JP2009087800A - Plasma display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma display panel whose image quality degradation or aging property deterioration due to the dispersion of brightness or the flickering of display are improved by suppressing the dispersion or variation of discharge starting voltage in discharge cells. <P>SOLUTION: The plasma display panel includes a partition wall 124 having a discharge space 130 formed by a front plate 110 and a back plate 120 arranged opposing each other and filled with discharge gas for partitioning the discharge space 130 into the discharge cells, phosphor layers 125R, 125G, 125B provided in the discharge cells, respectively, and non-luminescent layers 126R, 126G, 126B formed on the lower parts of the phosphor layers 125R, 125G, 125B by mixing independent or at least two types of phosphor base materials having no activating material. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a plasma display panel, and more particularly to stabilization of discharge characteristics thereof.

  In recent years, a plasma display apparatus has attracted attention as an image display device capable of realizing high definition and a large screen. A plasma display panel (hereinafter referred to as “PDP”) is a portion for displaying an image of a plasma display device. Neon, xenon, etc. are formed in a discharge space formed by arranging a front plate and a back plate facing each other and sealing the periphery. The discharge gas which consists of is enclosed. The front plate includes a display electrode formed of a striped transparent electrode and a metal bus electrode formed on a transparent glass substrate, a dielectric layer covering the display electrode, and a protective layer. On the other hand, the back plate is a striped address electrode formed on a glass substrate, a base dielectric layer covering the address electrode, a barrier rib formed on the base dielectric layer for partitioning a discharge space into discharge cells, a discharge It is comprised with the fluorescent substance layer formed in the cell. In such a configuration, a voltage is applied between the electrodes in each discharge cell to cause gas discharge, and the phosphor layer emits light with ultraviolet rays generated by the gas discharge to display an image. By providing phosphor layers that emit three primary colors of red, green, and blue as the phosphor layer, full color display can be performed by additively mixing these three primary colors.

In such a PDP discharge space, a dielectric layer, a barrier rib, a phosphor layer, and the like are formed as described above, and these are made into a paste by mixing an organic solvent, an organic binder, and the like with a base material, This is formed by coating, drying and baking. The organic binder and the like are thermally decomposed by firing, and a large amount of impure gas (for example, organic gas such as H ₂ O, CO ₂ , or hydrocarbon gas) having a property of inhibiting discharge is generated. When this impure gas is mixed into the discharge gas, the discharge start voltage changes and the discharge becomes unstable, causing problems such as variations in emission luminance and display flicker.

  Therefore, in order to remove the impure gas generated at the time of firing, an exhaust hole is provided on the back plate side of the PDP, and in the exhaust process in the manufacturing process, the impure gas is exhausted from the exhaust hole by the vacuum exhaust device outside the PDP. A method of sealing the discharge space by sealing the exhaust hole after sealing the discharge gas inside the PDP is used. However, there is a problem that the impure gas cannot be completely removed only by exhaust from the exhaust hole in the exhaust process, and a part of the impurity remains in the discharge space.

Further, in the aging process in which the discharge is performed for a long time in order to stabilize the discharge operation, there is a problem that part of the impure gas adsorbed on the protective layer or the like is re-released from the protective layer or the like by the stimulation of discharge. In order to solve these problems, there has been proposed a technique for reducing impure gas in which an adsorption film for adsorbing impure gas is formed on the surface of a partition wall in a discharge cell. (For example, see Patent Document 1)
JP 2003-303555 A

  However, in the above conventional PDP, red, green, and blue phosphor materials that have been stimulated by long-time discharge have different material characteristics, so that depending on the material, impure gas is emitted, or conversely, impure. A phenomenon such as gas adsorption occurs. As described above, since the impurity gas emission or adsorption characteristics of the respective phosphors are different, in the method of uniformly adsorbing the impurity gas by the adsorption film, the discharge start voltage varies among the discharge cells, and the cell display flickers. A malfunction occurs.

  The present invention has been made to solve the above-described problems, and can suppress the influence of the impurity gas emission characteristics or adsorption characteristics of the phosphor materials of red, green, and blue, and the variation and fluctuation of the discharge start voltage for each discharge cell. It is an object of the present invention to obtain a PDP in which image quality is reduced due to variations in luminance and display flickering and characteristic deterioration with time is improved.

