KR20060053521A - Plasma display device and driving method thereof - Google Patents

Abstract

The present invention relates to a plasma display device including a plasma display panel having a structure capable of realizing high efficiency. A plasma display panel according to an exemplary embodiment of the present invention includes a first substrate and a second substrate that are disposed to face each other, an address electrode is formed along one direction from the first substrate, and the first substrate and the second substrate A plurality of discharge cells partitioned by partition walls are formed in the interspace. In addition, display electrodes including a scan electrode and a sustain electrode are formed in the second substrate in a direction crossing the address electrode and at least one pair of the discharge cells faces each other. In addition, a dielectric layer is formed on the second substrate and has an opening that exposes a portion of the second substrate between at least one pair of display electrodes corresponding to each discharge cell. In the plasma display panel having such a structure, wall charges are concentrated in the openings of the dielectric layer to generate low discharge in the sustain period. Therefore, in the embodiment of the present invention, when the sustain discharge pulse is applied to the scan electrode and the sustain electrode in the sustain period, the low discharge in the sustain period is prevented by biasing the voltage of the address electrode to a positive voltage in at least some period.

PDP, Electrode, Opening, Dielectric Layer, Retention Period, Bias, High Efficiency, Discharge

Description

Plasma display device and driving method thereof {PLASMA DISPLAY DEVICE AND DRIVING METHOD THEREOF}

1 is a diagram illustrating a plasma display device according to an exemplary embodiment of the present invention.

2 is a partially exploded perspective view illustrating a plasma display panel according to a first embodiment of the present invention.

3 is a partial plan view of a plasma display panel according to a first exemplary embodiment of the present invention.

4 is a partial cross-sectional view taken along the line II of FIG. 2.

5 is a partial plan view of a plasma display panel according to a second exemplary embodiment of the present invention.

6 is a driving waveform diagram in a sustain period of a plasma display panel according to an exemplary embodiment of the present invention.

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

In general, a plasma display panel (PDP) is a display device that implements an image by using visible light generated by vacuum ultravilotet (VUV) emitted from a plasma formed by gas discharge to excite a phosphor layer. Such a plasma display panel has a high resolution and large screen configuration, and has been spotlighted as a next generation thin display device.

The general structure of the plasma display panel is a three-electrode surface discharge type structure. The three-electrode surface discharge type structure includes a front substrate on which a display electrode composed of two electrodes is formed, and a back substrate on which a address electrode is formed at a predetermined distance from the substrate, wherein the display electrode is covered by a dielectric layer. The space between the two substrates is partitioned into a plurality of discharge cells by partition walls, discharge gas is injected into the discharge cells, and a phosphor layer is formed on the rear substrate side.

In the plasma display panel configured as described above, millions of unit discharge cells are arranged in a matrix form. In order to simultaneously drive the discharge cells of the AC plasma display panel arranged in a matrix form, one frame is divided into a plurality of subfields having respective weights. Each subfield includes a reset period, an address period, and a sustain period. The reset period serves to erase the wall charges formed by the previous sustain discharge and to set up the wall charges in order to stably perform the next address discharge. The address period is a period in which a wall charge is accumulated in a cell (addressed cell) that is turned on by selecting a cell that is turned on and a cell that is not turned on in the panel. The sustain period is a period in which sustain discharge is performed to actually display an image in the addressed cell.

However, the plasma display panel goes through several steps from the input power to the final visible light, and in each of these processes, the energy conversion efficiency is deteriorated, and the path of discharge between the display electrodes is increased due to the dielectric layer covering the display electrodes. There is a problem that power consumption is increased. As described above, in the conventional plasma display panel, since the phosphor layer is formed only on the rear substrate side, the surface area of the phosphor layer capable of emitting light by visible light is low, thereby causing low luminance. That is, the conventional plasma display panel has a problem of low efficiency (ratio of luminance to power consumption).

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a plasma display panel which can effectively lower the discharge start voltage and improve the efficiency. Another object of the present invention is to provide a driving waveform suitable for driving a plasma display panel.

