KR20070097706A - Plasma display panel - Google Patents

Abstract

A plasma display panel is provided to generate a constant discharge start voltage by changing a size of a groove on a dielectric layer according to a size of a discharge gap. A plasma display panel includes first and second substrates(10,20), a barrier rib(16), an address electrode(11), first and second electrodes(31,32), and a dielectric layer(13). The barrier rib is arranged between the substrates and partitions discharge cells. The first and second substrates face each other. The address electrode is elongated in a first direction corresponding to the discharge cells. The first and second electrodes are elongated in a second direction and formed on one of the substrates. The second direction is normal to the first direction. The first and second electrodes form a discharge gap(G), which is spaced apart from a center portion of the discharge cell. The dielectric layer is arranged on the substrate to cover the first and second electrodes. A groove is formed to correspond to the discharge gap. The groove has a variable width in the first direction according to the discharge gap.

Description

Plasma Display Panel {PLASMA DISPLAY PANEL}

1 is a perspective view schematically illustrating an exploded view of a plasma display panel according to an exemplary embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1.

3 is a plan view showing an arrangement relationship between partitions and electrodes.

4 is a plan view of a transparent electrode forming a short gap.

5 is a plan view of a transparent electrode forming a long gap.

6 is a plan view showing the size relationship between the short gap discharge cell and the grooves formed in the dielectric layer thereof.

Fig. 7 is a plan view showing the size relationship between the long gap discharge cell and the groove formed in the dielectric layer thereof.

8 is a distribution chart of discharge start voltages according to discharge gaps and grooves of the dielectric layer.

9 is a distribution diagram of the discharge start voltage according to the discharge gap.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel, and more particularly, to a plasma display panel for improving discharge uniformity by varying the size of grooves formed between display electrodes to correspond to the size of a discharge gap.

In general, a plasma display panel is a visible light of red (R), green (G) and blue (B) generated by exciting the phosphor using a vacuum ultra-violet (VUV) emitted from the plasma obtained through gas discharge It is a display device for implementing an image.

As an example, an AC plasma display panel forms address electrodes on a back substrate and covers the address electrodes with a dielectric layer. The partition walls are disposed between the address electrodes on the dielectric layer to form a stripe shape, and phosphor layers of red (R), green (G), and blue (B) layers are formed on the partition walls. On the front substrate facing the rear substrate, display electrodes composed of a pair of sustain electrodes and scan electrodes are formed along the direction crossing the address electrodes, and a dielectric layer and an MgO protective film cover the display electrodes. The discharge cell is formed at the point where the pair of address electrodes on the rear substrate and the pair of display electrodes on the front substrate cross each other. In the plasma display panel, millions of unit discharge cells are arranged in a matrix form.

The memory characteristic is used to drive the discharge cells of the plasma display panel. In more detail, in order to generate a discharge between the sustain electrode and the scan electrode constituting the pair of display electrodes, a potential difference of more than a specific voltage is required, and the voltage at this boundary is called a firing voltage (Vf). When the scan voltage and the address voltage are respectively applied to the scan electrode and the address electrode, the discharge is started to form a plasma in the discharge cell, and the electrons and ions of the plasma move toward the electrodes having opposite polarities.

On the other hand, a dielectric layer is applied to each electrode of the plasma display panel, so that most of the moved space charges are stacked on the dielectric layer having opposite polarity, so that the net space potential between the scan electrode and the address electrode is originally applied to the address. It becomes lower than voltage Va, discharge becomes weak, and address discharge disappears. At this time, a relatively small amount of electrons are accumulated in the sustain electrode, and a relatively large amount of ions are accumulated in the scan electrode. The charges accumulated on the sustain electrode and the dielectric layer covering the scan electrode are wall charged (Qw). The space voltage formed between the sustain electrode and the scan electrode by these wall charges is referred to as wall voltage (Vw).

Subsequently, when the discharge sustain voltage Vs is applied to the sustain electrode and the scan electrode, the sum of the magnitudes of the discharge sustain voltage Vs and the wall voltage Vw (Vs + Vw) is the discharge start voltage Vf. If higher, sustain discharge occurs in the discharge cell. The vacuum ultraviolet (VUV) generated at this time excites the phosphor and emits visible light through the transparent front substrate.

However, when there is no address discharge between the scan electrode and the address electrode (that is, when no address voltage Va is applied), wall charges do not accumulate between the sustain electrode and the scan electrode, and consequently, the sustain electrode and the scan electrode. There is no wall voltage in between. At this time, only the discharge sustain voltage Vs applied to the sustain electrode and the scan electrode is formed in the discharge cell. Since the discharge sustain voltage is lower than the discharge start voltage Vf, the gas space between the sustain electrode and the scan electrode can be discharged. none.

