KR100748507B1 - 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 capable of increasing 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. First switching means connected to one side of the other side of the inductor L connected to the panel, and connected to the other side of the sustain driving power supply for applying a sustain voltage to the panel; Second switching means having one side connected to the other side of the inductor and having one side connected to the other side of the ground; Third switching means having one side connected to the other side of the first backflow prevention diode connected to the other side of the inductor, and one side connected to the other side of the capacitor connected to the ground; One side is connected to the other side and the other side of the second reverse flow prevention diode connected to the other side of the inductor, and comprises a fourth switching means connected to the other side and the other side of the capacitor, so that the rising interval and polling of the sustain pulse The efficiency of the overall circuit can be improved by reducing the pre-willing current that may occur at the completion of the section.

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;

5a to 5d are current flow charts for each section of the sustain pulse according to the present invention;

6 is a waveform diagram of sustain voltage applied to a panel according to the present invention (a) and a diagram of resonance current waveform of an inductor (b).

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

Css: Capacitor

D1, D2: Diode

L: Inductor

er_up, er_dn, sus_up, sus_dn, sus_high, sus_low: 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).

1 shows an energy recovery circuit of a sustain drive circuit of a conventional PDP, in which an inductor (L) and a capacitor (Css) for recovering and supplying energy and a sustain of the panel are turned on and off by switching control signals. Four switching means (S1-S4) forming a path for supplying and recovering energy to the electrode, two diodes (D1, D2) for preventing reverse current, and the sustain voltage and ground voltage It consists of two clamping diodes (DC1, DC2) to prevent unnecessary resonance.

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, and the sus_high switch is disposed at a time point at which one side is located between the other side of the inductor connected to the panel and the sustain driving power supply, and the rising period of the sustain voltage is completed. And a sus_low switch (second switching means) which is located between the first switching means and the other side of the inductor and the ground and is turned on when the polling period of the sustain voltage is completed, thereby increasing the rising and falling intervals of the sustain pulse. It is an object of the present invention to provide a sustain driving circuit of a plasma display panel that can reduce the pre-willing current that may occur at the completion point to improve the efficiency of the entire circuit.

The present invention for achieving the above object is the first switching means is connected to one side and the other side of the inductor (L) connected to the panel, the first switching means connected to the other side and the sustain driving power source for applying a sustain voltage to the panel; ; Second switching means having one side connected to the other side of the inductor and having one side connected to the other side of the ground; Third switching means having one side connected to the other side of the first backflow prevention diode connected to the other side of the inductor, and one side connected to the other side of the capacitor connected to the ground; One side is connected to the other side and the other side of the second backflow prevention diode connected to the other side of the inductor, characterized in that it comprises a fourth switching means connected to the other side and the other side of the capacitor.

The first switching means may be in an on state for a time when the sustain voltage Vs of the sustain driving power is applied to the panel.

In addition, the second switching means is characterized in that the on-state for a time when the ground voltage is applied to the panel.

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, a capacitor for storing the recovered energy and an LC resonance are used to recover the energy to the capacitor and supply the recovered energy to the panel. An inductor is required for this purpose. The er_up switch (third switching means) for performing the er_up operation, the er_dn switch (fourth switching means) for performing the er_dn operation, the sus_up switch (fifth switching means) for performing the sus_up operation, and the sus_dn operation You need a sus_dn switch (sixth switching means) to do this.

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 performing the above operation, and to improve the efficiency of the entire drive circuit by reducing the freewheeling current flowing in which the inductor's resonance current is polarized reversed. Make a point.

The pre-willing current is a current generated when the resonant current of the inductor is polarized inverted at the end of the rising period and the falling period of the sustain pulse (voltage). The present invention includes switching means in a path through which the pre-willing current flows. At the end of the rising period and the falling period, the switching means located in the path through which the freewill current flows are turned on to remove the freewill current.

4 is a diagram illustrating an embodiment of a sustain driving circuit of the PDP of the present invention, wherein a sus_high switch (first switching means) positioned between the sustain driving power supply Vs and the other side of the inductor L connected to one side of the panel is shown in FIG. And a sus_low switch (second switching means) located between the other side of the inductor and the ground.

That is, the sustain drive circuit of the PDP of the present invention supplies energy to the sustain electrode of the panel through one inductor L and one capacitor Css for recovering and supplying energy, and on / off by a switching control signal. Four switching means (er_up, er_dn, sus_up, sus_dn) forming a path for recovery, two diodes (D1, D2) for preventing reverse current, and the sustain voltage (Vs) and ground voltage are applied. Two switching means sus_high and sus_low are provided to block pre-willing currents that may occur in the interval.

The sus_high switch is turned on at the end of the rising interval of the sustain voltage, that is, at the point of time when the sus_up switch is changed from the er_up operation to the sus_up operation. The sus_low switch is turned on at the end of the polling period of the sustain voltage. When the sus_high switch and the sus_low switch are turned on, the time at which the sus_high switch and the sus_low switch are turned on is the maximum value of the sus_up operation time and the sus_dn operation time, respectively.

That is, the operation of turning on / off the sus_high switch is controlled in the same manner as the operation of turning on / off of the sus_up switch, and the operation of turning on / off of the sus_low switch is controlled in the same manner as the operation of turning on / off the sus_dn switch. Of course, the minimum value of the time for turning on / off the sus_high switch and the sus_low switch may be determined by a sustain driving circuit manufacturer of the PDP, and outputting an on / off control signal to each switch (for example, a switching controller). It is obvious that) should be provided.

