Patent Application
20090267511
The present invention relates to a method for manufacturing a plasma display panel, and more particularly concerns a method for manufacturing barrier ribs of a back face panel.
There have been strong demands for a display apparatus using a plasma display panel (hereinafter, referred to as “PDP”) as a display apparatus that can display high-quality television images on a large screen.
The PDP has a structure in which a front face panel and a back face panel are placed face to face with each other, with the peripheral portion being sealed by a sealing member, and a discharge gas such as neon and xenon is sealed in discharge spaces formed between the two panels. The front face panel is provided with display electrode pairs formed on one of surfaces of a glass substrate, each pair made up of a scanning electrode and a sustain electrode, and a dielectric layer and a protective layer that cover these electrodes. The back face panel is provided with a plurality of address electrodes formed into a stripe shape in a direction orthogonal to the display electrode pairs on one surface of a glass substrate, an undercoating dielectric layer that covers these address electrodes, barrier ribs that divide the discharge space for each of the address electrodes, and phosphor layers of red, green, and blue colors that are successively coated onto the side faces of each barrier rib and the undercoating dielectric layer.
The display electrode pairs and the address electrodes are made orthogonal to each other, with the intersecting portions formed into discharge cells. These discharge cells are arranged in a matrix shape, and three discharge cells having red, green, and blue phosphor layers aligned in the direction of the display electrode pairs are allowed to form a pixel for use in color display. The PDP successively applies predetermined voltages between the scanning electrodes and the address electrodes as well as between the scanning electrodes and the sustain electrodes to generate gas discharge, and by exciting the phosphor layers by using ultraviolet rays generated by the gas discharge, visible light rays are emitted so that a colored image is displayed.
In recent years, there have been strong demands for miniaturization of discharge cells in response to the development of high precision PDPs. When the size of a discharge cell is made smaller, the discharge space is also made smaller to cause an issue of degradation in the fluorescent luminance. In order to improve the fluorescent luminance in a predetermined size of discharge cells, an attempt has been made to narrow the width of barrier ribs; however, when the width of barrier ribs is made too narrow, an erroneous discharge tends to occur between the adjacent cells and the strength of the barrier ribs tend to deteriorate. Moreover, an attempt has been made to improve the fluorescent luminance by applying the phosphor layer to be formed on the inner walls of the discharge cell with a higher thickness; however, when the thickness of the phosphor is increased, the discharge space becomes smaller to cause a high discharge voltage.
In order to solve the issue of a reduction in the fluorescent luminance, for example, a method has been disclosed in which by using a photosensitive barrier-rib material containing a phosphor, the phosphor is contained in the entire barrier ribs so that the effective phosphor thickness is increased (for example, see Patent Document 1).
Here, for example, another method has been disclosed in which in order to improve the fluorescent luminance of discharge cells by forming a reflective layer on the surface of the barrier ribs, a glass paste layer serving as a first barrier-rib material is formed on a substrate, and after a glass paste layer serving as a white second barrier-rib material containing titania powder or zirconia powder has been formed on the surface thereof, a mold used for forming barrier ribs is pressed onto the surface of the second glass paste layer, and both of the glass paste layers are consequently subjected to plastic deformation so that barrier ribs are formed (for example, see Patent Document 2).
Patent Document 1: Japanese Unexamined Patent Publication No. 11-191368
Patent Document 2: Japanese Unexamined Patent Publication No. 11-213899
However, along with the recent developments of high precision devices, the aspect ratio of the barrier ribs becomes greater, resulting in an issue of insufficient strength when the barrier ribs are formed by the method of Patent Document 1 and an issue of increased number of processes and the subsequent complicated manufacturing processes. In contrast, in the method of Patent Document 2 in which the reflective layer is formed on the surface of the barrier ribs, an issue arises in which the luminance in the fine discharge cells is not sufficiently improved.
The present invention has been devised to solve these issues, and its objective is to provide a PDP that can achieve barrier ribs used for forming fine discharge cells capable of providing high-precision display and high-luminance display, with high precision at low costs, and also to provide a method for manufacturing such a PDP.
In order to achieve the above-mentioned objectives, the present invention is provided with the following arrangements.
According to a first aspect of the present invention, there is provided a plasma display panel comprising:
a front face panel prepared by forming paired display electrodes, a dielectric layer, and a protective layer on a glass substrate; and
a back face panel prepared by forming address electrodes, barrier ribs, and phosphor layers on a substrate, with the front face panel and the back face panel being made face to face with each other to form discharge spaces by sealing peripheral portions thereof,
wherein fluorescent barrier-rib portions are placed between the barrier ribs and each of the phosphor layers, with the fluorescent barrier-rib portions comprising a mixed material of a barrier-rib material and a phosphor material.
In accordance with this structure, it becomes possible to achieve barrier ribs having sufficient barrier-rib strength even in the case of fine discharge cells, and consequently to achieve a PDP having higher luminance.
According to a second aspect of the present invention, there is provided the plasma display panel according to the first aspect, wherein the fluorescent barrier-rib portions comprise a mixed material of the phosphor material and the barrier-rib material, with the phosphor material having a mixed ratio in a range of from 42 wt % to 67 wt %.
In accordance with this structure, it is possible to increase the fluorescent luminance while properly maintaining the strength of the barrier ribs.
According to a third aspect of the present invention, there is provided a method for manufacturing a plasma display panel which is provided with: a front face panel prepared by forming paired display electrodes, a dielectric layer, and a protective layer on a glass substrate; and a back face panel prepared by forming address electrodes, barrier ribs, and a phosphor layer on a substrate, with the front face panel and the back face panel being made face to face with each other to form discharge spaces by sealing peripheral portions thereof, comprising the steps of:
applying a barrier-rib material to the address electrodes so as to be covered therewith to form a barrier-rib portion-forming layer;
forming a fluorescent barrier-rib portion-forming layer at positions on the barrier-rib portion-forming layer that correspond to positions of the address electrodes by using a mixed material of a barrier-rib material and a phosphor material;
simultaneously pressing the fluorescent barrier-rib portion-forming layer and the barrier-rib portion-forming layer by using a forming mold having female concave portions corresponding to a pattern of the barrier ribs to mold the barrier ribs;
releasing the forming mold from the fluorescent barrier-rib portion-forming layer and the barrier-rib portion-forming layer;
firing and solidifying the fluorescent barrier-rib portion-forming layer and the barrier-rib portion-forming layer molded by the forming mold to form barrier ribs and fluorescent barrier-rib portions; and
forming phosphor portions comprising a phosphor material in a manner so as to cover the fluorescent barrier-rib portions,
thus manufacturing the back face panel.
