JP2001176400A - Plasma display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma display panel, in which an increase in discharge current is restrained as well as keeping a low discharge voltage, and moreover, good luminous efficiency can be obtained. SOLUTION: In the plasma display panel, the rear side of a dielectric layer 11 is coated with the first protection layer 12, and the portion except for the part opposing to the transparent electrodes Xa, Ya of at least a column voltaic pair (X, Y) on the rear side of the first protection layer 12, which oppose to each other and generate the discharge, is coated by the second protection layer 17 formed with SiO2 having a lower secondary electron emission factor than that of MgO that forms the first protection layer 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a panel structure of a surface discharge type AC plasma display panel.

[0002]

In recent years, a surface discharge AC plasma display panel (hereinafter, referred to as a PDP) has been attracting attention as a large and thin color screen display device, and its spread has been promoted. .

FIG. 8 is a perspective view showing a configuration of a conventional surface discharge type AC PDP in a state where a front glass substrate 1 side and a rear glass substrate 4 side are separated.

In FIG. 8, a plurality of row electrode pairs (X ′, Y ′) are arranged on the back side of a front glass substrate 1 and covered with a transparent dielectric layer 2.
On the back surface of the dielectric layer 2, a transparent protective layer 3 is formed.

Each of the row electrodes X 'and Y' is a transparent electrode Xa ', Y made of a transparent conductive film such as a wide ITO.
a 'and bus electrodes Xb' and Yb 'made of a metal film having a small width to compensate for the conductivity. The bus electrodes X' and Yb 'are formed at equal intervals in opposing portions of the row electrodes X' and Y '. The projections Xa ″ and Ya ″ are alternately arranged in the column direction so as to face each other across the discharge gap g ′.

[0006] By each row electrode pair (X ', Y'),
One display line (row) L of the matrix display is configured.

A plurality of column electrodes D 'are arranged on the display surface side of the rear glass substrate 4 so as to extend in a direction orthogonal to the row electrode pairs (X', Y '), and between the column electrodes D'. A strip-shaped partition wall 5 is formed so as to extend in parallel, and the three primary colors of red (R), green (G), and blue (B) are respectively provided so as to cover the side surface of the partition wall 5 and the column electrode D ′. The color-coded phosphor layers 6R, 6G, and 6B are sequentially formed in the column direction.

The front glass substrate 1 and the rear glass substrate 4 configured as described above are opposed to each other in parallel via a discharge space, and a neon light is interposed between the front glass substrate 1 and the rear glass substrate 4. And a discharge gas in which xenon and the like are mixed.

In this manner, in each display line L, the discharge space where the column electrode D 'intersects the row electrode pair (X', Y ') is defined by the partition walls 5,
Discharge cells serving as unit light emitting regions as described later are formed, and one pixel is formed by three adjacent discharge cells on which the phosphor layers 6R, 6G, and 6B are formed.

[0010] The protective layer 3 of the PDP having the above-described configuration is for protecting the dielectric layer 2 from plasma discharge generated in the discharge space, and is formed of MgO.

As described above, the reason why the protective layer 3 is formed of MgO is that the discharge voltage required for the discharge at the time of forming an image can be suppressed low because the secondary electron emission coefficient of the MgO layer is large. It is for a reason.

However, when the emission of secondary electrons from the protective layer 3 increases, the discharge current increases, and the discharge region also extends outside each discharge cell, and the luminous efficiency in each discharge cell decreases. Problem.

The present invention has been made to solve the above-mentioned problems of the conventional surface-discharge AC plasma display panel.

[0014] That is, an object of the present invention is to provide a plasma display panel capable of suppressing a discharge voltage and suppressing an increase in a discharge current, as well as obtaining good luminous efficiency.

[0015]

According to a first aspect of the present invention, there is provided a plasma display panel for achieving the above object.
A plurality of row electrode pairs are provided on the back side of the front substrate, extending in the row direction and juxtaposed in the column direction to form respective display lines, and a plurality of row electrode pairs covered with a dielectric layer are provided. A plurality of column electrodes extending in the column direction and arranged in the row direction are provided on the side facing each other, and a discharge cell is formed at a portion where the column electrode and the row electrode pair intersect in the discharge space between the front substrate and the rear substrate. In the plasma display panel to be formed, the back surface side of the dielectric layer is covered with a first protective layer, and the second side is formed of a material having a lower secondary electron emission coefficient than the material forming the first protective layer. The second protective layer covers at least a portion of the back surface side of the first protective layer other than a portion of the row electrode pair that opposes a portion that generates a discharge opposite to each other. There.