The plasma display panel driven as described above forms a discharge gap between the sustain electrode and the scan electrode, and more specifically, between the transparent electrode of the sustain electrode and the transparent electrode of the scan electrode.

These transparent electrodes may be formed by an etching method as an example. Even when the transparent electrode is formed by another method including this visual method, it is difficult to form the transparent electrode with a uniform size over the entire plasma display panel due to a process error. In other words, it is difficult to form a discharge gap with a uniform size throughout the plasma display panel.

That is, the plasma display panel has a non-uniform transparent electrode size and a non-uniform discharge gap size, and thus, a non-uniform discharge start voltage.

Referring to FIG. 9 showing the distribution of discharge start voltages according to the discharge gap, the relatively long gap discharge cells LC have a high discharge start voltage Vf, and the short gap discharge cells SC are low. The discharge start voltage Vf is provided, and the discharge cells MC of the intermediate discharge gap have a discharge start voltage Vf between the long gap and the short gap discharge start voltage.

The present invention is to solve the above problems, an object of the present invention is to form a groove corresponding to the size of the discharge gap between the display electrodes when the discharge gap is non-uniform, thereby improving the discharge uniformity To provide.

According to an embodiment of the present invention, a plasma display panel includes a first substrate and a second substrate disposed to face each other, a partition wall disposed between the two substrates to partition discharge cells, and a first cell corresponding to the discharge cells. Address electrode extending in a second direction, a first electrode and a second electrode formed in one of the two substrates corresponding to the discharge cells, respectively, extending in a second direction crossing the first direction, and the first electrode And a dielectric layer formed on the substrate to cover an electrode and the second electrode, wherein the first electrode and the second electrode form a discharge gap spaced apart from each other at a center portion of the discharge cell, and the dielectric layer includes the discharge gap. The groove may correspond to the groove, and the groove may have a distance in a first direction different from the discharge gap.

The discharge gap may be formed in at least two sizes. At least two distances in the first direction of the groove may be formed.

The larger the discharge gap, the greater the distance in the first direction of the groove.

The smaller the discharge gap, the smaller the distance in the first direction of the groove.

The first electrode and the second electrode include a bus electrode extending in the second direction from both sides of the first direction of the discharge cell, and a transparent electrode protruding from the bus electrode in the first direction, wherein the discharge gap May be formed between the transparent electrode of the first electrode and the transparent electrode of the second electrode.

At least two first distances between the transparent electrode and the groove may be formed.

The greater the first distance between the transparent electrode and the groove, the smaller the distance in the first direction of the groove.

The smaller the first direction distance between the transparent electrode and the groove, the greater the distance in the first direction of the groove.

The groove may be formed in the dielectric layer in the discharge cell.

The groove may independently correspond to the discharge cells formed along the second direction.

A protective film may be formed on the surface of the dielectric layer and the inner surface of the groove.

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, and like reference numerals designate like elements throughout the specification.

1 is a perspective view schematically illustrating an exploded plasma display panel according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1.

Referring to these drawings, the plasma display panel according to an embodiment is disposed on the first substrate (hereinafter referred to as "back substrate") 10 and the second substrate (hereinafter referred to as "back substrate") which are disposed to face each other at predetermined intervals. 20 "and partition walls 16 provided between the substrates 10 and 20. The " front substrate " The partition wall 16 is formed at a predetermined height between the rear substrate 10 and the front substrate 20 to partition the plurality of discharge cells 17. The discharge cells 17 are filled with a discharge gas (for example, a mixed gas including neon (Ne), xenon (Xe), etc.) so as to generate a vacuum ultraviolet ray by gas discharge, and absorbs the vacuum ultraviolet ray A phosphor layer 19 for emitting visible light is provided.

In order to implement an image by gas discharge, the plasma display panel includes an address electrode 11 and a first electrode (hereinafter, " hold ") corresponding to each discharge cell 17 between the rear substrate 10 and the front substrate 20. An electrode "31 and a second electrode (hereinafter referred to as" scan electrode ") 32 are provided.

As an example, the address electrode 11 is formed along the first direction (y-axis direction in the drawing) on the inner surface of the back substrate 10 to form discharge cells 17 adjacent to the y-axis direction. Corresponds continuously. In addition, the plurality of address electrodes 11 are arranged side by side to correspond to the discharge cells 17 adjacent to each other in a second direction (the x-axis direction in the drawing) that crosses the y-axis direction.

