KR100684808B1 - Plasma display panel - Google Patents

Abstract

A plasma display panel is provided to improve image display performance, to increase opening rate of a discharging cell, and to prevent blocking of visible ray by greatly reducing reflection of external light. A rear substrate(10) is opposite to a front substrate(20). Discharging cells(18R) are formed to divide a space between the front substrate and the rear substrate. Display electrodes(25) are opposite to each discharging cell to form a discharging gap. Address electrodes(12) are formed to be crossed with the display electrodes in the discharging cell. Projection units(41) are formed on the front substrate to show a curved surface. Black dots(43) correspond to each projection unit and absorb light.

Description

Plasma Display Panel {PLASMA DISPLAY PANEL}

1 is a perspective view of a plasma display panel according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of portion A of FIG. 1.

It is a figure explaining the positional relationship of a convex part and a black spot.

4 is a schematic diagram illustrating a process of reducing reflection of external light by convex portions and black spots.

FIG. 5 is a plan view illustrating an arrangement relationship between display electrodes and discharge cells in the plasma display panel illustrated in FIG. 1.

FIG. 6 is a cross-sectional view taken along the line VI-VI of FIG. 5.

FIG. 7 is an electrode layout diagram illustrating an arrangement relationship between display electrodes and discharge cells in a plasma display panel according to a second exemplary embodiment of the present invention.

8 is a cross-sectional view taken along the line VII-VII of FIG. 7.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel (hereinafter referred to as a PDP), and more particularly, to a PDP which improves image display performance by reducing reflection of light (hereinafter, external light) incident on the PDP from the outside on the surface of the PDP. will be.

PDP is a display device that implements an image by using visible light generated by the ultraviolet light emitted from the plasma formed by the gas discharge to excite the phosphor layer. Such PDPs have been spotlighted as next-generation flat panel displays because they can be composed of high resolution large screens.

The general structure of the PDP is a three-electrode surface discharge type structure, in which a pair of electrodes are formed on opposite surfaces of the front substrate to face each other, and a rear substrate spaced from the front substrate includes an address electrode. In this case, a plurality of discharge cells defined by the barrier ribs are formed between the front substrate and the rear substrate along the intersection points of the electrodes and the address electrode. A phosphor layer is formed inside this discharge cell, and discharge gas is inject | poured.

In the PDP configured as described above, millions of unit discharge cells are arranged in a matrix form. These discharge cells select the discharge cells that are turned on and the discharge cells that are not turned on by using the storage characteristics of wall charges, and display an image by discharging the selected discharge cells.

In the selected discharge cell, the phosphor is excited by vacuum ultraviolet rays during discharge to emit visible light of a unique color to the front substrate. At this time, since part of the visible light is blocked by the display electrode positioned on the upper surface of the discharge cell, the light emission luminance is actually lowered.

In addition, a difficulty in displaying an image when the PDP is driven is reflection of external light. The external light reflection refers to a phenomenon in which external light is reflected from the surface of the front substrate while the PDP is driven. External light existing in the vicinity of the PDP is reflected from the surface of the PDP while the PDP is driven and interferes with visible light. For this reason, the luminance of visible light emitted from the PDP is degraded or distorted, resulting in poor display performance of the image.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and provides a PDP which improves the display performance of an image by reducing external light reflected from the surface of the PDP.

Still another object of the present invention is to provide a PDP having high emission luminance by reducing the blocking of visible light emitted from a discharge cell.

In order to achieve the above object, the plasma display panel provided in the present invention comprises a front substrate, a back substrate facing the front substrate, discharge cells formed by partitioning a space between the front substrate and the back substrate, each of the above; Display electrodes formed to correspond to the discharge cells of the discharge gaps, and address electrodes formed to intersect the display electrodes in the discharge cells, and having convex portions forming curved surfaces on the front substrate, respectively. Black spots are formed that correspond to and absorb light.

