KR20070092498A - Red phosphors for plasma display pannel and plasma display pannel empolying the red phosphors layer - Google Patents

Abstract

A red phosphor for a plasma display panel and the plasma display panel employing a red phosphor layer are provided to manufacture red phosphor having high color purity by forming the red phosphor layer with MgGeO3:Mn phosphor or a mixture of MgGeO3:Mn phosphor. A rear substrate(221) is disposed in parallel to a front substrate(211). A plurality of discharge cells(226) are defined by a barrier rib(224) which is disposed between the front and the rear substrates. A plurality of address electrodes(222) are extended over the discharge cells which are disposed in a cross direction. A rear dielectric layer(223) is formed to cover the address electrodes. Red, green and blue phosphor layers are disposed within the discharge cells. A plurality of pairs of sustain electrodes(214) are extended across the extended direction of the address electrodes. A front dielectric layer(215) is formed to cover the pairs of sustain electrodes. The discharge cells are filled with discharge gas. The red phosphor layer includes MgGeO3:Mn phosphor.

Description

Red phosphors for plasma display panel and a plasma display panel comprising a fluorescent film produced therefrom {Red phosphors for plasma display pannel and plasma display pannel empolying the red phosphors layer}

1 is a perspective view schematically showing a plasma display panel manufactured according to an embodiment of the present invention.

The present invention relates to a red phosphor for a plasma display panel, and more particularly, to a plasma display panel having a red phosphor for a plasma display panel with improved color purity and a fluorescent film formed from the phosphor.

Phosphor is a material that emits light by energy stimulation. It is generally used in light sources such as mercury fluorescent lamps and mercury-free fluorescent lamps, and various devices such as electron emitting devices and plasma display panels. It is expected to be used as.

Plasma Display Panel (PDP) is a display that uses light emission by ultraviolet rays generated by discharge of a mixed gas of neon and xenon encapsulated between glass substrates. At this time, each phosphor generates visible light by resonance emission light (147 nm vacuum ultraviolet ray) of xenon (Xe) ions.

As the red phosphor contained in the red fluorescent film of the plasma display panel, (Y, Gd) BO ₃ : Eu having the highest luminance is widely used. However, (Y, Gd) BO ₃ : Eu has higher luminance than other types of red phosphors, but has disadvantages of poor color purity and long afterglow time. Therefore, in order to improve color purity, a color correction filter is added inside the plasma display panel or a color correction function is added to a filter located in front of the plasma display panel. However, such a method reduces the brightness of the plasma display panel. There is a problem that requires a separate device. On the other hand, a method using a mixture of phosphors with excellent color purity, such as Y (V, P) O ₄ : Eu, has been proposed, but the relative luminance is 65% compared to (Y, Gd) BO ₃ : Eu, in particular, the luminance saturation characteristics This is not good and the luminance ratio of the red peak of the PDP falls further. In addition, since the raw material is expensive for the lamp, in particular, it is difficult to mass-produce because it uses non-environmental substances harmful to the human body.

In order to solve the above problems, an object of the present invention is to provide a red phosphor for a plasma display panel having a low luminance reduction rate and improved color purity.

Moreover, an object of this invention is to provide the plasma display panel provided with the fluorescent film formed from said red fluorescent substance.

In order to achieve the above object, the present invention

Provided is a red phosphor for a plasma display panel containing MgGeO ₃ : Mn.

In addition, in order to achieve the above other object, the present invention

Transparent front substrate; A rear substrate disposed in parallel with the front substrate; Light emitting cells partitioned by barrier ribs disposed between the front substrate and the rear substrate; Address electrodes extending over light emitting cells arranged in one direction; A rear dielectric layer covering the address electrodes; A red, green, and blue fluorescent film disposed in the light emitting cell; Sustain electrode pairs extending in a direction crossing the address electrode; A front dielectric layer covering the sustain electrode pairs; And a discharge gas in the light emitting cell. The plasma display panel includes a plasma display panel including a MgGeO ₃ : Mn phosphor.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

The present invention provides a red phosphor for a plasma display panel containing MgGeO ₃ : Mn. MgGeO ₃ : Mn may be used alone or in combination with (Y, Gd) BO ₃ : Eu as a red phosphor for a plasma display panel.

MgGeO ₃ : Mn used in the present invention is a red phosphor and has high color purity. The most widely used red phosphor for plasma display panels is (Y, Gd) BO ₃ : Eu, which has the highest luminance, and the MgGeO ₃ : Mn red phosphor of the present invention has a luminance compared to such (Y, Gd) BO ₃ : Eu. Since it is disadvantageous, it can be used by mixing with (Y, Gd) BO ₃ : Eu phosphor. Due to the mixed use, it is possible to prevent the deterioration of luminance while improving the color purity.