  In order to achieve the above-described object, the PDP of the present invention includes a partition wall for enclosing a discharge gas in a discharge space formed by a front plate and a back plate arranged opposite to each other and partitioning the discharge space into discharge cells. A PDP having a phosphor layer provided in the discharge cell and an electrode group that generates a discharge in the discharge cell and causes the phosphor layer to emit light, and is disposed below the phosphor layer or inside the phosphor layer. In addition, a non-light emitting layer is formed by combining phosphor base materials having no activator alone or in combination of two or more.

  According to such a configuration, the influence of the impure gas emission characteristics or adsorption characteristics of each phosphor material is suppressed, and the variation and fluctuation of the discharge start voltage for each discharge cell are suppressed to reduce the image quality due to the luminance variation and display flicker. And deterioration of characteristics over time can be improved.

Further, the phosphor base material having no activator is a red phosphor base material made of (Y, Gd) BO ₃ , a green phosphor base material made of Zn ₂ SiO ₄ , or a blue fluorescent light made of BaAlMg ₁₀ O _17. It may be at least one of the matrix materials. According to such a configuration, by using the material for forming each phosphor layer, it is possible to easily suppress the influence of the impurity gas release characteristics or adsorption characteristics of each phosphor material and simplify the manufacturing process.

  Furthermore, the discharge cell is composed of a red discharge cell having a red phosphor layer, a red discharge cell having a green phosphor layer, and a blue discharge cell having a blue phosphor layer, and a blue phosphor is formed below the red phosphor layer. A red non-light-emitting layer in which a red phosphor base material or a green phosphor base material is mixed is provided on the base material, and a red phosphor base material or a green phosphor base material is provided on the blue phosphor base material under the green phosphor layer. A green non-light emitting layer may be provided, and a blue non-light emitting layer composed solely of a red phosphor base material or a green phosphor base material may be provided below the blue phosphor layer. According to such a configuration, the phosphor base material having the impure gas release characteristics or the adsorption characteristics opposite to the adsorption characteristics of each phosphor material is provided in the same discharge cell. Impurity gas emission or adsorption can be effectively canceled out to reduce variations and fluctuations in the discharge start voltage and suppress deterioration of characteristics over time.

  Further, in the red discharge cell, the red non-light emitting layer and the red phosphor layer are formed so that the weight ratio is 1: 1, and the red non-light emitting layer is formed of a blue phosphor base material and a red phosphor base material or It is desirable to form the green phosphor base material by mixing it at a weight ratio of 70:30 to 50:50. According to such a configuration, the variation in the discharge start voltage of the red discharge cell can be minimized.

  Further, in the green discharge cell, the green non-emitting layer and the green phosphor layer are formed so that the weight ratio is 1: 1, and the green non-emitting layer is formed of a blue phosphor matrix material and a red phosphor matrix material or It is desirable to form the green phosphor base material by mixing it at a weight ratio of 70:30 to 50:50. According to such a configuration, the variation in the discharge start voltage of the green discharge cell can be minimized.

  In the blue discharge cell, the blue non-light emitting layer and the blue phosphor layer are preferably formed to have a weight ratio of 2: 1. According to such a configuration, the variation in the discharge start voltage of the blue discharge cell can be minimized.

  According to the PDP of the present invention, each phosphor is formed by forming a non-light emitting layer formed of a phosphor base material having no activator singly or in a mixture of two or more kinds in the lower part of the phosphor layer or inside the phosphor layer. Suppress the influence of impure gas release characteristics or adsorption characteristics of body materials, and suppress variations and fluctuations in the discharge start voltage for each discharge cell to improve image quality degradation and temporal characteristics degradation due to luminance variations and display flickering Can do.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment)
FIG. 1 is a partial cross-sectional perspective view of a PDP in an embodiment of the present invention. The PDP 100 has a configuration in which a discharge gas is sealed in a discharge space 130 formed by a front plate 110 and a back plate 120 arranged to face each other. On the transparent front glass substrate 111 of the front plate 110, a stripe-shaped scanning electrode 112, a sustain electrode 113 and a black stripe 114 are formed, and a dielectric layer 115 and an MgO protective layer 116 are formed so as to cover them. And are formed. Striped address electrodes 122 orthogonal to the scanning electrodes 112 are formed on the back glass substrate 121 of the back plate 120, and a base dielectric layer 123 is formed so as to cover the address electrodes. A partition wall 124 is formed on the underlying dielectric layer 123 in parallel with the address electrode 122 so as to sandwich the discharge space 130 into discharge cells. A phosphor layer 125 is formed on the barrier rib 124 and the base dielectric layer 123 in the discharge cell. A non-light emitting layer 126 made of a phosphor base material having no activator is formed below the phosphor layer 125.