According to an aspect of the present invention, a plasma display device includes a first substrate having an address electrode formed in one direction, and a scan electrode and a sustain electrode formed in a direction opposite to the first substrate so as to face the first substrate. A second substrate, a plurality of discharge cells partitioned by partition walls in a space between the first substrate and the second substrate, and covering the scan electrode and the sustain electrode arranged to face at least one pair of the discharge cells. A plasma display panel including a dielectric layer forming an opening exposing a portion of the second substrate between at least a pair of the scan electrode and the sustain electrode corresponding to a discharge cell, and in the sustain period, the scan electrode and the sustain electrode Apply a plurality of sustain discharge pulses alternately to And a driving unit for setting the electrode to a positive voltage. In this case, the partial period corresponds to the first half of the period during which the sustain discharge pulse is applied.

According to another feature of the present invention, a plurality of discharge cells are formed by a plurality of display electrodes including a plurality of first electrodes and a plurality of second electrodes and a plurality of third electrodes formed in a direction crossing the display electrodes. A method of driving a frame by dividing the frame into a plurality of subfields having respective weights is provided. In this driving method, the display electrodes are arranged such that at least one pair faces each other in a discharge cell, and a section, which is at least a part of the display electrodes among the dielectric layers covering the display electrodes, is exposed, and in the sustain period, the first Alternately applying a plurality of sustain discharge pulses to an electrode and a second electrode, and setting the third electrode to a positive voltage in some of the periods during which the sustain discharge pulse is applied.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention. Like parts are designated by like reference numerals throughout the specification.

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

First, a schematic structure of a plasma display device according to an exemplary embodiment of the present invention will be described in detail with reference to FIG. 1.

1 is a diagram illustrating a plasma display device according to an exemplary embodiment of the present invention.

As shown in FIG. 1, a plasma display device according to an exemplary embodiment of the present invention includes a plasma display panel 100, a controller 200, an address electrode driver 300, a sustain electrode driver 400, and a scan electrode driver 500. It includes.

The plasma display panel 100 includes a plurality of address electrodes A1 to Am extending in the column direction, and a plurality of sustain electrodes X1 to Xn and scan electrodes Y1 to Yn extending in pairs in the row direction. Include.

The controller 200 receives an image signal from the outside and outputs an address driving control signal, a sustain electrode X driving control signal, and a scan electrode Y driving control signal. The controller 200 divides and drives one frame into a plurality of subfields, and each subfield is composed of a reset period, an address period, and a sustain period.

The address electrode driver 300 receives the address electrode A driving control signal from the controller 200 and applies a display data signal for selecting a discharge cell to be displayed to each address electrode.

The sustain electrode driver 400 receives the sustain electrode X driving control signal from the controller 200 and applies a driving voltage to the sustain electrode X.

The scan electrode driver 500 receives the scan electrode Y driving control signal from the controller 200 and applies a driving voltage to the scan electrode Y.

Next, the plasma display panel 100 will be described in detail with reference to FIGS. 2 to 5. 2 to 5, the scan electrode Y is indicated by reference numeral 21, the sustain electrode is indicated by reference numeral 22, and the address electrode A is indicated by reference numeral 12. In FIG.

2 is a partially exploded perspective view illustrating a plasma display panel according to a first embodiment of the present invention.

As shown in FIG. 2, in the plasma display panel according to the first embodiment of the present invention, the rear substrate 10 and the front substrate 20 having an arbitrary size are disposed substantially parallel to each other at a predetermined interval. In the space between the back substrate 10 and the front substrate 20, a plurality of discharge cells 18 partitioned by the partition wall 16 are formed.

On the opposite surface of the front substrate 20 of the back substrate 10, a plurality of address electrodes 12 are formed along one direction (y-axis direction of the drawing), and covering the address electrodes 12, The dielectric layer 14 is formed on the front side. The address electrodes 12 are located side by side with a predetermined distance from neighboring ones.

A partition wall 16 is formed on the dielectric layer 14 to partition the plurality of discharge cells 18. The partition wall 16 has a first partition wall member 16a formed along a direction parallel to the address electrode 12 (y-axis direction in the drawing) and a direction intersecting with the first partition wall member 16a (x-axis direction in the drawing). It includes a second partition member (16b) formed along the). Such a barrier rib structure is not limited to the above-described structure, and a barrier rib structure having various shapes such as a stripe-type barrier rib structure made of only a barrier rib member in parallel with the address electrode can be applied to the present invention, which also belongs to the scope of the present invention.

In the discharge cell 18, a phosphor layer 19 of red, green, and blue, which absorbs vacuum ultraviolet rays and emits visible light, is formed, and a discharge gas (for example, a mixed gas of Xe and Ne) is injected to form a predetermined discharge and Light emission will occur.