When used in combination with MgGeO ₃ : Mn phosphor, the appropriate content of (Y, Gd) BO ₃ : Eu is preferably 0 to 70% by weight of the total content of the red phosphor. If the content of (Y, Gd) BO ₃ : Eu exceeds 70% by weight, it is not preferable because it is difficult to realize the characteristics of the MgGeO ₃ : Mn phosphor because of the large loss in color purity.

The MgGeO ₃ : Mn phosphor may further include MnO and MgF ₂ . The MnO is 0.01 to 30% by weight, MgF ₂ is preferably 3.0 to 50% by weight. If the content of MnO is less than 0.01% by weight, the effect of MnO addition is insignificant and undesirable. If the content of MnO is more than 30% by weight, the loss of luminance is large.

All. In addition, the total content of MnO and MgF ₂ is preferably 3.0 to 50% by weight. When the total content of MnO and MgF ₂ is less than 3.0% by weight, it is not preferable because the loss of color purity is large, and when it exceeds 50% by weight, it is not preferable because the loss of luminance is large.

The red phosphor of the present invention may be mixed with a binder, an organic solvent, or the like to prepare a paste composition, followed by printing, drying and firing to prepare a fluorescent film.

A plasma display panel having a fluorescent film formed from the phosphor according to the present invention will be described.

The plasma display panel of the present invention comprises a transparent front substrate; A rear substrate disposed in parallel with the front substrate; Light emitting cells partitioned by barrier ribs disposed between the front substrate and the rear substrate; Address electrodes extending over light emitting cells arranged in one direction; A rear dielectric layer covering the address electrodes; A red, green, and blue fluorescent film disposed in the light emitting cell; Sustain electrode pairs extending in a direction crossing the address electrode; A front dielectric layer covering the sustain electrode pairs; And a discharge gas in the light emitting cell. The plasma display panel includes a plasma display panel including a MgGeO ₃ : Mn phosphor. The structure thereof is described in more detail with reference to FIG. 1 as follows.

Referring to FIG. 1, the plasma display panel includes a front panel 210 and a rear panel 220.

The front panel 210 is a front substrate 211, the rear of the front substrate (more specifically, the sustain electrode pairs 214 disposed on the rear surface of the front substrate and extended across a row of light emitting cells 226, A front dielectric layer 215 and a passivation layer 216 covering the sustain electrode pairs are provided.

The rear panel 220 is disposed on the rear substrate 221 disposed in parallel with the front substrate, and in front of the rear substrate (more specifically, the front substrate 221a of the rear substrate) and intersects with the pair of sustain electrodes. Barrier ribs formed between the address electrodes 222 extending so as to extend, the rear dielectric layer 223 covering the address electrodes, and the front substrate and the rear substrate (more specifically, on the rear dielectric layer) to partition the light emitting cells 226 ( 224, and a red phosphor film 225a, a green phosphor film 225b, and a blue phosphor film made of red, green, and blue phosphors that emit visible light by receiving ultraviolet rays emitted from discharge gas by a sustain discharge. 225c).

According to one embodiment of the present invention, the red fluorescent film 225a may be manufactured using a fluorescent film forming paste composition containing MgGeO ₃ : Mn. The red phosphor may be used in combination with MgGeO ₃ : Mn alone or with (Y, Gd) BO ₃ . In addition, the MgGeO ₃ : Mn phosphor may further include MnO and MgF ₂ . The content for these added compounds is as described above.

In order to facilitate printing of the phosphor for PDP of the present invention, the phosphor is mixed with a binder and a solvent to form a paste, and then printed by a screen method through a screen mesh prepared in advance, and dried and calcined to obtain a fluorescent film. The drying temperature is suitably 100 to 150 ℃, firing temperature is carried out at 350 to 600 ℃, in particular about 450 ℃ to remove the organic matter of the paste. Ethyl cellulose is used as the binder, and the binder content is 10 to 30 parts by weight based on 100 parts by weight of the phosphor. If the content of the binder is less than the above range, the binding force of the fluorescent film is lowered, and if the content of the binder is more than the above range, the phosphor content in the fluorescent film is relatively decreased, which is undesirable because characteristics such as color purity are reduced.

As the solvent, BCA (butyl carbitol) or terpineol (Terpineol) is used, and the content thereof is used based on 100 parts by weight of the phosphor based on 70 to 300 parts by weight. If the content of the solvent is less than the above range, the phosphor is not dispersed properly or the viscosity is high, and printing is difficult. If the content exceeds the above range, the phosphor content per unit volume is too low, which is undesirable because the luminance in the PDP panel is lowered.