Next, a method for manufacturing the PDP 100 will be described. First, a method for manufacturing the front plate 110 will be described. On the front glass substrate 111, each of the N scanning electrodes 112 and the sustain electrode 113 paired therewith are formed in a stripe shape. The scan electrode 112 and the sustain electrode 113 are formed by applying a silver paste containing silver as a main component by screen printing and then baking. Next, scan electrode 112 and sustain electrode 113 are covered with dielectric layer 115. The dielectric layer 115 is formed by applying and baking a paste containing a bismuth oxide glass material by screen printing. The paste containing the glass material is, for example, 30 wt% bismuth oxide (Bi ₂ O ₃ ), 28 wt% zinc oxide (ZnO), 23 wt% boron oxide (B ₂ O ₃ ), and 2.4 wt%. % Silicon oxide (SiO ₂ ) and 2.6 wt% aluminum oxide (Al ₂ O ₃ ). Further, it is formed by mixing 10% by weight of calcium oxide (CaO), 4% by weight of tungsten oxide (WO ₃ ) and an organic binder (a solution of 10% ethyl cellulose in α-terpineol).

  Here, the organic binder is obtained by dissolving a resin in an organic solvent. In addition to ethyl cellulose, an acrylic resin can be used as the resin, and butyl carbitol can be used as the organic solvent. Furthermore, you may mix a dispersing agent (for example, glyceryl trioleate) in such an organic binder. The coating thickness is adjusted so that the dielectric layer 115 has a predetermined thickness (about 40 μm). Further, an MgO protective layer 116 is formed on the surface of the dielectric layer 115. The MgO protective layer 116 is made of magnesium oxide (MgO), and is formed to have a predetermined thickness (about 0.5 μm) by, for example, a sputtering method or an ion plating method.

  Next, a method for manufacturing the back plate 120 will be described. A silver paste for electrodes is screen-printed on the back glass substrate 121 and fired to form M address electrodes 122 in stripes. A base dielectric layer 123 is formed by applying and baking a paste containing a bismuth oxide glass material on the address electrode 122 by screen printing. Similarly, a paste containing a bismuth oxide-based glass material is repeatedly applied at a predetermined pitch by a screen printing method and then baked to form partition walls 124. The discharge space 130 is partitioned by the barrier ribs 124 to form discharge cells. The gap dimension of the partition wall 124 is about 130 μm to 240 μm in the case of a full HD television or an HD television of 42 inches to 50 inches. A non-light emitting layer 126 made of a phosphor base material having no activator is formed on the base dielectric layer 123 sandwiched between the partition walls 124. Further, a phosphor layer 125 is formed on the barrier ribs 124 and the non-light emitting layer 126 in the discharge cell. Details of the non-light emitting layer 126 and the phosphor layer 125 will be described later.

  The front plate 110 and the back plate 120 manufactured in this manner are overlapped so that the sustain electrodes 113 of the front plate 110 and the address electrodes 122 of the back plate 120 are orthogonal to each other, and sealing glass is attached to the peripheral portion. After the coating, it is sealed by baking at about 450 ° C. for 10 to 20 minutes. Thereafter, the discharge space 130 is once evacuated to high vacuum, and then a discharge gas (for example, helium-xenon-based, neon-xenon-based activated gas) is sealed at a predetermined pressure, thereby completing the PDP 100.

