KR20030040718A - Plasma display panel - Google Patents

Abstract

PURPOSE: A plasma display panel is provided to achieve improved uniformity of luminance by permitting barrier ribs to have different pitches, thicknesses and heights. CONSTITUTION: A plasma display panel comprises an upper substrate(31) on which a pair of sustaining electrodes(32), an upper dielectric layer(34) and a protection film(35) are formed; and a lower substrate(36) on which an address electrode(37X), a lower dielectric layer(38), a barrier rib(39) and a phosphor layer(40). The upper substrate and the lower substrate are spaced apart from each other by the barrier rib. The barrier rib of the plasma display panel has the largest pitch at the center of the plasma display panel, and the pitch decreases as it goes from the center toward the peripheral part of the plasma display panel.

Description

Plasma Display Panel {PLASMA DISPLAY PANEL}

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 designed to increase luminance uniformity of the entire panel.

Plasma Display Panel (hereinafter referred to as "PDP") displays an image including text or graphics by emitting phosphors by 147 nm ultraviolet rays generated during discharge of He + Xe or Ne + Xe inert mixed gas. . Such a PDP is not only thin and easy to enlarge, but also greatly improved in quality due to recent technology development. In particular, the three-electrode AC surface discharge type PDP has advantages of low voltage driving and long life because wall charges are accumulated on the surface during discharge and protect the electrodes from sputtering caused by the discharge.

Referring to FIG. 1, a discharge cell of a three-electrode AC surface discharge type PDP is formed on an upper substrate 11 and serves as a pair of sustain electrodes 12Y and 12Z serving as a scan electrode and a sustain electrode, respectively, and on a lower substrate 16. And an address electrode 17X formed on the substrate.

The sustain electrode pair 12Y is formed of indium tin oxide (Indium-Tin-Oxide: hereinafter referred to as "ITO") having good transmittance. In each of the sustain electrode pairs 12Y and 12Z, a metal bus electrode 13 is formed to reduce resistance. The upper dielectric layer 14 and the passivation layer 15 are stacked on the upper substrate 11 on which the sustain electrode pairs 12Y and 12Z are formed.

The address electrode 17X is orthogonal to the sustain electrode pairs 12Y and 12Z. The lower dielectric layer 18 and the partition wall 19 are formed on the lower substrate 16 on which the address electrode 17X is formed, and the phosphor layer 20 is coated on the surfaces of the lower dielectric layer 18 and the partition wall 19.

An inert mixed gas such as He + Xe or Ne + Xe for discharging is injected into the discharge space of the discharge cells provided between the upper and lower substrates 11 and 16 and the partition wall 19.

The PDP is driven by dividing one frame period into several subfields having different emission counts in order to realize gray levels of an image. Each subfield is further divided into a reset period for uniformly generating discharge, an address period for selecting a discharge cell, and a sustain period for implementing gray levels according to the number of discharges. For example, when the image is to be displayed with 256 gray levels, the frame period (16.67 ms) corresponding to 1/60 second is divided into eight subfields. In addition, each of the eight subfields is divided into an address period and a sustain period. Here, the reset period and the address period of each subfield are the same for each subfield, while the sustain period and the number of discharges thereof are 2 ⁿ (n = 0,1,2,3,4,5,6, 7) is increased in proportion. As described above, since the sustain period is changed in each subfield, gray levels of an image can be realized.

PDPs are larger in size than other flat panel display devices (FPDs) such as 40 ″, 50 ″, and 60 ″. Therefore, since the lengths of the electrodes 12Y, 12Z, 13, and 17X are long in the PDP, the voltage drop due to the length of the electrode appears to be relatively large in the center and the peripheral part of the PDP. In addition, since the PDP is injected into the discharge gas at a pressure lower than atmospheric pressure therein, the upper and lower substrates 11, 11 and 16 are formed by a central portion where the upper and lower substrates 11 and 16 are supported only by the partition wall 19 and a sealing material (not shown). The force exerted on the substrates 11 and 16 at the periphery where 16 is bonded is different. As a result, although the conventional PDP is somewhat different depending on the size of the panel, as shown in FIG. 2, the luminance of the center portion is approximately 20% lower than that of the peripheral portion in each of the horizontal direction and the vertical direction.

Accordingly, it is an object of the present invention to provide a PDP in which the luminance uniformity of the entire panel is increased.

1 is a view showing a discharge cell structure of a conventional three-electrode AC surface discharge type plasma display panel.

FIG. 2 is a diagram showing luminance unevenness in the conventional three-electrode AC surface discharge type plasma display panel shown in FIG. 1; FIG.

3 illustrates a plasma display panel according to a first embodiment of the present invention.

4 is a view showing the partition shown in FIG.

FIG. 5 is a view illustrating a case where the first embodiment illustrated in FIG. 3 is applied to a rectangular bulkhead.

FIG. 6 is a view showing a case where the first embodiment shown in FIG. 3 is applied to a delta partition.

7 illustrates a plasma display panel according to a second embodiment of the present invention.

