KR100646218B1 - Driving apparatus for plasma display panel - Google Patents

Abstract

The present invention relates to a driving device of a plasma display panel, and according to the present invention, by reducing the size of an external sustain voltage source for sustain driving of a plasma display panel, it is possible to alleviate the withstand voltage characteristics required for the driving elements of the plasma display panel, The present invention provides a driving apparatus for a plasma display panel which reduces power and increases driving efficiency of the plasma display panel.

 The driving device of the plasma display panel according to the present invention includes a 1/2 sustain voltage source (Vs / 2) having a half value of the sustain voltage (Vs) required for sustain driving of the plasma display panel, a 1/2 sustain voltage source and a panel. An energy supply / recovery unit installed between (Cp) to generate LC resonance using switching elements to supply / recover voltage for sustain driving to the panel, and 1/2 installed between the sustain voltage source and the panel. The back voltage circuit unit for backing the sustain voltage to the sustain voltage (Vs), the source terminal is grounded, and the drain terminal is connected to the first switch (S1) and the energy supply / recovery unit which are commonly connected to the energy supply / recovery unit, the back voltage circuit unit and the panel. And a first capacitor C1 coupled between the two sustain voltage sources.

Description

Driving device of plasma display panel {DRIVING APPARATUS FOR PLASMA DISPLAY PANEL}

1 is a view showing the structure of a typical plasma display panel.

2 is a diagram illustrating a method of expressing image gradation of a conventional plasma display panel.

3 is a view showing a driving waveform of a conventional plasma display panel.

4 is a diagram illustrating a sustain driving circuit included in a scan electrode driving unit of a conventional plasma display panel.

FIG. 5 is a diagram showing driving waveforms and switch timings of the sustain driving circuit shown in FIG. 4; FIG.

6 is a diagram illustrating a sustain driving circuit included in a scan electrode driving unit of a plasma display panel driving apparatus according to the present invention;

FIG. 7 is a diagram showing driving waveforms and switch timings of the sustain driving circuit shown in FIG. 6;

 The present invention relates to a driving device of a plasma display panel, and more particularly, to reduce the withstand voltage characteristics required for driving devices of the plasma display panel by reducing the size of an external sustain voltage source for sustain driving of the plasma display panel. The present invention relates to a driving apparatus of a plasma display panel for reducing power and increasing driving efficiency of the plasma display panel.

In general, a plasma display panel forms a unit cell with a space between partition walls formed between a front substrate and a rear substrate, and each cell includes neon (Ne), helium (He), or a mixture of neon and helium (Ne +). A main discharge gas such as He) and an inert gas containing a small amount of xenon are filled. When discharged by a high frequency voltage, the inert gas generates vacuum ultraviolet rays and emits phosphors formed between the partition walls to realize an image. Such a plasma display panel has a spotlight as a next generation display device because of its thin and light configuration.

1 illustrates a structure of a general plasma display panel. As shown, the plasma display panel is coupled in parallel with the front substrate 101, which is the display surface on which the image is displayed, and the rear substrate 111 forming the rear surface, with a predetermined distance therebetween.

The front substrate 101 is a scan electrode 102 (Y electrode) and a sustain electrode 103 (Z electrode), that is, a transparent electrode formed of a transparent ITO material for mutual discharge in one discharge cell and maintaining light emission of the cell. And the scan electrode 102 and the sustain electrode 103 provided as a bus electrode b made of a metal material are formed in pairs. The scan electrode 102 and the sustain electrode 103 are covered by one or more dielectric layers 104 which limit the discharge current and insulate the electrode pairs, and the magnesium oxide top surface of the dielectric layer 104 to facilitate the discharge conditions. A protective layer 105 on which (MgO) is deposited is formed.

The rear substrate 111 is arranged such that a plurality of discharge spaces, that is, barrier ribs 112 of a stripe type (or well type) for forming discharge cells are maintained in parallel. In addition, a plurality of address electrodes 113 (X electrodes) for performing address discharge to generate vacuum ultraviolet rays are disposed in parallel with the partition wall 112. On the upper side of the rear substrate 111, R, G and B phosphors 114 which emit visible light for image display during address discharge are coated. A white dielectric 115 is formed between the address electrode 113 and the phosphor 114 to protect the address electrode 113 and reflect the visible light emitted from the phosphor 114 to the front substrate 101.

A method of implementing gray levels of an image in such a plasma display panel is shown in FIG. 2.