  FIG. 2 is a diagram illustrating a driving apparatus for the PDP 100. The PDP 100 is connected to the driving device 150 to constitute a PDP device. A display driver circuit 153, a display scan driver circuit 154, and an address driver circuit 155 are connected to the PDP 100. Address discharge is performed by applying a predetermined voltage to the scan electrode 112 and the address electrode 122 corresponding to the discharge cell to be lit. The controller 152 controls this voltage application. Thereafter, a sustain discharge is performed by applying a pulse voltage between the sustain electrode 113 and the scan electrode 112. Due to the sustain discharge, ultraviolet rays are generated in the discharge cells in which the address discharge has been performed, and the phosphor layer excited by the ultraviolet rays emits light so that the discharge cells are turned on. An image is displayed by a combination of lighting and non-lighting of each color discharge cell.

  FIG. 3 is a detailed partial cross-sectional view of the PDP in the embodiment of the present invention. The configuration of the non-light emitting layer and the phosphor layer made of a phosphor matrix material that does not have an activator, which is the main feature of the embodiment of the present invention, will be described in detail with reference to FIG. Striped scanning electrodes 112 and the like are formed on the front glass substrate 111 of the front plate 110, and a dielectric layer 115 and an MgO protective layer 116 are formed so as to cover them. Striped address electrodes 122 orthogonal to the scanning electrodes 112 are formed on the back glass substrate 121 of the back plate 120, and a base dielectric layer 123 is formed so as to cover the address electrodes.

  A partition wall 124 is formed on the underlying dielectric layer 123 in parallel with the address electrode 122 therebetween, and partitions the discharge space 130 into red discharge cells 130R, green discharge cells 130G, and blue discharge cells 130B. A red phosphor layer 125R, a green phosphor layer 125G, and a blue phosphor layer 125B are formed on the barrier rib 124 and the base dielectric layer 123 in the discharge cell.

The red phosphor layer 125R is made of (Y, Gd) BO ₃ : Eu in which Eu is added as an activator to the red phosphor base material (Y, Gd) BO ₃ , and the green phosphor layer 125G is a green phosphor base material. Zn _{2 Zn} 2 _SiO was added to the SiO ₄ Mn as an activator material 4: consists Mn, _BaMgAl 10 _{O 17} is a blue phosphor layer 125B was added as an activator material for Eu blue phosphor host material _BaMgAl 10 _{O 17} : Made of Eu.

  Below the red phosphor layer 125R, the green phosphor layer 125G, and the blue phosphor layer 125B, a red non-light emitting layer 126R made of a phosphor base material having no activator, a green non-issuing layer 126G, and a blue non-light emitting layer 126B. Is formed. These non-light emitting layers are formed by applying and drying a phosphor paste containing a phosphor base material having no activator by an inkjet method. If each phosphor layer has a thickness of about 5 μm or more, it can emit light by sufficiently absorbing ultraviolet rays having a very short wavelength of 147 nm generated by discharge. Further, visible light generated by light emission can have a luminance equal to or higher than that of the phosphor layer alone, because each non-light emitting layer functions as a reflective layer.

When a conventional PDP that does not have the red non-light emitting layer 126R, the green non-light emitting layer 126G, and the blue non-light emitting layer 126B made of a phosphor base material having no activator is discharged for a long time, (Y, Gd) BO ₃ From the red phosphor layer 125R made of: Eu and the green phosphor layer 125G made of Zn ₂ SiO ₄ : Mn or YBO ₃ : Tb, many impurity gases containing H ₂ O are knocked out and released. Therefore, the discharge start voltage (hereinafter referred to as Vf) decreases in the red discharge cell 130R and the green discharge cell 130G in which these phosphor layers are formed. On the other hand, since the blue phosphor layer 125B made of BaAlMg ₁₀ O ₁₇ : Eu absorbs impure gas, Vf increases in the blue discharge cell 130B on which the blue phosphor layer 125B is formed.

  These are because the impurity gas emission characteristics or adsorption characteristics of the phosphor base materials of the respective phosphor materials are different, and as a result, the discharge start voltage varies from discharge cell to discharge cell, causing problems such as display cell flicker. It was.