In accordance with this manufacturing method, in the molding step, the barrier-rib portions comprising only the barrier-rib material are formed, and the fluorescent barrier-rib portions containing a phosphor material and the barrier-rib material are formed on the side faces of each of the barrier-rib portions; thus, it becomes possible to easily manufacture barrier ribs that can ensure sufficient barrier-rib strength and also improve the luminance.
According to a fourth aspect of the present invention, there is provided the method for manufacturing a plasma display panel according to the third aspect, wherein in the molding step, by simultaneously pressing the fluorescent barrier-rib portion-forming layer and the barrier-rib portion-forming layer by using the forming mold, with a flowability of the material for forming the fluorescent barrier-rib portion-forming layer in response to a stress application being made smaller than a flowability of the material for forming the barrier-rib portion-forming layer in response to a stress application, each of the female-mold concave portions is filled with the material for forming the barrier-rib portion-forming layer to form a barrier-rib core portion of the barrier rib while the material for forming the fluorescent barrier-rib portion-forming layer forms fluorescent barrier-rib portions on two side-wall portions of the barrier-rib core portion.
In accordance with this manufacturing method, the fluorescent barrier-rib portions can be formed on the entire surfaces of the side faces of the core portion of each of the barrier ribs, without causing the material for the core portion of each barrier rib and the fluorescent barrier-rib forming layer to be mixed with each other.
According to a fifth aspect of the present invention, there is provided the method for manufacturing a plasma display panel according to the fourth aspect, further comprising the steps of:
forming a phosphor portion-forming layer on the fluorescent barrier-rib portion;
simultaneously pressing the phosphor portion-forming layer, the fluorescent barrier-rib portions, and the barrier-rib portion-forming layer by using the forming mold having the female concave portions corresponding to the pattern of the barrier ribs to carry out molding;
releasing the forming mold from the barrier ribs, the fluorescent phosphor barrier portions, and the phosphor portion-forming layer; and
firing and solidifying the barrier ribs, the fluorescent barrier-rib portions, and the phosphor portion-forming layer molded by the forming mold.
In accordance with this manufacturing method, by carrying out a molding step only once, the core portion comprising only the barrier-rib material is formed, and the fluorescent barrier-rib portions containing a phosphor material and the barrier-rib material and the phosphor portions comprising only the phosphor material are formed on the side faces thereof so that it is possible to manufacture discharge cells having improved luminance, with sufficient barrier-rib strength being maintained.
According to a sixth aspect of the present invention, there is provided the method for manufacturing a plasma display panel according to the fifth aspect, wherein by simultaneously pressing the phosphor portion-forming layer, the fluorescent barrier-rib portion-forming layer, and the barrier-rib portion-forming layer by using the forming mold, with the flowability of the phosphor portion-forming layer in response to the stress application being made smaller than the flowability of the fluorescent barrier-rib portions in response to the stress application, each of the female-mold concave portions is filled with the material for forming the barrier-rib portion-forming layer to form the barrier-rib core portion of the barrier rib while the material for forming the fluorescent barrier-rib portion-forming layer forms the fluorescent barrier-rib portions on the two side-wall portions of the barrier-rib core portion and the material for forming the phosphor portion-forming layer further forms the phosphor portion-forming layer on each of the fluorescent barrier rib portions.
In accordance with this manufacturing method, the phosphor portion-forming layer can be formed over the entire faces of the side faces of the fluorescent barrier-rib portion-forming layer in the molding process.
According to a seventh aspect of the present invention, there is provided the method for manufacturing a plasma display panel according to any one of the third to sixth aspects, wherein the fluorescent barrier-rib portions comprise a mixed material of the phosphor and the barrier-rib material, with the phosphor material having a mixed ratio in a range of from 42 wt % to 67 wt %.
In accordance with this manufacturing method, it becomes possible to improve the fluorescent luminance, with the strength of the barrier ribs being sufficiently maintained.
According to an eighth aspect of the present invention, there is provided a method for manufacturing a plasma display panel which is provided with: a front face panel prepared by forming paired display electrodes, a dielectric layer, and a protective layer on a glass substrate; and a back face panel prepared by forming barrier ribs and a phosphor layer on a substrate, with the front face panel and the back face panel being made face to face with each other to form discharge spaces by sealing peripheral portion thereof, comprising the steps of:
applying a fluorescent assistant material composition containing a barrier-rib material and a fluorescent assistant material onto one of side faces of each of concave portions of a forming mold having the concave portions corresponding an inverted pattern to the barrier ribs so as to form a fluorescent assistant material layer;
filling a void in a center of each of the concave portions with a barrier-rib material composition so as to form a barrier-rib forming layer;
making the substrate in contact with the forming mold so that the substrate and the barrier-rib material composition are bonded to each other;
curing the fluorescent assistant material composition and the barrier-rib material composition;
releasing the forming mold from the fluorescent assistant material composition and the barrier-rib material composition;
firing and solidifying the barrier-rib material composition and the fluorescent assistant material composition so that barrier-rib portions are formed by the barrier-rib material composition while fluorescent barrier-rib portions are formed by the fluorescent assistant material composition; and
forming phosphor portions comprising a phosphor material in a manner so as to cover the fluorescent barrier-rib portions.
In accordance with this manufacturing method, the luminance is improved by the fluorescent assistant material (fluorescent barrier-rib portions) that is exposed to the surface portion of each barrier rib after the firing process, and since the center portion of the barrier rib comprises only the barrier-rib material, the strength of the barrier rib itself can be sufficiently maintained.
According to a ninth aspect of the present invention, there is provided the method for manufacturing a plasma display panel according to the eighth aspect, wherein in the step of forming the fluorescent assistant material layer, the fluorescent assistant material composition is applied in a state in which an oil repellent treatment has been carried out on a bottom face of each of the concave portions.
With this method, in the fluorescent assistant material forming step in which the fluorescent assistant material composition is applied to one of the side faces of each concave portion, the coating process is carried out only on the side faces with high precision because of repellence exerted on the concave portion bottom face having an oil repellent property.
According to a 10th aspect of the present invention, there is provided the method for manufacturing a plasma display panel according to the eighth or ninth aspect, wherein in the step of forming the fluorescent assistant material layer, the fluorescent assistant material composition is applied in a state in which a lipophilic treatment has been carried out on the side-face portions of each of the concave portions.