Next, an operation of an embodiment of the circuit of the present invention having the configuration of FIG. 4 will be described with reference to FIGS. 5A to 5D.

5A to 5D show current flows for four operations for an energy recovery circuit, that is, an er_up operation, a sus_up operation, an er_dn operation, and a sus_dn operation.

5a shows the current flow for the er_up operation. As shown, the er_up switch is turned on to supply the capacitor Css charged current to the sustain electrode of the panel. The capacitor Css, the diode D1, the inductor L and the panel are turned on. A path to be connected is formed, and the energy charged in the capacitor Css by the formed path is supplied to the sustain electrode of the panel by LC resonance.

FIG. 5B shows the current flow for the sus_up operation. As shown in FIG. 5B, the sus_up switch is turned on to apply the voltage Vs of the sustain driving power supply to the sustain electrode of the panel, and at the same time, the resonance current of the inductor L is inverted. The sus_high switch is turned on at the same time in order to remove the pre-willing current. That is, a path of the sustain driving power supply and the panel is formed, and a sustain voltage is applied to the sustain electrode of the panel, and a path is connected to the sustain driving power supply and the sus_high switch to form a capacitor parasitic to the diode D1 and the er_dn switch by Vs / 2. The charging current path flows through the sus_high switch, which eliminates the current component flowing through the inductor L.

Therefore, when the sus_up switch is turned on, a sustain voltage is applied to the sustain electrode of the panel, and the sus_high switch is turned on when the sus_up switch is turned on, that is, at the end of the rising interval, thereby increasing the polarity of the resonance current flowing through the inductor L. The inversion can be prevented.

Figure 5c shows the current flow for the er_dn operation, as shown in the sus_up switch and sus_high switch is turned off, the er_dn switch is turned on to form a path connecting the panel and the inductor L, the diode D2 and the capacitor Css of the panel The energy supplied to the sustain electrode is charged to the capacitor Css.

After the er_dn operation, which is the energy recovery operation, is performed as shown in FIG. 5D, the sus_dn operation of the present invention turns off the er_dn switch and turns on the sus_dn switch to apply a ground voltage to the panel. The sus_low switch is turned on at the time when the sus_dn switch is turned on, that is, when the polling period of the sustain voltage is completed, thereby preventing the resonant current polarity of the inductor L from being inverted. In other words, in the case of er_dn operation, the sus_dn switch and the sus_low switch are turned on at the same time until the next sustain pulse er_up operation is performed, thereby applying the ground voltage to the sustain electrode of the panel and simultaneously reversing the resonant current polarity of the inductor. By eliminating the thing, the overall efficiency of the driving circuit can be improved.

FIG. 6 shows simulation results of the circuit of an embodiment of the present invention shown in FIG. 4, which shows a sustain voltage waveform (a) applied to a sustain electrode of a panel and a resonance current waveform (b) of an inductor.

As can be seen in Figure 6, the pre-willing current that can be generated by the polarity inversion of the inductor resonance current at the time when the rising section (1) of the sustain pulse is completed and when the falling period (3) is completed is shown in FIG. It can be seen that much reduced compared to the conventional resonant current wave shown. That is, the efficiency of the whole drive circuit can be improved.

Although not shown, the clamping diode may be disposed between the contact point and the sustain driving power supply of the inductor L and the sus_high switch and between the contact point and the ground of the inductor L and the sus_low switch, respectively. This is to prevent unnecessary resonance caused by the voltage Vs of the driving power supply and the ground voltage.

As described in detail above, the present invention has a sus_high switch (first switching means) and another of the inductor, wherein one side is located between the other side of the inductor connected to the panel and the sustain driving power supply and is turned on when the rising period of the sustain voltage is completed. By including a sus_low switch (second switching means) located between one side and the ground and turned on when the polling period of the sustain voltage is completed, the prewilling that may occur when the rising and falling sections of the sustain pulse is completed. Reducing the current has the effect of improving the efficiency of the entire circuit.

Claims (5)

First switching means, one side of which is connected to the other side of the inductor L connected to the panel, the first switching means of which is connected to the other side of the sustain driving power source for applying a sustain voltage to the panel; Second switching means having one side connected to the other side of the inductor and having one side connected to the other side of the ground; Third switching means having one side connected to the other side of the first backflow prevention diode connected to the other side of the inductor, and one side connected to the other side of the capacitor connected to the ground; And a fourth switching means having one side connected to the other side of the second backflow prevention diode connected to the other side of the inductor and having the other side connected to the other side of the capacitor. Driving circuit. The method of claim 1, One side of the inductor and one side of the inductor is connected, and the other side of the sustain driving power source is connected, and when the state of the switch is configured to further include a fifth switching means for applying a sustain voltage of the sustain driving power source to the panel. A sustain drive circuit for a plasma display panel. The method of claim 1, And a sixth switching means for applying the ground voltage to the panel when one side and one side of the inductor are connected, the other side of the ground is connected, and the state of the switch is on. Sustain drive circuit. The method of claim 1, And the first switching means is in an on state for a time when the sustain voltage of the sustain driving power is applied to the panel. The method of claim 1, And the second switching means is in an on state for the time when the ground voltage is applied to the panel.

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