2 is a diagram illustrating a method of implementing image grayscale of a conventional plasma display panel. As shown, a gray level display method of a conventional plasma display panel divides one frame into several subfields having different number of emission times, and each subfield has a reset period (RPD) for discharging all cells and a discharge. It is divided into an address period APD for selecting a cell to be used and a sustain period SPD for implementing gray scale according to the number of discharges. For example, when displaying an image with 256 gray levels, a frame period (16.67 ms) corresponding to 1/60 second is divided into eight subfields SF1 through SF8, and eight subfields SF1 through. SF8) Each is subdivided into a reset period, an address period and a sustain period.

The reset period and the address period of each subfield are the same for each subfield. The address discharge for selecting the cell to be discharged is caused by the voltage difference between the address electrode and the transparent electrode which is the scan electrode. The sustain period is increased at a rate of 2 ⁿ ( ^where n = 0, 1, 2, 3, 4, 5, 6, 7) in each subfield. As described above, since the sustain period is different in each subfield, the gray level of the image is expressed by adjusting the sustain period of each subfield, that is, the number of sustain discharges. The driving waveforms according to the driving method of the plasma display panel are shown in FIG. 3.

3 is a view illustrating a driving waveform according to a driving method of a conventional plasma display panel. As shown, the plasma display panel is driven by being divided into a reset period for initializing all cells, an address period for selecting a cell to be discharged, and a sustain period for maintaining discharge of the selected cell.

In the reset period, a rising ramp waveform Ramp-up is simultaneously applied to all scan electrodes in the setup period. This rising ramp waveform causes a weak dark discharge within the full discharge cells. By this setup discharge, positive wall charges are accumulated on the address electrode and the sustain electrode, and negative wall charges are accumulated on the scan electrode.

After the rising ramp waveform is supplied in the set-down period, the ramp ramp starts to fall from the positive voltage lower than the peak voltage of the rising ramp waveform and then falls to a specific voltage level below the ground (GND) level voltage. By causing a slight erase discharge in these cells, the wall charges excessively formed in the scan electrode are sufficiently erased.

By this set-down discharge, wall charges such that the address discharge can stably occur remain uniformly in the cells.

The negative scan signal is sequentially applied to the scan electrodes in the address period, and the positive data signal is applied to the address electrode in synchronization with the scan signal. As the voltage difference between the scan signal and the data signal and the wall voltage generated in the reset period are added, address discharge is generated in the discharge cell to which the data signal is applied. In the cells selected by the address discharge, wall charges are formed such that a discharge can occur when the sustain voltage Vs is applied. The sustain electrode is supplied with a positive voltage Vzb during the set down period and the address period so as to reduce the voltage difference with the scan electrode so as to prevent erroneous discharge from the scan electrode.

In the sustain period, a sustain signal Su is alternately applied to the scan electrode and the sustain electrodes. In the cell selected by the address discharge, as the wall voltage and the sustain signal in the cell are added, a sustain discharge, that is, a display discharge occurs between the scan electrode and the sustain electrode every time the sustain signal is applied.

In this way, the driving process of the plasma display panel in one subfield is completed.

 On the other hand, the driving device for driving the plasma display panel includes a sustain driving circuit for applying alternating sustain pulses to the scan electrode and the sustain electrode to generate sustain discharge, that is, display discharge, during the sustain period in the cells addressed in the above address period. Include.

The sustain driving circuit is included in the scan electrode driving unit and the sustain electrode driving unit, respectively. The sustain driving circuits of the scan electrode driving unit and the sustain electrode driving unit are equivalent to each other, so for convenience, the sustain driving circuit included in the scan electrode driving unit is as follows. .

4 is a diagram illustrating a sustain driving circuit included in a scan electrode driving unit of a conventional plasma display panel.

As shown in FIG. 4, the conventional sustain drive circuit uses an energy recovery circuit to recover unnecessary power generated in the panel, that is, reactive power. The driving method of the sustain driving circuit included in the scan electrode driver is described with reference to FIG. 5 as follows.

First, in the first state 1 of FIG. 5, energy is supplied from the capacitor C1 to the panel Cp through a supply path passing through the first switch S1, the first diode D1, and the inductor L1. In the third state, energy is recovered from the panel Cp to the capacitor C1 by a recovery path passing through the inductor L1, the second diode D2, and the second switch S2.

However, such an energy recovery circuit uses a high voltage of several hundred volts as an external sustain voltage source for maintaining the panel at a sustain potential, thereby generating an excessive load on the driving elements of the plasma display panel and driving the plasma display panel. It is required to have a high level of withstand voltage characteristics, not only to increase the manufacturing cost, but also to increase the power consumption to cause various problems such as lowering the driving efficiency of the plasma display panel.