According to the plasma display panel of the first aspect, when a plasma discharge for forming a display image is performed, the secondary electron emission coefficient of the material forming the second protective layer is increased by the first protective layer. This discharge is mainly generated in a portion of the first protective layer which is not covered by the second protective layer and is in direct contact with the discharge space S since the material has a lower secondary electron emission coefficient. Is done.

Since the area of the portion of the first protective layer in contact with the discharge space is limited by the second protective layer, the discharge voltage during discharge can be suppressed to a low state by the first protective layer. The increase in the discharge current is suppressed by the second protective layer having a lower secondary electron emission coefficient than that of the first protective layer.

Further, the discharge region of the discharge generated via the first protective layer is opposed to the portion of the row electrode pair facing the discharge electrode, that is, the discharge cell having high utilization efficiency of visible light emission. , The luminous efficiency of the entire panel is improved.

According to a second aspect of the present invention, in order to achieve the above object, in addition to the configuration of the first aspect, the material forming the first protective layer is magnesium oxide, and the second protective layer Is characterized in that the material forming is silicon dioxide or a transparent dielectric.

According to the plasma display panel of the second aspect, the material forming the first protective layer is magnesium oxide having a high secondary electron emission coefficient, and the material forming the second protective layer is the same. By using silicon dioxide or a transparent dielectric material having a lower secondary electron emission coefficient than magnesium oxide, the second protective layer suppresses an increase in discharge current at the time of discharge, and at the same time through the first protective layer. The discharge region of the generated discharge is concentrated in a portion facing the portion of the row electrode pair that generates the discharge in opposition to each other, that is, in a central portion of the discharge cell where the efficiency of using visible light emission is high. Luminous efficiency is improved.

In order to achieve the above object, a plasma display panel according to a third aspect of the present invention extends in the row direction on the back side of the front substrate and is arranged side by side in the column direction to form display lines and is covered with a dielectric layer. A plurality of row electrode pairs are provided, and a plurality of column electrodes extending in the column direction are provided on the side of the rear substrate facing the front substrate via the discharge space, and the front substrate and the rear substrate are provided. In a plasma display panel in which a discharge cell is formed at a portion where a column electrode and a row electrode pair intersect in a discharge space between substrates, a discharge is generated by opposing the row electrode pair on the back surface of the dielectric layer. It is characterized in that only a part including a part opposite to a part to be covered is covered with a protective layer.

According to the plasma display panel of the third aspect of the present invention, when a discharge for forming a display image is performed, a required secondary electron emission in the dielectric layer covering the row electrode pair is performed. It is mainly generated in a portion covered with a protective layer having a coefficient.

The protective layer is formed only on a part of the back surface of the dielectric layer, which includes a part facing the part of the row electrode pair facing the discharge generating part, Since the discharge area is limited, the increase in the discharge current is suppressed, and the discharge is concentrated in the central portion of the discharge cell where the utilization efficiency of visible light emission is high, so that the luminous efficiency of the entire panel is improved. You.

A plasma display panel according to a fourth aspect of the present invention is characterized in that, in order to achieve the above object, in addition to the configuration of the third aspect, the material forming the protective layer is magnesium oxide.

According to the plasma display panel of the fourth aspect, since the material forming the protective layer is magnesium oxide having a high secondary electron emission coefficient, the discharge regions face each other of the row electrode pairs. The portion facing the portion that generates the discharge, that is, the central portion of the discharge cell having high utilization efficiency of visible light emission, is concentrated, thereby improving the luminous efficiency of the entire panel.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the present invention will be described below in detail with reference to the drawings.

FIGS. 1 and 2 show a first embodiment of a plasma display panel (hereinafter referred to as PDP) according to the present invention. FIG. 1 is a plan view schematically showing a PDP in this embodiment. FIG. 2 shows V1 in FIG.
It is sectional drawing in the -V1 line.

In FIGS. 1 and 2, a plurality of rows (sustain) are provided on the rear surface of a front glass substrate 10 which is a display surface.
The electrode pairs (X, Y) are arranged in parallel so as to extend in the row direction of the front glass substrate 10 (the left-right direction in FIG. 1).

