to the Z electrode). The reverse case also works.

5, sustain pulses of the Y electrode and the Z electrode are alternately applied to each electrode. That is, the ground voltage is applied to the Z electrode while the sustain pulse (rising period, the sustain voltage application period, and the polling period) is applied to the Y electrode, and the sustain pulse is applied to the Z electrode while the ground voltage is applied to the Y electrode.

The operation and current flow for each section shown in FIG. 5 will now be described with reference to FIG. 6.

Section 1 of FIG. 5 is a section in which a sustain pulse of the Y electrode is polled, and is a section in which energy supplied to the Y electrode of the panel is charged to the Y electrode energy recovery unit 110. FIG. 6A shows a current flow in the section ①. will be. ① The operation of the driving circuit for the section is a path connecting only the Y_er_dn switch and Z_sus_dn switch among the switches provided in the driving circuit to connect the Y electrode of the panel, the diode D3, the inductor L _Y , and the capacitor C _Y. Is formed to charge the energy supplied to the Y electrode of the panel to the capacitor (C _Y ), and a ground voltage is applied to the Z electrode.

The section 2 is a section in which the sustain pulse of the Z electrode which supplies the energy charged to the Y electrode energy recovery unit 110 to the Z electrode at the same time the ground voltage is applied to the Y electrode, rises, Figure 6b is the current flow for the section ② Will be shown. ② The operation of the driving circuit for the section turns off the Z_sus_dn switch, turns on the Y_er_dn switch, the Y_sus_dn switch, and the Z_er_up switch 220 to apply the ground voltage to the Y electrode, and at the same time, the Y electrode energy recovery unit 11 and the panel. The Z electrode is connected to form a path to supply energy charged in the Y electrode energy recovery unit 110 to the Z electrode. Even if the Y_er_dn switch is turned off after a predetermined time (at least 100 [ns] or more), the energy charged in the capacitor C _Y may be supplied to the Z electrode because current flows through the body diode of the Y_er_dn switch.

Section 3 is a section in which the ground voltage is continuously applied to the Y electrode and the sustain driving voltage Vs is applied to the Z electrode. FIG. 6C shows a current flow in the section 3. 3. The operation of the driving circuit for the section turns off the Y_er_dn switch and the Z_er_up switch 220, and turns on the Z_sus_up switch to apply the sustain driving voltage Vs to the Z electrode. Since the Y_sus_dn switch is in an ON state, a ground voltage is applied to the Y electrode.

The section ④ is a section in which the ground voltage is continuously applied to the Y electrode and the energy supplied to the Z electrode is charged to the Z electrode energy recovery unit 210. FIG. 6D shows a current flow for the section ④. ④ The operation of the driving circuit for the section is turned off the Z_sus_up switch was turned on, and the Z_er_dn switch provided in the Z electrode energy recovery unit 210 is turned on to turn on the Z electrode, the diode D4 and the inductor L _Z of the panel. The capacitor C _Z forms a path to which the capacitor C _{Z is} connected to charge the capacitor C _Z with the energy supplied to the Z electrode of the panel. In this section, the Y_sus_dn switch is on, so that the ground voltage is continuously applied to the Y electrode.

The section ⑤ is a section in which the sustain pulse of the Y electrode rises while the ground voltage is applied to the Z electrode and the energy charged in the Z electrode energy recovery unit 210 is supplied to the Y electrode. ⑤ Operation of the driving circuit for the section turns off the Y_sus_dn switch, turns on the Z_er_dn switch, Z_sus_dn switch, and Y_er_up switch 120 to apply the ground voltage to the Z electrode and at the same time the Z electrode energy recovery unit ( A path connecting the 210 and the Y electrode of the panel is formed to supply energy charged in the Z electrode energy recovery unit 210 to the Y electrode. Since the Z_er_dn switch is turned off after a predetermined time (at least 100 [ns] or more) as described in section ②, current flows through the body diode of the Z_er_dn switch, so that the energy charged in the capacitor C _Z is applied to the Y electrode. Can be supplied.

