KR20030040719A - Plasma display panel - Google Patents

Abstract

PURPOSE: A plasma display panel is provided to achieve improved uniformity of luminance by restricting the luminance difference between the peripheral part and center of the plasma display panel. CONSTITUTION: A plasma display panel comprises plural pairs of sustaining electrodes(32) for causing sustaining discharge; an upper dielectric layer(34) and a protection film(35) covering the sustaining electrodes; and black matrices(33) arranged between the pairs of sustaining electrodes in the direction parallel to the sustaining electrodes, wherein each of the black matrices has a width increasing 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 method and apparatus for driving a plasma display panel, and more particularly, to a plasma display panel for enhancing 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 usually formed of indium tin oxide (ITO). 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.

Such a PDP is driven by dividing one frame period into several subfields having different emission counts in order to realize gray level 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 17 are long in the PDP, the voltage drop due to the length of the electrode appears as a relatively large difference in the center part 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 perspective 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 plan view showing the black matrix shown in FIG.

5 is a graph showing a relationship between a black matrix width and luminance.

6 is a plan view showing another structure of the black matrix shown in FIG.

7 is a cross-sectional view illustrating a plasma display panel according to a second embodiment of the present invention.

FIG. 8 is a plan view illustrating the black matrix shown in FIG. 7; FIG.

9 is a plan view illustrating a black matrix of a plasma display panel according to a third exemplary embodiment of the present invention.

10 is a plan view showing another structure of the black matrix shown in FIG.

11 is a view showing a degree of luminance unevenness in the plasma display panel according to the present invention;

<Description of Symbols for Main Parts of Drawings>

11,31,40: upper substrate 12Y, 12Z, 32, 42: sustain electrode pair

15,35,50: Protective film 16,36: Lower substrate

17X, 37X: Address electrodes 14,18,34,38,45,49: Lower dielectric layer

19,39: bulkhead 20,40: fluorescent layer

33,41,43,47,51: Black Matrix

In order to achieve the above object, the PDP according to the present invention is formed between a plurality of sustain electrode pairs for generating a sustain discharge and the sustain electrode pairs in a direction parallel to the sustain electrode pairs, and toward the periphery of the panel. It is characterized by including a black matrix formed so as to widen.

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 width of the black matrix 33 formed between each of the sustain electrode pairs 32 increases from the center portion to the periphery portion.

An upper dielectric layer 34 and a protective film 35 are stacked on the upper substrate 31 of the PDP so as to cover the sustain electrode pair 32 including the bus electrodes.

Each of the sustain electrode pairs 32 is composed of a relatively wide transparent electrode and a metal electrode for compensating electrical resistance of the transparent electrode. The sustain electrode pair 32 includes a scan electrode and a sustain electrode. A scan signal for scanning a panel and a sustain signal for sustaining discharge are mainly supplied to the scan electrode, and a sustain signal is mainly supplied to the sustain electrode. A black matrix (BM, 33) is formed between the sustain electrode pairs 32 in a direction parallel to the sustain electrode pairs 33. The black matrix 33 prevents light interfering between discharge cells. .

Looking at the luminance relationship between the black matrix 33 and the panel, as shown in FIG. 5, the narrower the width of the black matrix 33 is, the higher the luminance of the PDP is. Therefore, in order to compensate for the luminance difference with low luminance at the center of the PDP and large luminance at the periphery, the width of the black matrix 33 is narrowed at the center of the panel, and the width of the black matrix 33 is widened toward the periphery of the panel. Compensates for the luminance difference in the center and periphery. In this case, the center width W1 of the black matrix 33 may be formed to have a small difference within about 20% of the peripheral width W2 in consideration of the panel size and the luminance of the peripheral part. Since the black matrix 33 is wider from the center to the periphery, the black matrix 33 may be widened in a curved shape as shown in FIG. 4, and as shown in FIG. 6, the black matrix 33 is linear in the periphery of the black matrix 41. Can be widened.

Wall charges generated during plasma discharge are accumulated in the upper dielectric layer 34. The passivation layer 35 prevents damage to the upper dielectric layer 34 due to sputtering generated during plasma discharge and increases emission efficiency of secondary electrons. As the protective film 35, magnesium oxide (MgO) is usually used.

The address electrode 37 is orthogonal to the sustain electrode pair 32. The lower dielectric layer 38 and the barrier rib 39 are formed on the lower substrate 36 on which the address electrode 37 is formed, and the phosphor layer 40 is coated on the surfaces of the lower dielectric layer 38 and the barrier rib 39.

The partition wall 39 is formed in parallel with the address electrode 37X to prevent ultraviolet rays and visible light generated by the discharge from leaking to the adjacent discharge cells.

The phosphor layer 40 is excited by ultraviolet rays generated during plasma discharge 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.