With this arrangement, in the fluorescent assistant material forming step, since the fluorescent assistant material composition is allowed to have an affinity for the side faces of each concave portion, the coating process is stably carried out on the side faces.
According to an 11th aspect of the present invention, there is provided the method for manufacturing a plasma display panel according to the eighth aspect, further comprising the steps of:
prior to the step of forming the fluorescent assistant material layer, filling the concave portions with a barrier-rib material composition; and
forming a gap used for forming a fluorescent assistant material layer between the filled barrier-rib material composition and the side-face portions of each of the concave portions,
wherein in the step of forming the fluorescent assistant material layer, the fluorescent assistant material composition is applied so as to be inserted into the gap for forming a fluorescent assistant material layer.
With this manufacturing method, it is possible to positively form the barrier-rib material onto the center portion of each barrier rib and consequently to enhance the strength of the barrier rib.
According to a 12th aspect of the present invention, there is provided the method for manufacturing a plasma display panel according to the eighth aspect, wherein the forming mold is constituted by a first forming mold for molding the side-face portions of each of the concave portions and a second forming mold having an end portion used for molding a bottom face of each of the concave portions, which is fitted and inserted into the first forming mold, and the fluorescent assistant material forming step is carried out, with the end portion of the second forming mold being placed above a position of the bottom face of each of the concave portions corresponding an inverted pattern to the barrier ribs, and the step of forming the barrier-rib portion-forming layer is then carried out, with the end portion of the second forming mold being placed at the position of the bottom face of each of the concave portions corresponding an inverted pattern to the barrier ribs.
With this manufacturing method, in the fluorescent assistant material forming step, the fluorescent assistant material composition can be positively applied to one of the side faces of each concave portion by using the second forming mold, while it is hardly applied to the bottom portion and the other side face on the opposing side of each concave portion; thus, it becomes possible to carry out the coating process only on the slanted side face with high precision.
According to a 13th aspect of the present invention, there is provided the method for manufacturing a plasma display panel according to the 12th aspect, wherein in the step of forming the fluorescent assistant material layer, the fluorescent assistant material composition is applied in a state in which an oil repellent treatment has been carried out on a surface of the second forming mold used for forming the concave portions.
In accordance with this arrangement, since the oil repellent treatment is carried out on the surface of the second forming mold used for forming the concave portion, the fluorescent assistant material composition to be applied to one of the side faces of each concave portion in the fluorescent assistant material forming step is made repellent against the surface of the second forming mold so that it is hardly applied to the side face on the opposing side of each concave portion; thus, it becomes possible to carry out the coating process only on the slanted side face with high precision.
According to a 14th aspect of the present invention, there is provided the method for manufacturing a plasma display panel according to any one of the eighth, ninth, 11th to 13th aspects, wherein the fluorescent assistant material contains at least one material selected from a phosphor material and a reflective pigment.
With this arrangement, since the fluorescence of the phosphor layer can be assisted more positively, it becomes possible to manufacture a PDP with high luminance.
As described above, according to the present invention, since a portion comprising the mixed material of both of the barrier-rib material and the phosphor material is prepared, the corresponding portion is allowed to exert both of the function as the barrier rib and the function as the phosphor so that it is possible to achieve a barrier-rib structure of a PDP that can increase the effective phosphor thickness while properly maintaining the barrier-rib strength, and a manufacturing method for such a barrier-rib structure, and consequently to realize a PDP having fine discharge with high precision and high luminance. Moreover, since the portion comprising the mixed material of both of the barrier-rib material and the phosphor material is prepared, the effect for restraining the separation between the portion (barrier ribs) comprising the barrier-rib material and the portion (phosphor layer) comprising the phosphor material can be expected.
These and other aspects and features of the present invention will become clear from the following description taken in conjunction with the preferred embodiments thereof with reference to the accompanying drawings, in which:
Before the description of the present invention proceeds, it is to be noted that like parts are designated by like reference numerals throughout the accompanying drawings.
Hereinafter, a first embodiment in the present invention will be discussed in detail with reference to the drawings.
Referring to the drawings, embodiments of the present invention will be described below.
On a front face substrate 10 forming the front face panel 1, a plurality of paired display electrodes 16, constituted by scanning electrodes 14 and sustain electrodes 15 covered with a dielectric layer 12 and a protective layer 13, are arranged in parallel with one another. Each of the paired display electrodes 16 is constituted by a transparent electrode that transmits visible light and a bus electrode used for lowering the resistance of the transparent electrode.
On the other hand, on a back face substrate 20 forming the back face panel 2, a plurality of address electrodes 22 covered with an undercoating dielectric layer 21 are arranged in parallel with one another in a direction orthogonal to the paired display electrodes 16. Barrier ribs 23, used for separating the discharge cells 11 for each address electrode 22, are formed between the adjacent address electrodes 22. Moreover, a phosphor layer 24 is formed on the undercoating dielectric layer 21 as well as on the side faces of each barrier rib 23.
Meanwhile, although not shown in
The phosphor layer 24 is constituted by the portion of the phosphor material of the fluorescent barrier-rib portion 66 and a phosphor portion 24A formed only by the phosphor material in a manner so as to cover the fluorescent barrier-rib portion 66.
Here, the barrier-rib portion 23A, the fluorescent barrier-rib portion 66, and the phosphor portion 24A form three structural portions with respective clear borders, but the border lines are not necessarily formed linearly, and have arbitrary shapes such as a straight line, a curved line, and a zig-zag line; however, for convenience of easy understanding of the present embodiment, these are simplified, and linearly illustrated in
For example, a gas, such as a neon gas and a xenon gas, is sealed in the discharge cell 11 as a gas that emits ultraviolet rays through discharging. The phosphor layer 24 (that is, the phosphor material in the fluorescent barrier-rib portion 66 and the phosphor material in the phosphor portion 24A) is excited by the ultraviolet rays generated by the discharge inside the discharge cell 11 so that visible light is generated to display an image. As described above, the PDP has the structure in which the discharge cells 11, arranged in a matrix shape, form an image display area, with the various electrodes being formed on the surface opposing to the front face substrate 10 and the surface opposing to the back face substrate 20, and by applying various driving voltages to these electrodes from external driving circuits, an image is displayed.
As an example, the barrier rib 23 is designed into a trapezoidal shape in its cross section with 120 μm in height, 35 μm in upper bottom area, 50 μm in lower bottom area, and 220 μm in pitch. However, the present invention is not intended to be limited by these designed values, and the shape of the barrier ribs 23 may be formed into a lattice shape, a stripe shape, or the like. In addition, with respect to the base member of a forming mold 131, not particularly limited, a material, such as plastics, metal, ceramics, or glass, may be used.