On the opposite side of the back substrate 10 of the front substrate 20, the display electrode 21 including the scan electrode 21 and the sustain electrode 22 along the direction crossing the address electrode 12 (the x-axis direction of the drawing). , 22) are formed. The display electrodes 21 and 22 extend from the bus electrodes 21b and 22b extending along the direction crossing the address electrode 12 (the x-axis direction in the drawing) and the discharge cells 18 from the bus electrodes 21b and 22b. It includes the enlarged electrodes (21a, 22a) extending toward the center of. For example, a pair of bus electrodes 21b and 22b may correspond to each discharge cell 18. In this case, a pair of enlarged electrodes 21a and 22a may be formed to face each other in each discharge cell 18.

The enlarged electrodes 21a and 22a serve to cause plasma discharge in the discharge cell 18, and may be made of indium tin oxide (ITO) or the like, which is a transparent material, to secure the aperture ratio. 21b and 22b may be made of an opaque metal to compensate for the high resistance of the enlarged electrodes 21a and 22a to ensure current conduction.

The dielectric layer 24 is formed on the front substrate 20 while covering the display electrodes 21 and 22. The dielectric layer 24 is formed with an opening 24a exposing a portion of the front substrate 20 on a surface opposite the back substrate 10.

An MgO passivation layer 26 is formed on the front substrate 20 to cover the dielectric layer 24. The MgO passivation layer 26 protects the dielectric layer 24 from collision of ionized ions during plasma discharge, and increases discharge efficiency by having a high secondary electron emission coefficient.

 3 is a partial plan view illustrating a plasma display panel according to a first exemplary embodiment of the present invention, and FIG. 4 is a partial cross-sectional view taken along the line II of FIG. 2.

3 and 4, in the first embodiment of the present invention, the opening 24a of the dielectric layer corresponds to the central portion of each discharge cell 18 between the facing electrodes 21a and 22a facing each other. Is formed.

The opening 24a of the dielectric layer shortens the path D of the discharge formed between the display electrodes 21 and 22. That is, since the discharge path between the display electrodes 21 and 22 may be formed through the opening 24a of the dielectric layer between the display electrodes 21 and 22, the discharge path D is straightened to shorten the path. . In addition, the initial discharge in the sustain discharge can be substantially induced to the opposite discharge by the opening 24a of the dielectric layer. Therefore, in the embodiment of the present invention, the discharge voltage can be reduced by reducing the length of the discharge path D and inducing the initial discharge to the opposite discharge.

Next, a plasma display panel according to a second exemplary embodiment of the present invention will be described in detail. The second embodiment of the present invention has the same basic configuration as that of the first embodiment, and the structure of the display electrode is different from that of the first embodiment. The same reference numerals are used for the same components as in the first embodiment.

5 is a partial plan view of a plasma display panel according to a second exemplary embodiment of the present invention.

As shown in FIG. 5, the display electrodes 31 and 32 are bus electrodes 31b and 32b extending long along the direction crossing the address electrode 12 (the x-axis direction in the drawing), and the bus electrodes 31b and 32b. ) And enlargement electrodes 31a and 32a. The enlarged electrodes 31a and 32a play a role of causing plasma discharge in the discharge cells 18 and are made of indium tin oxide (ITO), which is a transparent material, to secure the aperture ratio, and the bus electrodes 31b. , 32b) is to compensate for the high resistance of the enlarged electrodes 31a and 32a to ensure current conduction, and may be made of an opaque metal material. In this case, a pair of bus electrodes 31b and 32b may be formed to correspond to each discharge cell 18, and a pair of enlarged electrodes 31a and 32a may be formed to face each other in each discharge cell 18.

In the second embodiment of the present invention, the magnification electrodes 31a and 32a extend from the bus electrodes 31b and 32b in the direction crossing the bus electrodes 31b and 32b (y-axis direction in the drawing). , 32a1 and second portions 31a2 and 32a2 connected to the first portions 31a1 and 32a1 and formed to face each other at the center of each discharge cell 18. In the second embodiment of the present invention, the current flowing through the enlarged electrodes 31a and 32a can be reduced by reducing the area of the enlarged electrodes 31a and 32a having a small contribution to the discharge.

