JP2003217453A - Plasma display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma display device having improved emission efficiency. <P>SOLUTION: The plasma display device comprises a pair of boards on front and back sides opposed to each other so that a discharge space partitioned with barrier ribs is formed between the boards, a plurality of display electrodes consisting of scanning electrodes 4 and maintaining electrodes 5 arrayed on the board 3 on the side of a front panel 1 so that discharge cells are formed between the barrier ribs, a dielectric layer 21 formed on the board 3 on the front side so that the display electrodes are covered, and a fluorescent layer for emitting a light with electric discharge between the display electrodes. At least two recess 22 existing in each of the discharge cells are formed in the surface of the dielectric layer 21 on the side of the discharge space. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display device known as a display device.

[0002]

2. Description of the Related Art In recent years, expectations for large screens and wall-mounted televisions as interactive information terminals are increasing. As display devices therefor, there are many liquid crystal display panels, field emission displays, electroluminescence displays, and the like, some of which are commercially available and some of which are under development. Among these display devices, plasma display panel (hereinafter referred to as PDP)
Is a self-luminous type that can display beautiful images, and it is easy to increase the screen size.
It has attracted attention as a thin display device with excellent visibility, and high definition and large screen are being promoted.

This PDP is roughly classified into A drive type.
There are C type and DC type, and there are two types of discharge type, a surface discharge type and a counter discharge type, but at present, due to high definition, large screen and ease of manufacturing, AC type and surface discharge type PDPs are currently available. Are becoming mainstream.

FIG. 8 shows an example of the panel structure of the PDP. As shown in FIG. 8, the PDP is composed of a front panel 1 and a rear panel 2.

The front panel 1 is a striped display electrode in which a scan electrode 4 and a sustain electrode 5 are paired on a transparent front substrate 3 such as a glass substrate made of sodium borosilicate glass by the float method. 6 are arranged in a plurality of pairs, a dielectric layer 7 is formed so as to cover the display electrode 6 group, and a protective film 8 made of MgO is formed on the dielectric layer 7. . The scanning electrode 4
And sustain electrode 5 are transparent electrodes 4a, 5a and Cr / electrically connected to transparent electrodes 4a, 5a, respectively.
The bus electrodes 4b and 5b are made of Cu / Cr or Ag. Although not shown, a plurality of black stripes serving as a light shielding film are formed between the display electrodes 6 in parallel with the display electrodes 6.

In the rear panel 2, the address electrodes 10 are formed in a direction orthogonal to the display electrodes 6 on the rear substrate 9 arranged so as to face the front substrate 3.
A dielectric layer 11 is formed so as to cover the address electrodes 10, and a plurality of stripe-shaped partition walls 12 are formed on the dielectric layer 11 between the address electrodes 10 in parallel with the address electrodes 10 and between the partition walls 12. It is configured by forming a phosphor layer 13 on the side surface of and the surface of the dielectric layer 11. The phosphor layer 1 is used for color display.
In general, three colors of red, green, and blue are normally arranged in order.

The front panel 1 and the rear panel 2 are arranged such that the substrates 3 and 9 face each other with a minute discharge space sandwiched therebetween so that the display electrodes 6 and the address electrodes 10 are orthogonal to each other, and A panel is constructed by sealing with a sealing member, and then filling a discharge gas, which is a mixture of neon and xenon, in the discharge space at a pressure of about 66500 Pa (500 Torr).

The discharge space of this panel is partitioned into a plurality of partitions by partition walls 12, and the display electrodes 6 are provided so that a plurality of discharge cells to be light emitting pixel regions are formed between the partition walls 12. The display electrodes 6 and the address electrodes 10 are arranged orthogonal to each other.

That is, as shown in FIG.
The display electrodes 6 are formed by arranging the sustain electrodes 5 and the sustain electrodes 5 with the discharge gap 14 in between, and the region surrounded by the display electrodes 6 and the barrier ribs 12 becomes the light emitting pixel region 15, and the display electrodes of the adjacent discharge cells. A non-light emitting area 16 is provided between the areas 6.