Next, a manufacturing method for the back face panel 2 will be described in detail.
The barrier-rib material for forming the barrier ribs 23, for example, includes metal oxides, such as boron oxide, silicon oxide, bismuth oxide, lead oxide, or titanium oxide, and the resulting material forms the barrier ribs 23 when fused through a firing process.
Next, following the process for coating and forming the barrier-rib portion, as shown in
The phosphor-containing barrier-rib material contains a phosphor material and a barrier-rib material, and in addition to these, a solvent and an organic additive, etc. are added thereto. The barrier-rib material comprises a metal oxide or the like, such as boron oxide, silicon oxide, bismuth oxide, lead oxide, or titanium oxide, and formed into the barrier ribs 23 when fused by firing. Specific examples of the phosphor material are shown below: The blue color phosphor material includes a phosphor material, such as ZnS:Ag, BaMgAl10O17:Eu, BaMgAl14O23:Eu or BaNgAl16O26:Eu. The green color phosphor material includes a phosphor material, such as ZnS:Cu, Zn2SiO4:Mn, Y2O2S:Tb or YBO3:Tb. The red color phosphor material includes a phosphor material, such as Y2O3:Eu, Zn3(PiO4)2:Mn, YVO4:Eu or (Y, Gd)BO3:Eu.
When the fluorescent barrier-rib portion-forming layer 33 is thin, the thickness of the fluorescent barrier-rib portion 66 to be formed on each of the two side faces of the wall of the barrier-rib portion 23A also becomes thin, resulting in the possibility that the strength of the barrier rib 23 including the barrier-rib portion 23A in combination with the fluorescent barrier-rib portion 66 might be lowered too much. Therefore, in order to make the thickness of the fluorescent barrier-rib portion 66 to have the thickness of 5 μm or more at the middle portion between the top and the bottom portions of the finished fluorescent barrier rib 23, the thickness of the coated fluorescent barrier-rib portion-forming layer 33 is preferably controlled.
Next, following the process for forming the fluorescent barrier-rib portion-forming layer 33,
By pressing the forming mold 34 onto the back face substrate 20, the end face of the male-mold convex portion 34A of the forming mold 34 is allowed to press the barrier-rib portion-forming layer 32 and the fluorescent barrier-rib portion-forming layer 33 so that along the side face of the female-mold concave portion of the forming mold 34, the material to form the barrier-rib portion-forming layer 32 and the material to form the fluorescent barrier-rib portion-forming layer 33 are allowed to flow into the female-mold concave portion 35. In the first embodiment of the present invention, the flowability of the material to form the fluorescent barrier-rib portion-forming layer 33 in response to a stress application is made smaller than the flowability of the material to form the barrier-rib portion-forming layer 32 in response to a stress application.
The flowability of each of the barrier-rib portion-forming layer 32 and the fluorescent barrier-rib portion-forming layer 33 in response to the stress application is controllable by adjusting the compounding ratio of a resin material into the materials. As a result of this arrangement that makes the material for forming the fluorescent barrier-rib portion-forming layer 33 and the material for forming the barrier-rib portion-forming layer 32 different from each other in their flowability, the first embodiment of the present invention allows the material to form the barrier-rib portion-forming layer 32 to more easily flow to be deformed, in comparison with the material to form the fluorescent barrier-rib portion-forming layer 33 that flows along the surface of the female-mold concave portion 35 of the forming mold 34, by the pressing process of the forming mold 34. For this reason, the material to form the barrier-rib portion-forming layer 32 flows to be deformed so as to form the barrier-rib core portion 36, and intrudes in the female-mold concave portion 35 down to the bottom of the female-mold concave portion 35 so that the fluorescent barrier-rib portion-forming layer 33 having a smaller flowability is molded to be positioned on the periphery of the barrier-rib core portion 36 as well as on the bottom face of the discharge cell 11. Therefore, even by the pressing process of the forming mold 34, the barrier-rib portion-forming layer 32 and the fluorescent barrier-rib portion-forming layer 33 are not mixed with each other, and it is possible to prevent a fluorescent barrier-rib portion-forming layer 33 having another color from being directed into the adjacent discharge cell over the barrier-rib core portion 36 to cause a mixed color.
Therefore, in the center portion inside the female-mold concave portion 35, a barrier-rib core portion 36 made of only the barrier-rib portion-forming layer 32 is formed, and a fluorescent barrier-rib portion-forming layer 33 prior to the firing process, that is, a base fluorescent barrier-rib portion 37, which contains a phosphor material having a different color and a barrier-rib material and is used for forming a fired fluorescent barrier-rib portion 66, is formed on the surface side of the female-mold concave portion 35, that is, on the two side walls of the barrier rib core portion 36 as well as on the bottom of the discharge cell 11. That is, the barrier-rib core portion 36 and the base fluorescent barrier-rib portion 37 that covers the barrier-rib core portion 36 are formed so that a barrier-rib portion-forming layer prior to the firing, that is, a base barrier rib 38 to be used for forming a fired barrier rib 23, can be formed. Since the material used for forming the fluorescent barrier-rib portion-forming layer 33 exerts a small flowability even upon application of a stress, the base fluorescent barrier-rib portion 37 becomes gradually thinner in its film thickness toward the top of the base barrier rib 38. Moreover, the base fluorescent barrier rib 37 may be adjusted in its material for the fluorescent barrier-rib portion-forming layer 33 so that its rate of the barrier-rib material made of a glass paste is gradually increased toward the top of the base barrier rib 38, with the result that only the barrier-rib material is filled in the vicinity of the top of the base barrier rib 38. That is, the materials in the fluorescent barrier-rib portion-forming layer 33 may be adjusted so that the flowability of the barrier-rib material becomes higher in comparison with that of the phosphor material.