The row electrode X is formed of a T-shaped ITO
And the like, and a bus electrode Xb made of a metal film extending in the row direction of the front glass substrate 10 and connected to the narrow base end of the transparent electrode Xa.

Similarly, the row electrode Y is formed in a T-shape with a transparent electrode Ya made of a transparent conductive film such as ITO and a narrow base end of the transparent electrode Ya extending in the row direction of the front glass substrate 10. It is constituted by a bus electrode Yb made of a connected metal film.

The row electrodes X and Y are connected to the front glass substrate 10
Are arranged alternately in the column direction (vertical direction in FIG. 1).
The transparent electrodes Xa and Ya arranged in parallel along the bus electrodes Xb and Yb extend to the row electrode side of the mating partner, and the top sides of the wide portions of the transparent electrodes Xa and Ya have the required widths, respectively. Are opposed to each other via a discharge gap g.

On the back of the front glass substrate 10,
A dielectric layer 11 is formed so as to cover the row electrode pair (X, Y). The dielectric layer 11 has bus electrodes Xb and Yb of the row electrode pair (X, Y) on the back side thereof. , A strip-shaped raised dielectric layer 11 extending in the row direction
A is formed.

Further, on the back side of the dielectric layer 11,
A first protective layer 12 made of MgO is formed.

On the other hand, on the display-side surface of the rear glass substrate 13 arranged in parallel with the front glass substrate 10, column (address) electrodes D are paired with each other for each row electrode pair (X, Y). At positions facing the transparent electrodes Xa and Ya, they are arranged in parallel with a predetermined interval therebetween so as to extend in a direction (column direction) orthogonal to the row electrode pairs (X, Y).

On the display-side surface of the rear glass substrate 13,
Further, a white dielectric layer 14 covering the column electrode D is formed, and a strip-shaped partition 15 is formed on the dielectric layer 14.

The partition walls 15 are formed between the column electrodes D adjacent to each other.
Are arranged at predetermined intervals so as to extend in the column direction at an intermediate position between the front glass substrate 10 and the rear glass substrate 13 by the strip-shaped partition walls 15 so that each row electrode pair ( X, Y) transparent electrodes Xa and Ya
Are divided into strips at each of the opposing portions.

A phosphor layer 16 in which the three primary colors of red, green and blue are arranged in order in the row direction is formed between the adjacent partitions 15. The surface and the surface of the dielectric layer 14 are covered.

The discharge space S partitioned by each partition 15
Inside, a discharge gas is sealed. The above configuration is almost the same as the conventional PDP. The PDP further includes a portion facing the raised dielectric layer 11A of the first protective layer 12 and a portion of the dielectric layer 11 adjacent to both sides of the raised dielectric layer 11A on the back side of the first protective layer 12. A strip-shaped transparent second protection layer 17 extending in the row direction is formed so as to cover a portion opposed to a portion having a required width.

The second protective layer 17 is formed of SiO ₂ or a transparent dielectric material having a low secondary electron emission coefficient, and the interval between two adjacent second protective layers 17 has a required width d. It is set as follows. Therefore, the first protective layer 12 comes into contact with the discharge space S only in a band-like portion having a required width d between the two adjacent second protective layers 17.

Although the setting of the width d will be described later, at least the respective transparent electrodes Xa and Ya of the row electrodes X and Y facing each other are formed in a portion between two adjacent second protective layers 17. Is set to be located at

In the PDP, the row electrode pairs (X, Y) each constitute one display line (row) L of the matrix display screen, and each pair of the transparent spaces S separated by the partition walls 15 forms a transparent space. One discharge cell C is defined for each portion facing the electrodes Xa and Ya.

In the image display in this PDP, first, an address operation is selectively performed between one row electrode of a row electrode pair (X, Y) and a column electrode D in each discharge cell C by selective opposing discharge (selective writing). (Discharge) is performed, and light-emitting cells (discharge cells in which wall charges are formed in the dielectric layer 11) and non-light-emitting cells (discharge cells in which wall charges are not formed in the dielectric layer 11) are present in all display lines L. , Distributed on the panel corresponding to the image to be displayed.

