KR20080100489A - Plasma display panel - Google Patents

Abstract

Provided is a plasma display panel for reducing a black luminance by forming a shielding film partially so that the light emission of a reset discharge may be shielded, while keeping the display luminance by the reset discharge and the stability of the drive. In the plasma display panel, a front-side substrate, in which discharge slit are formed between a plurality of display electrodes by arranging the display electrodes in a predetermined direction, and a back-side substrate, in which a plurality of address electrodes are arranged in a direction to intersect with the display electrodes, are so arranged to confront each other that the intersecting portions between the display electrodes and the address electrodes may become cells, thereby to generate a reset discharge for address preparations with the discharge slits and a sustained discharge for the display with the addressed cells. A shielding film (31) is arranged in the light emitting area of the front-side substrate by the reset discharge.

Description

Plasma Display Panel {PLASMA DISPLAY PANEL}

The present invention relates to a plasma display panel (PDP), and more particularly, to an electrode structure of a three-electrode surface discharge type PDP.

As a conventional PDP, an AC drive type three-electrode surface discharge type PDP is known. The PDP is provided with a plurality of display electrodes capable of surface discharge in the horizontal direction on the inner surface of one substrate (for example, the substrate on the front side or the display surface side), and the other substrate (for example, the substrate on the back side). A plurality of address electrodes for light emitting cell selection are provided on the inner side in the direction crossing the display electrodes, and the intersection of the display electrodes and the address electrodes is one cell (unit light emitting region). One pixel is comprised of three cells, a red (R) cell, a green (G) cell, and a blue (B) cell.

The PDP is manufactured by sealing the periphery by facing the substrate on the front side and the substrate on the back side thus produced, and then sealing the discharge gas therein.

The PDP of this structure is generally driven by the address / display separation method. In this driving, one frame is composed of a plurality of subframes (hereinafter, referred to as 'SF') to which weights of luminance are assigned. For example, eight subframes SF1 to SF8 having a luminance ratio of 1: 2: 4: 8: 16: 32: 64: 128 are configured. Each SF comprises a reset period (address preparation period) for initializing all cells, an address period for selecting a cell to emit light, and a sustain period for maintaining light emission of the selected cell. Then, the gray scale display is performed by emitting the cells for the period of the desired subframe.

In the above reset period, reset discharge is generated in all cells. In the address period, address discharge is generated in a cell to emit light. In the sustain period, sustain discharge (sustain discharge) is generated in the cell in which the address discharge is generated.

In the display of this PDP, as described above, in the reset period, discharge is generated for all cells for initialization. For this reason, the part of the black display of a screen is also light-emitted lightly, and when light emission by this reset discharge is large, the contrast of a screen will fall. In addition, in the present invention, the luminance when black display is performed is referred to as black luminance (or 'background luminance').

Conventionally, in order to reduce such black brightness, the method of applying the obtuse wave or the ramp waveform voltage as a voltage for reset discharge, and generating a reset discharge with weak discharge intensity was taken (refer patent document 1).

[Patent Document 1] Japanese Patent Application Laid-Open No. 11-352924

<Start of invention>

Problems to be Solved by the Invention

However, in order to improve the contrast, the lower the black luminance is, the better.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it has been noted that the light shielding film is partially formed so as to shield the light emission of the reset discharge from the light emission forms of the reset discharge and the sustain discharge. It is to reduce the black luminance while maintaining the luminance and the stability effect of driving.

Means for solving the problem

The present invention provides a substrate on the front side in which slits for surface discharge are formed between display electrodes by arranging a plurality of display electrodes in a predetermined direction, and a substrate on the back side in which a plurality of address electrodes are arranged in a direction crossing the display electrodes. A plasma display panel which is disposed so that an intersection of a display electrode and an address electrode becomes a cell, and generates a reset discharge for address preparation and a sustain discharge for display between display electrodes of an addressed cell in a slit between the display electrodes, A light shielding film is disposed in a light emitting area caused by reset discharge of a substrate on the front side.

Effect of the Invention

According to the present invention, since the light emission due to the reset discharge is shielded, it is possible to make both the reduction of the black luminance and the improvement of the display luminance compatible, and the display contrast can be improved.

1 is an explanatory diagram showing a configuration of a PDP of the present invention.

2 is an explanatory diagram showing a first embodiment of the present invention;

3 is a sectional view taken along the line III-III of FIG.

