JP4134588B2 - Plasma display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a plasma display apparatus known as a display device.
[0002]
[Prior art]
In recent years, expectations for large screens and wall-mounted televisions as interactive information terminals have increased. There are many display devices for this purpose, such as liquid crystal display panels, field emission displays, electroluminescence displays, etc., some of which are commercially available and some are under development. Among these display devices, the plasma display panel (hereinafter referred to as PDP) is a self-luminous type capable of displaying beautiful images and is easy to enlarge. For this reason, a display using PDP has excellent visibility. It is attracting attention as a thin display device, and high definition and large screen are being promoted.
[0003]
This PDP is broadly divided into AC type and DC type in terms of driving, and there are two types of discharge types, a surface discharge type and a counter discharge type. From the viewpoint of high definition, large screen, and ease of manufacturing. At present, AC type and surface discharge type PDPs are becoming mainstream.
[0004]
FIG. 11 shows an example of the panel structure of the PDP. As shown in FIG. 11, the PDP is composed of a front panel 1 and a rear panel 2.
[0005]
The front panel 1 includes a plurality of stripe-shaped display electrodes 6 that are paired with a scanning electrode 4 and a sustaining electrode 5 on a transparent front substrate 3 such as a glass substrate made of sodium borosilicate glass or the like by a float method. The 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 scan electrode 4 and the sustain electrode 5 are made of transparent electrodes 4a and 5a and Cr / Cu / Cr or Ag that is electrically connected to the transparent electrodes 4a and 5a and supplies power to the transparent electrodes 4a and 5a, respectively. It consists of bus electrodes 4b and 5b.
[0006]
In addition, the rear panel 2 forms an address electrode 10 in a direction orthogonal to the display electrode 6 on the rear substrate 9 opposed to the front substrate 3 so as to cover the address electrode 10. A dielectric layer 11 is formed, and a plurality of stripe-shaped partition walls 12 are formed in parallel with the address electrodes 10 on the dielectric layer 11 between the address electrodes 10, and the side surfaces between the partition walls 12 and the dielectric layer 11 The phosphor layer 13 is formed on the surface. For color display, the phosphor layer 13 is usually arranged in order of three colors of red, green, and blue.
[0007]
The front panel 1 and the rear panel 2 are arranged so that the substrates 3 and 9 are opposed to each other with a minute discharge space so that the display electrodes 6 and the address electrodes 10 are orthogonal to each other, and the periphery is a sealing member. And a discharge gas obtained by mixing neon and xenon in the discharge space is sealed at a pressure of about 66500 Pa (500 Torr) to form a panel.
[0008]
The discharge space of the panel is divided into a plurality of sections by the barrier ribs 12, and a display electrode 4 is provided between the barrier ribs 12 so that a plurality of discharge cells serving as unit light emitting regions are formed. 6 and the address electrode 10 are arranged orthogonally.
[0009]
In this PDP, an image is displayed by generating a discharge by a periodic voltage applied to the address electrode and the display electrode, and irradiating the phosphor layer with the ultraviolet light by the discharge to convert it into visible light.
[0010]
As shown in FIG. 12, 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 the discharge gap 14 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 is a unit light emitting region 15. Further, since the non-light emitting region is 16, black stripes may be formed for the purpose of improving contrast.
[0011]
[Problems to be solved by the invention]
For the development of this PDP, further higher brightness, higher efficiency, lower power consumption, and lower cost are indispensable. In order to achieve high efficiency, it is necessary to control the discharge and suppress the discharge at the shielded portion as much as possible. As one of the techniques for improving the efficiency, as described in, for example, Japanese Patent Laid-Open No. 8-250029, light emission in a portion masked by the metal row electrode by increasing the dielectric film thickness on the metal row electrode is performed. Methods for suppressing are known. However, in the above-described conventional structure, light emission in a direction perpendicular to the electrode is suppressed, but discharge in a direction parallel to the electrode is not suppressed, and the discharge spreads to the vicinity of the partition. In this case, the partition walls cause a decrease in electron temperature and recombination of electrons and ions, which may reduce efficiency.
[0012]
Further, when the film thickness of the dielectric on the electrode is increased, there arises a problem that discharge in the address period is difficult to occur.
[0013]
The present invention has been made to solve such problems, and aims to improve luminous efficiency and stabilize panel driving.
[0014]
[Means for Solving the Problems]
In order to achieve this object, in the present invention, at least one recess asymmetric with respect to the discharge gap is formed on the surface of each discharge cell on the discharge space side of the dielectric layer.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
That is, according to the first aspect of the present invention, there is provided a discharge cell between a pair of front and back substrates disposed opposite to each other so as to form a discharge space partitioned by a barrier between the substrates, and the barrier. A plurality of display electrodes arranged on the front substrate so as to face each other via a discharge gap on the front substrate, and formed on the front substrate so as to cover the display electrodes A dielectric layer and a phosphor layer that emits light by discharge between the display electrodes, and a recess is formed on a surface on the discharge space side of the dielectric layer for each discharge cell, the recess between the partition walls And the area of the portion located on one display electrode of the recess is the area of the portion located on the other display electrode. this was formed so as to be larger It is characterized in.
