KR100705280B1 - Plasma Display Apparatus and Driving Method thereof - Google Patents

Abstract

The present invention relates to a plasma display device and a driving method thereof.

As described above, the present invention provides a plasma display panel in which a scan electrode and a sustain electrode to which negative polarity pulses are alternately applied in a sustain period and an address electrode to which a data pulse is applied in an address period are formed, and a signal is applied to the electrodes. Each driving unit for driving the plasma display panel and the driving unit are controlled to supply a narrow pulse having a width smaller than that of the negative sustain pulse to the scan electrode or the sustain electrode at the end of the sustain period. It includes a control unit.

Negative sustain, erase pulse, wall charge, sustain electrode

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.

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

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

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

5 schematically illustrates a plasma display device according to the present invention;

6 is a view for explaining a method of driving a 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, to a plasma display device which can improve driving characteristics by improving driving pulses applied during a sustain period when driving a plasma display panel using a negative sustain pulse. And a driving method thereof.

In general, a plasma display panel (hereinafter referred to as a PDP) has a reset pulse for initializing a discharge cell, an address pulse for selecting a cell to be discharged, and a discharge cell for maintaining a discharge cell. Sustain pulses are applied a predetermined number of times according to the gray level values of the respective subfields, and the phosphors emit light by the gas discharge generated. 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. Scan electrode 102 and sustain electrode 103 are covered by one or more upper dielectric layers 104 that limit discharge current and insulate between electrode pairs, and facilitate discharge conditions on top of upper dielectric layer 104. For this purpose, 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. Each of the fields 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 diagram 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 voltage level of the negative ramp. -down) 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, the negative scan pulse Scan is sequentially applied to the scan electrodes Y, and the 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 positive electrode DC voltage Zdc is supplied to the sustain electrode Z 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. Cations are accumulated on the address 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 sustain pulse su is described above to have 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. Negative sustain is driven to accumulate.

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, a negative negative sustain pulse (-sus) is 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, an ion bombardment amount is increased in the magnesium oxide (MgO) layer 105 formed on the front panel 100 to improve the secondary electoral 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.

At this time, it is important to remove the wall charges remaining on each electrode (Y, Z, X) after the aforementioned sustain period for inducing and maintaining light emission of the discharge cells. This is because all the residual wall charges must be removed to improve the driving margin in the reset period, the address period, and the sustain period in the subsequent subframe.

However, in the driving of the negative sustain type plasma display as described above, there is no conventionally proposed an erasing method for removing the residual wall charges. This residual wall charge has a problem of lowering the driving margin by lowering the discharge characteristics in the reset period and the address period of the next subsequent subframe.

Accordingly, the present invention provides a plasma display device and a drive thereof capable of smoothly erasing wall charges present in a cell after sustain discharge when a negative sustain type plasma display panel is driven, and stable discharge in the next subfield reset and address period. The purpose is to provide a method.

In the plasma display apparatus according to the present invention for achieving the above object, a plasma display panel having a scan electrode and a sustain electrode to which the negative sustain pulses are alternately applied to each other in the sustain period and an address electrode to which the data pulse is applied to the address period are formed. And a driving unit for driving the plasma display panel by applying a signal to the electrodes, and controlling the driving unit so that at the end of the sustain period, a narrow pulse having a width smaller than that of the negative sustain pulse is generated. And a pulse controller for supplying any one of the sustain electrodes.

The narrow pulse has the same polarity as the negative sustain pulse applied to the scan electrode and the sustain electrode in the sustain period.

The pulse controller may adjust the width of the narrow pulse in proportion to a gap between the scan electrode and the sustain electrode.

The pulse controller is characterized in that for adjusting the width of the narrow pulse to 500 kHz or less.

The pulse controller is characterized in that the voltage of the narrow pulse is greater than or equal to the voltage of the negative sustain pulse applied to the scan electrode and the sustain electrode in the sustain period.

In the method of driving a plasma display device according to the present invention, a negative sustain pulse is alternately applied to a scan electrode and a sustain electrode in a sustain period, and a narrow pulse having a width smaller than that of the negative sustain pulse is applied at the end of the sustain period. It is characterized in that the supply to any one of the scan electrode or the sustain electrode.

The narrow pulse has the same polarity as the negative sustain pulse applied to the scan electrode and the sustain electrode in the sustain period.

The width of the narrow pulse is adjusted in proportion to the gap between the scan electrode and the sustain electrode.

The width of the narrow pulse is characterized in that it is adjusted to less than 500㎱.