4 is an explanatory diagram showing a second embodiment of the present invention;

5 is a cross-sectional view taken along the line V-V in FIG.

6 is an explanatory diagram showing a third embodiment of the present invention;

FIG. 7 is a sectional view taken along line VIII-VIII in FIG. 6. FIG.

8 is an explanatory diagram showing a comparative example when no light shielding film is disposed;

FIG. 9 is a sectional view taken along line VIII-VIII in FIG. 8A. FIG.

<Explanation of symbols for the main parts of the drawings>

10: PDP

11: Front side board

12: transparent electrode

13: bus electrode

17, 24: dielectric layer

19: shield

21: back side substrate

28R, 28G, 28B: phosphor layer

29: bulkhead

30: discharge space

A: address electrode

L: display line

X, Y: display electrode

<Best Mode for Carrying Out the Invention>

In the present invention, the substrate on the front side and the substrate on the back side include substrates such as glass, quartz, ceramics, and the like, and substrates on which the desired components such as electrodes, insulating films, dielectric layers, and protective films are formed.

The plurality of display electrodes may be disposed on the substrate on the front side in a constant direction, and may have a discharge slit formed between the display electrodes. In addition, the plurality of address electrodes may be disposed on the back side substrate in a direction crossing the display electrodes.

The display electrode and the address electrode can be formed using various materials and methods known in the art. As the material used for the electrode includes, for example, a conductive material of metal such as ITO, a transparent conductive material such as SnO ₂ or, Ag, Au, Al, Cu, Cr. As a method for forming the electrode, various methods known in the art can be applied. For example, it may be formed using a thick film forming technique such as printing, or may be formed using a thin film forming technique consisting of physical deposition or chemical deposition. As a thick film formation technique, the screen printing method etc. are mentioned. As a physical deposition method, a vapor deposition method, a sputtering method, etc. are mentioned among thin film formation techniques. Examples of the chemical deposition method include a thermal CVD method, an optical CVD method, a plasma CVD method, and the like.

In this invention, the light shielding film should just be arrange | positioned in the light emitting area | region by reset discharge of the board | substrate of the front side. This light shielding film can be formed using various materials and methods well-known in the said field | area. For example, the light shielding film can be formed using a black pigment or a dark dielectric. In addition, as long as the light shielding film is a region where insulation is not required, the light shielding film may be formed using the same material as the above-described electrode.

In the above configuration, the light shielding film is preferably disposed at the center portion of the slit. Further, the light shielding film may be disposed at the edge portion of one side of the display electrode of the slit when one display electrode becomes an anode at the time of reset discharge occurrence.

The present invention also provides a display electrode comprising a substrate on the front side provided by arranging a plurality of display electrodes for surface discharge in one direction, and a substrate on the back side provided by a plurality of address electrodes in a direction intersecting the display electrode. And a plasma display panel which is disposed so that an intersection of the and address electrodes becomes a cell, and generates a reset discharge for address preparation between the display electrode and the address electrode and a sustain discharge for display between the display electrode of the addressed cell. A light shielding film is disposed in a light emitting area caused by reset discharge of a substrate on the front side.

Hereinafter, this invention is explained in full detail based on embodiment shown in drawing. In addition, this invention is not limited by this, A various deformation | transformation is possible.

1 (a) and 1 (b) are explanatory diagrams showing the configuration of the PDP of the present invention. FIG. 1A is an overall view, and FIG. 1B is a partially exploded perspective view. This PDP is an AC drive type 3-electrode surface discharge PDP for color display.

The PDP 10 is composed of a substrate 11 on the front side and a substrate 21 on the back side. As the substrate 11 on the front side and the substrate 21 on the back side, a glass substrate, a quartz substrate, a ceramic substrate, or the like can be used.

On the inner surface of the substrate 11 on the front side, the display electrodes X and the display electrodes Y are arranged at equal intervals in the horizontal direction. Both the adjacent display electrode X and the display electrode Y become display lines L. FIG. Each display electrode X, Y is a wide transparent electrode 12 such as ITO, SnO ₂ , and the like, for example, Ag, Au, Al, Cu, Cr, and a laminate thereof (for example, Cr / Cu / Cr. Lamination structure), and the narrow metal bus electrode 13 is comprised. The display electrodes X and Y use a thick film formation technique such as screen printing for Ag and Au, and other thin film formation techniques such as vapor deposition and sputtering, and etching techniques for the desired number, thickness, width, and spacing. It can be formed as.