The address electrodes 11 are covered with a dielectric layer 13 covering the inner surface of the back substrate 10 as described above. The dielectric layer 13 prevents cations or electrons from directly colliding with the address electrode 11 during discharge, thereby preventing damage to the address electrode 11, and also forms and accumulates wall charges. Since the address electrode 11 is disposed on the rear substrate 10 and does not prevent the visible light from being irradiated forward, the address electrode 11 may be formed as an opaque electrode. That is, the address electrode 11 may be formed of a metal electrode having excellent electrical conductivity.

The partition wall 16 is actually provided on the dielectric layer 13 of the rear substrate 10 to partition the discharge cells 17. The partition wall 16 is disposed at predetermined intervals along the y-axis direction between the first partition wall members 16a extending in the y-axis direction, and extends in the x-axis direction. The discharge cells 17 are formed in a matrix structure including the second partition wall members 16b formed.

In addition, the partition wall may be formed of first partition wall members extending in the y-axis direction, and the first partition wall members may be arranged side by side in the x-axis direction to form discharge cells in a stripe structure. Not shown)

The phosphor layer 19 formed in each of the discharge cells 17 is, for example, coated with a photosensitive phosphor face on the side of the partition wall 16 and the surface of the dielectric layer 13 surrounded by the partition walls 16, and drying it, It is formed by exposure, development, and baking.

The phosphor layer 19 is formed of phosphors of the same color in the discharge cells 17 formed along the y-axis direction. In addition, the phosphor layer 19 is repeatedly formed by the phosphors of red (R), green (G), and blue (B) in the discharge cells 17 repeatedly arranged along the x-axis direction.

Referring to FIG. 2, the sustain electrode 31 and the scan electrode 32 are provided on the inner surface of the front substrate 20 to correspond to each discharge cell 17 to cause gas discharge in the discharge cells 17. To form a surface discharge structure. The sustain electrode 31 and the scan electrode 32 extend in the x-axis direction crossing the address electrode 11.

Each of the sustain electrodes 31 and the scan electrodes 32 is formed of transparent electrodes 31a and 32a for generating a discharge and bus electrodes 31b and 32b for applying a voltage signal to the transparent electrodes 31a and 32a, respectively. do.

The transparent electrodes 31 a and 32 a are portions which cause surface discharge inside the discharge cell 17 and are formed of a transparent material (for example, indium tin oxide (ITO)) to secure the aperture ratio of the discharge cell 17. The bus electrodes 31b and 32b are formed of a highly conductive metal material to compensate for the high electrical resistance of the transparent electrodes 31a and 32a.

Referring to FIG. 3, the transparent electrodes 31a and 32a protrude from the outer edge of the discharge cell 17 along the y-axis direction to the center to form surface discharge structures with each of the widths W31 and W32. The discharge gap G is formed in the center portion of the discharge cell 17.

The bus electrodes 31b and 32b are disposed on the transparent electrodes 31a and 32a, respectively, and extend in the x-axis direction at the outside of the discharge cell 17. Therefore, when a voltage signal is applied to the bus electrodes 31b and 32b, a voltage signal is applied to each of the transparent electrodes 31a and 32a connected to the bus electrodes 31b and 32b.

Referring back to FIGS. 1 and 2, the sustain electrode 31 and the scan electrode 32 are covered with the dielectric layer 40 while crossing the address electrodes 11 and facing each other corresponding to the discharge cells 17. The dielectric layer 40 forms and accumulates wall charges during discharge while protecting the sustain electrode 31 and the scan electrode 32 from gas discharge.

This dielectric layer 40 is covered with a protective film 23. For example, the protective film 23 is formed of transparent MgO to protect the dielectric layer 40, thereby increasing the secondary electron emission coefficient upon discharge.

During the plasma display panel driving, a reset discharge is generated by a reset pulse applied to the scan electrode 31 in the reset period, and the scan pulse and the address electrode 11 applied to the scan electrode 32 in the addressing period following the reset period. The address discharge is generated by the address pulse applied to the C1, and then the sustain discharge is generated by the sustain pulse applied to the sustain electrode 31 and the scan electrode 32 in the sustain period.

The sustain electrode 31 and the scan electrode 32 serve as electrodes for applying sustain pulses required for sustain discharge, and the scan electrodes 32 serve as electrodes for applying reset pulses and scan pulses, and the address electrodes. Reference numeral 11 serves as an electrode for applying an address pulse. The sustain electrode 32, the scan electrode 32, and the address electrode 11 may differ in their roles according to voltage waveforms applied to the sustain electrodes 32, the scan electrodes 32, and the address electrodes 11, and are not necessarily limited to these roles.