At this time, the length of the line segment connecting the black spot at any one point of the curved surface with respect to one of the convex portion is preferably the same anywhere, for example, the curved surface of the convex portion may form a spherical surface.

In addition, each of the convex portions may form a hemispherical shape, and the black spot is formed at the center of the convex portion.

In addition, the display electrode may have one or more inclined surfaces. For example, the cross section of the display electrode may have an inverted triangle shape.

Optionally, the display electrode includes a transparent electrode formed on the front substrate and a metal electrode formed on the transparent electrode, and a cross section of the metal electrode has an inverted triangle shape.

In addition, the display electrodes may be formed by a combination of line portions that are spaced apart from each other by a predetermined distance and extend in a direction crossing the address electrodes.

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 can 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.

1 is a perspective view of a plasma display panel (hereinafter referred to as PDP) according to an embodiment of the present invention.

In the PDP of the present embodiment, the front substrate 20 and the rear substrate 10 are disposed to face each other, and partition walls divide the space therebetween to form discharge cells 18 in a matrix form. The discharge cells 18 form a subpixel which is the minimum unit for displaying an image. In addition, the display electrode 25 and the address electrode 12 are formed corresponding to each discharge cell 18.

The front substrate 20 is formed of a transparent material such as tempered glass through which visible light is transmitted. In addition, the convex part 41 and the black spot 43 are formed on the front substrate 20 (refer FIG. 2). Here, the convex portion 41 changes the incidence path of the external light toward the black spot 431, and the black spot 43 absorbs the external light so that reflection of the external light does not occur.

The display electrode 25 is formed corresponding to each discharge cell. The display electrode 25 may be formed as a pair of the scan electrode 21 and the sustain electrode 23, and the scan electrode 21 and the sustain electrode 23 face the discharge cell 18 and have a discharge gap g. To form. Here, the scan electrode 21 selects the discharge cell 18 that is turned on by working with the address electrode (not shown), and the sustain electrode 23 is selected for the discharge cell 18 that is selected by working with the scan electrode 21. A discharge is formed during the sustain period.

The display electrode 25 is embedded and protected by a dielectric layer 28 formed of a dielectric (for example, PbO, B ₂ O ₃ , SiO ₂ ). The dielectric layer 28 prevents the charged particles from colliding and damaging the display electrode 25 during discharge.

The dielectric layer 28 is then covered with a protective film (eg, MgO) again. The protective film 29 prevents the charged particles from directly colliding with the dielectric layer 28 during the discharge to damage the dielectric layer 28. When the charged particles collide, the protective film 29 emits secondary electrons to increase discharge efficiency.

In addition, an address electrode 12 may be formed on the rear substrate 10 facing the front substrate 20. As shown, the address electrode 12 crosses the display electrode 25 and extends in one direction (y-axis direction in the figure) corresponding to each discharge cell 18. The address electrode 12 selects a discharge cell 18 that is turned on by working with the scan electrode 21.

The address electrode 12 is embedded and protected by the dielectric layer 14, and a partition 16 is formed thereon to partition the discharge cells 16.

In the discharge cell 18, a phosphor layer 19 that emits visible light for each color is formed. The phosphor layer 19 is formed in discharge cells for red (R), green (G), and blue (B) to display an image, and the red discharge cells 18R, green discharge cells 18G, and blue discharge cells are formed. (B) forms one set, and forms one pixel.

As described above, the discharge cells 18 in which the phosphor layer 19 is formed are filled with a mixed discharge gas such as neon and xenon.

FIG. 2 is an enlarged view of portion 'A' of FIG. 1, and FIG. 3 is a diagram illustrating a relationship between the convex portion and the black spot.

As illustrated in FIG. 2, convex portions 41 having a curved surface are formed on the front substrate 20, and black spots 43 are provided to correspond to the convex portions 41.

Since the convex portion 41 is formed to face the front surface (the direction in which visible light comes out from the discharge cell), the surface of the front substrate 20 has an uneven surface. The block portion 41 may be formed by forming a portion of the front substrate 20.