In this PDP, the display electrodes X and the display electrodes Y are arranged at equal intervals, and the display electrodes L and the adjacent display electrodes X and Y are both display lines L. However, the display is paired. Even if the electrodes X and Y are PDPs arranged at intervals (non-discharge gaps) in which discharge does not occur, the present invention can be applied.

On the display electrodes X and Y, the dielectric layer 17 is formed so as to cover the display electrodes X and Y. The dielectric layer 17 is formed by applying a low melting glass paste onto the substrate 11 on the front side by screen printing and firing. The dielectric layer 17 may be formed by forming a SiO ₂ film by plasma CVD.

On the dielectric layer 17, a protective film 18 for protecting the dielectric layer 17 from damage caused by collision of ions caused by discharge during display is formed. This protective film is formed of MgO. The protective film can be formed by a thin film formation process known in the art, such as electron beam vapor deposition or sputtering.

On the inner surface of the substrate 21 on the back side, a plurality of address electrodes A are formed in a direction intersecting the display electrodes X and Y in plan view, and a dielectric layer 24 is formed covering the address electrodes A. FIG. The address electrode A generates address discharge for selecting a light emitting cell at an intersection with one display electrode Y, and is formed in a three-layer structure of Cr / Cu / Cr. In addition, this address electrode A can also be formed with Ag, Au, Al, Cu, Cr, etc., for example. Similarly to the display electrodes X and Y, the address electrode A uses a thick film formation technique such as screen printing for Ag and Au, and other thin film formation techniques such as a vapor deposition method and a sputtering method and an etching technique. , Thickness, width and spacing. The dielectric layer 24 can be formed using the same material and the same method as the dielectric layer 17.

On the dielectric layer 24 between the adjacent address electrode A and the address electrode A, a plurality of stripe barrier ribs 29 are formed. The shape of the partition wall 29 is not limited to this, The mesh shape which partitions discharge space for every cell may be sufficient. The partition 29 can be formed by a sand blast method, a printing method, a photo etching method, or the like. For example, in the sand blasting method, a glass paste made of a low melting glass fleet, a binder resin, a solvent, or the like is applied onto the dielectric layer 24 and dried, and then a cutting mask having an opening of a partition pattern is formed on the glass paste layer. It forms by cutting cutting particle in the state which formed, cutting the glass paste layer exposed to the opening of a mask, and baking further. In the photoetching method, instead of cutting into cutting particles, a photosensitive resin is used for the binder resin, and is formed by baking after exposure and development using a mask.

Phosphor layers 28R, 28G, and 28B of red (R), green (G), and blue (B) are formed on the side and bottom of the concave groove-shaped discharge space between the partition walls 29. The phosphor layers 28R, 28G, and 28B apply a phosphor paste containing phosphor powder, a binder resin, and a solvent into a recessed groove-shaped discharge space between the partition walls 29 by a screen printing method or a method using a dispenser. After repeating for each color, it forms by baking. The phosphor layers 28R, 28G and 28B may be formed by photolithography using a sheet-like phosphor layer material (so-called 'green sheet') containing phosphor powder, a photosensitive material and a binder resin. In this case, by attaching a sheet of a desired color to the entire display area on the substrate, performing exposure and development, and repeating this for each color, a phosphor layer of each color can be formed between the corresponding partition walls.

The PDP disposes the above-described substrate 11 on the front side and the substrate 21 on the back side to face each other so that the display electrodes X, Y and the address electrode A intersect, seal the periphery, and are discharged surrounded by the partition 29. It is produced by filling the space 30 with the discharge gas which mixed Xe and Ne. In this PDP, the discharge space 30 at the intersection of the display electrodes X, Y and the address electrode A is one cell (unit light emitting area) which is the minimum unit of display. One pixel is composed of three cells of R, G, and B.

The display is performed by the address / display separation method. In this driving, one frame is composed of eight subframes SF1 to SF8 to which luminance weight is assigned. The luminance ratio of the subframes SF1 to SF8 is 1: 2: 4: 8: 16: 32: 64: 128.

Each SF is composed of a reset period for initializing all cells, an address period for selecting a cell to emit light, and a sustain period for maintaining light emission of the selected cell. Then, gradation display is performed by emitting the cells for the period of the desired subframe.