The plasma display panel selects a discharge cell 17 to be turned on by the address discharge due to the interaction between the address electrode 11 and the scan electrode 32, and the interaction between the sustain electrode 31 and the scan electrode 32. The selected discharge cell 17 is driven by sustain discharge, thereby realizing an image.

As shown in FIG. 2, the dielectric layer 40 covering the sustain electrode 31 and the scan electrode 32 forms a groove 41. As shown in Fig. 3, this groove 41 corresponds to the discharge gap G and is formed inside the discharge cell 17 on the xy plane.

The passivation layer 23 is formed on the surface of the dielectric layer 40 and the inner surface of the groove 41, and is formed on the inner surface of the front substrate 20 surrounded by the groove 41. Accordingly, the protective layer 23 may protect the dielectric layer 40 and the front substrate 20 from discharge.

In general, the discharge start voltage Vf is determined by the discharge gap G between the sustain electrode 31 and the scan electrode 32. That is, the larger the discharge gap G is, the higher the discharge start voltage Vf is, and the smaller the discharge gap G is, the lower the discharge start voltage Vf is.

The discharge start voltage Vf is also determined by the y-axis direction GL of the groove 41. That is, as the distance GL in the y-axis direction of the groove 41 formed in the dielectric layer 40 increases, the discharge start voltage Vf decreases, and as the distance GL in the y-axis direction of the groove 41 decreases, the discharge starts. The voltage Vf becomes high.

In other words, the distance GL in the y-axis direction of the groove 41 determines the distance L between the transparent electrodes 31a and 32a and the groove 41 facing the groove 41. Accordingly, when the distance GL in the y-axis direction of the groove 41 is longer, the distance L between the transparent electrodes 31a and 32a and the groove 41 facing the hole is shortened, and the discharge start voltage is lowered. This can be confirmed through an experiment in which the grooves 41 are formed in the dielectric layer 40 and the distance GL in the y-axis direction of the grooves 41 is variously formed to measure the discharge start voltage.

Therefore, as the discharge gap G increases, the distance GL in the y-axis direction of the groove 41 increases. As the discharge gap G increases, the discharge start voltage that is increased is offset by the discharge start voltage that decreases as the distance GL in the y-axis direction of the groove 41 increases.

In addition, as the discharge gap G decreases, the distance GL in the y-axis direction of the groove 41 decreases. The discharge start voltage lowered as the discharge gap G becomes smaller is offset by the discharge start voltage increased as the distance GL in the y-axis direction of the groove 41 increases.

As the discharge gap G increases or decreases in this manner, the distance GL in the y-axis direction of the groove 41 increases or decreases. As a result, the discharge start voltage in each of the discharge cells 17 is uniformly adjusted. Therefore, the discharge uniformity of the plasma display panel may be improved.

On the other hand, the discharge gap G is formed between the sustain electrode 31 and the scan electrode 32 but is actually formed between the transparent electrode 31a of the sustain electrode 31 and the transparent electrode 32a of the scan electrode 32. do.

The transparent electrodes 31a and 32a are formed in various sizes in the discharge cells 17 due to various factors in the process. The transparent electrodes 31a and 32a are formed in at least two sizes. More specifically, the transparent electrodes 31a and 32a are formed in different sizes for each of the discharge cells 17.

Therefore, the distance GL in the y-axis direction of the groove 41 may be formed in at least two types. More specifically, the distance GL may be formed differently for each of the discharge cells 17.

As described above, the larger the discharge gap G, the larger the distance GL in the y-axis direction of the groove 41, and the smaller the discharge gap G, the smaller the distance GL in the y-axis direction of the groove 41. Becomes smaller. As a result, the uniformity of the discharge start voltage is improved.

4 to 7, the relationship between the transparent electrodes 31a and 32a and the groove 41 may be described again. Hereinafter, the short gap SG and the long gap LG are represented by dividing the relative sizes of the discharge gaps G, and the first distance GL1 and the second distance GL2 in the y-axis direction are the y-axis of the groove 41. The relative sizes of the directional distances GL are distinguished from each other.

In FIG. 4, the transparent electrodes 131a and 132a form a discharge gap G as a short gap SG. As shown in FIG. 6, when the transparent electrodes 131a and 132a form a short gap SG, the groove 141 forms a small first distance GL1 to correspond to the short gap SG. Here, "small first distance GL1" means smaller than the second distance GL2.

The transparent electrodes 131a and 132a forming the short gap SG generate sustain discharge at a low discharge start voltage, and the groove 141 having the first distance GL1 may slightly lower the discharge start voltage.

When the discharge start voltages of the transparent electrodes 131a and 132a are sufficiently low due to the short gap SG, the first distance GL1 of the groove 141 may be further reduced, and in some cases, the groove 141 may be provided. It may not be.