In contrast, as the phosphor content of the base barrier rib 38 becomes higher, the improvement of the fluorescent luminance in the discharge cell 11 is expected; however, as the phosphor content of the barrier rib 23 becomes higher, the strength of the barrier rib 23 is lowered. In the first embodiment of the present invention, the mixed ratio between the barrier-rib material and the phosphor material in the fluorescent barrier-rib portion-forming layer 33 is adjusted so that the phosphor material is set to 42 wt % to 67 wt % relative to the weight of the entire materials of the fluorescent barrier-rib portion-forming layer 33; thus, a barrier rib 23, which has a comparatively higher fluorescent luminance even in a miniaturized discharge cell 11, and exerts a barrier-rib strength and elastic modulus that can withstand practical use, is achieved. That is, when the phosphor content is less than 42 wt %, the improvement of the fluorescent luminance in the discharge cell 11 is not expected, while in the case of the phosphor content exceeding 67 wt %, the strength of the barrier rib 23 is undesirably lowered. Therefore, by setting the phosphor content to 42 wt % or more, the improvement of fluorescent luminance in the discharge cell 11 can be expected, and by also setting the phosphor content to 67 wt % or less, it becomes possible to provide sufficient strength and elastic modulus that allow the barrier rib 23 to withstand practical use.
Moreover, simultaneously as the base barrier rib 38 is formed, a remaining portion other than the portion that has flowed therein to form the barrier-rib core portion 36 of the material for forming the barrier-rib portion-forming layer 32 is left between the male-mold convex portion 34A of the forming mold 34 and the back face substrate 20, and this remaining portion of the material for forming the barrier-rib portion-forming layer 32 is used for forming an undercoating dielectric layer forming layer prior to a firing process, that is, a base undercoating dielectric layer 39 for use in forming an undercoating dielectric layer 21 after the firing process. The base undercoating dielectric layer 39 is formed with a thickness that can at least cover the address electrodes 22.
Following the above-mentioned forming mold copying process,
Next,
After this firing process, as shown in
Therefore, the phosphor portion 24A having only the phosphor material exerts a function as the phosphor layer main portion, and since the fluorescent barrier-rib portion 66, formed on the side faces of the barrier-rib portion 23A and the bottom face of the discharge cell 11, and comprising a mixed material of a phosphor material and a barrier-rib material, also contains the phosphor material, the fluorescent barrier-rib portion 66 is also allowed to function as a phosphor layer assistant portion. Consequently, it can also be said that the phosphor layer 24 in the first embodiment has a two-layer structure of the phosphor portion 24A and the fluorescent barrier-rib portion 66.
In the PDP produced by the manufacturing method of the first embodiment of the present invention, since the composition of the barrier-rib portion 23A corresponding to the core portion of the barrier rib 23 is a glass paste, it is confirmed that even when the elastic deformation rate of the fluorescent barrier-rib portion 66 is set to about ⅕ of that of a barrier-rib portion 23A comprising only a glass paste, the resulting PDP can be put into practical use by using prototype samples. In recent years, however, one example indicating the miniaturization of a discharge cell in response to the higher precision of a PDP shows that, for example, in comparison with a current PDP (not high precision) of 42 inches that has a cell aperture ratio of 66%, a high-precision PDP of 50 inches has a cell aperture ratio of 50%. Even in the case of PDPs of the same size, a PDP of high precision needs to have a smaller cell size and a thinner phosphor layer to cause a reduction in luminance, and the width of the barrier rib also becomes thinner to cause a reduction in strength. Here, in the case of a PDP as one example of the present embodiment in which the thickness of the barrier-rib portion is 20 μm and the thickness of the respective fluorescent barrier-rib portions on the two side faces of the barrier-rib portion is 5 μm, the total thickness of the barrier rib becomes 30 μm. In this case, since the thickness of the fluorescent barrier-rib portion is as small as 5 μm, the effective luminance is reduced to one half, with the result that in order to ensure 0.5 or more as the fluorescent luminance, from the graph of
Therefore, as has been explained earlier, the content of phosphor material relative to the barrier-rib material of the fluorescent barrier-rib portion 66 after the firing process is preferably set in the range of from 42 wt % to 67 wt %. Moreover, in an attempt to put preference on the fluorescent luminance rather than the strength of the barrier rib 23, the content ratio of phosphor material is preferably set in the range of from 50 wt % to 67 wt %.
In the same manner as in the first embodiment,
As shown in
Here, with respect to such a relationship between the flowability and the applied stress in which the flowability of the material to form the fluorescent barrier-rib portion-forming layer 33 in response to a stress application is made smaller than the flowability of the material to form the barrier-rib portion-forming layer 32 in response to a stress application, the same relationship as that described in the first embodiment is adopted; therefore, the explanation thereof is omitted.
In the second embodiment of the present invention, the flowability of the material to form the phosphor portion-forming layer 40 in response to a stress application is made smaller than the flowability of the material to form the fluorescent barrier-rib portion-forming layer 33 in response to a stress application. Therefore, it is possible to prevent mixed colors or the like from occurring due to a flow of the phosphor portion-forming layer 40, and also to mold the respective films with predetermined film thicknesses.
With this arrangement, in the same manner as in the first embodiment, the material to form the barrier-rib portion-forming layer 32 is allowed to flow more easily to be deformed in comparison with the material to form the fluorescent barrier-rib portion-forming layer 33 that flows along the surface of the female-mold concave portion 35 of the forming mold 34 by the pressing process of the forming mold 34 applied to the back face substrate 20. For this reason, the material to form the barrier-rib portion-forming layer 32 flows to be deformed so as to form the barrier-rib core portion 36, and intrudes into the bottom of the female-mold concave portion 35 in the female-mold concave portion 35 so that the fluorescent barrier-rib portion-forming layer 33 having a smaller flowability is molded to be positioned on the periphery of the barrier-rib core portion 36. Therefore, even by the pressing process of the forming mold 34, the fluorescent barrier-rib portion-forming layer 33 to form the base fluorescent barrier-rib portion 37 and the barrier-rib portion-forming layer 32 to form the barrier-rib core portion 36 are not mixed with each other, and it is possible to prevent a base fluorescent barrier-rib portion 37 having another color from being directed into the adjacent discharge cell over the barrier-rib core portion 36 to cause a mixed color.
Moreover, a remaining portion other than the portion that has flowed therein to form the barrier-rib core portion 36 of the material for forming the barrier-rib portion-forming layer 32 is left between the male-mold convex portion 34A of the forming mold 34 and the back face substrate 20, and this remaining portion of the material for forming the barrier-rib portion-forming layer 32 is used for forming the undercoating dielectric layer forming layer prior to a firing process, that is, a base undercoating dielectric layer 39 for use in forming a fired undercoating dielectric layer 21. At this time, a remaining portion other than the portion that has flowed therein to form the base fluorescent barrier-rib portion 37 of the material for forming the fluorescent barrier-rib portion-forming layer 33 is left on the base undercoating dielectric layer 39.