In the reset period, a reset voltage is applied between all the display electrodes X and Y to generate a reset discharge, thereby making the charged state of each cell uniform.

In the address period, a scanning voltage is sequentially applied to the display electrode Y, and a voltage is applied to the desired address electrode A during this time, thereby generating an address discharge at the intersection of the display electrode Y and the address electrode A, thereby selecting the light emitting cells.

In the sustain period, sustain discharge (also referred to as 'display discharge' or 'sustain discharge') is generated between the display electrode X and the display electrode Y by using wall charges formed on the display electrode Y of the cell by the address discharge.

The address discharge is a counter discharge between the address electrode A and the display electrode Y that face the vertical direction, and the sustain discharge is a surface discharge between the display electrodes X and Y arranged in parallel on the plane.

<First Embodiment>

2 (a), 2 (b), 2 (c) and 3 are explanatory diagrams showing the first embodiment of the present invention. Fig. 2A shows a state where the PDP is viewed in a plan view. FIG. 2B shows the light emission intensity during reset discharge in the III-III cross section of FIG. 2A. As can be seen from this figure, the reset discharge is generated in the slits between the transparent electrodes. (B) of FIG. 2 has shown the light emission intensity at the time of sustain discharge in III-III cross section of (a) of FIG. As can be seen from this figure, the sustain discharge is generated in the entire transparent electrode between the bus electrodes. FIG. 3 shows a III-III cross section of FIG.

In this example, the dark light shielding film 31 is disposed in the slit between the display electrode X and the display electrode Y of the front substrate 11. By this light shielding film 31, the dotted line part of FIG.2 (b) shields light emission at the time of reset discharge. In addition, in the light emission at the time of sustain discharge, the dotted line part of FIG.2 (c) is shielded. By shielding in this way, most of light emission by reset discharge can be shielded, and light shielding of light emission by sustain discharge can be suppressed small. Therefore, the extraction efficiency of the light toward the display surface side in the discharge space is larger in light emission by sustain discharge than light emission by reset discharge.

The light shielding film 31 is formed using a black pigment or a dark dielectric. The light shielding film 31 may be formed using the same material as that of the bus electrode 13 as long as it is a region where insulation is not required.

Arrangement of this light shielding film is effective in the case of the drive system used for reset discharge mainly by surface discharge between XY electrodes (between display electrode X and display electrode Y). Thereby, the light emission at the reset discharge can be blocked more efficiently, and the light emission at the sustain discharge can be taken out efficiently, and the display brightness can be improved while reducing the black brightness.

Second Embodiment

4 and 5 are explanatory views showing a second embodiment of the present invention. 4 shows a plan view of the PDP. FIG. 5 shows a V-V cross section of FIG. 4.

In this example, the light shielding film 32 is arrange | positioned at the slit edge of the display electrode Y side of the board | substrate 11 of the front side. This arrangement is effective in the case of the drive system which is mainly used for the surface discharge which generates either the display electrode X or the display electrode Y as an anode, and is used for reset discharge. In the case of this example, since strong reset discharge is generated on the display electrode Y side of the anode, it is possible to effectively shield the reset discharge by the light shielding film 32. On the contrary, when the display electrode X side is used as the anode, the light shielding film 32 is disposed on the slit edge of the display electrode X side.

In the arrangement of such a light shielding film, the reset discharge emits light which is biased toward either the display electrode X or the display electrode Y from the slit center portion. As a result, light emission during reset discharge can be blocked more efficiently, and sustain discharge can be taken out more efficiently, thereby improving display brightness and reducing black brightness.

Third Embodiment

6 and 7 are explanatory views showing the third embodiment of the present invention. 6 shows a state in which the PDP is viewed in a plan view. FIG. 7 shows the VIII-VIII cross section of FIG. 6.

In this example, the light shielding film 33 is arrange | positioned in the intersection area | region of the address electrode A and the display electrode Y of the board | substrate 11 of the front side.

This arrangement can effectively shield the reset discharge in the case of the drive system which mainly uses the counter discharge between the address electrode A and the display electrode Y as the reset discharge. On the contrary, in the case of the drive system using the counter discharge between the address electrode A and the display electrode X as the reset discharge, the light shielding film 33 is formed at the intersection of the address electrode A and the display electrode X of the front substrate 11. Place it.