By forming an opening in the dielectric layer portion between the display electrodes 31 and 32, the discharge path can be reduced, thereby lowering the discharge voltage. That is, in the plasma display panel having such a structure, a discharge path is formed through the opening 24a of the dielectric layer near the gap between the display electrodes 21 and 22, and the discharge path is formed between the display electrodes 21 and 22 through the discharge path. A discharge path is formed in the entire electrode by diffusing inward from the opening 24a of the dielectric layer near the gap. Therefore, the discharge starts from the opening 24a of the dielectric layer to discharge the entire electrode, thereby facilitating the generation of charged particles and excitation species, thereby increasing efficiency.

However, in the structure of the plasma display panel, wall charges and space charges are concentrated around the opening 24a of the dielectric layer between the display electrodes 21 and 22, so that the sustain discharge pulse having the voltage Vs is applied to the scan electrodes in this state. In this case, the discharge may occur between the address electrode 12 and the scan electrode 21 as well as the discharge between the sustain electrode 22 and the scan electrode 21. When discharge occurs between the address electrode 12 and the scan electrode 21 as well as between the sustain electrode 22 and the scan electrode 21 in the sustain period, between the address electrode 12 and the scan electrode 21 in the sustain period. In comparison with the case where no discharge occurs, the positive wall charges are attracted to the address electrode 12 relatively, so that the amount of positive wall charges formed on the sustain electrode 22 is reduced. Therefore, the wall voltage between the sustain electrode 22 and the scan electrode 21 is lowered so that the discharge may be weak or no discharge may occur when the pulse of the Vs voltage is applied to the sustain electrode 22. Therefore, sustain discharge is not sustained and low discharge may occur in the sustain period. Hereinafter, an embodiment capable of preventing such low discharge in a sustain period will be described in detail with reference to FIG. 6.

Hereinafter, a driving waveform applied to the address electrodes A1 to Am, the sustain electrodes X1 to Xn, and the scan electrodes Y1 to Yn in the sustain period of each subfield will be described with reference to FIG. 6. The following description will be made based on the discharge cells formed by one address electrode, sustain electrode and scan electrode. In addition, the wall charges mentioned below refer to charges that are formed on the walls of the discharge cells (eg, dielectric layers) close to each electrode and accumulate in the electrodes. This wall charge is not actually in contact with the electrode itself, but here the wall charge is described as "formed", "accumulated" or "stacked" on the electrode. In addition, a wall voltage refers to the potential difference formed in the wall of a discharge cell by wall charge.

6 is a driving waveform diagram in a sustain period of a plasma display panel according to an exemplary embodiment of the present invention.

As shown in Fig. 6, in the sustain period, the sustain discharge pulse of the Vs voltage is applied to the scan electrode Y and the sustain electrode X in order. If the wall voltage is formed between the scan electrode Y and the sustain electrode X by the address discharge in the address period, the discharge is performed in the scan electrode Y and the sustain electrode X by the wall voltage and the Vs voltage in the sustain period. This happens. Thereafter, the process of applying the sustain discharge pulse of the Vs voltage to the scan electrode Y and the process of applying the sustain discharge pulse of the Vs voltage to the sustain electrode X are repeated the number of times corresponding to the weight indicated by the corresponding subfield. .

인 경우에, 바이어스 전압을 인가하는 기간은

정도로 할 수 있다. According to the first embodiment of the present invention, when the sustain discharge pulse is applied to the scan electrode (Y) and the sustain electrode (X) in the sustain period, the voltage of the address electrode (A) is biased to a positive voltage during a partial period. At this time, a part of the period is a period before the period during which the sustain discharge pulse is applied. That is, the bias voltage of the address electrode A is applied until the wall charge is formed after the sustain discharge by the sustain discharge pulse. The reason is that wall charges start to accumulate on each electrode after the sustain discharge, because the bias voltage of the address electrode A prevents the accumulation of the wall charges. For example, the width of the sustain discharge pulse

If is, the period of applying the bias voltage is

I can do that.

The bias voltage of the address electrode A is lower than the high voltage Vs of the sustain discharge pulse. When the address voltage Va is used as the bias voltage, an additional power supply does not need to be used. As such, when a positive bias voltage is applied to the address electrode A when the sustain discharge pulse is applied to the scan electrode Y and the sustain electrode X in the sustain period, the scan electrode Y and the address electrode A are separated. The voltage difference is reduced so that no discharge occurs between scan electrode Y and address electrode A, and only discharge occurs between scan electrode Y and sustain electrode X. The charge is attracted a lot so that the discharge occurs even when the voltage Vs is applied to the sustain electrode X later.