The present invention to solve this problem is to reduce the size of the external sustain voltage source for driving the sustained plasma display panel to alleviate the breakdown voltage characteristics required for the drive elements of the plasma display panel, while reducing the power consumption of the plasma display panel An object of the present invention is to provide a driving device of a plasma display panel which increases driving efficiency.

The driving device of the plasma display panel of the present invention for achieving the above object is a 1/2 sustain voltage source (Vs / 2) having a half value of the sustain voltage (Vs) required for sustain driving of the plasma display panel, and 1 An energy supply / recovery unit installed between the sustain voltage source and the panel Cp to generate LC resonance using switching elements to supply / recover voltage for sustain driving to the panel, and between the 1/2 sustain voltage source and the panel. A back voltage circuit part for backing the 1/2 sustain voltage to the sustain voltage (Vs), the source terminal being grounded, and the drain terminal having a first switch (S1) and energy supply commonly connected to the energy supply / recovery part, the back voltage circuit part and the panel. And a first capacitor (C1) connected between the / recovery portion and the 1/2 sustain voltage source.

The energy supply / recovery section includes an energy supply / recovery capacitor (Cs) grounded at one end, an inductor (L) connected between the energy supply / recovery capacitor and the panel, and a second parallel connection between the energy supply / recovery capacitor and the inductor. And a switch S2 and a third switch S3, and a first diode D1 connected in series between the second switch and the inductor and a second diode D2 connected in series between the third switch and the inductor. do.

The drain end of the second switch is connected to the other end of the energy supply / recovery capacitor, the source end is connected to the anode end of the first diode, and the source end of the third switch is connected to the other end of the energy supply / recovery capacitor and drained A stage is connected to the cathode of the second diode, one end of the inductor is commonly connected to the cathode of the first diode and the anode of the second diode and the other end is connected to the panel.

A third diode D3 is installed between the 1/2 sustain voltage source and the energy supply / recovery capacitor.

The anode end of the third diode is connected to the 1/2 sustain voltage source and the cathode end is connected to the other end of the energy supply / recovery capacitor.

A first capacitor C1 is connected in parallel between the anode terminal of the third diode and the 1/2 sustain voltage source.

The back voltage circuit unit includes a second capacitor C2 provided between the 1/2 sustain voltage source and the panel, and a fourth switch S4 connected in parallel to the second capacitor.

The source terminal of the fourth switch is connected in common with the other end of the inductor, the other end of the second capacitor, the drain end of the first switch, and the panel.

And a fourth diode D4 provided between the 1/2 sustain voltage source and the fourth switch connected in parallel to the second capacitor.

The anode end of the fourth diode is connected to the 1/2 sustain voltage source and the cathode end is commonly connected to one end of the second capacitor and the drain end of the fourth switch.

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

6 is a diagram illustrating a sustain driving circuit included in the scan electrode driving unit of the plasma display panel driving apparatus according to the present invention.

As shown in FIG. 6, the sustain driving circuit according to the present invention has an energy supply / recovery provided between a 1/2 sustain voltage source Vs / 2 and a 1/2 sustain voltage source Vs / 2 and a panel Cp. The back voltage circuit portion 602 and the source terminal grounded between the portion 601, the half sustain voltage source Vs / 2 and the panel Cp are grounded, and the drain stage is the energy supply / recovery portion 601 and the back voltage circuit portion. 602 and a first switch S1 commonly connected to the panel Cp.

The half sustain voltage source Vs / 2 supplies a half sustain voltage Vs / 2 having a half value of the sustain voltage Vs required for sustain driving of the plasma display panel Cp.

The energy supply / recovery unit 601 supplies the panel Cp by generating LC resonance using the switching elements with the 1/2 sustain voltage Vs / 2 supplied from the 1/2 sustain voltage source Vs / 2. Recover.

The back voltage circuit unit 602 backs the 1/2 sustain voltage Vs / 2 to the sustain voltage Vs and supplies it to the panel Cp.

The first switch S1 is turned on to maintain the panel Cp in the ground state while charging the voltage between both ends of the back voltage circuit unit 602 to Vs / 2.

The energy supply / recovery unit 601 includes an energy supply / recovery capacitor Cs having one end grounded, an inductor L connected between the energy supply / recovery capacitor Cs and the panel Cp, and an energy supply / recovery unit. The second switch S2 and the third switch S3 connected in parallel between the recovery capacitor Cs and the inductor L, and the first diode D1 connected in series between the second switch S2 and the inductor L. And a second diode D2 connected in series between the third switch S3 and the inductor L.

The energy supply / recovery capacitor Cs is charged by receiving a 1/2 sustain voltage Vs / 2 from a 1/2 sustain voltage source Vs / 2.

