KR20070004391A - Plasma display apparatus and driving method thereof - Google Patents

Abstract

A plasma display device and a driving method thereof are provided to generate a surface discharge on the plasma display device even while a negative pulse is applied on a sustain electrode, by keeping the magnitude of the negative pulse equal to the magnitude of a sustain voltage. A plasma display device includes scan electrodes(Y1~Yn), sustain electrodes(Z), and a pulse controller(201). During a set-up period of a reset period, a scan pulse having a ramp-up waveform is applied on the scan electrode. A negative pulse, which has the same magnitude as a sustain pulse, is applied on the sustain electrode to generate a sustain discharge. The negative pulse is supplied from the same voltage source as the sustain voltage. The sustain pulse is a negative pulse, which initiates discharge when the sustain pulse is changed from a high potential to a low potential. The distance between the scan and sustain electrodes is greater than 150mum.

Description

Plasma display device and driving method thereof {Plasma Display Apparatus and Driving Method}

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

2 is a diagram illustrating a method of implementing image gradation of a typical plasma display panel.

3 is a view illustrating a driving waveform according to a driving method of a conventional plasma display panel.

4 is a view showing a driving waveform according to a negative sustain driving method of a conventional plasma display panel.

5 is a view for explaining a plasma display device according to the present invention;

6 is a view showing a driving waveform according to the negative sustain driving method of the plasma display device according to the present invention.

The present invention relates to a plasma display device and a driving method thereof, and more particularly, when driving a plasma display panel using a negative sustain pulse, the surface discharge mode can be used by applying a negative pulse to the sustain electrode during the setup period of the reset section. The present invention relates to a plasma display device and a driving method thereof.

In general, a plasma display panel (PDP) is a reset pulse for initializing a discharge cell at each electrode, an address pulse for selecting a cell to be discharged, and a sustain pulse for maintaining discharge of the discharge cell. Is applied a predetermined number of times according to the gradation value of each subfield, and the phosphor emits light by the gas discharge generated accordingly. The PDP repeats the above-described reset, addressing, and sustain for each subfield constituting the frame. However, in order to improve the PDP driving characteristics, a wall remaining on each electrode side before the start of each subfield is started. It is necessary to apply an erase pulse to remove the charge.

1 illustrates a structure of a general plasma display panel.

As shown in FIG. 1, a plasma display panel includes a front panel in which a plurality of sustain electrode pairs formed by pairing a scan electrode 102 and a sustain electrode 103 are arranged on a front glass 101 that is a display surface on which an image is displayed. 100 and the rear panel 110 on which the plurality of address electrodes 113 are arranged so as to intersect the plurality of sustain electrode pairs on the rear glass 111 forming the rear surface are coupled in parallel with a predetermined distance therebetween. do.

The front panel 100 is made of a scan electrode 102 and a sustain electrode 103, that is, a transparent electrode (a) formed of a transparent ITO material and a metal material to mutually discharge and maintain light emission of the cells in one discharge cell. The scan electrode 102 and the sustain electrode 103 provided as the bus electrode b are included in pairs. The scan electrode 102 and the sustain electrode 103 are covered by one or more upper dielectric layers 104 that limit the discharge current and insulate the electrode pairs, and to facilitate the discharge conditions on the upper dielectric layer 104 top surface. A protective layer 105 on which magnesium oxide (MgO) is deposited is formed.

The rear panel 110 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 which perform address discharge to generate vacuum ultraviolet rays are arranged in parallel with the partition wall 112. On the upper side of the rear panel 110, R, G, and B phosphors 114 which emit visible light for image display during address discharge are coated. A lower dielectric layer 115 is formed between the address electrode 113 and the phosphor 114 to protect the address electrode 113.

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

2 is a diagram illustrating a method of implementing image grayscale of a general plasma display panel.

As shown in FIG. 2, in the conventional method of expressing a gray level of a plasma display panel, a frame is divided into several subfields having different number of emission times, and each subfield is a reset period (RPD) for initializing all cells again. ) Is divided into an address period APD for selecting a cell to be discharged and a sustain period SPD for implementing gradation 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 to SF8 as shown in FIG. 2, and eight subfields. Each of the SFs SF1 to SF8 is divided 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. In this way, since the sustain period is different in each subfield, the gray scale 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 in FIG. 3, 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, the rising ramp waveform Ramp-up is simultaneously applied to all the scan electrodes Y during the setup period SU. Due to this rising ramp waveform, discharge occurs in the discharge cells of the full screen. By this setup discharge, positive wall charges are accumulated on the address electrode X and the sustain electrode Z, and negative wall charges are accumulated on the scan electrode Y. During the set down period SD, after the rising ramp waveform is supplied, the ramp ramp starts to fall from the positive voltage lower than the peak voltage of the rising ramp waveform and then falls to the base voltage GND or a specific negative voltage level. ) Is applied. As a result, a weak erase discharge is generated in the discharge cells, so that the excessively formed wall charge is partially erased, and the wall charge enough to cause the address discharge to be stably caused by the set down discharge remains uniformly in the discharge cells. .