The section ⑥ is a section in which the ground voltage is continuously applied to the Z electrode and the sustain driving voltage Vs is applied to the Y electrode. FIG. 6F shows a current flow in the section ⑥. The operation of the driving circuit for the section (6) turns off the Z_er_dn switch and the Y_er_up switch 120, and turns on the Y_sus_up switch to apply the sustain driving voltage Vs to the Y electrode. Since the Z_sus_dn switch is on, the ground voltage is applied to the Z electrode.

FIG. 7 shows the sustain pulse waveform applied to the two electrodes and the resonance current waveforms of the inductors L _Y and L _Z as the actual simulation results for the circuit shown in FIG.

As shown in FIG. 7, the inductor L _Y provided in the Y electrode energy recovery unit at the time when the rising section of the sustain pulse applied to the Z electrode, which is the point at which the polling section of the sustain pulse applied to the Y electrode ends, is started. The inductor (L _Z ) provided in the Z electrode energy recovery unit is inverted when the resonant current of the inverted phase is reversed and the rising interval of the sustain pulse applied to the Y electrode starts, which is the end of the polling period of the sustain pulse applied to the Z electrode. It can be seen that the resonant current of is reversed.

That is, the energy charged in the Y electrode energy recovery unit is supplied to the Z electrode when the polling period of the Y electrode sustain pulse is completed, and the energy charged in the Z electrode energy recovery unit is completed the polling period of the Z electrode sustain pulse. Since it is supplied to the Y electrode at this time, the resonant current flowing in the inductor of each electrode can be reversed in polarity to remove the pre-willing current consumed by heat, thereby improving the overall efficiency of the driving circuit.

As described in detail above, the present invention is connected to the two sustain electrodes (Y, Z) of the panel, respectively, Y and Z electrode energy recovery unit for supplying and recovering energy to the panel, and when the energy of one electrode (Y) By including the switching means for supplying the energy stored in the recovery unit to the other electrode (Z), the efficiency of the entire circuit is reduced by reducing the pre-willing current that may occur when the rising section and the falling section of the sustain pulse is completed. There is an effect that can be improved.

In addition, the present invention has the effect of reducing the overall cost by eliminating the clamping diode that was previously a pass of the free willing current.

Claims (8)

A first electrode energy recovery unit for recovering energy from the first electrode of the panel and supplying the recovered energy to the second electrode of the panel; A second electrode energy recovery unit for recovering energy from the second electrode and supplying the recovered energy to the first electrode; First switching means for supplying the energy recovered in said second electrode energy recovery part to said first electrode when it is turned on; And a second switching means for supplying the energy recovered in said first electrode energy recovery part to said second electrode when it is conducting. The method of claim 1, further comprising: a diode between the first electrode energy recovery unit and the first electrode to prevent the energy recovered in the first electrode energy recovery unit from being supplied to the first electrode. A sustain drive circuit of a plasma display panel. The method of claim 1, further comprising a diode between the second electrode energy recovery unit and the second electrode to prevent the energy recovered in the second electrode energy recovery unit from being supplied to the second electrode. A sustain drive circuit of a plasma display panel. The sustain driving circuit of claim 1, wherein each of the electrode energy recovery units has a capacitor, an inductor, and a switching means (er_dn switch) connected to ground at one side thereof in series. The method of claim 4, wherein the other side of the capacitor is connected to one side of the inductor, the other side of the inductor is connected to one side of the switching means, and the other side of the switching means is connected to a corresponding electrode for recovering energy. A sustain drive circuit for a plasma display panel. The method of claim 4, wherein the other side of the capacitor is connected to one side of the switching means, the other side of the switching means is connected to one side of the inductor and the other side of the inductor is connected to a corresponding electrode for recovering energy. A sustain drive circuit for a plasma display panel. The sustain driving circuit of claim 1, wherein the first switching means is turned on when the polling period of the sustain pulse applied to the first electrode ends. 2. The sustain driving circuit of claim 1, wherein the second switching means is turned on at the end of the polling period of the sustain pulse applied to the second electrode.

Images