  In the PDP of the present invention, the red phosphor layer 125R, the green phosphor layer 125G, and the blue phosphor layer 125B have a red non-light-emitting layer 126R and a green non-light-emitting layer 126G made of a phosphor base material having no activator. Then, the blue non-light emitting layer 126B is formed, and the fluctuation of Vf is suppressed by acting the impure gas emission characteristics and adsorption characteristics of these non-light emitting layers. The effect of suppressing the fluctuation of Vf varies depending on the ratio of the non-light emitting layer and the phosphor layer. As a result of the experiment, it was found that the variation in Vf can be most effectively suppressed when the weight ratio of the non-light-emitting layer and the fluorescent layer is formed in the range of 1: 1 to 3.

  Both the red phosphor base material without the red phosphor material and the activator and the green phosphor base material without the green phosphor material and the activator release an impure gas due to long-term discharge. Has the effect of decreasing Vf over time. On the other hand, it has been clarified that both the blue phosphor material and the blue phosphor base material having no activator have an action of absorbing impure gas by long-term discharge and thereby increasing Vf over time. . In the present invention, a temporal change in Vf is suppressed by combining a phosphor material having these contradicting actions and a phosphor base material having no activator in the same discharge cell.

表１は、赤色蛍光体母体材料と青色蛍光体母体材料との混合比率を変えて形成した非発光層を、赤色蛍光体層１２５Ｒ、緑色蛍光体層１２５Ｇ、青色蛍光体層１２５Ｂのそれぞれの下部に形成した赤色放電セル１３０Ｒ、緑色放電セル１３０Ｇ、青色放電セル１３０Ｂでの２００時間点灯前後の放電開始電圧Ｖｆの変動を測定したものである。表１から明らかなように、赤色放電セル１３０Ｒにおいては、赤色非発光層１２６Ｒと赤色蛍光体層１２５Ｒとを重量比が１：１となるように形成するとともに、赤色非発光層１２６Ｒを、青色蛍光体母体材料と赤色蛍光体母体材料とを７０：３０〜５０：５０の重量比で混合して形成するとＶｆの変動が小さい赤色放電セル１３０Ｒを形成することができる。

Table 1 shows a non-light-emitting layer formed by changing the mixing ratio of the red phosphor base material and the blue phosphor base material, below the red phosphor layer 125R, the green phosphor layer 125G, and the blue phosphor layer 125B. The variation of the discharge start voltage Vf before and after lighting for 200 hours in the red discharge cell 130R, the green discharge cell 130G, and the blue discharge cell 130B formed in the above is measured. As is apparent from Table 1, in the red discharge cell 130R, the red non-light emitting layer 126R and the red phosphor layer 125R are formed so that the weight ratio is 1: 1, and the red non-light emitting layer 126R is When the phosphor base material and the red phosphor base material are mixed and formed at a weight ratio of 70:30 to 50:50, a red discharge cell 130R with a small variation in Vf can be formed.

  Further, in the green discharge cell 130G, the green non-light emitting layer 126G and the green phosphor layer 125G are formed so that the weight ratio is 1: 1, and the green non-light emitting layer 126G is formed of a blue phosphor base material and a red color. When the phosphor base material is mixed and formed at a weight ratio of 70:30 to 50:50, the green discharge cell 130R having a small variation in Vf can be formed.

  Further, in both the red discharge cell 130R and the green discharge cell 130G, it is more desirable to mix the blue phosphor base material and the red phosphor base material in a weight ratio of 60:40.

  On the other hand, as shown in Table 1, in the blue discharge cell 130B, it is impossible to suppress the variation of Vf under the same conditions as those of the red discharge cell 130R and the green discharge cell 130G. As shown in Table 1, in the blue discharge cell 130B, the blue non-light emitting layer 126B and the blue phosphor layer 125B are formed so as to have a weight ratio of 2: 1, and the blue non-light emitting layer 126B is made red fluorescent. It can be seen that the Vf variation is the smallest when the base material is 100%, which is a single material. Although not described in Table 1, the green phosphor base material also has the effect of releasing an impure gas by a long-time discharge in the same manner as the red phosphor base material, and instead of the red phosphor base material, a green phosphor is used. Similar results were obtained when the base material was used.