In this PDP, a discharge is generated by a periodic voltage applied to the address electrodes and the display electrodes, and ultraviolet rays generated by the discharge are irradiated to the phosphor layer to convert it into visible light, thereby displaying an image. Be seen.

[0011]

In order to develop the PDP, it is indispensable to further increase the brightness, increase the efficiency, reduce the power consumption, and reduce the cost. In order to achieve high efficiency, it is necessary to control the discharge and suppress the discharge in the shielded area as much as possible. As one of the methods for improving the efficiency, there is known a method of increasing the film thickness of the dielectric layer on the bus electrode of the display electrode so as to suppress the light emission of the portion shielded by the bus electrode.

However, in the above-mentioned conventional structure, since the thickened portion of the dielectric layer is only on the bus electrode, the discharge spreads in the direction parallel to the bus electrode, and even near the partition wall where the electron temperature decreases. Discharge reaches and efficiency decreases. Further, since the partition wall of the rear substrate and the thickened portion of the dielectric layer of the front panel are in contact with each other to form a gap, erroneous discharge may occur in the direction parallel to the electrodes, and the image quality may be deteriorated.

Further, in the prior art, since the discharge is concentrated in the discharge gap, luminance saturation of the phosphors in the vicinity thereof is likely to occur and the efficiency is lowered.

In order to improve the efficiency of such a PDP,
As shown in FIG. 9, the non-light emitting region 16 between adjacent discharge cells
Is narrowed and the display electrode 6 on the side of the discharge gap 14 is widened to widen the spread of discharge. In this case, however, erroneous discharge with adjacent cells is increased. It has been difficult to achieve both the narrowing of 16 and the widening of the display electrode 6 to widen the spread of discharge.

The present invention has been made to solve the above problems, and an object thereof is to improve the luminous efficiency and the image quality.

[0016]

In order to achieve this object, the present invention is one in which a recess is formed on the surface of the dielectric layer on the side of the discharge space so that at least two recesses exist for each discharge cell. .

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS That is, the invention according to claim 1 of the present invention comprises a pair of front side and rear side substrates which are arranged so as to face each other so that a discharge space partitioned by a partition wall is formed between the substrates. A plurality of display electrodes arranged on the front substrate so that discharge cells are formed between the barrier ribs, a dielectric layer formed on the front substrate so as to cover the display electrodes, A phosphor layer that emits light when discharged between display electrodes, and a recess is formed on the surface of the dielectric layer on the side of the discharge space so that at least two recesses exist for each discharge cell. There is.

Further, in the present invention, a groove is formed so as to connect the concave portions of each discharge cell.

A plasma display device according to an embodiment of the present invention will be described below with reference to the drawings of FIGS. 1 to 5. 1 to 5, the same parts as those shown in FIG. 8 are designated by the same reference numerals and the description thereof will be omitted.

FIG. 1 shows a structure of a discharge cell portion in a panel of a plasma display device according to an embodiment of the present invention. In the figure, numeral 21 is formed on a front substrate 3 so as to cover a display electrode 6. The surface of the dielectric layer 21 on the side of the discharge space is formed with the concave portions 22 so that at least two discharge cells are formed for each discharge cell forming the light emitting pixel region 15. This recess 22 is shown in FIG.
As shown in FIG. 5, the electrodes are separated into islands so as to be arranged in a portion orthogonal to the display electrodes 6 in a portion inside the bus electrodes 4b and 5b and the partition wall 12, that is, in a direction parallel to the partition wall 12. Is formed. The recess 22 has a rectangular parallelepiped shape and is formed to have a depth of 20 μm.