Here, the phosphor portion-forming layer 40, which has a smaller flowability than that of the fluorescent barrier-rib portion-forming layer 33, is molded between the end face of the male-mold convex portion 34A of the forming mold 34 and the base fluorescent barrier-rib portion 37 so as to stay, as it is, without moving so much; thus, a base phosphor layer 41 is formed. Consequently, even by the pressing process of the forming mold 34, the phosphor portion-forming layer 40 to form the base phosphor layer 41 and the barrier-rib portion-forming layer 32 to form the barrier-rib core portion 36 are not mixed with each other, and it is possible to prevent the base phosphor portion-forming layer 41 having another color from being directed into the adjacent discharge cell over the barrier-rib core portion 36 to cause a mixed color.
Therefore, according to the second embodiment, simultaneously as the barrier-rib core portion 36, the base fluorescent barrier-rib portion 37 and the base undercoating dielectric layer 39 are molded by the flowing of the material to form the barrier-rib portion-forming layer 32 as well as by the flowing of the material to form the fluorescent barrier-rib portion-forming layer 33, through the pressing process of the forming mold 34 to the back face substrate 20, the material to form the phosphor portion-forming layer 40 is allowed to flow so that the base phosphor portion 41 is molded; therefore, the process exclusively used for molding the base phosphor portion 41 is no longer required so that the manufacturing process can be simplified as a whole, and it becomes possible to ensure a sufficient barrier-rib strength and consequently to achieve a PDP in which the fluorescent luminance is improved.
Here, the exposing process in
The third embodiment and the embodiments thereafter of the present invention have been devised to solve the aforementioned issues as well as the following issues.
In order to solve the issue of a luminance reduction, for example, a method has been disclosed in which a white pigment layer having a reflective property, for example, typically comprising titanium oxide, or a reflective colored pigment layer is placed beneath the phosphor layer (for example, see Patent Document 3 (Japanese Unexamined Patent Publication No. 10-188820) and Patent Document 4 (Japanese Unexamined Patent Publication No. 8-138559)). Moreover, another method has been disclosed in which a mixed material of a barrier-rib material and a phosphor material is embedded in opening portions formed by a photosensitive film so as to form barrier ribs so that a fluorescent property is applied to the surface of the barrier rib to improve the luminance (for example, see Patent Document 1).
In the method of Patent Document 3 or Patent Document 4, however, although the luminance as the phosphor layer is improved, the layer having a reflective property (hereinafter, referred to as a reflective layer) needs to be placed beneath the phosphor layer, with the result that the virtual discharge space is narrowed to cause a reduction in the discharging efficiency and a subsequent issue of a reduction in the luminance. This issue has become more conspicuous as the recent miniaturization of the discharge cell progresses in response to the current developments of high-precision PDPs. Here, it is proposed that even when the virtual discharge space becomes smaller by the reflective layer, the discharge space is ensured by narrowing the barrier ribs correspondingly; however, when the width of the barrier rib is made too narrow, other issues arise in which defective cracked barrier ribs are caused and an erroneous discharge occurs between the adjacent cells.
In contrast, according to the method described in Patent Document 1, the effective thickness of the phosphor layer can be increased without narrowing the discharge space. However, since the respective barrier ribs having fluorescent colors of blue, green and red need to contain phosphors corresponding to the respective fluorescent colors, the pasting, exposing and developing processes of photosensitive films, the embedding process of the barrier-rib materials and the separating process of the photosensitive films have to be repeated three times, and complicated processes are consequently required, and since a large amount of resist films has to be used, the manufacturing costs become higher. Moreover, although the phosphor only needs to be exposed to the surface of the barrier rib, the phosphor material has to be contained in the entire barrier ribs to be formed. As the content of the phosphor materials increases, the adhesion of the barrier-rib material to form the barrier ribs deteriorates, making it difficult to ensure the strength of the barrier ribs to cause defective barrier ribs due to falling or the like.
In order to solve these issues in addition to the aforementioned issues with the present invention, the objective of the following embodiments is to provide a PDP in which barrier ribs that can form fine discharge cells capable of achieving both of high-precision display and high-luminance display are realized at low costs with high precision, and a manufacturing method for such barrier ribs.
On a front face substrate 10 forming the front face panel 1, a plurality of paired display electrodes 16, constituted by scanning electrodes 14 and sustain electrodes 15 covered with a dielectric layer 12 and a protective layer 13, are arranged in parallel with one another. Each of the paired display electrodes 16 is constituted by a transparent electrode that transmits visible light and a bus electrode used for lowering the resistance of the transparent electrode.
On a back face substrate 20 forming the back face panel 2, a plurality of address electrodes 22 covered with an undercoating dielectric layer 21 are arranged in parallel with one another in a direction orthogonal to the paired display electrodes 16. Barrier ribs 23, used for separating the discharge cells 11 for each address electrode 22, are formed between the adjacent address electrodes 22. Moreover, a phosphor layer 24 is formed on the undercoating dielectric layer 21 as well as on the side faces of each barrier rib 23.
Here, although not shown in
In a manner similar to
Here, the barrier-rib portion 23B, the fluorescent assistant layer (fluorescent barrier-rib portion) 70 and the phosphor portion 24B form three structural portions with respective clear borders, but the border lines are not necessarily formed linearly, and have arbitrary shapes such as a straight line, a curved line and a zig-zag line; however, for convenience of easy understanding of the third embodiment, these are simplified, and linearly illustrated in
For example, a gas, such as a neon gas and a xenon gas, is sealed in the discharge cell 11 as a gas that discharges ultraviolet rays through discharging. The phosphor layer 24 (that is, the phosphor material in the fluorescent assistant layer (fluorescent barrier-rib portion) 70 and the phosphor material in the phosphor portion 24B) is excited by the ultraviolet rays generated by the discharge inside the discharge cell 11 so that visible light is generated to display an image. As described above, the PDP has the structure in which the discharge cells 11, arranged in a matrix shape, form an image display area, with the various electrodes being formed on the surface opposing to the front face substrate 10 and the surface opposing to the back face substrate 20, and by applying various driving voltages to these electrodes from external driving circuits, an image is displayed.
Next, a method for manufacturing the back face panel 2 will be described in detail.