The viscosity of the composition for forming a fluorescent film is 5,000 to 50,000 cps, particularly 20,000 cps. If the viscosity of the phosphor composition is less than 5,000 cps, the printing liquid flows into the next cell during printing, and thus the printing film may not be formed at the correct position. If the viscosity exceeds 50,000 cps, the viscosity is too high, so it is not preferable to print properly.

The compositions of the present invention may further add additives such as dispersants, plasticizers, antioxidants, leveling agents and the like, as required, all of which are known to the extent that they are commercially available to those of ordinary skill in the art. The amount of the additive is preferably added to about 0.1 to 10 parts by weight based on the total composition.

The red fluorescent film uses a phosphor containing MgGeO ₃ : Mn according to the present invention, and the green fluorescent film and the blue fluorescent film may be used as long as they are commonly available in the manufacture of a plasma display panel. Specifically, examples of the green phosphor include ZnSiO ₄ : Mn, YBO ₃ : Tb, (Ba, Sr) MgAl ₁₀ O ₁₉ : Mn, and the like, and BaMgAl ₁₀ O ₁₇ : Eu is preferable as the blue phosphor .

The front substrate 211 and the rear substrate 221 is generally formed of glass, the front substrate is preferably a high light transmittance.

The address electrodes 222 disposed on the front surface 221a of the rear substrate and extending over the light emitting cells 226 are typically formed of a metal having high electrical conductivity, for example, Al. The address electrode 222 is used for the address discharge together with the Y electrode 312. The address discharge is a discharge for selecting the light emitting cells 226 to emit light, and the sustain discharge described later may occur in the light emitting cells 226 in which the address discharges are made.

The address electrodes 222 are covered by the rear dielectric layer 223. The rear dielectric layer 223 prevents charged particles from colliding with the address electrodes 222 and damaging the address electrodes during address discharge. The rear dielectric layer 223 is formed as a dielectric capable of inducing charged particles. Such dielectrics include PbO, B ₂ O ₃ , SiO _2, and the like.

A partition wall 224 partitioning the light emitting cells 226 is formed between the front substrate 211 and the rear substrate 221, and the partition wall 224 is formed between the front substrate 311 and the rear substrate 221. It secures a discharge space, prevents crosstalk between adjacent light emitting cells 226, and widens the surface area of the phosphor layer 225. The partition wall 224 is formed of a glass component including elements such as Pb, B, Si, Al, and O, and a filler such as ZrO ₂ , TiO ₂ , and Al ₂ O ₃ as necessary. With Cr, Cu, Co, Fe, TiO ₂ Pigments such as may be included.

The sustain electrode pairs 214 extend in a direction crossing the direction in which the address electrode 222 extends over the light emitting cells 226 in a row. The sustain electrode pair 214 includes a pair of sustain electrodes 212 and 213 causing a sustain discharge, and the sustain electrode pair 214 is arranged in parallel on each other at predetermined intervals on the front substrate 211. It is. One of the sustain electrodes 212 and 213 is the X electrode 213 and the other is the Y electrode 212. The sustain discharge is caused by the potential difference between the X electrode 213 and the Y electrode 212.

Each of the X electrode 213 and the Y electrode 212 includes the transparent electrodes 213b and 212b and the bus electrodes 213a and 212a. However, in some cases, the X electrode 213 and the Y electrode 212 are common to the scan electrode only with the bus electrode without the transparent electrode. An electrode may be configured.

The transparent electrodes 213b and 212b are formed of a transparent material that is a conductor and does not prevent light emitted from the phosphor from advancing to the front substrate 211. Such materials include indium tin oxide (ITO). However, since the transparent conductor such as ITO has a large resistance, when the sustain electrode is composed of only the transparent electrode, the voltage drop in the longitudinal direction of the transparent electrode becomes large, and thus, the power required to drive the plasma display panel increases. The response speed of the image becomes slow. In order to improve this, bus electrodes 213a and 212a formed of a metal having high electrical conductivity, for example, Ag, are disposed at the outer end of the transparent electrode.

The sustain electrodes 212 and 213 are covered by the front dielectric layer 215. The front dielectric layer 215 can prevent the adjacent X electrode 213 and the Y electrode 212 from being directly energized during the sustain discharge, and prevent the charged particles from damaging the sustain electrodes 212 and 213 by damaging them. there is a high transmittance is formed as a dielectric, as this dielectric material include _{PbO, B 2 O 3, SiO} 2.

A passivation layer 216 may be formed between the front dielectric layer 215. At this time, the protective film prevents charged particles from colliding with the front dielectric layer 215 during the sustain discharge, and emits a lot of secondary electrons during the sustain discharge. The protective film may be formed as MgO.