The voltage of the narrow pulse may be supplied equal to or greater than the voltage of the negative sustain pulse applied to the scan electrode and the sustain electrode in the sustain period.

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 of 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 500 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 500. The driver 502, the scan driver 503 for driving the scan electrodes Y1 to Yn, the sustain driver 504 for driving the sustain electrodes Z serving as a common electrode, and the plasma display panel 500. In driving, the scan driver 503 and the sustain driver 504 described above are controlled to adjust the supply of the reset pulse in the reset period. A pulse control section 501 for adjusting the supply of scan pulses of the scan pulses and supplying narrow pulses at the end of the sustain period, and a driving voltage generation section for supplying driving voltages required for the respective driving sections 502, 503, and 504 ( 505).

The data driver 502 is subjected to inverse gamma correction and error diffusion by an inverse gamma correction circuit, an error diffusion circuit, and the like not shown, and then data mapped to each subfield is supplied by the subfield mapping circuit. The data driver 502 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 503 supplies the reset pulses to the scan electrodes Y1 to Yn during the reset period under the control of the pulse controller 501, and supplies the scan pulses to the scan electrodes Y1 to Yn during the address period. The negative sustain pulse is supplied to the scan electrodes Y1 to Yn during the sustain period under the control of the sustain pulse controller, and the narrow pulse smaller than the width of the negative sustain pulse is supplied to the scan electrodes Y1 to Yn at the end of the sustain period. .

The sustain driver 504 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 503 described above during the sustain period, thereby performing a negative sustain pulse (−). sus) is supplied to the sustain electrodes Z, and like the scan driver, a narrow pulse smaller than the width of the negative sustain pulse is supplied to the scan electrodes Y1 to Yn at the end of the sustain period.

Meanwhile, the narrow pulse supplied by the scan driver or the sustain driver at the end of the sustain period may be supplied to only one electrode of the scan electrode or the sustain electrode, and may be supplied to both the scan electrode and the sustain electrode.

The pulse controller 501 is configured to control operation timing and synchronization of the scan driver 503, the sustain driver 504, and the data driver 502 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 502, 503, 504. In particular, in order to improve driving characteristics of the plasma display panel to which the negative sustain pulse (-sus) is applied, the pulse control unit 501 of the present invention is different from the prior art and has the same polarity as the negative sustain pulse at the end of the sustain period. The scan driver 503 and the sustain driver 504 are controlled to supply the narrow pulse to the scan electrode Y or the sustain electrode Z0.

The pulse controller 501 may be provided inside the scan driver 503 and the sustain driver 504.

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 an energy recovery circuit (not shown) and a driving switch element (not shown) in the scan driver 503, and a sustain control signal CTRZ. Includes a switch control signal for controlling the on / off time of the energy recovery circuit and the driving switch element in the sustain driver 504.

The driving voltage generator 505 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.

6 is a view for explaining a method of driving a plasma display device according to the present invention.

As shown in FIG. 6, the method of driving the plasma display apparatus according to the present invention includes a reset period for initializing all screens of the plasma display panel, an address period for selecting cells, and a sustain period for maintaining discharge of the selected cells. Driven by dividing into.

First, during the setup period of the reset section, the positive ramp pulse rising up to the setup voltage Vset-up is simultaneously applied to all the scan electrodes Y, and the negative pulse is applied to the sustain electrode Z. At this time, the voltage of the negative pulse is the same voltage level as that of the negative sustain pulse supplied in the subsequent sustain period. This causes a weak discharge in the discharge cells of the entire screen due to the potential difference between the scan electrode and the sustain electrode to accumulate wall charges.

Thereafter, in the set-down period, the wall charges accumulated in the discharge cells are erased in the set-up period so that the wall charges of all the discharge cells can be uniformed, starting at the ground level on all the scan electrodes Y at a predetermined voltage (-Vy). A negative ramp pulse descending until is applied, and at the same time, the ground electrode is maintained at the sustain electrode. Here, the magnitude of the predetermined voltage below the ground level may be adjusted according to the characteristics of the plasma display panel. In other words, if the wall charges are excessively accumulated in the discharge cell during the setup period, the absolute voltage of the falling lamp is increased to eliminate the wall charges that are excessively accumulated. If the wall charges are accumulated in the discharge cell, the address discharge is smoothly performed in the address period afterwards. In order to reduce the absolute voltage of the falling lamp, do not eliminate the wall charge if possible.

