JP2003308790A - Plasma display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve luminous efficiency and to stabilize panel drive in a plasma display device. <P>SOLUTION: The plasma display device has a plurality of display electrodes formed on a front substrate in an opposed array via a discharge gap in every display line and composed on discharge electrodes 18a and bus electrodes 18b for feeding the discharge electrodes 18a, a dielectric layer formed on the front substrate to coat the display electrodes, and a phosphor layer for emitting light upon a discharge between the display electrodes. A discharge space side surface of the dielectric layer has, for every discharge cell, at least two recesses 17a and 17b by the discharge gap 14, and the discharge electrodes 18a of the display electrodes are formed for perpendicular projection from the bus electrodes 18b to the discharge gap 14 so as to be opposed on bottoms of the recesses 17a and 17b via the discharge gap 14. <P>COPYRIGHT: (C)2004,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. 10 shows an example of a panel structure of the PDP. As shown in FIG. 10, 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
The sustain electrodes 5 are composed of transparent electrodes 4a and 5a serving as discharge electrodes and bus electrodes 4b and 5b made of Cr / Cu / Cr or Ag electrically connected to the transparent electrodes 4a and 5a, respectively. There is.

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 sealing a discharge gas, which is a mixture of Ne and Xe, in the discharge space at a pressure of about 66500 Pa (500 Torr).

The discharge space of this panel is divided into a plurality of sections by partition walls 12, and the display electrodes 4 are provided so that a plurality of discharge cells serving as unit light emitting regions are formed between the partition walls 12. The display electrodes 6 and the address electrodes 10 are arranged orthogonal to each other.

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

As shown in FIG. 11, the scan electrodes 4 and the sustain electrodes 5 are alternately arranged in the column direction so as to be adjacent to each other with a discharge gap 14 therebetween in each line A of the matrix display. Here, a region surrounded by the partition wall 12, the pair of scan electrodes 4 and the sustain electrode 5 becomes a unit light emitting region 15. Further, since the non-light emitting area is 16, black stripes may be formed for the purpose of improving the contrast.

[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.

Further, in order to improve the efficiency, it is necessary to narrow the non-light emitting region 16 with the adjacent cell and widen the electrode on the discharge gap side to widen the spread of discharge as shown in FIG.
In this case, since erroneous discharge with adjacent cells increases, it is not possible to reduce the non-light emitting area with adjacent cells and to widen the electrode width and spread the discharge horizontally and horizontally.

The present invention has been made to solve such problems, and an object thereof is to improve luminous efficiency and stabilize panel driving.

[0016]

In order to achieve this object, the present invention provides at least two recesses with respect to a discharge gap on the surface of each discharge cell on the discharge space side of a dielectric layer, and The discharge electrode of the display electrode is formed so as to vertically project from the bus electrode toward the discharge gap so as to face the bottom surface of the recess via the discharge gap.

[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 discharge electrode and a bus for supplying electric power to the discharge electrode, the discharge electrode being arranged between the barrier ribs so as to be opposed to each other through a discharge gap on the front substrate so that discharge cells are formed between the barrier ribs. A plurality of display electrodes including electrodes, 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. At least two recesses are formed with respect to the discharge gap on the surface of each discharge cell on the discharge space side of the layer, and the discharge electrode of the display electrode is
It is characterized in that it is formed by vertically projecting from the bus electrode toward the discharge gap so as to face the bottom surface of the recess via the discharge gap.

The invention described in claim 2 is the same as claim 1.
In the above, the discharge electrode is a transparent electrode.

The invention described in claim 3 is the same as that of claim 1.
In the above, the discharge electrode is characterized in that the width of the portion of the bottom surface of the recess facing the discharge gap is equal to or smaller than the width of the recess.

The invention according to claim 4 is the same as claim 1.
In the above, the discharge electrode has a shape in which a portion of the bottom surface of the concave portion facing the discharge gap is divided into a plurality of portions.

The invention described in claim 5 is the same as claim 1.
In the above, the discharge electrode is characterized in that the middle portion is hollow.

The invention according to claim 6 is the same as claim 1.
In the above, at least one groove is formed so as to connect the concave portions of each discharge cell.

The invention described in claim 7 is the same as claim 1.
6 to 6, the discharge space is filled with a mixed gas of Ne and Xe, and the partial pressure of Xe is set to 5 to 30%.

A plasma display device according to an embodiment of the present invention will be described below with reference to the drawings of FIGS. In addition, in FIGS. 1 to 9, FIGS.
The same parts as those shown in 1 are assigned the same reference numerals and explanations thereof will be omitted.

FIG. 1 shows a perspective view of a part of a front panel of a plasma display device according to an embodiment of the present invention. In the figure, a dielectric formed on a front substrate 3 so as to cover display electrodes. On the surface of the body layer 7 on the side of the discharge space,
Two recesses 17a and 17b are formed in each of the discharge cells. Further, FIG. 2 shows the positional relationship between the recesses 17a and 17b and the display electrode and the partition wall 12. As shown in FIG. 2, the recesses 17a and 17b are formed inside the partition wall 12. .