  In the above description, the case where the non-light-emitting layer is formed below the phosphor layer, that is, on the base dielectric layer has been described. However, the phosphor base material, which is a non-light-emitting layer material, is mixed inside the phosphor layer. It is also possible to make it.

  As described above, each phosphor material is formed by forming a non-light-emitting layer formed of a phosphor base material having no activator alone or in a mixture of two or more kinds at the lower part of the phosphor layer or inside the phosphor layer. Can suppress the influence of impure gas release characteristics or adsorption characteristics, and suppress variations and fluctuations in the discharge start voltage for each discharge cell to improve image quality degradation and temporal characteristics degradation due to luminance variations and display flickering. .

  INDUSTRIAL APPLICABILITY The present invention can realize a PDP apparatus with little deterioration in image quality due to variations in discharge and characteristic deterioration with time even for long-time discharge, and is useful for a display device with a large screen.

The partial cross section perspective view of PDP in embodiment of this invention The figure which shows the drive device of the PDP Detailed partial sectional view of the PDP

Explanation of symbols

100 PDP
DESCRIPTION OF SYMBOLS 110 Front plate 111 Front glass substrate 112 Scan electrode 113 Sustain electrode 114 Black stripe 115 Dielectric layer 116 MgO protective layer 120 Back plate 121 Glass substrate 122 Address electrode 123 Base dielectric layer 124 Partition 125R Red phosphor layer 125G Green phosphor layer 125B Blue phosphor layer 130 Discharge space 130R Red discharge cell 130G Green discharge cell 130B Blue discharge cell 126R Red non-light-emitting layer 126G Green non-light-emitting layer 126B Blue non-light-emitting layer 150 Driver 152 Controller 153 Display driver circuit 154 Display scan driver circuit 155 Address driver circuit

Claims (6)

A discharge gas is contained in a discharge space formed by the front plate and the back plate arranged to face each other, a partition for partitioning the discharge space into discharge cells, a phosphor layer provided in the discharge cell, A plasma display panel having an electrode group for generating a discharge in the discharge cell to cause the phosphor layer to emit light, and having no activator below the phosphor layer or inside the phosphor layer A plasma display panel, wherein a non-light emitting layer formed by mixing phosphor base materials alone or in combination of two or more kinds is formed. The phosphor base material having no activator is a red phosphor base material made of (Y, Gd) BO ₃ , a green phosphor base material made of Zn ₂ SiO ₄ , or a blue phosphor made of BaAlMg ₁₀ O ₁₇ The plasma display panel according to claim 1, wherein the plasma display panel is at least one of a base material. The discharge cell includes a red discharge cell having a red phosphor layer, a red discharge cell having a green phosphor layer, and a blue discharge cell having a blue phosphor layer, and the blue phosphor layer is disposed below the red phosphor layer. A red non-light emitting layer obtained by mixing the red phosphor base material or the green phosphor base material with a phosphor base material is provided, and the red phosphor base material is added to the blue phosphor base material below the green phosphor layer. Alternatively, a green non-light emitting layer mixed with the green phosphor base material is provided, and a blue non-light emitting layer in which the red phosphor base material or the green phosphor base material is provided alone is provided below the blue phosphor layer. The plasma display panel according to claim 1. In the red discharge cell, the red non-light-emitting layer and the red phosphor layer are formed so that a weight ratio is 1: 1, and the red non-light-emitting layer is formed of the blue phosphor base material and the red phosphor. The plasma display panel according to claim 3, wherein the base material or the green phosphor base material is mixed at a weight ratio of 70:30 to 50:50. In the green discharge cell, the green non-light emitting layer and the green phosphor layer are formed so as to have a weight ratio of 1: 1, and the green non-light emitting layer is formed of the blue phosphor base material and the red fluorescent material. The plasma display panel according to claim 3, wherein the base material or the green phosphor base material is mixed at a weight ratio of 70:30 to 50:50. 4. The plasma display panel according to claim 3, wherein in the blue discharge cell, the blue non-light emitting layer and the blue phosphor layer are formed so that a weight ratio is 2: 1. 5.

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