7 and 8, the PDP according to the second embodiment of the present invention includes a horizontal black matrix 43 and a sustain electrode pair 42 formed between each pair of sustain electrodes 42 on the upper substrate 40. And a first dielectric layer 45 formed to cover the horizontal black matrix 43, a vertical black matrix 47 formed on the first dielectric layer 45, and a second stacked on the vertical black matrix 47. The dielectric layer 49 and the protective film 50 are provided. Since other essential components of the PDP according to the present invention are the same as in the first embodiment, a description thereof will be omitted.

Each of the sustain electrode pairs 42 is composed of a relatively wide transparent electrode and a metal electrode for compensating electrical resistance of the transparent electrode. The sustain electrode pair 42 is composed of a scan electrode and a sustain electrode, the scan signal for the panel scan and the sustain signal for sustaining the discharge are mainly supplied to the scan electrode, and the sustain signal is mainly supplied to the sustain electrode. The horizontal black matrix 43 formed in parallel with the sustain electrode pairs 42 and formed between the sustain electrode pairs 42 prevents optical interference between discharge cells.

Charges generated by the plasma discharge are accumulated in the first and second dielectric layers 45 and 49.

The vertical black matrix 47 is formed on the first dielectric layer 45 in a direction crossing the horizontal black matrix 43. The width of each vertical black matrix 47 is wider from the center to the periphery of the panel. As the width of the vertical black matrix 47 is narrower, the brightness of the panel increases, and the width of the vertical black matrix 47 decreases, so that the luminance difference in the center part and the peripheral part of the PDP can be compensated for. That is, the width of the vertical black matrix 47 is narrowed at the center of the panel and widened toward the periphery of the panel, thereby compensating for the difference in luminance between the center and the periphery of the PDP. In this case, the median width W3 of the vertical black matrix 47 is preferably formed to have a difference within about 20% of the peripheral width W4 in consideration of the panel size and the luminance of the peripheral part. The vertical black matrix 47 may be wider in a curved form as it goes from the center portion to the periphery portion, or may be widened in a straight line shape.

9 and 10, in the PDP according to the third embodiment of the present invention, the width of the black mattress 51 becomes wider according to the position of the panel. Since other essential components of the PDP according to the present invention are the same as in the first embodiment, a description thereof will be omitted.

Each of the sustain electrode pairs not shown is composed of a relatively wide transparent electrode and a metal electrode for compensating the electrical resistance of the transparent electrode. The sustain electrode pair includes a scan electrode and a sustain electrode. The scan electrode is mainly supplied with a scan signal for scanning a panel and a sustain signal for sustaining discharge, and the sustain signal is mainly supplied to the sustain electrode.

The black matrix 51 formed in parallel with the sustain electrode pair and formed between each sustain electrode pair prevents optical interference between discharge cells. The black matrix 51 is formed to have a constant width and its width is determined according to the position of the formed panel. The width of the black matrix 51 positioned at the center of the panel is formed to be narrow, whereas the width of the black matrix 51 increases toward the periphery of the panel. As the width of the black matrix 51 is narrower, the area blocking the visible light becomes smaller, so that the luminance is increased. On the contrary, as the width of the black matrix 51 is wider, the area for blocking visible light becomes larger, so that the luminance becomes smaller. Therefore, the width of the black matrix 51 is narrowed at the center of the panel and wider toward the periphery of the panel, thereby compensating for the difference in luminance between the center and the peripheral portion of the PDP. In this case, the width W5 of the central position of the black matrix 51 may be formed to have a difference within about 20% of the width W6 of the peripheral position in consideration of the panel size and the luminance of the peripheral portion.

As described above, the PDP according to the present invention can be seen in FIG. 11 by adjusting the widths of the black matrices formed between the sustain electrode pairs in correspondence to the luminance difference. May be limited. Therefore, the PDP according to the present invention can realize uniform luminance over the full screen.

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 (7)

A plurality of sustain electrode pairs for causing sustain discharge, And a black matrix formed between the sustain electrode pairs in a direction parallel to the sustain electrode pairs, the black matrix being wider from the center portion to the periphery of the panel. The method of claim 1, And the width of each of the black matrices increases from a central portion to a peripheral portion. The method of claim 1, The width of the black matrix is constant and the plasma display panel, characterized in that the width is changed according to the position of the panel. The method of claim 1, And a center width of the black matrix is less than 20% of the peripheral width. The method of claim 1, A first dielectric layer formed to cover the sustain electrode pair and the black matrix; A vertical black matrix formed on the first dielectric layer so as to intersect with the black matrix; And a first dielectric layer formed on the vertical black matrix. The method of claim 5, Wherein each of the vertical black matrices is formed to be wider from the center to the periphery of the panel. The method of claim 6, The center width of the vertical black matrix is smaller than 20% of the peripheral width plasma display panel, characterized in that formed.