In
In the third embodiment of the present invention, a paste-state fluorescent assistant material composition 132 and a fluorescent assistant material are used. The fluorescent assistant material composition 132 to be used here refers to a paste-state composition that contains a barrier-rib material and a fluorescent assistant material as inorganic main components to which a solvent, an organic additive and the like are added. The barrier-rib material forming the barrier ribs 23 comprises a metal oxide or the like, such as boron oxide, silicon oxide, bismuth oxide, lead oxide and titanium oxide, and formed into the barrier ribs 23 when fused by firing. Moreover, the fluorescent assistant material refers to at least one material selected from a phosphor material and a reflective material. Moreover, with respect to a material for assisting fluorescence of the blue phosphor layer (hereinafter, referred to as a blue fluorescent assistant material), a blue phosphor material, or a white or blue reflective material is selected. With respect to a material for assisting fluorescence of the green phosphor layer (hereinafter, referred to as a green fluorescent assistant material), a green phosphor material, or a white or green reflective material is selected. With respect to a material for assisting fluorescence of the red phosphor layer (hereinafter, referred to as a red fluorescent assistant material), a red phosphor material, or a white or red reflective material is selected. The fluorescent assistant material is allowed to assist fluorescence from the phosphor portion 24B when it is exposed to the surface of the discharge cell 11.
Next, specific examples of the fluorescent assistant material are shown below: Examples of the blue fluorescent assistant material include a phosphor material, such as ZnS:Ag, BaMgAl10O17:Eu, BaMgAl14O23:Eu, or BaMgAl16O26:Eu; or a reflective material, such as titanium oxide, aluminum oxide, or a Co—Al—Cr-based pigment. Examples of the green fluorescent assistant material include a phosphor material, such as ZnS:Cu, Zn2SiO4:Mn, Y2O2S:Tb, or YBO3:Tb; or a reflective material, such as titanium oxide, aluminum oxide, or a Ti—Zn—Co—Ni-based pigment. Examples of the red fluorescent assistant material include a phosphor material, such as Y2O3:Eu, Zn3(PiO4)2:Mn, YVO4:Eu, or (Y, Gd)BO3:Eu; or a reflective material, such as titanium oxide or an iron-oxide-based pigment.
With respect to the ratio between the fluorescent assistant material and the barrier-rib material, as the content of the fluorescent assistant material becomes higher, the improvement of the fluorescent luminance in the discharge cell 11 is expected; however, since the adhesion to the barrier-rib portion 23B is lowered, issues, such as coming-off and lighting-failure, tend to occur. Therefore, by adjusting the mixed ratio of the barrier-rib material and the fluorescent assistant material to 42 wt % to 67 wt %, a barrier rib 23B, which has a comparatively higher fluorescent luminance even in a miniaturized discharge cell 11, and exerts a sufficient strength that can withstand practical use, is achieved. That is, when the content of the fluorescent assistant material is less than 42 wt %, the improvement of the fluorescent luminance in the discharge cell 11 is not expected, while in the case when the content of the fluorescent assistant material is 42 wt % or more, the improvement of the fluorescent luminance in the discharge cell 11 is expected. In contrast, in the case of the fluorescent assistant material exceeding 67 wt %, the adhesion to the surface of the barrier-rib portion 23B is undesirably lowered, while in the case when the fluorescent assistant material is set to 67 wt % or less, the adhesion to the surface of the barrier-rib portion 23B (in other words, strength) is sufficiently improved so as to withstand practical use.
Moreover, the barrier-rib material composition refers to a paste-state composition that is composed of a barrier-rib material, a solvent, an organic additive and the like, and used for forming the barrier-rib portion 23B.
Next, respective steps used for manufacturing the back face panel 2 will be described with reference to
As shown in
Here, the forming mold 131 of the back face panel 2 is provided with a convex portion 138 and a concave portion 130 formed therein, which respectively correspond to respective discharge cells 11 and respective barrier-rib portions 23B of the back face panel 2 with reversed shapes in the concave and convex portions.
The dispenser tank 133 is provided with respective aperture portions 134 on its bottom face, which are formed at positions that are allowed to face the two side faces (for example, two side faces 136a) of each convex portion 138, and by supplying air into the dispenser tank 133 from an air supply port 135, the paste-state fluorescent assistant material composition 132, housed in the dispenser tank 133, is discharged from the respective aperture portions 134 into the concave portion side faces 136a of each convex portion 138 to be applied thereon. In this third embodiment, first, the following description will discuss operations in which only the dispenser tank 133 for blue color is prepared, and by using the dispenser tank 133 housing a blue-color fluorescent assistant material composition 132, the blue-color fluorescent assistant material composition 132 is applied to the concave portion side faces 136a for blue color of each convex portion 138 in the forming mold 131.
Next,
Following the step for applying the blue-color fluorescent assistant material composition 132,
With respect to the injection-coating method, different from the process in
Next, following the step of injecting the barrier-rib material composition 129,
At this time, with respect to the back face substrate 20, address electrodes 22 are formed on a plain glass plate, and the undercoating dielectric layer 21 is formed in a manner so as to cover the address electrodes 22, and the surface of the undercoating dielectric layer 21 is made in contact with the forming mold 131. Prior to the contact thereof, a positioning process is carried out between the back face substrate 20 and the forming mold 131. That is, the back face substrate 20 and the forming mold 131 are positioned so that the center of each address electrode 22 on the back face substrate 20 is located in the center of each convex portion 138 of the forming mold 131. By carrying out this process, either the barrier-rib material composition 129 or the fluorescent assistant material composition 132, applied or injected to the forming mold 131, is made in contact with the back face substrate 20.
Next, following the step of making the back face substrate 20 and the forming mold 131 in contact with each other,
Next, following the step of curing the fluorescent assistant material composition 132 and the barrier-rib material composition 129,
Next, following the step of mold-releasing the fluorescent assistant material composition 132 and the barrier-rib material composition 129 from the forming mold 131,
Next, following the step of firing the fluorescent assistant material composition 132 and the barrier-rib material composition 129,
In a PDP manufactured by using the back face panel 2 in this manner, since the blue-color fluorescent assistant layer 70 is allowed to emit light by ultraviolet rays generated when the blue-color discharge cells are turned on, the light-emission intensity of the blue-color phosphor portion 24B is compensated for by the light emission of the blue-color fluorescent assistant layer 70 so that the light-emission intensity can be improved. Alternatively, since blue-color visible light generated upon turning on of the blue-color discharge cells 11 is reflected by the blue-color fluorescent assistant layer 70, the light-emission intensity of the blue-color phosphor portion 24B is compensated for by the reflection of the blue-color fluorescent assistant layer 70 so that the light-emission intensity can be improved.