In addition, black spots 43 are provided corresponding to the respective block portions 41. As illustrated in FIG. 3, the black spot 43 is formed at the same position anywhere in the line segment connecting the black spot 43 at any point located on the curved surface 411 of the block portion 41. That is, as illustrated in FIG. 3, arbitrary points "A" and "B" on the curved surface 411 and "r1" "r2", which are lines connecting the black spot 0, have the same size everywhere. Therefore, the curved surface 411 preferably forms a spherical surface, and has a hemispherical shape in three dimensions. At this time, the black spot (0) is located in the center of the hemisphere.

The convex portion 41 and the black spot 0 formed as described above condense and absorb the external light to the black spot 0 as illustrated in FIG. 4, thereby reducing the reflection of external light on the surface of the PDP.

External light incident from the outside toward the front substrate 20 is changed in its incidence path at the curved surface 411 of the block portion 41 to face the black spot. Since the refractive indices are changed to n1 and n2 around the curved surface 411, and the refractive surface forms the curved surface 411, most of the external light is refracted toward the black spot 0.

In this way, the external light refracted toward the black spot 0 is not reflected but is absorbed in the black spot 0 as it is. On the other hand, since the visible light emitted from the discharge cell 18 passes through the front substrate 20 without interfering with the black spot 0, the reflection of external light is reduced than before, so that the image display ability is improved.

5 is a plan view illustrating an arrangement relationship between a discharge cell and a display electrode of the PDP shown in FIG. 1, and FIG. 6 is a cross-sectional view taken along the line VI-VI of FIG. 5.

In the present embodiment, the discharge cells 18 are partitioned in a closed manner by the horizontal bulkhead 16a and the vertical bulkhead 16b. The horizontal partition 16a extends long in the x-axis direction, and the vertical partition 16b extends long in the y-axis direction intersecting with the horizontal partition 16a. Accordingly, the discharge cells 18 are partitioned in a checkerboard shape.

The scan electrode 21 and the sustain electrode 23 of the display electrode 25 face the discharge cell 18 to form a discharge gap g. The scan electrode 21 and the sustain electrode 23 extend long while maintaining a constant distance g from each other in the x-axis direction intersecting the vertical partition 16b. Moreover, it is located in the upper surface with respect to the discharge cell 18 of 1 row which comprises a column in the x-axis direction (refer FIG. 6).

The display electrode 25 formed as described above includes a transparent electrode 251 formed on the opposite surface 201 of the front substrate 20 facing the rear substrate 10 and a metal electrode formed on the transparent electrode 251. 253).

The transparent electrode 251 is formed long in the x-axis direction while forming a strip shape. The metal electrode 253 is positioned in a bar shape at an end portion of the transparent electrode 251 that is adjacent to the longitudinal side surface or the horizontal partition wall 16a. The metal electrode 253 is formed long in the x-axis direction similarly to the transparent electrode 251.

In addition, the metal electrode 253 is formed to have at least one inclined surface in the direction toward the back substrate 10. 6 illustrates that the cross section of the metal electrode 253 is formed in an inverted triangle.

As illustrated in FIG. 6, the metal electrode 253 of the present exemplary embodiment is formed such that a vertex thereof has an inverted triangular cross-section toward the rear substrate 10. The three-dimensional shape of the metal electrode 253 forms a triangular column shape.

The metal electrode 253 having such a cross-sectional shape prevents visible light generated during the discharge process of the discharge cell 18 from being blocked by the metal electrode 253 when passing through the front substrate 20.

"L ₁ " and "l ₂ " in FIG. 6 illustrate a transmission path of visible light. Each of "l ₁ " and "l ₂ " advances toward the metal electrode 253 at a predetermined angle θ ₁ , θ ₂ with respect to the back substrate 10. On the inclined surface of the metal electrode 253, the reflection angle is determined according to the inclination angle (60 degrees) of the inclined surface, and is reflected toward the front substrate 20. As a result, visible light is transmitted out of the front substrate 20 while reducing the loss of visible light by the metal electrode 253.