FIG. 8 is a view showing a case where the second embodiment shown in FIG. 7 is applied to a rectangular bulkhead.

FIG. 9 illustrates a case where the second embodiment shown in FIG. 3 is applied to a delta partition.

10 is a graph showing a relationship between partition height and luminance.

11 illustrates a plasma display panel according to a third embodiment of the present invention.

FIG. 12 is a graph illustrating luminance deviation between a central portion and a peripheral portion of the plasma display panel shown in FIG. 11;

<Description of Symbols for Main Parts of Drawings>

11,31: upper substrate 14,34: upper dielectric layer

15,35: protective film 16,36: lower substrate

17X, 37X: Address electrode 18,38: Lower dielectric layer

19,39,4142,51,52,53,61: bulkhead 20,40: fluorescent layer

12Y, 12Z, 32: sustain electrode 13: bus electrode

In order to achieve the above object, the plasma display panel according to the present invention is a plasma display panel having a sustain electrode pair for causing a sustain discharge and an address electrode for address discharge, the partition wall of which pitch decreases from the center to the periphery of the panel; It characterized by having a.

Other objects and features of the present invention in addition to the above object will be apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 3 to 11.

3 and 4, in the PDP according to the first embodiment of the present invention, the pitch of the partition wall 39 becomes narrower from the center portion to the periphery portion. In this case, the pitch refers to the distance between two adjacent partitions 39.

The PDP includes an upper plate having an unillustrated sustain electrode pair, an upper dielectric layer 34 and a passivation layer 35 sequentially formed on the upper substrate 31, an address electrode 37X sequentially formed on the lower substrate 36, A lower plate having a lower dielectric layer 38, a partition 39, and a phosphor layer 40 is provided. The upper substrate 31 and the lower substrate 36 are spaced apart in parallel by the partition wall 39.

Each of the sustain electrode pairs 32 has a relatively wide width and is composed of a transparent electrode made of ITO for transmitting visible light, and a metal electrode for compensating for the resistance component of the transparent electrode. The sustain electrode pair 32 is composed of a scan / sustain electrode and a sustain electrode. The scan signal for panel scanning and the sustain signal for discharge sustaining are mainly supplied to the scan / hold electrode, and the sustain signal is mainly supplied to the sustain electrode. Charges are accumulated in the upper dielectric layer 34 and the lower dielectric layer 38. The protective layer 35 prevents damage to the upper dielectric layer 34 due to sputtering, thereby increasing the lifetime of the PDP and increasing the emission efficiency of secondary electrons. As the protective film 35, magnesium oxide (MgO) is usually used.

The address electrode 37X is formed to cross the sustain electrode pair 32. The address electrode 37X is supplied with a data signal for selecting cells to be displayed.

The partition wall 39 is formed in parallel with the address electrode 37X to prevent the ultraviolet rays generated by the discharge from leaking to the adjacent cells. In the PDP, the pitch W2 of the partition wall 39 is greatest in the center portion, and the pitch W1 of the partition wall 39 decreases toward the periphery portion. As the pitch of the barrier ribs 39 increases, the discharge space increases, so that the luminance increases. Therefore, the luminance increases in the central portion where the partition 39 has a large pitch, and the luminance decreases toward the peripheral portion. Accordingly, by varying the pitch of the partition wall 39, it is possible to compensate for the difference in luminance of the central portion and the peripheral portion of the PDP. In consideration of the panel size and the luminance of the periphery, the peripheral pitch difference with respect to the central pitch of the partition 39 is preferably set within about 20%. The pitch of the bulkhead 39 is increased in the center portion and smaller as the periphery thereof is applied to the rectangular bulkhead 41 or the delta type bulkhead 42 shown in FIGS. 5 and 6 as well as the stripe-shaped bulkhead 39. Can be. The rectangular partition 41 and the delta partition 42 also have a larger pitch at the center and a smaller pitch at the periphery. That is, since luminance increases in the center portion of the PDP and decreases in the peripheral portion, uniform luminance is realized in the entire PDP screen.

The phosphor layer 40 is applied to the surfaces of the lower dielectric layer 38 and the partition wall 39 to generate visible light of any one of red, green, and blue. An inert mixed gas such as He + Xe or Ne + Xe for discharging is injected into the discharge space of the discharge cells provided between the upper and lower substrates 31 and 36 and the partition wall 39.

The PDP cell of this structure is selected by the counter discharge between the address electrode 37X and the scan / sustain electrode 32Z, and then sustains the discharge by the surface discharge between the sustain electrode pairs 32. In the PDP cell, the fluorescent material 40 emits light by ultraviolet rays generated during sustain discharge, so that visible light is emitted outside the cell. As a result, the PDP having cells displays an image.

Referring to FIG. 7, in the PDP according to the second embodiment of the present invention, the pitch of the barrier rib 51 is constant and the thickness of the barrier rib 51 becomes thicker from the center portion to the periphery portion. In this case, the pitch refers to the distance between two adjacent partition walls 51. Hereinafter, other essential components according to the present invention are the same as the first embodiment, so description thereof will be omitted.