By the way, in order to achieve high efficiency of the PDP, it is essential to control the discharge in each light emitting pixel region. In particular, when the discharge spreads in the direction perpendicular to the display electrodes, the bus electrode blocks the emitted light from the phosphor layer, so it is necessary to suppress the spread of the discharge to the shielded portion. Further, since the partition wall does not exist in this direction, all the ultraviolet rays leaking from the partition wall and the light emission from the phosphor layer are shielded by the black stripe.
Further, the spread of the discharge in the direction parallel to the display electrodes causes a decrease in efficiency due to a decrease in electron temperature near the barrier ribs.

In the present invention, the concave portion 22 is formed on the surface of the dielectric layer 21 on the discharge space side so that at least two concave portions 22 are provided for each discharge cell forming the light emitting pixel region. As shown in the figure, since the bottom surface of the recess 22 in which the thickness of the dielectric layer 21 is thin has a large capacitance, electric charges for discharge are concentratedly formed on the bottom surface of the recess 22. It is possible to limit the discharge area as follows. On the other hand, in FIG. 3 having the structure without the concave portion 22, since the film thickness of the dielectric layer 21 is constant, the capacitance is constant on the surface of the dielectric layer, and the discharge is generated as shown in B of FIG. The phosphor spreads in the vicinity of the electrode and the phosphor in the shielded part emits light, resulting in reduced efficiency. Further, since electric charges are formed up to a portion close to the adjacent cell, erroneous discharge with the adjacent cell is likely to occur.

As one of methods for preventing this and improving efficiency, for example, as shown in FIG. 4, the dielectric film thickness on the bus electrodes 4b and 5b is increased to suppress light emission at the portion masked by the bus electrodes. It is known how to do it. However, in this method, the spread of the discharge is narrowed as shown by C in FIG. 4, so that the probability of exciting Xe of the discharge gas is reduced, and the efficiency may be reduced. That is, in a general PDP, I
The reason for using the transparent electrode of TO is that the voltage of the sustain electrode and the scan electrode is alternately changed so that the discharge is alternately spread over the sustain electrode and the scan electrode so that the discharge is spread. However, in the configuration as shown in FIG.
Since the discharge concentrates on the thinned portion of the dielectric layer and the discharge distance cannot be gained, the probability of Xe excitation decreases and the efficiency decreases. Further, in this structure, since it is not possible to control the discharge with respect to the barrier ribs, the discharge spreads to the vicinity of the barrier ribs, and the electron temperature is lowered there, so that the discharge efficiency is lowered.

On the other hand, in the present invention, by forming two recesses 22 with the discharge gap 14 sandwiched as shown in FIG. 2, for example, as shown in FIG. Discharge is carried out beyond the portion that protrudes across the gap 14, and the discharge distance is extended, so that Ne / Xe
The probability that Xe in the gas will be excited is increased, and both discharge control and high efficiency can be achieved. Further, also in the direction of the barrier ribs, by separating the spread of the discharge from the barrier ribs, the electron temperature can be prevented from lowering, the discharge can be performed in an ideal state, and the efficiency can be improved.

Further, when the thickness of the dielectric film is constant as in the conventional case, the discharge is generated from the center of the discharge cell, and the intensity there becomes the strongest. Therefore, there is a problem in that the luminance saturation of the phosphor in the center of the discharge cell is likely to occur and the efficiency is reduced. However, according to the present invention, as described above, the discharge occurs only on the bottom surface of the concave portion, so Discharge positions can be dispersed from the center of the cell.

Further, in the PDP, the bus electrode is separated from the light emitting region as much as possible in order to increase the extraction efficiency of light emitted from the phosphor, that is, in order to increase the aperture ratio of the discharge cell. Since the distance between the discharge cell and the display electrode of the discharge cell becomes small, electric charge easily moves between adjacent discharge cells, and discharge cells that do not want to emit light emit light, so-called crosstalk occurs, and display quality is significantly deteriorated. Issues arise. In the present invention, the recess 22
By adjusting the shape and the place of formation, it is possible to control the position where a large amount of wall charges are generated, and thus it is possible to prevent the occurrence of crosstalk between adjacent discharge cells.