When the second switch S2 is turned on, the energy stored in the energy supply / recovery capacitor Cs is supplied to the panel Cp.

When the third switch S3 is turned on, energy of the panel Cp is recovered to the energy supply / recovery capacitor Cs.

The drain end of the second switch S2 is connected to the other end of the energy supply / recovery capacitor Cs, the source end is connected to the anode end of the first diode D1, and the source end of the third switch S3 is The other end of the energy supply / recovery capacitor Cs is connected, the drain end is connected to the cathode end of the second diode D2, and one end of the inductor L is connected to the cathode end and the second end of the first diode D1. It is preferable to be commonly connected to the anode end of the diode D2 and the other end to the panel Cp.

By thus setting the directions of the first diode D1 and the second diode D2, the reverse current between the energy supply / recovery capacitor Cs and the panel Cp is blocked.

The third diode (D3) is installed between the 1/2 sustain voltage source (Vs / 2) and the energy supply / recovery capacitor (Cs), and the anode end of the third diode (D3) is the 1/2 sustain voltage source (Vs / 2) and the cathode end is preferably connected to the other end of the energy supply / recovery capacitor (Cs).

By setting the direction of the third diode D3 in this way, the reverse current from the energy supply / recovery capacitor Cs to the 1/2 sustain voltage source Vs / 2 can be interrupted.

It is preferable to connect the first capacitor C1 in parallel between the anode terminal of the third diode D3 and the 1/2 sustain voltage source Vs / 2.

As such, by connecting the first capacitor C1 in parallel between the anode terminal of the third diode D3 and the 1/2 sustain voltage source Vs / 2, the potential of the 1/2 sustain voltage source Vs / 2 can be stably maintained. have.

In addition, the back voltage circuit unit 602, which is an important component of the present invention, includes a second capacitor C2 and a second capacitor C2 disposed in parallel between the 1/2 sustain voltage source Vs / 2 and the panel Cp. 4 switch S4.

In addition, the source terminal of the fourth switch S4 may be commonly connected to the other end of the inductor L, the second end of the second capacitor C2, the drain end of the first switch S1, and the panel Cp.

In this manner, when the first switch S1 is turned on to form a loop connecting the 1/2 sustain voltage source Vs / 2, the second capacitor C2, and the ground, 1/2 sustain is performed on the second capacitor C2. The voltage Vs / 2 is charged.

In addition, when the fourth switch S4 is turned on, the 1/2 sustain voltage source Vs / 2 is supplied to the 1/2 sustain voltage Vs / 2 already charged in the second capacitor C2. The sustain voltage Vs plus the voltage Vs / 2 is supplied to the panel Cp.

The fourth diode D4 is provided between the 1/2 sustain voltage source (Vs / 2) and the fourth switch S4 connected in parallel to the second capacitor C2, and the anode end of the fourth diode D4 is 1 /. It is preferable to be connected to the second sustain voltage source Vs / 2 and the cathode terminal is commonly connected to one end of the second capacitor C2 and the drain end of the fourth switch S4.

By setting the direction of the fourth switch S4 in this way, the reverse current from the back voltage circuit section 602 to the half sustain voltage source (Vs / 2) is cut off.

The operation of the sustain driving circuit of the plasma display panel driving apparatus according to the present invention will be described in more detail with reference to FIG. 7 as follows.

FIG. 7 is a diagram illustrating driving waveforms and switch timings of the sustain driving circuit shown in FIG. 6.

As shown in FIG. 7, the sustain driving circuit of the plasma display panel driving apparatus according to the present invention includes (1) grounding the panel Cp and simultaneously supplying / recovering capacitors Cs, first capacitors C1 and 2nd state (state1) for charging the capacitor C2 to Vs / 2 (2) Second state for supplying the voltage charged to the capacitor Cs for energy supply / recovery to the panel Cp through LC resonance ( state2) (3) The third state (state3) for supplying the sustain voltage (Vs) back-pressured by the back-pressure circuit unit 602 to the panel (Cp) (4) The energy supply / recovery capacitor ( It is driven by dividing into a fourth state (state4) to recover to Cs).

Hereinafter, a detailed operation of each state of the sustain driving circuit of the plasma display panel driving apparatus according to the present invention will be described in detail.

(1) first state (state1)

 The first switch S1 is turned on and the remaining first to third switches S2, S3, and S4 are turned off.

Therefore, the voltage applied to the panel Cp becomes the ground level, and the energy supply / recovery capacitor Cs, the first capacitor C1, and the second capacitor C2 are at the half sustain voltage Vs / 2. Is charged.