After the address (data write) operation, a sustaining pulse is alternately applied to the row electrodes X and Y of all the display lines L. Each time the sustaining pulse is applied, each light emitting cell C is applied. The phosphor layers 16 of the red, green and blue colors of the discharge cells C are respectively excited and emitted by the ultraviolet light generated by the surface discharge (sustain discharge) occurring in the above, thereby forming a display image. At this time, since the secondary electron emission coefficient γ ′ of the SiO ₂ layer or the transparent dielectric layer constituting the second protective layer 17 is lower than the secondary electron emission coefficient γ of the MgO layer constituting the first protective layer 12, Each discharge is generated mainly in a portion where the first protective layer 12 is in contact with the discharge space S.

The discharge space S of the first protective layer 12
Is limited by the second protective layer 17 to a band-like portion having a width d between the two adjacent second protective layers 17, so that the discharge voltage at the time of discharge is equal to the first voltage. The MgO layer constituting the protective layer 12 suppresses the discharge current, and the increase in the discharge current is suppressed by the second protective layer 17.

Further, since the discharge region of the discharge generated via the first protective layer 12 is concentrated in the central portion of the discharge cell C having high utilization efficiency of visible light emission, the luminous efficiency of the entire panel is improved. .

FIG. 3 is a characteristic diagram showing the relationship between the width d between two adjacent second protective layers 17 and the luminous efficiency in the discharge cell C.

In FIG. 3, it can be seen that the luminous efficiency in the discharge cell C is maximized when the width d is in the range of 265 to 315 μm, which is approximately one third of the vertical width of the discharge cell C.

FIG. 4 shows a second embodiment of the present invention.
It is a top view which shows the example of.

In the PDP of this embodiment, as in the case of the first embodiment, the back side of the first protection layer has a lower secondary electron emission coefficient than that of the MgO layer forming the first protection layer. The second protective layer 17 ′ is covered by a layer 17 ′. The second protective layer 17 ′ has, for each discharge cell C, a rectangular portion at a portion facing the transparent electrodes Xa and Ya, which are the pair of the row electrodes X and Y. A window 17a is formed, and in this window 17a, the first protective layer is configured to be in contact with a discharge space between the rear glass substrate. The configuration of the other parts is almost the same as in the first example.

Also in the PDP of this example, the area of the first protective layer in contact with the discharge space is limited in the window 17a by the second protective layer 17 '. The MgO layer constituting the first protective layer suppresses the discharge current, the increase in the discharge current is suppressed by the second protective layer 17 ′, and the discharge region of the discharge generated through the first protective layer uses the emission of visible light. Since the light is concentrated on the central portion of the discharge cell C having high efficiency, the luminous efficiency of the entire panel is improved.

The vertical width d 'of the window 17a from which the first protective layer is exposed is approximately one third of the vertical width of the discharge cell C, as in the case of the first example. 265-31
It is preferably set in the range of 5 μm, whereby
The luminous efficiency in each discharge cell C is maximized.

A third example in the embodiment of the present invention is as follows.
A description will be given based on FIGS.

FIG. 5 is a plan view schematically showing a PDP in this example, and FIG. 6 is a sectional view taken along line V6-V6 in FIG. In the PDP in this example, a band-shaped protective layer 22 made of MgO has at least the tip portions of transparent electrodes Xa and Ya opposed to each other via a gap g between row electrodes X and Y on the back side of dielectric layer 11. Are formed so as to extend along the row direction. The configuration of the other parts is almost the same as in the first example.

The PDP in this example is composed of a protective layer 22 made of MgO having a high secondary electron emission coefficient γ.
Are formed only at portions of the transparent electrodes Xa and Ya opposed to each other at least via the gap g where the discharge occurs, and at least the portions opposed to the leading end portions.
As in the case of DP, the area of the portion of the protective layer 22 contributing to the discharge, which is in contact with the discharge space, is limited, so that the discharge voltage at the time of discharge is suppressed low by the MgO layer constituting the protective layer 22 and the discharge current is reduced. Is suppressed.

Further, the discharge region of the discharge generated via the protective layer 22 is formed by a discharge cell C having high utilization efficiency of visible light emission.
, The luminous efficiency of the entire panel is improved.

The vertical width d of the protective layer 11 is set in the range of 265 to 315 μm, which is approximately one third of the vertical width of the discharge cell C, as in the above-described examples. Is preferable, whereby the luminous efficiency in each discharge cell C is maximized.

FIG. 7 shows a fourth embodiment according to the present invention.
It is a top view which shows the example of.