The partition 51 is formed in a stripe shape and prevents ultraviolet rays generated by the discharge from leaking into adjacent cells. The thickness T1 of the partition wall 51 is the smallest in the center portion of the PDP, and the thickness T2 of the partition wall 51 becomes larger toward the peripheral portion. As the thickness of the partition wall 51 increases, the discharge space decreases, so that the brightness decreases from the center of the PDP toward the periphery. Therefore, the luminance increases in the central portion having the largest thickness of the partition wall 51 and the luminance decreases toward the peripheral portion. That is, since the thickness of the partition wall 51 is small in the center portion and increases in thickness toward the periphery portion, the difference in luminance between the center portion and the peripheral portion of the PDP can be compensated for. In consideration of the panel size and the luminance of the periphery, the peripheral thickness difference with respect to the central thickness of the partition wall 51 is preferably set within about 20%. The thickness of the partition wall 51 is smaller in the center portion and larger as the periphery portion is applied to the rectangular partition wall 52 or the delta partition wall 53 shown in FIGS. 8 and 9 as well as the stripe-shaped partition wall 51. Can be. The rectangular bulkhead 52 and the delta-type bulkhead 53 also have a smaller thickness of the bulkhead at the center and a larger thickness of the bulkhead toward the periphery. Accordingly, since luminance increases in the center portion of the PDP and decreases in the peripheral portion, uniform luminance is realized in the entire PDP screen.

10 and 11, in the PDP according to the third embodiment of the present invention, the pitch of the partition wall 61 is constant and the height of the partition wall 61 decreases from the center portion to the periphery portion. In this case, the pitch refers to the distance between two adjacent partition walls 61, and since the other essential components according to the present invention are the same as the first embodiment will be omitted.

The partition wall 61 is formed in a stripe shape and prevents ultraviolet rays generated by the discharge from leaking into adjacent cells. The height of the partition wall 61 is the largest in the central portion of the PDP and becomes smaller toward the periphery. As shown in the graph of FIG. 10, as the height of the partition wall 61 increases, the brightness increases, and as the height of the partition wall 61 decreases, the brightness decreases. If the height of the partition 61 is high, the discharge space is increased, so that the brightness is increased. If the height of the partition 61 is decreased, the discharge space is reduced, the brightness is reduced. Accordingly, the luminance decreases from the center of the PDP toward the periphery. Therefore, the luminance is increased at the central portion where the height of the partition wall 61 is the largest, and the luminance decreases toward the peripheral portion. That is, since the height of the partition wall 61 becomes smaller from the center portion to the periphery portion, the luminance difference between the center portion and the peripheral portion of the PDP can be compensated for. In consideration of the panel size and the luminance of the peripheral portion, it is preferable that the peripheral thickness difference with respect to the central thickness of the partition wall 61 is set within about 20%. At this time, the pitch of the partition 61 is constant.

This increase in the height of the partition wall 61 in the center portion and the smaller toward the peripheral portion can be applied not only to the strip-shaped partition wall 61 but also the rectangular partition wall or delta partition wall not shown. The rectangular bulkhead and the delta type bulkhead also have a height of the bulkhead at the center portion and become smaller toward the periphery portion, so that the luminance difference decreases within ± 1% at the periphery and the center portion of the PDP as shown in FIG. 12. As a result, uniform luminance is realized over the PDP full screen.

As described above, the PDP according to the present invention increases the pitch of the partition wall or increases its thickness from the central portion to the peripheral portion. Alternatively, the height of the partition wall is made smaller from the center portion to the periphery portion, thereby reducing the difference in luminance between the center portion and the periphery portion of the PDP. Accordingly, the PDP according to the present invention can realize a uniform luminance in the entire PDP panel.

Those skilled in the art through the above description can be seen that various changes and modifications can be made without departing from the spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (10)

A plasma display panel comprising a sustain electrode pair for causing sustain discharge and an address electrode for address discharge, And a barrier rib, the pitch of which decreases from the center of the panel toward the periphery thereof. The method of claim 1, The center pitch of the partition wall is greater than 20% of the peripheral portion of the plasma display panel. A plasma display panel comprising a sustain electrode pair for causing sustain discharge and an address electrode for address discharge, And a partition wall formed to be thicker from the center portion to the periphery of the panel. The method of claim 3, wherein And the thickness of the central portion of the partition wall is smaller than the peripheral portion in at least one of a horizontal direction and a vertical direction. The method of claim 3, wherein And a center thickness of the partition wall is less than 20% of the peripheral portion. The method of claim 3, wherein And a pitch between the barrier ribs is constant. A plasma display panel comprising a sustain electrode pair for causing sustain discharge and an address electrode for address discharge, And a barrier rib formed to have a height lowered from the center to the periphery of the panel. The method of claim 7, wherein And a height of the central portion of the partition wall is greater than that of the peripheral portion in at least one of a horizontal direction and a vertical direction. The method of claim 7, wherein And a height of the central portion of the partition wall is greater than 20% of the peripheral portion. The method of claim 7, wherein And a pitch between the barrier ribs is constant.