FIGS. 5 to 7 show the structure of the discharge cell portion serving as the light emitting pixel region of the panel according to another embodiment of the present invention.

In the example shown in FIG. 5, the concave portion 22 formed in the dielectric layer 21 is provided in a portion inside the bus electrodes 4b, 5b and the partition 12 in a direction parallel to the display electrode 6, that is, in the partition 12. It is formed so as to be separated into islands so as to be juxtaposed in a direction orthogonal to each other.

The examples shown in FIGS. 6 and 7 are examples corresponding to FIGS. 1 and 5, respectively, and have a shape in which at least one groove 23 is formed so as to connect the recesses 22 of the respective discharge cells. Is.

By forming at least one groove 23 so as to connect the recesses 22 of the respective discharge cells in this way, it is possible to generate a discharge from that portion and to serve as a pilot fire for the discharge. it can. Thereby, the discharge voltage can be lowered and the efficiency can be improved.

As described above, according to the present invention, since the shape of the recess 22 can be variously controlled, the shape of the recess 22 may be a shape such as a cylinder, a cone, a triangular prism, a triangular pyramid, or the like. It is not limited to the form.

[0032]

As described above, according to the plasma display device of the present invention, the concave portion is formed on the surface of the dielectric layer on the side of the discharge space so that at least two concave portions exist for each discharge cell forming the light emitting pixel region. Since the bottom surface of the recess where the film thickness of the dielectric layer is thin has a large capacitance, the wall charge formed in that part is larger than in other parts, and the discharge starts due to the decrease in film thickness. Since the voltage lowers, the discharge mainly occurs on the bottom surface of the concave portion, which can suppress the discharge spreading in the horizontal and vertical directions on the display electrode, thereby improving the efficiency. Moreover, by forming the two recesses, it is possible to reduce the brightness saturation of the phosphor layer located in the center of the light emitting pixel region that is most exposed to the ultraviolet rays generated by the discharge, and to effectively use the phosphor. You can

[Brief description of drawings]

FIG. 1 is a perspective view showing a structure of a discharge cell portion in a panel of a plasma display device according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram for explaining effects of the plasma display device.

FIG. 3 is a schematic configuration diagram for explaining a discharge situation of a conventional plasma display device.

FIG. 4 is a schematic configuration diagram for explaining a discharge situation of another conventional plasma display device.

FIG. 5 is a perspective view showing a structure of a discharge cell portion of a panel of a plasma display device according to another embodiment of the present invention.

FIG. 6 is a perspective view showing a structure of a discharge cell portion of a panel of a plasma display device according to another embodiment of the present invention.

FIG. 7 is a perspective view showing a structure of a discharge cell portion of a panel of a plasma display device according to another embodiment of the present invention.

FIG. 8 is a perspective view showing a panel structure of a general plasma display device.

FIG. 9 is a plan view showing a configuration of a discharge cell portion of the plasma display device.

[Explanation of symbols]

1 Front panel 2 Rear panel 3, 9 substrate 4 scanning electrodes 5 sustaining electrodes 6 display electrodes 10 address electrodes 12 partitions 13 Phosphor layer 21 Dielectric layer 22 recess 23 groove

Continued front page    (72) Inventor Hiroyuki Yonehara             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 5C040 FA01 FA04 GB03 GD01 GD10                       LA12 MA20

Claims (2)

[Claims] 1. A pair of front-side and back-side substrates that are arranged so as to face each other so that a discharge space partitioned by barrier ribs is formed between the substrates, and the front side so that discharge cells are formed between the barrier ribs. A plurality of display electrodes arranged on the substrate, a dielectric layer formed on the front substrate so as to cover the display electrodes, and a phosphor layer that emits light by a discharge between the display electrodes. The plasma display device is characterized in that recesses are formed on the surface of the dielectric layer on the side of the discharge space so that at least two recesses exist for each discharge cell. 2. The plasma display device according to claim 1, wherein at least one groove is formed so as to connect the concave portions of each discharge cell.