In the PDP of this example, the protection layer 22 of the PDP of the third example is formed in a strip shape so as to extend in the row direction, whereas the protection layer 32 of an MgO layer , On the back side of the dielectric layer,
Each of the discharge cells C is independently formed in a rectangular island shape so as to include at least a portion of the transparent electrodes Xa and Ya opposed to each other with a gap g between the row electrodes X and Y opposed to each other. I have. For the configuration of other parts,
This is almost the same as the third example.

Also in the PDP in this example, the protective layer 32 made of MgO having a high secondary electron emission coefficient γ is provided at least at the tip portions of the transparent electrodes Xa and Ya facing each other via the gap g where discharge occurs. Since the protective layer 3 is formed so as to include the opposing portion, the protective layer 3 contributes to the discharge similarly to the PDP of each of the above-described examples.
2 has a limited area in contact with the discharge space, the discharge voltage at the time of discharge is lower than that of MgO forming the protective layer 32.
In addition to being suppressed low by the layer, the increase in the discharge current is suppressed, and the discharge region of the discharge generated via the protective layer 32 is concentrated in the central portion of the discharge cell C having high utilization efficiency of visible light emission. Thus, the luminous efficiency of the entire panel is improved.

The vertical width d of the protective layer 11 is set in the range of 265 to 315 μm, which is approximately one third of the vertical width of the discharge cell C, as in the above-described examples. Is preferable, whereby the luminous efficiency in each discharge cell C is maximized.

[Brief description of the drawings]

FIG. 1 is a plan view schematically showing an example of the present invention.

FIG. 2 is a sectional view taken along line V1-V1 of FIG.

FIG. 3 is a characteristic diagram showing a relationship between a width between two adjacent second protective layers and luminous efficiency in a discharge cell in the same example.

FIG. 4 is a plan view schematically showing another example of the present invention.

FIG. 5 is a plan view schematically showing still another example of the present invention.

FIG. 6 is a sectional view taken along line V6-V6 of FIG.

FIG. 7 is a plan view schematically showing still another example of the present invention.

FIG. 8 is a perspective view schematically showing a configuration of a conventional PDP.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 front glass substrate (front substrate) 11 dielectric layer 12 first protective layer 13 rear glass substrate (rear substrate) 14 dielectric layer 15 partition 16 phosphor layer 17, 17 ′ second protection Layer 17a Window part 22, 32 Protective layer X Row electrode Y Row electrode Xa Transparent electrode Ya Transparent electrode Xb Bus electrode Yb Bus electrode D Column electrode C Discharge cell L Display line S Discharge Space g ... gap

Claims (4)

[Claims] A plurality of pairs of row electrodes which extend in the row direction on the back side of the front substrate and are arranged in the column direction to form display lines, respectively, and are covered with a dielectric layer; A plurality of column electrodes extending in the column direction and arranged in the row direction are provided on the side facing the substrate with the discharge space therebetween, and the column electrode and the row electrode pair of the discharge space between the front substrate and the rear substrate intersect with each other. In a plasma display panel in which a discharge cell is formed in a portion, a back surface side of the dielectric layer is covered with a first protective layer,
Further, the second protective layer formed of a material having a lower secondary electron emission coefficient than that of the material forming the first protective layer is opposed to at least the row electrode pairs on the back side of the first protective layer. A plasma display panel, characterized in that a portion excluding a portion facing a portion generating discharge is covered. 2. The plasma display panel according to claim 1, wherein the material forming the first protective layer is magnesium oxide, and the material forming the second protective layer is silicon dioxide or a transparent dielectric. 3. A plurality of row electrode pairs which extend in the row direction on the back side of the front substrate and are arranged side by side in the column direction to form display lines, respectively, and are provided with a plurality of row electrode pairs covered with a dielectric layer. A plurality of column electrodes extending in the column direction and arranged in the row direction are provided on the side facing the substrate with the discharge space therebetween, and the column electrode and the row electrode pair of the discharge space between the front substrate and the rear substrate intersect with each other. In a plasma display panel in which a discharge cell is formed in a part, only a part of a back surface of the dielectric layer, which includes a part facing a part of the row electrode pair facing the discharge generating part, is included. A plasma display panel, which is covered with a protective layer. 4. The plasma display panel according to claim 3, wherein the material forming the protective layer is magnesium oxide.