As described above, as the first distance L1 between the transparent electrodes 131a and 132a and the groove 141 facing the electrode becomes smaller, the discharge start voltage is lowered.

In FIG. 5, the transparent electrodes 231a and 232a form the discharge gap G as the long gap LG. As shown in FIG. 7, when the transparent electrodes 231a and 232a form a long gap LG, the groove 241 forms a large second distance GL2 to correspond to the long gap LG. Here, the "large second distance GL2" means larger than the first distance GL1.

Since the transparent electrodes 231a and 232a forming the long gap LG generate sustain discharge at a high discharge start voltage, the groove 241 having the second distance GL2 can significantly lower the discharge start voltage.

As described above, as the second distance L2 between the transparent electrodes 231a and 232a and the groove 241 facing the electrode becomes smaller, the discharge start voltage is lowered.

The distance L2 between the long gap LG is smaller than the distance L1 between the first and second gaps SG. Accordingly, the discharge of the transparent electrodes 231a and 232a forming the second distance L2 is higher than the voltage difference at which the discharge start voltage is lowered in the transparent electrodes 131a and 132a forming the first distance L1. The voltage difference at which the starting voltage is lowered is greater.

As such, when the transparent electrodes 131a and 132a form the short gap SG, the groove 141 has the first distance GL1, and when the transparent electrodes 231a and 232a form the long gap LG. The groove 241 has a second distance GL2. That is, by controlling the discharge start voltage by variably controlling the distance GL in the y-axis direction of the groove 41, the plasma display panel can obtain improved discharge uniformity as shown in FIG. 8.

8 shows discharge start voltages for each color of the phosphor layer 19. That is, from the discharge cells 17 having the short gap SG and the grooves 141 of the first distance GL1 to the discharge cells 17 of the grooves 241 of the long gap LG and the second distance GL2. Up to now, all the discharge cells 17 have almost the same discharge start voltage despite the difference in the discharge gap G.

The distribution of the discharge start voltage of FIG. 8 obtained in the plasma display panel in which the distance GL in the y-axis direction of the groove 41 is adjusted according to the discharge gap G is obtained in the plasma display panel having only the discharge gap G. The discharge uniformity is improved over the distribution of the discharge start voltage in FIG.

8 and 9 separately illustrate the discharge start voltages Vf_B, Vf_G, and Vf_R provided with the blue, green, and red phosphor layers and the discharge start voltage Vf_W at full white, respectively.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the scope of the invention.

As described above, according to the plasma display panel according to the present invention, a discharge gap is formed between the first electrode and the second electrode, a groove is formed in the dielectric layer corresponding to the discharge gap, and the distance in the first direction of the groove. Is formed in a relationship proportional to the size of the discharge gap in more detail according to the size of the discharge gap, thereby improving the uniformity of the discharge start voltage in spite of the discharge gap unevenness.

Claims (12)

A first substrate and a second substrate spaced apart from each other; Barrier ribs disposed between the substrates to partition discharge cells; An address electrode extending in a first direction corresponding to the discharge cell; First and second electrodes each extending in a second direction crossing the first direction and formed on one of the substrates in correspondence with the discharge cells; And A dielectric layer formed on the substrate to cover the first electrode and the second electrode, The first electrode and the second electrode, to form a discharge gap spaced apart from each other at the center of the discharge cell, The dielectric layer forms a groove corresponding to the discharge gap, And the groove has a distance in a first direction different from the discharge gap. According to claim 1, And at least two discharge gaps. The method of claim 2, And at least two distances in the first direction of the groove. According to claim 1, And the larger the discharge gap, the greater the distance in the first direction of the groove. According to claim 1, And the smaller the discharge gap, the smaller the distance in the first direction of the groove. According to claim 1, The first electrode and the second electrode, A bus electrode extending in the second direction from both sides of the first direction of the discharge cell, and a transparent electrode protruding from the bus electrode in the first direction, The discharge gap, And a plasma display panel formed between the transparent electrode of the first electrode and the transparent electrode of the second electrode. The method of claim 6, And at least two first distances between the transparent electrode and the groove. The method of claim 7, wherein The greater the first directional distance between the transparent electrode and the groove, the smaller the distance in the first direction of the groove. The method of claim 7, wherein The smaller the first direction distance between the transparent electrode and the groove, the greater the distance in the first direction of the groove. According to claim 1, And the groove is formed in the dielectric layer in the discharge cell. According to claim 1, And the groove independently corresponds to the discharge cells formed along the second direction. According to claim 1, And a passivation layer formed on the surface of the dielectric layer and the inner surface of the groove.

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