In the address period, the negative scan pulse (-Vsp) is applied to the scan electrode (Y) while maintaining the scan bias voltage (Vscan) lower than the ground voltage level and higher than the voltage (-Vs) of the negative sustain pulse applied in the sustain period. Supply. At this time, the sustain electrode is maintained at the ground level. In addition, the address electrode X supplies a data pulse in synchronization with the negative scan pulse -Vsp applied to the scan electrode. As a result, the voltage difference between the negative scan pulse and the data pulse and the wall voltage generated during the reset period are added, and an address discharge is generated in the cell to which the data pulse is applied.

In the sustain period, a negative sustain pulse sus is alternately applied to the scan electrode and the sustain electrode. Such a negative sustain pulse causes a sustain discharge, that is, a display discharge, between the scan electrode and the sustain electrode every time a negative sustain pulse is applied in addition to the wall voltage in the cell selected in the address period. At this time, the address electrode is held at the ground level.

On the other hand, at the end of the sustain period, a pulse having a narrow width w2 that is narrower than the width w1 of the negative sustain pulse applied during the sustain period is supplied to the scan electrode Y. In this case, the narrow pulse may be supplied to the sustain electrode Z although not shown.

At this time, the width of the narrow pulse should be 1/2 or less of the negative sustain pulse. That is, if the width of the narrow pulse is limited to a numerical value, the wall charge can be erased to 500 mW or less. This is because when the width of the narrow pulse is more than 500 mV, the wall charge is not erased by the discharge by the narrow pulse but the pulse is maintained after the discharge to form the wall charge in the cell.

In addition, the voltage of the narrow pulse is equal to the voltage of the negative sustain pulse or the absolute voltage is made larger. At this time, if the voltage of the narrow pulse is made larger than the voltage of the negative sustain pulse, the width of the narrow pulse can be made narrower than the upper limit of the numerical limits of the narrow pulse as described above. This is because when a high voltage pulse is applied, discharge can easily occur to erase wall charges in the cell.

As such, the width or voltage of the narrow pulse applied at the end of the sustain period can be adjusted according to the distance between the scan electrode Y and the sustain electrode Z. That is, as the distance between the scan electrode (Y) and the sustain electrode (Z) increases, the width or voltage of the narrow pulse is also increased.

Further, the narrow pulse may be supplied with a positive polarity opposite to that of the sustain pulse, but is preferably supplied to the scan electrode and the sustain electrode with the same polarity as the sustain pulse in consideration of the voltage source.

On the other hand, although not shown in Fig. 6, the driving method of the plasma display apparatus according to the present invention includes an erase pulse including a ramp waveform so as to completely erase the wall charges not erased by the narrow pulse by providing an erase period after the sustain period. You can also supply.

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.

As described above, according to the plasma display device and the driving method thereof, a negative sustain pulse is used to effectively erase the wall charges accumulated in the cell after the sustain period during driving of the plasma display panel, thereby improving driving margin characteristics. There is.

Claims (10)

A plasma display panel including a scan electrode and a sustain electrode to which the negative sustain pulses are alternately applied in the sustain period, and an address electrode to which the data pulse is applied in the address period; Respective driving units for driving the plasma display panel by applying a signal to the electrodes; And By controlling the driving unit, at the end of the sustain period, a narrow pulse having a width less than or equal to 0.5 times the width of the negative sustain pulse and having a voltage larger than the voltage of the negative sustain pulse is selected from among the scan electrode or the sustain electrode. Pulse control unit to supply to either electrode Plasma display device comprising a. The method of claim 1, And the narrow pulse has the same polarity as that of the negative sustain pulse applied to the scan electrode and the sustain electrode in the sustain period. The method of claim 1, The pulse controller And controlling the width of the narrow pulse in proportion to a gap between the scan electrode and the sustain electrode. The method according to claim 1 or 3, And the pulse controller controls the width of the narrow pulse to 500 mW or less. delete In the driving method of the plasma display apparatus for applying a negative sustain pulse alternately to the scan electrode and the sustain electrode in the sustain period, At the end of the sustain period, a narrow pulse having a width less than or equal to 0.5 times the width of the negative sustain pulse and having a voltage greater than the voltage of the negative sustain pulse is supplied to any one of the scan electrode and the sustain electrode. A driving method of a plasma display device, characterized in that. The method of claim 6, And the narrow pulse has the same polarity as that of the negative sustain pulse applied to the scan electrode and the sustain electrode in the sustain period. The method of claim 6, And the width of the narrow pulse is adjusted in proportion to the gap between the scan electrode and the sustain electrode. The method according to claim 6 or 8, And the width of the narrow pulse is controlled to 500 mW or less. delete

Images