Note that the above-mentioned description has exemplified a structure in which the blue-color fluorescent assistant layer 70 is formed on the surface of each barrier-rib portion 23B having one kind of color; however, a discharge cell of another color may be incorporated into the barrier-rib portion 23B. In this case, after a coating process of the fluorescent assistant layer 70 having one kind of color, or after the drying process thereof, fluorescent assistant material compositions having different colors can be applied to a pair of concave portion side faces 136b and a pair of concave portion side faces 136c (see
Moreover, upon application of the fluorescent assistant material composition to the convex portion 138, the fluorescence assisting property can be applied not only to the side face portions of the barrier-rib portion 23B, but also to the bottom portion of the discharge cell 11. Moreover, the content of the fluorescent assistant material to be applied to the concave portion side faces 136a, 136b and the convex portion 138 may be changed. That is, a fluorescent assistant material containing the reflective material more may be applied to the concave portion side faces 136a and 136b, while a fluorescent assistant material containing the phosphor material more may be applied to the convex portion 138.
Moreover, prior to the process of
Moreover, by applying a lipophilic material such as a long chain aliphatic acid to the concave portion side faces 136a and 136b to impart a lipophilic property thereto, the affinity of the fluorescent assistant material composition for the concave side faces 136a and 136b is improved so that the coating process of the fluorescent assistant material composition can be carried out quickly.
Here, the barrier-rib portion 23C, the fluorescent assistant layer (fluorescent barrier-rib portion) 70 and the phosphor portion 24C form three structural portions with respective clear borders; however, the border lines are not necessarily formed linearly, and have arbitrary shapes such as a straight line, a curved line and a zig-zag line; however, for convenience of easy understanding of the fourth embodiment, these are simplified and illustrated linearly. That is, the fluorescent assistant layer (fluorescent barrier-rib portion) 70 is formed on the barrier-rib portion 23C intentionally in a manner so as to cover the barrier-rib portion 23C, and there is a clear border between the fluorescent assistant layer (fluorescent barrier-rib portion) 70 and the barrier-rib portion 23C. Moreover, there is a clear border between the fluorescent assistant layer (fluorescent barrier-rib portion) 70 and the phosphor portion 24C as well. After completion of the panel, the barrier-rib material is fused, but since the phosphor material remains as powder, as it is, the respective borders can be recognized when the cross section is observed. It can also be said that, in the barrier rib 23, the barrier-rib portion 23C functions as the barrier-rib main body portion, while the above-mentioned fluorescent assistant layer (fluorescent barrier-rib portion) 70 functions as a barrier-rib assistant portion. Moreover, it can also be said that, in the phosphor layer 24, the phosphor portion 24C functions as the phosphor-layer main body portion, while the fluorescent assistant layer (fluorescent barrier-rib portion) 70 functions as a phosphor-layer assistant portion. Consequently, the above-mentioned fluorescent assistant layer (fluorescent barrier-rib portion) 70 has both of functions, that is, the function as the barrier-rib assistant portion and the function as the phosphor-layer assistant portion.
Next, following the injecting step of the barrier-rib material composition 129,
Next, following the gap-forming step,
Next, following the step of applying the blue-color fluorescent assistant material composition 132, as shown in
Thereafter, following the step of injecting the barrier-rib material composition 129, the step of making the back face substrate 20 and the barrier-rib material composition 129 of the forming mold 131 in contact with each other so that the back face substrate 20 and the barrier-rib material composition 129 of the forming mold 131 are bonded to each other (in the same manner as in
In this manner, as shown in
The back face panel 2 thus formed makes it possible to achieve a PDP having basically the same effects as those shown in the third embodiment; however, by using the core member 71 preliminarily formed on the concave portion 130, the fluorescent assistant material composition 132 can be more positively injected and applied only to the side faces of a predetermined concave portion 130.
Here, the above-mentioned description has exemplified a structure in which only the blue-color fluorescent assistant material composition 132 is injected and applied thereto as the fluorescent assistant material composition 132; however, even in the case when a red-color or green-color fluorescent assistant material composition 132 is injected and applied to the side faces of the concave portion 130 having the corresponding color, it becomes possible to achieve the back face panel 2 that is free from mixed colors of these.
Moreover, as shown in
Next, following the step of position-adjusting the end portion 153 of the second forming mold 151,
Next, following the step of applying the blue-color fluorescent assistant material composition 132, as shown in
Next,
Next, following the step of injecting the barrier-rib material composition 129, the step of making the back face substrate 20 and the barrier-rib material composition 129 of the first forming mold 150 in contact with each other so that the back face substrate 20 and the barrier-rib material composition 129 of the first forming mold 150 are bonded to each other (in the same manner as in
The back face panel 2 thus formed makes it possible to achieve a PDP having basically the same effects as those shown in the third embodiment; however, by using the second forming mold 151, the fluorescent assistant material composition 132 can be more positively injected and applied only to the side faces of a predetermined concave portion 130 (in other words, with the position of the barrier-rib bottom face being controlled with high precision).
Here, the above-mentioned description has exemplified a structure in which only the blue-color fluorescent assistant material composition 132 is injected and applied thereto as the fluorescent assistant material composition 132; however, even in the case when a red-color or green-color fluorescent assistant material composition 132 is injected and applied to the respective side faces thereof, it becomes possible to achieve the back face panel 2 that is free from mixed colors of these.
Moreover, prior to the process of
In each of the above-mentioned various embodiments of the present invention, since the barrier rib 23 is made of a barrier-rib portion 23A to 23D comprising only a barrier-rib material and a fluorescent assistant material 66, 70 that is formed by mixing a fluorescent assistant material and the barrier-rib material, the barrier-rib strength is not lowered, and even in the case of a high precision device with a fine barrier-rib dimension, it becomes possible to increase the barrier-rib strength.
By properly combining the arbitrary embodiments of the aforementioned various embodiments, the effects possessed by the embodiments can be produced.
The present invention makes it possible to achieve a PDP that can increase the effective phosphor thickness, with the barrier-rib strength being properly maintained, and a manufacturing method for such a PDP, and the PDP is effectively applicable to an image display apparatus or the like having a large size with high precision.
Moreover, the present invention makes it possible to achieve a manufacturing method for a PDP that can improve the luminance of the phosphor layer without narrowing the discharge space, with the barrier-rib strength being properly maintained, and the method is effectively applicable to an image display apparatus or the like having a large size with high precision.
Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart therefrom.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-295140 | Oct 2006 | JP | national |
| 2007-005600 | Jan 2007 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2007/071018 | 10/29/2007 | WO | 00 | 5/9/2008 |