The display electrode is composed of a discharge electrode 18a made of a transparent electrode formed so as to be opposed to each other through a discharge gap for each display line, and a bus electrode 18b for supplying power to the discharge electrode 18a. The discharge electrode 18a of the display electrode is formed so as to vertically project from the bus electrode 18b toward the discharge gap 14 so as to be opposed to the bottom surface of the recesses 17a and 17b via the discharge gap 14. The discharge electrode 18a has a recess 17
The width of the portions of the bottom surfaces of a and 17b that face each other via the discharge gap 14 is equal to the width of the recesses 17a and 17b, or is narrower than the width of the recesses 17a and 17b.
In the example shown in FIG. 2, the width of the portion of the discharge electrode 18a facing the discharge gap 14 is set to be the recesses 17a and 17b.
It is configured to be narrower than the width of.

Here, 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 perpendicularly to the electrodes, the bus electrode blocks the emitted light from the phosphor, and therefore it is necessary to prevent the discharge from spreading to the shielded portion.
Further, since the partition wall does not exist in this direction, all the ultraviolet rays leaked from the partition wall and the light emitted from the phosphor are blocked by the black stripe. Further, the spread of the discharge in the direction parallel to the electrodes causes a decrease in efficiency due to a decrease in electron temperature near the partition wall.

FIG. 8 shows a diagram for explaining the effect of forming two recesses in the dielectric, and FIG. 9 shows a diagram for comparison. In FIG. 8 and FIG. 9, A indicates discharge. In FIG. 8, since the thickness of the dielectric film on the bottom surfaces of the two recesses 17a and 17b is reduced, the capacitance C at that portion is increased. Therefore, the charges for discharging are recessed 17a, 17b.
Since it is formed intensively on the bottom surface of, the discharge area can be limited. On the other hand, in FIG. 9, since the film thickness of the dielectric is constant, the capacitance C is constant on the dielectric surface, the discharge A spreads in the vicinity of the electrode, and the fluorescent material in the shielded portion is caused to emit light. Is reduced. 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.

Further, as one of means for preventing this and improving efficiency, for example, as disclosed in Japanese Patent Laid-Open No. 8-250029, the metal film is formed by increasing the dielectric film thickness on the metal line electrode. A method for suppressing light emission in a masked portion is known. However, in this method, since the spread of the discharge A is narrowed, the probability of exciting Xe is reduced, which may lead to a reduction in efficiency. That is, the reason why ITO is used for the front panel in a general PDP is that the voltage of the sustain electrodes and the scan electrodes is alternately changed so that the discharge is driven so as to spread alternately over the sustain electrodes and the scan electrodes. Cage,
It is designed to spread the discharge. However, in such a method, the discharge concentrates on the thinned portion of the dielectric, and the discharge distance cannot be gained. Therefore, the probability of Xe excitation decreases, and the efficiency decreases. Further, in this structure, since the discharge cannot be controlled 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.

In the present embodiment, for example, as shown in FIG. 8, two recesses 17a and 17b are formed with the discharge gap sandwiched therebetween, so that the discharge A is projected from the bottoms of the recesses 17a and 17b with the discharge gap 14 sandwiched therebetween. Therefore, the discharge distance is extended, the probability that Xe in the Ne / Xe gas is excited is increased, and discharge control and high efficiency can be achieved at the same time. Further, in the direction of the barrier ribs as well, the spread of the discharge is separated from the barrier ribs to prevent the electron temperature from lowering, so that the discharge can be performed in an ideal state and the efficiency can be improved.

Further, the discharge electrode 18a of the display electrode is connected to the discharge gap 14 on the bottom surfaces of the recesses 17a and 17b.
It is possible to suppress the accumulation of charges in the vicinity of the barrier ribs 12 by forming the electrodes so as to be opposed to each other through the bus electrodes 18b so as to vertically project toward the discharge gap 14 and separating the electrodes from the barrier ribs 12. Moreover, it is possible to suppress the discharge near the partition wall 12.

When the discharge electrode 18a is made of a transparent electrode, it is possible to efficiently take out light emitted from the phosphor.

On the other hand, when the discharge electrode 18a is made of an opaque metal electrode like the bus electrode 18b, cost reduction can be achieved. In this case, since the light emitted from the phosphor is blocked by the electrodes,
As shown in FIG. 3, the discharge electrode 18a includes recesses 17a, 1
The efficiency of extracting light can be improved by forming a shape in which a portion facing the discharge gap 14 on the bottom surface of 7b is divided into a plurality of parts, or by making the middle part hollow as shown in FIG. Further, when such a shape is used for the transparent electrode, the effect of reducing the current consumption due to the reduction of the electrode area can be obtained.