In the address period, a negative scan pulse Scan is sequentially applied to the scan electrodes Y, and a positive data pulse data is applied to the address electrodes X in synchronization with the scan pulse. An address discharge is generated in the discharge cell to which the data pulse is applied while the voltage difference between the scan pulse and the data pulse and the wall voltage caused by the wall charge generated in the initialization period are added. In the discharge cells selected by the address discharge, wall charges such that a discharge can occur when a sustain voltage is applied are formed. At this time, the sustain electrode Z is supplied with a positive DC voltage Zdc to reduce the voltage difference between the scan electrode Y during the set-down period and the address period so as to prevent erroneous discharge from the scan electrode Y.

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

After the sustain discharge is completed, a ramp waveform (Ramp-ers) having a small pulse width and a low voltage level is supplied to the sustain electrode Z to erase the wall charge remaining in the discharge cells of the full screen.

On the other hand, the plasma display device as described above has a relatively low potential difference as the positive sustain pulse su is alternately applied to the scan electrode Y side and the sustain electrode Z side during the sustain period. The cations are accumulated on the electrode (X) side. At this time, the cations, which are heavier than the electrons, exert an ion bombardment on the fluorescent layer (114 in FIG. 1) of the rear panel on which the above-described address electrode X is formed, which shortens the lifespan of the plasma display apparatus. Caused it.

Recently, as shown in FIG. 4, the above-described sustain pulse su has a negative voltage level, and electrons are formed on the rear panel on which the scan electrode Y and the sustain electrode Z are formed. The driving of the negative sustain method which accumulates is made.

4 is a diagram illustrating a driving waveform according to a negative sustain driving method of a conventional plasma display panel.

As shown in FIG. 4, negative negative sustain pulses (-sus) are alternately applied to the scan electrode (Y) and the sustain electrode (Z) during the sustain period.

Accordingly, as described above, electrons are accumulated in the rear panel 110 having the fluorescent layer 114 formed by the negative sustain pulse (-sus) described above. Thus, the impact on the fluorescent layer 114 is reduced. On the other hand, in the process of accumulating cations in the front panel 100, the ion bombardment amount is increased in the magnesium oxide (MgO) layer 105 formed on the front panel 100 to improve the secondary electron generation rate. .

That is, while preventing the loss of the fluorescent layer 114, the secondary electron generation amount is increased to increase the lifetime of the plasma display device and to lower the discharge start voltage.

Meanwhile, the aforementioned negative sustain pulse (-sus) may be applied to a long gap structure, which is a new electrode structure.

Although the distance between the electrodes was about 60 to 80 um, a method of increasing the amount of light passing between the electrodes has been proposed by widening the electrode interval by 150 um or more, which is called a long gap structure. According to the long gap structure, the light emission efficiency may be improved by increasing the amount of light emitted from the phosphor.

In order to implement the long gap structure, it is common to form the long gap structure by reducing the conventional electrode area, that is, the ITO area. According to the long gap structure, when the sustain voltage is set to the ground voltage during discharge between the scan electrode and the sustain electrode, an opposite discharge is caused.

The opposite discharge means a discharge between the scan electrode and the data electrode. That is, when the voltage difference is applied between the sustain electrode set to the voltage of the scan electrode and the ground voltage in the long gap structure, the discharge is performed by the voltage difference between the scan electrode and the data electrode prior to the discharge between the scan electrode and the sustain electrode. As a result, as described above, it can be seen that the long gap structure is driven on the premise of the occurrence of the counter discharge. This requires a driving method separate from the driving method in the conventional surface discharge mode.

Accordingly, an object of the present invention is to provide a plasma display device and a method of driving the same, by applying a negative pulse having the same magnitude as a sustain voltage to a sustain electrode in a reset section so as to use a surface discharge mode.

The plasma display device according to the present invention comprises: a scan electrode and a sustain electrode; And a pulse control unit configured to apply a scan pulse having a ramp-up waveform to the scan electrode and to apply a negative pulse having the same magnitude as the sustain pulse for sustain discharge to the scan electrode during a setup period of a reset period. It features.