(2) second state (state2)

The second switch S2 is turned on and the remaining first, third and fourth switches S1, S3, and S4 are turned off.

Therefore, the energy charged in the energy supply / recovery capacitor Cs is supplied to the panel Cp through LC resonance.

The energy supply path is made from the energy supply / recovery capacitor Cs to the second switch S2-the first diode D1-the inductor L-the panel Cp.

The first diode D1 blocks the flow of reverse current from the panel Cp to the energy supply / recovery capacitor Cs.

(3) third state (state3)

The fourth switch S4 is turned on while the second switch S2 is turned on, and the remaining first and third switches S1 and S3 maintain the turned off state.

Accordingly, the voltage Vs / 2 charged to the second capacitor C2 and the voltage Vs / 2 supplied from the 1/2 sustain voltage source Vs / 2 in the first state state1 are added to the panel Cp. Is supplied.

(4) fourth state (state4)

The third switch S3 is turned on, and the remaining first, second, and fourth switches S1, S2, and S4 maintain a turn off state.

As a result, energy is recovered from the panel Cp to the energy supply / recovery capacitor Cs.

The energy recovery path is made from the panel Cp to the inductor L-the second diode D2-the third switch S3-the energy supply / recovery capacitor Cs.

The second diode D2 blocks the flow of reverse current from the energy supply / recovery capacitor Cs to the panel Cp.

As described above, it will be understood by those skilled in the art that the above-described technical configuration may be implemented in other specific forms without changing the technical spirit or essential features of the present invention.

Therefore, the exemplary embodiments described above are to be understood as illustrative and not restrictive in all respects, and the scope of the present invention is indicated by the appended claims rather than the detailed description above, and the meaning and scope of the claims and All changes or modifications derived from the equivalent concept should be interpreted as being included in the scope of the present invention.

As described in detail above, the present invention lowers the size of the external sustain voltage source for sustain driving of the plasma display panel, thereby alleviating the breakdown voltage characteristics required for driving devices of the plasma display panel, and reducing power consumption, thereby reducing the plasma display panel. Provided is a driving device of a plasma display panel for increasing driving efficiency.

Claims (10)

A half sustain voltage source Vs / 2 having a half value of the sustain voltage Vs required for sustain driving of the plasma display panel; An energy supply / recovery unit provided between the 1/2 sustain voltage source and the panel Cp to generate LC resonance using switching elements to supply / recover voltage for sustain driving to the panel; A back voltage circuit unit installed between the half sustain voltage source and the panel to back the half sustain voltage to a sustain voltage Vs; A source switch having a ground terminal and a drain stage connected to the energy supply / recovery unit, the back pressure circuit unit, and the panel in common; And And a first capacitor (C1) connected between the energy supply / recovery unit and the 1/2 sustain voltage source. The method of claim 1, The energy supply / recovery unit An energy supply / recovery capacitor Cs whose one end is grounded; An inductor (L) connected between the energy supply / recovery capacitor and a panel; A second switch S2 and a third switch S3 connected in parallel between the energy supply / recovery capacitor and the inductor; A first diode (D1) connected in series between said second switch and said inductor; And a second diode (D2) connected in series between the third switch and the inductor. The method of claim 2, The drain end of the second switch is connected to the other end of the energy supply / recovery capacitor and the source end is connected to the anode end of the first diode, The source end of the third switch is connected to the other end of the energy supply / recovery capacitor and the drain end is connected to the cathode end of the second diode, And one end of the inductor is commonly connected to the cathode end of the first diode and the anode end of the second diode, and the other end of which is connected to the panel. The method of claim 3, wherein And a third diode (D3) is provided between the 1/2 sustain voltage source and the energy supply / recovery capacitor. The method of claim 4, wherein And an anode end of the third diode is connected to the 1/2 sustain voltage source, and a cathode end is connected to the other end of the energy supply / recovery capacitor. delete The method according to any one of claims 1 to 5, The back pressure circuit unit A second capacitor C2 provided between the 1/2 sustain voltage source and the panel; And a fourth switch (S4) connected in parallel to the second capacitor. The method of claim 7, wherein And a source terminal of the fourth switch is commonly connected to the other end of the inductor, the other end of the second capacitor, the drain end of the first switch, and the panel. The method of claim 8, And a fourth diode (D4) disposed between the 1/2 sustain voltage source and a fourth switch connected in parallel to the second capacitor. The method of claim 9, And an anode end of the fourth diode is connected to the 1/2 sustain voltage source, and a cathode end is commonly connected to one end of the second capacitor and the drain end of the fourth switch.

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