[0022]
Furthermore, the invention described in claim 2 is characterized in that, in claim 1, a mixed gas of Ne and Xe is sealed in the discharge space, and the Xe partial pressure is set to 5 to 30%.
[0023]
Hereinafter, a plasma display device according to an embodiment of the present invention will be described with reference to FIGS. 1 to 10, the same parts as those shown in FIGS. 11 and 12 are denoted by the same reference numerals and description thereof is omitted.
[0024]
FIG. 1 is 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 layer formed on a front substrate 3 so as to cover a display electrode 6. On the surface on the discharge space side of FIG. 7, an asymmetric recess 17 is formed around the discharge gap for each discharge cell. The recess 17 is formed inside the partition wall 12. That is, the place where the recess is formed is the surface of the dielectric layer on the discharge space side, and is located on the pair of display electrodes which are the regions between the barrier ribs and are opposed to each other through the discharge gap.
[0025]
FIG. 2 shows the positional relationship between the concave portion 17 and the display electrodes 6 and the barrier ribs 12. As shown in FIG. 2, the concave portion 17 has a pair of display electrodes 6 facing each other with a discharge gap 14 therebetween. The concave portion 17 is formed so as to be located on the upper side, and the shape of the portion located on the scanning electrode 4 which is one display electrode 6 is the shape of the portion located on the sustaining electrode 5 which is the other display electrode 6. It is formed in a trapezoidal shape that is larger than the shape. In other words, the area of the concave portion 17 located on the scanning electrode 4 which is one display electrode 6 is formed to be larger than the area of the portion located on the sustaining electrode 5 which is the other display electrode 6. .
[0026]
3 and 4 are views showing a plasma display apparatus according to another embodiment of the present invention. In this embodiment, the corners of the recesses 17 are rounded, and the other parts have the same configuration as that of the embodiment shown in FIGS.
[0027]
By the way, in order to achieve high efficiency of the PDP, it is necessary to control the discharge and suppress the discharge in the shielded portion as much as possible. As one of the techniques for improving the efficiency, as described in, for example, Japanese Patent Laid-Open No. 8-250029, light emission in a portion masked by the metal row electrode by increasing the dielectric film thickness on the metal row electrode is performed. Methods for suppressing are known. However, in the above-described conventional structure, light emission in a direction perpendicular to the electrode is suppressed, but discharge in a direction parallel to the electrode is not suppressed, and the discharge spreads to the vicinity of the partition. In this case, since the electron temperature is lowered by the partition walls, the efficiency may be lowered. Furthermore, it is known that when the discharge is performed in the vicinity of the barrier ribs, the barrier ribs are negatively charged. As a result, positive ions are attracted, so that etching is caused by generation of electron-ion recombination or ion bombardment of the barrier ribs. It has been known. As a result, the etched barrier ribs may fall on the phosphor, and the characteristics may be deteriorated.
[0028]
On the other hand, in the present embodiment, by forming the concave portion 17 for each discharge cell and forming the concave portion 17 inside the barrier rib 12, the discharge can be controlled only on the bottom surface of the concave portion 17, and the vicinity of the barrier rib It is possible to suppress the discharge at. Furthermore, since MgO is also formed on the side surface of the recess 17, etching on the side surface of the recess 17 does not occur.
[0029]
This discharge area control will be described with reference to FIGS. FIG. 9 is a diagram for explaining the effect when a concave portion is formed in a dielectric, and FIG. 10 shows a conventional structure. In FIG. 9, since the film thickness of the dielectric on the bottom surface of the recess 17 decreases, the capacitance C of that portion increases. Therefore, electric charges for discharging are concentrated on the bottom surface of the recess 17. In addition, since the dielectric film is thinner at the bottom surface than at the other portions, the discharge starts from the bottom surface. In other words, since the thickness of the dielectric is increased except for the bottom surface of the concave portion 17, the capacity of the portion is reduced, and the electric charge existing in the portion is reduced. Furthermore, since the dielectric film is thick, the discharge voltage also increases. Due to these effects, the discharge 18 is limited to the bottom surface of the recess 17. By applying this principle, if the size of the recess is changed, the amount of charge formed in that portion can be arbitrarily controlled.
[0030]
However, as described above, when the thickness of the dielectric on the metal electrode is increased, it is difficult for the discharge in the address period to occur, which may cause a problem that the drive margin of the panel is lowered.