7 is an electrode layout diagram illustrating an arrangement relationship between display electrodes and discharge cells in a plasma display panel according to a second exemplary embodiment of the present invention.

In the second embodiment, the display electrode 55 is a combination of the line portions 511. This line portion is a metal electrode made of metal (eg, Ag). Each of the scan electrode 51 and the sustain electrode 53 is composed of a plurality of line portions 511. The first line portion 511a and the first line portion 511a facing the discharge cell 18 form a discharge gap g. The second line part 511b is positioned at a distance from the discharge gap g at a constant distance from the first line part 511a, that is, adjacent to the horizontal partition wall 511.

The first line part 511a and the second line part 511b maintain a constant distance from each other and extend in a bar shape in the x-axis direction of the drawing. As a result, there is an advantage that the aperture ratio of the discharge cells can be increased in comparison with the first embodiment.

Each of the line portions 511a and 511b has an inverted triangle in cross-sectional shape. FIG. 8 is a cross-sectional view taken along the line VII-VII of FIG. 7.

As illustrated in FIG. 8, the cross-sectional shape of the line portion forms an inverted triangle in which a vertex thereof faces the rear substrate 10. Accordingly, the line portion forms two inclined surfaces toward the back substrate 10.

"L ₃ " and "l ₄ " in FIG. 8 illustrate a transmission path of visible light. Each of "l ₁ " and "l ₂ " advances toward the first line portion 511a and the second line portion 511b while forming predetermined angles θ ₃ and θ ₄ with respect to the back substrate 10. In the inclined surfaces of the line portions 511a and 511b, a reflection angle is determined according to the inclination angle (60 degrees) of the inclined surface, and is reflected toward the front substrate 20. As a result, the visible light is not blocked by the line portion made of the metal and is transmitted outside the front substrate, thereby improving the luminescence brightness.

As described above, although the present invention has been described by way of limited embodiments and drawings, the present invention is not limited thereto and is intended by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalents of the claims to be described.

According to the present invention, the above-mentioned problem can be solved, and the external light reflection can be greatly reduced as compared with the past, and the image display performance of the PDP can be increased. For example, since the reflection of external light is low, the contrast and contrast ratio of the bright room are improved, and therefore, there is an advantage that the gradation expression can be made clearer.

In addition, according to the second embodiment of the present invention, it is possible to prevent the visible light from being blocked while increasing the aperture ratio of the discharge cells. This has the effect of greatly improving the image display performance of the PDP.

Claims (10)

Front substrate; A rear substrate facing the front substrate; Discharge cells formed by partitioning a space between the front substrate and the rear substrate; Display electrodes formed to correspond to the respective discharge cells to form a discharge gap; And, Address electrodes formed to cross the display electrode in the discharge cell; Including, And convex portions forming curved surfaces on the front substrate, and black spots respectively corresponding to the convex portions to absorb light. The method of claim 1, And the length of the line segments connecting the black spot at any one of the curved surfaces with respect to one of the convex portions is the same everywhere. The method of claim 2, And a curved surface of the convex portion forms a spherical surface. The method of claim 1, Each convex portion has a hemispherical shape. The method of claim 4, wherein The black spot is formed in the center of the convex portion plasma display panel. The method according to any one of claims 1 to 5, And the display electrode has at least one inclined surface in a direction toward the rear substrate. The method of claim 6, And a cross section of the display electrode has an inverted triangle shape. The method of claim 7, wherein The display electrode, A transparent electrode formed on the front substrate and a metal electrode formed on the transparent electrode, And a cross section of the metal electrode having an inverted triangle shape. The method of claim 7, wherein The display electrode, A plasma display panel formed by a combination of line portions spaced apart from each other by a predetermined distance and extending in a direction crossing the address electrode. The method of claim 9, And the line portion is formed of a metal electrode.

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