Here, a method of increasing the partial pressure of Xe is generally known in order to achieve high efficiency of the PDP. However, when the Xe partial pressure is increased, the problem that the discharge voltage is increased occurs, and the amount of generated ultraviolet rays increases,
There is a problem that the brightness is easily saturated. For that purpose, there is known a method of increasing the thickness of the dielectric film to reduce the capacitance of the dielectric film and reducing the charge formed by one pulse. Along with this, there arises a problem that the transmittance of the dielectric film itself is lowered and the efficiency is lowered. Also,
If the film thickness is simply increased, there is a problem that the discharge voltage further increases.

According to the present invention, the discharge space is filled with the mixed gas of Ne and Xe, and the current is controlled by the shapes of the recesses 17a and 17b in the PDP having the partial pressure of Xe of 5 to 30%. It is possible to prevent the saturation of the brightness that occurs at a high Xe partial pressure. That is, the discharge current can be controlled by limiting the discharge region by forming the recesses 17a and 17b having the optimum size in each light emitting pixel region. Further, the amount of current flowing can be arbitrarily limited by changing the shapes or sizes of the recesses 17a and 17b. Furthermore, according to the present embodiment, since the current control is performed only by the dielectric, it is possible to use high Xe partial pressure without changing the circuit or driving method.

5 to 7 are perspective views showing a part of the front panel of the plasma display device according to another embodiment of the present invention. First, in the example shown in FIG. 5, at least one groove 19 is formed so as to connect the recesses 17a and 17b of the respective discharge cells. In this case, it is possible to reduce the discharge start voltage and increase the discharge distance. It will be possible.

Further, in the example shown in FIG. 6, the bus electrode 18b
The two recesses 17a and 17b are formed side by side so as to be perpendicular to, and in this case, the discharge start voltage can be lowered. Further, in the example shown in FIG. 7, as shown in FIG. 6, at least one groove 19 is formed so as to connect two recesses 17a and 17b formed side by side so as to be perpendicular to the bus electrode 18b.

In the above description, the two recesses 17 are provided.
Although the example in which a and 17b are formed has been described, two or more may be formed, and the shape of the recess may be a polygon, a circle, or an ellipse, and the present invention is not limited to the above description as long as the above object is achieved. .

[0039]

As described above, according to the plasma display device of the present invention, the discharge can be controlled and the driving in the address period can be stabilized.
Further, it is possible to effectively utilize the improvement in efficiency due to the high Xe partial pressure, and it is possible to achieve the improvement in panel efficiency and the improvement in image quality.

[Brief description of drawings]

FIG. 1 is a perspective view showing a main structure of a plasma display device according to an embodiment of the present invention.

FIG. 2 is a plan view showing an arrangement relationship of main parts of the device.

FIG. 3 is a plan view showing an arrangement relationship of main parts of a plasma display device according to another embodiment of the present invention.

FIG. 4 is a plan view showing an arrangement relationship of main structure of a plasma display device according to another embodiment of the present invention.

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

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

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

FIG. 8 is a schematic view for explaining a discharge state of the plasma display device according to the present invention.

FIG. 9 is a schematic diagram for explaining a discharge state of a conventional plasma display device.

FIG. 10 is a perspective view showing a panel structure of a plasma display device.

FIG. 11 is a plan view showing an arrangement relationship of main parts 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 7 Dielectric layer 10 address electrodes 12 partitions 13 Phosphor layer 14 discharge gap 17a, 17b recess 18a discharge electrode 18b bus electrode 19 groove

Claims (7)

[Claims] 1. A pair of front-side and back-side substrates that are arranged to face each other so as to form a discharge space partitioned by barrier ribs between the substrates, and the front side so that discharge cells are formed between the barrier ribs. A plurality of display electrodes each of which is formed on the substrate in such a manner that they are opposed to each other through a discharge gap for each display line, and includes a discharge electrode and a bus electrode for supplying power to the discharge electrode, and the display electrode is covered. A dielectric layer formed on the front-side substrate and a phosphor layer that emits light by a discharge between the display electrodes, and a discharge gap is formed on the surface of each discharge cell on the discharge space side of the dielectric layer. At least two recesses are formed, and the discharge electrode of the display electrode is formed so as to vertically project from the bus electrode toward the discharge gap so as to face the discharge electrode on the bottom surface of the recess. And a plasma display device. 2. The plasma display device according to claim 1, wherein the discharge electrode is a transparent electrode. 3. The discharge electrode according to claim 1, wherein the width of a portion of the discharge electrode facing the bottom surface of the recess via the discharge gap is equal to or smaller than the width of the recess. Plasma display device. 4. The plasma display device according to claim 1, wherein the discharge electrode has a shape in which a portion of the bottom surface of the concave portion facing the discharge gap is divided into a plurality of portions. 5. The plasma display device according to claim 1, wherein the discharge electrode has a hollow middle portion. 6. 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. 7. The plasma display device according to claim 1, wherein the discharge space is filled with a mixed gas of Ne and Xe and the partial pressure of Xe is set to 5 to 30%.