The negative pulse may be supplied from the same voltage source as the sustain voltage.

The sustain pulse is a negative pulse that starts to discharge when changing from a high level to a low level.

The distance between the scan electrode and the sustain electrode is characterized in that more than 150um.

A driving method of a plasma display device according to the present invention includes applying a scan pulse having a ramp-up waveform to the scan electrode during a setup period of a reset section; And applying a negative pulse having the same magnitude as the sustain pulse for sustain discharge to the sustain electrode during the setup period of the reset section.

Hereinafter, a plasma display device and a driving method thereof according to the present invention will be described in detail with reference to the accompanying drawings.

5 is a view for explaining a plasma display device according to the present invention.

As shown in Fig. 5, the plasma display apparatus of the present invention drives driving pulses to the address electrodes X1 to Xm, the scan electrodes Y1 to Yn, and the sustain electrode Z in the above-described reset period, address period and sustain period. Is applied and data for supplying data to the plasma display panel 200 representing an image made of a frame by the combination of at least one subfield and the address electrodes X1 to Xm formed in the plasma display panel 200. The driver 202, the scan driver 203 for driving the scan electrodes Y1 to Yn, the sustain driver 204 for driving the sustain electrodes Z serving as a common electrode, and the plasma display panel 200. In driving, the scan driver 203 and the sustain driver 204 described above are controlled to adjust the supply of the reset pulse in the reset period. A pulse control unit 201 for adjusting the supply of scan pulses and controlling the supply of the sustain pulses in the sustain period, and a driving voltage generating unit for supplying driving voltages required for the respective grooves 202, 203, and 204 ( 205).

The data driver 202 is subjected to inverse gamma correction and error diffusion by an inverse gamma correction circuit, an error diffusion circuit, and the like, and then data mapped to each subfield is supplied by the subfield mapping circuit. The data driver 202 samples and latches data in response to a data timing control signal CTRX from a timing controller (not shown), and then supplies the data to the address electrodes X1 to Xm. Done. In addition, an erase pulse is supplied to the address electrodes X1 to Xm during the erase period.

The scan driver 203 supplies the reset pulses to the scan electrodes Y1 to Yn during the reset period under the control of the pulse controller 201, the scan pulses to the scan electrodes Y1 to Yn during the address period, Under the control of the sustain pulse controller, a negative sustain pulse is supplied to the scan electrodes Y1 to Yn during the sustain period, and an erase pulse is supplied to the scan electrodes Y1 to Yn during the erase period.

The sustain driver 204 supplies a bias voltage having a predetermined magnitude to the sustain electrodes Z during the address period under the control of the pulse controller, and alternately operates with the scan driver 203 described above during the sustain period to perform a negative sustain pulse (−). sus is supplied to the sustain electrodes Z, and an erase pulse is supplied to the sustain electrode Z during the erase period.

The pulse controller 201 is configured to control operation timing and synchronization of the scan driver 203, the sustain driver 204, and the data driver 202 in the reset period, the address period, the sustain period, and the erase period. The control signal is supplied to each of the driving units 202, 203, and 204.

In particular, the pulse control unit 201 of the present invention is distinguished from the prior art by applying a negative pulse (-sus) to the sustain electrode in the setup period of the reset period is characterized in that to use the surface discharge mode.

The data control signal CTRX described above includes a sampling clock for latching data, a latch control signal, a switch control signal for controlling the on / off time of the energy recovery circuit and the driving switch element. The scan control signal CTRY includes a switch control signal for controlling on / off time of the energy recovery circuit (not shown) and the driving switch element (not shown) in the scan driver 203, and the sustain control signal CTRZ. Includes a switch control signal for controlling the on / off time of the energy recovery circuit and the drive switch element in the sustain driver 204.

The driving voltage generator 205 generates a setup voltage Vsetup, a scan common voltage Vscan-com, a scan voltage -Vy, a sustain voltage Vs, a data voltage Vd, and the like. These driving voltages may vary depending on the composition of the discharge gas or the structure of the discharge cell.

The operation of the plasma display device of the present invention of FIG. 5 will be described more clearly by the following driving method.

6 is a view showing a driving waveform according to the negative sustain driving method of the plasma display panel according to the present invention.

As shown in FIG. 6, in the present invention, while a reset pulse having a ramp-up waveform is applied to a scan electrode in a setup period of a reset period, a negative sustain pulse having the same magnitude as a sustain pulse for sustain discharge is applied to the sustain electrode. It is characterized by being applied.

In addition, in the present invention, it should be noted that the sustain pulse for sustain discharge applied to the scan electrode and the sustain electrode is a reverse sustain pulse at which the discharge starts when it falls from a high level to a low level.