In the sustain period, when a positive voltage is applied to the address electrode A while the sustain discharge pulse is applied to the scan electrode Y and the sustain electrode X, the sustain electrode X and the scan electrode are applied. An electric field is formed between not only (Y) but also between the address electrode A and the scan electrode Y to widen the discharge region, and the vacuum ultraviolet rays generated at the time of discharge are well transmitted to the fluorescent film, so that the brightness and luminous efficiency of the plasma display panel are improved. Is increased.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

According to the present invention, in the plasma display panel according to the present invention, a discharge path is formed inside the opening of the dielectric layer formed between the display electrodes, thereby shortening the discharge path. Therefore, the plasma display panel can be driven at a low voltage, thereby improving efficiency. In this structure, however, since wall charges are concentrated in the openings of the dielectric layer, discharge occurs not only between the scan electrode and the sustain electrode in the sustain period, but also between the scan electrode and the address electrode, so that low discharge occurs in the sustain period. Therefore, in the embodiment of the present invention, when the sustain discharge pulse is applied to the scan electrode and the sustain electrode in the sustain period, the voltage difference between the scan electrode and the address electrode is reduced by biasing the voltage of the address electrode A with a positive voltage. Discharge does not occur between the electrode and the address electrode.

In addition, if the voltage of the address electrode is biased to a positive voltage when the sustain discharge pulse is applied to the scan electrode and the sustain electrode in the sustain period as in the embodiment of the present invention, scanning is performed in addition to the electric field between the sustain electrode and the scan electrode. A large electric field is also formed between the electrode and the address electrode, so that the discharge region is widened. In addition, it is possible to more efficiently transfer the vacuum ultraviolet rays generated during discharge to the phosphor layer, thereby improving the brightness and the discharge efficiency of the plasma display device.

Claims (9)

A first substrate having an address electrode formed in one direction, a second substrate disposed opposite to the first substrate and having a scan electrode and a sustain electrode formed in a direction crossing the address electrode, the first substrate and the A plurality of discharge cells partitioned by barrier ribs in the space between the second substrates and at least one pair of the scan electrodes covering the scan electrodes and the sustain electrodes arranged to face at least one pair of the discharge cells and corresponding to the discharge cells A plasma display panel including a dielectric layer forming an opening exposing a portion of the second substrate between a storage electrode and a sustain electrode; In the sustain period, the driving unit alternately applies a plurality of sustain discharge pulses to the scan electrode and the sustain electrode, and sets the address electrode to a positive voltage during a period during which the sustain discharge pulse is applied. Plasma display device comprising a. The method of claim 1, The partial period is a period corresponding to the first half of the period during which the sustain discharge pulse is applied. The method of claim 2, The positive voltage at which the address electrode is set is the same voltage as that applied to the address electrode to select a discharge cell to be turned on in an address period. The method according to any one of claims 1 to 3, The scan electrode and the sustain electrode may include a pair of bus electrodes extending in a direction crossing the address electrode, and a pair of magnification electrodes extending from the bus electrode toward the center of each discharge cell and facing each other. Display device. The method of claim 4, wherein And an opening of the dielectric layer is formed between the enlarged electrodes facing each other. The method according to any one of claims 1 to 3, An opening of the dielectric layer corresponding to a central portion of each of the discharge cells. In a plasma display device in which a plurality of discharge cells are formed by a plurality of display electrodes including a plurality of first electrodes and a plurality of second electrodes and a plurality of third electrodes formed in a direction crossing the display electrodes, a frame is formed. In the driving method divided into a plurality of subfields having respective weights, The display electrodes may be arranged such that at least one pair faces each other in a discharge cell, and a section that is at least a portion between the display electrodes of the dielectric layers covering the display electrodes is exposed. In the retention period, Alternately applying a plurality of sustain discharge pulses to the first electrode and the second electrode, and Setting the third electrode to a positive voltage during a period of time during which the sustain discharge pulse is applied; Method of driving a plasma display device comprising a. The method of claim 7, wherein In the address period, Applying a scan voltage and an address voltage to the first electrode and the third electrode, respectively, to select a discharge cell to be turned on, And the positive voltage of the third electrode is the same voltage as the address voltage. The method of claim 8, The partial period is a period corresponding to the first half of the period during which the sustain discharge pulse is applied.

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