[0031]
In this regard, according to the present embodiment, as shown in FIG. 1 to FIG. 4, by making the shape of the recess 17 asymmetric, it is easy to generate a discharge with one row electrode of the front panel during an address operation. Can do.
[0032]
Here, in order to achieve high efficiency of the PDP, a method of increasing the Xe partial pressure is generally known. However, when the Xe partial pressure is increased, there arises a problem that the discharge voltage is increased, and an amount of ultraviolet rays is increased, thereby causing a problem of easily causing luminance saturation. For this purpose, a method is known in which the dielectric film thickness is increased, the dielectric capacity is decreased, and the charge formed by a single pulse is reduced. In this case, however, the dielectric film thickness is increased. Accordingly, there arises a problem that the transmittance of the dielectric film itself is lowered and the efficiency is lowered. Further, simply increasing the film thickness causes a problem that the discharge voltage further increases.
[0033]
According to the present invention, in a PDP in which a mixed gas of Ne and Xe is sealed in the discharge space and the Xe partial pressure is 5 to 30%, the current is controlled by the shape of the recess 17 so that the high Xe partial pressure is obtained. It is possible to prevent the generated luminance saturation. In other words, the discharge current can be controlled by limiting the discharge region by forming the recesses 17 having the optimum size in each light emitting pixel region. Further, the amount of current flowing arbitrarily can be limited by changing the shape or size of the recess 17. Furthermore, according to the present embodiment, since the current control is performed only with a dielectric, it is possible to use a high Xe partial pressure without changing a circuit or a driving method.
[0034]
5 to 8 show other embodiments of the present invention. First, in the embodiment shown in FIG. 5, a trapezoidal concave portion 17 is one display electrode 6 with respect to the discharge gap 14. In this example, the concave portion 17 is formed so as to be located on the bus electrode 4 b of the scanning electrode 4. In this case, even if the shape of the concave portion 17 is not an asymmetric trapezoidal shape, even if it is a rectangular symmetrical shape as shown in FIG.
[0035]
Further, in the embodiment shown in FIGS. 7 and 8, the concave portion 17 has a shape protruding so as to be positioned on the bus electrode 4b of the scanning electrode 4 which is one of the display electrodes 6. FIG. 7 shows an example in which a projecting portion 17a having a curved surface is formed, and FIG. 8 shows an example in which a sharp projecting portion 17b is formed. In this case, the same effect can be obtained.
[0036]
【The invention's effect】
As described above, according to the plasma display device of the present invention, the discharge can be controlled, the driving in the address period can be stabilized, and the efficiency improvement by the high Xe partial pressure can be effectively utilized. Thus, an improvement in panel efficiency and an improvement in image quality can be achieved.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a main part 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. 4 is a plan view showing the arrangement relationship of the main parts of the plasma display device according to the embodiment. FIG. 5 is a plan view showing the main parts of the plasma display device according to another embodiment of the invention. FIG. 6 is a plan view showing the positional relationship of the main structure of a plasma display device according to another embodiment of the present invention. FIG. 7 is a plan view of the plasma display device according to another embodiment of the present invention. FIG. 8 is a plan view showing an arrangement relationship of a main part structure of a plasma display device according to another embodiment of the present invention. FIG. 9 is a discharge state of the plasma display device according to the present invention. FIG. 10 is a schematic view for explaining a discharge state of a conventional plasma display device. FIG. 11 is a perspective view showing a panel structure of the plasma display device. Plan view showing the arrangement relationship of [Description of symbols]
DESCRIPTION OF SYMBOLS 1 Front panel 2 Back panel 3, 9 Substrate 4 Scan electrode 5 Sustain electrode 6 Display electrode 7 Dielectric layer 10 Address electrode 12 Partition wall 13 Phosphor layer 14 Discharge gap 17 Recesses 17a and 17b Projection

Claims (2)

A pair of front-side and back-side substrates arranged opposite to each other so as to form a discharge space partitioned by a partition between the substrates, and a display line on the front-side substrate so that a discharge cell is formed between the partitions. A plurality of display electrodes formed so as to be opposed to each other through a discharge gap, a dielectric layer formed on the front substrate so as to cover the display electrodes, and light emission by discharge between the display electrodes to and a phosphor layer, wherein a recess in the surface of the discharge space side of the dielectric layer of each discharge cell, wherein the recess is a region between the partition walls, facing each other across the discharge gap A plasma display characterized in that an area of a portion located on a pair of display electrodes and located on one display electrode of the concave portion is larger than an area of a portion located on the other display electrode. apparatus. The plasma display apparatus according to claim 1, wherein a mixed gas of Ne and Xe is sealed in the discharge space, and the Xe partial pressure is set to 5 to 30%.

Images