In addition, the present invention is characterized by using a surface discharge, even though a negative sustain pulse is applied.

In addition, the present invention is characterized by applying a negative voltage to the sustain electrode in the setup period of the reset period in order to use the surface discharge mode. In the long gap structure, when the sustain electrode is kept in the ground (GND) state during the reset period, the opposite discharge between the scan electrode and the data electrode relatively close to that of the scan electrode and the sustain electrode occurs.

After the opposite discharge is generated, in order to form the surface discharge on the scan electrode and the sustain electrode again, an appropriate discharge voltage must be applied according to the amount of wall charge accumulated after the opposite discharge.

On the other hand, the present invention is characterized in that the same pulse as that used during the surface discharge is applied to the scan electrode, while a negative bias having the same magnitude as the sustain voltage applied for the sustain discharge is applied. That is, in the present invention, the reset is performed by using the surface discharge rather than the opposite discharge. In this case, a voltage source having the same magnitude as that of the negative sustain pulse is used. Accordingly, cost and size can be reduced by not requiring a separate voltage source.

According to the present invention, when a negative sustain voltage is applied to the sustain electrode in the setup section of the reset section, a reset pulse applied for forming a surface discharge may be applied to the scan electrode. That is, a negative sustain pulse is applied to the sustain electrode while the reset pulse of the ramp-up waveform is applied to the scan electrode in the setup period of the reset section. As a result, the voltage difference between the scan electrode and the sustain electrode becomes larger.

On the other hand, in the present invention, the reset pulse of the ramp down waveform is applied to the scan electrode in the set down period, while the positive sustain pulse is applied to the sustain electrode.

In other words, a ramp-up waveform is applied to the scan electrode in the setup section of the reset section, a ramp-down waveform is applied to the scan electrode in the set-up section, while a negative sustain pulse is applied to the sustain electrode during the setup section, and positive during the set-down section. A sustain pulse of is applied.

As described above, an abrupt polarity reversal occurs between the scan electrode and the sustain electrode during the setup period of the reset period, so that discharge may easily occur.

Meanwhile, as described above, when the ramp-up waveform is applied to the scan electrode in the reset period, the present invention sets the magnitude of the negative voltage applied to the sustain electrode equal to the magnitude of the sustain voltage (-Z bias). do.

This is possible by driving a negative sustain pulse having the same magnitude as the negative sustain pulse applied to the scan electrode and the sustain electrode in the sustain section in the reset section, without a separate negative voltage source. I'm trying to.

As a result, the present invention enables driving pulses to be applied to the scan electrodes in the reset section in the same manner as in the case of surface discharge, wherein the same voltage source is used for the scan electrodes and the sustain electrodes. Therefore, it is possible to reduce the size and cost by applying a negative pulse of the same magnitude as the sustain voltage without having a separate negative voltage source.

As such, the technical configuration of the present invention described above can be understood by those skilled in the art that the present invention can 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 foregoing detailed description, and the meaning and scope of the claims are as follows. And all changes or modifications derived from the equivalent concept should be interpreted as being included in the scope of the present invention.

The present invention allows the surface discharge mode to be used even when a negative pulse is applied to the sustain electrode during the setup period of the reset section, and by applying a negative pulse having the same magnitude as the sustain voltage so as not to have a separate negative voltage source. And reduce costs.

Claims (8)

Scan electrodes and sustain electrodes; And And a pulse controller for applying a scan pulse having a ramp-up waveform to the scan electrode and applying a negative pulse having the same magnitude as the sustain pulse for sustain discharge to the scan electrode during a setup period of a reset period. Plasma display device. The plasma display apparatus of claim 1, wherein the negative pulse is supplied from the same voltage source as the sustain voltage. The plasma display apparatus of claim 1, wherein the sustain pulse is a negative pulse that starts to discharge when the sustain pulse changes from a high level to a low level. The plasma display apparatus of claim 1, wherein a distance between the scan electrode and the sustain electrode is 150 um or more.  In the driving method of the plasma display device, Applying a scan pulse having a ramp-up waveform to the scan electrode during a setup period of a reset period; And And applying a negative pulse having the same magnitude as the sustain pulse for sustain discharge to the sustain electrode during the setup period of the reset section. The method of claim 1, wherein the negative pulse is supplied from the same voltage source as the sustain voltage. The method of claim 1, wherein the sustain pulse is a negative pulse that starts to discharge when the sustain pulse changes from a high level to a low level. The method of claim 1, wherein the distance between the scan electrode and the sustain electrode is 150 um or more.

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