That is, the arrangement of the light shielding film is a drive which is mainly used for reset discharges by mainly opposing discharges between the AY electrodes (between the address electrodes A and the display electrodes Y) or between the AX electrodes (between the address electrodes A and the display electrodes X). Valid in the case of a scheme. As a result, the light emission at the reset discharge can be blocked more efficiently, and the light emission at the sustain discharge can be taken out more efficiently, and the display brightness can be improved and the black brightness can be reduced.

Comparative Example

8 (a), 8 (b), 8 (c) and 9 are explanatory diagrams showing a comparative example when the light shielding film of the present invention is not arranged. FIG. 8A shows a state where the PDP is viewed in a plan view. FIG. 8B shows the luminescence intensity at the time of reset discharge in the VIII-VIII cross-section of FIG. 8A. FIG. 8C shows the luminescence intensity at the time of sustain discharge in the VIII-VIII cross section of FIG. 8A. FIG. 9 shows a VIII-VIII cross section in FIG. 8A.

In an AC type PDP, black brightness depends on the light emission luminance of the reset discharge, and display brightness depends on the light emission luminance of the sustain discharge, and the light emission luminance is determined, respectively. As the performance of the display, it is desirable to reduce the black luminance and increase the display luminance.

Generally, the reset discharge applies a voltage waveform due to an obtuse wave (a voltage pulse whose voltage gradually rises or falls) between XY electrodes (between the display electrode X and the display electrode Y), between the AY electrodes, or between the AX electrodes. And discharge is generated. Therefore, in the reset discharge caused by the surface discharge between the XY electrodes, light is emitted from a portion limited to a narrow region of the center portion between the electrodes from one end of the electrode (see FIG. 8B). Similarly, the reset discharge caused by the counter discharge between the AY electrodes emits light at a location limited to a narrow region centered on the cross region between the AY electrodes.

On the other hand, since sustain discharge discharges by applying the voltage waveform by a square wave between XY electrodes, it emits light in the wide area | region across the whole discharge space between bus electrodes (refer FIG.8 (c)).

In other words, the light emission of the sustain discharge is light emission widened to the entire surface of the electrode, whereas the light emission of the reset discharge due to the obtuse wave is light emission limited between the ends of the electrode (slit region).

In the present invention, the two light emitting modes are different from each other. When FIG. 8C and FIG. 2C are compared, when there is no light shielding film of the present invention, the luminance of the sustain discharge is large. However, in terms of the luminance difference between the sustain discharge and the reset discharge, the light shielding film of the present invention is larger than the light shielding film. Therefore, the contrast of the screen can be improved by disposing the light shielding film of the present invention.

As described above, with the panel structure in which the light shielding film of the present invention is disposed, the light emission by the light shielding film can effectively shield the reset light emission while maintaining the high extraction efficiency of the sustain light emission.

As described above, according to the present embodiment, by disposing the light shielding film in the region emitting light in the reset discharge, it is possible to make both the reduction of the black luminance and the improvement of the display luminance possible, thereby improving the contrast of the screen. As a result, the background luminance can be reduced without lowering the reset performance (without narrowing the driving margin).

Claims (4)

By arranging a plurality of display electrodes in a constant direction, a substrate on the front side in which slits for surface discharge are formed between the display electrodes, and a substrate on the back side in which the plurality of address electrodes are arranged in a direction intersecting the display electrode, A plasma display panel which is disposed so that an intersection of address electrodes becomes a cell, and generates reset discharge for address preparation and sustain discharge for display between display electrodes of addressed cells in slits between the display electrodes, A light shielding film is disposed in a light emitting area caused by reset discharge of the substrate on the front side. The method of claim 1, The light shielding film is disposed in the center portion of the slit. The method of claim 1, The light shielding film is disposed at an edge portion of one display electrode side of the slit, and the one display electrode becomes an anode when reset discharge occurs. A substrate on the front side provided by arranging a plurality of display electrodes for surface discharge in one direction and a substrate on the back side on which a plurality of address electrodes are arranged in a direction intersecting the display electrode are provided. A plasma display panel which is disposed so as to be a cell, and which generates a reset discharge for address preparation between the display electrode and the address electrode and a sustain discharge for display between the display electrodes of the addressed cell. A light shielding film is disposed in a light emitting area caused by reset discharge of the substrate on the front side.

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