The discharge gas is filled in the light emitting cell 226. The discharge gas is, for example, a Ne-Xe mixed gas containing 5% to 10% of Xe, and at least a part of Ne may be replaced with He as necessary.

Hereinafter, preferred examples and comparative examples of the present invention are described. The following examples are described for the purpose of more clearly expressing the present invention, but the contents of the present invention are not limited to the following examples.

Example

Example 1

100 parts by weight of MgGeO ₃ : Mn fluorescent material was mixed with butyl carbitol acetate and ethyl cellulose to prepare a paste composition. The phosphor paste composition prepared above was printed on the partition wall of the plasma display panel to prepare a red phosphor film.

At this time, the composition of the discharge gas in the plasma display panel was adjusted to 55% by weight of Ne, 35% by weight of He and 15% by weight of Xe. The results were obtained by examining the relative luminance and color purity, which are shown in Table 1 below.

Example 2

MgGeO ₃ : 30 parts by weight of Mn fluorescent material and (Y, Gd) BO ₃ It carried out similarly to Example 1 except having used 70 weight part.

Example 3

MgGeO ₃ : 40 parts by weight of Mn fluorescent material and (Y, Gd) BO ₃ The same procedure as in Example 1 was carried out except that 60 parts by weight was used.

Example 4

MgGeO ₃ : 50 parts by weight of Mn fluorescent material and (Y, Gd) BO ₃ The same procedure as in Example 1 was carried out except that 50 parts by weight were used.

Example 5

MgGeO ₃ : 60 parts by weight of Mn fluorescent material and (Y, Gd) BO ₃ It carried out similarly to Example 1 except having used 40 weight part.

Example 6

MgGeO ₃ : 70 parts by weight of Mn fluorescent material and (Y, Gd) BO ₃ It carried out similarly to Example 1 except having used 30 weight part.

Comparative Example 1

MgGeO ₃ : (Y, Gd) BO ₃ without using Mn fluorescent material Except that 100 parts by weight of the fluorescent material was used in the same manner as in Example 1.

The results of the Examples and Comparative Examples are shown in Table 1 below:

MgGeO ₃ : Mn (Y, Gd) BO ₃ Relative luminance (%) x y Example 1 100 0 30 0.710 0.280 Example 2 30 70 79 0.652 0.344 Example 3 40 60 72 0.657 0.339 Example 4 50 50 65 0.661 0.334 Example 5 60 40 58 0.667 0.327 Example 6 70 30 51 0.674 0.319 Comparative Example 1 0 100 100 0.643 0.354

Referring to Table 1, in Example 1, 100 parts by weight of MgGeO ₃ : Mn fluorescent material was used, the color purity was very high and the relative luminance was low. In Examples 2 to 6, the fluorescent film was prepared by mixing the (Y, Gd) BO ₃ red fluorescent material commonly used in the MgGeO ₃ : Mn fluorescent material and showed high color purity and high loss in relative luminance. Did. Comparative Example 1 showed a lower value than the embodiments of the present invention in terms of color purity. In Example 1, the relative luminance was lower than that of the (Y, Gd) BO ₃ red fluorescent substance alone, but when the Ne-cut filter was used, the reduced luminance was very small. ) Compared with the case of using the BO ₃ red fluorescent substance, the luminance difference becomes small.

Red phosphor for plasma display panel according to the present invention can be obtained by using the MgGeO ₃ : Mn phosphor alone or mixed to obtain a red phosphor having a high color purity characteristics, the plasma having a fluorescent film prepared from the red phosphor paste composition The display panel may improve color reproduction compared to a panel using a conventional red phosphor.

Claims (8)

Red phosphor for a plasma display panel containing MgGeO ₃ : Mn. The red phosphor of claim 1, wherein the phosphor further comprises (Y, Gd) BO ₃ : Eu. The phosphor for plasma display panel according to claim 2, wherein the content of (Y, Gd) BO ₃ : Eu is 0 to 70% by weight of the total phosphor. The phosphor of claim 1, wherein the phosphor further comprises MnO and MgF ₂ . The phosphor for plasma display panel according to claim 4, wherein the MnO is 0.01 to 30% by weight, MgF ₂ is 3.0 to 50% by weight, and the total content of MnO and MgF ₂ is 3.0 to 50% by weight. . Transparent front substrate; A rear substrate disposed in parallel with the front substrate; Light emitting cells partitioned by barrier ribs disposed between the front substrate and the rear substrate; Address electrodes extending over light emitting cells arranged in one direction; A rear dielectric layer covering the address electrodes; A red, green, and blue fluorescent film disposed in the light emitting cell; Sustain electrode pairs extending in a direction crossing the address electrode; A front dielectric layer covering the sustain electrode pairs; And a discharge gas in the light emitting cell; wherein the red fluorescent film comprises MgGeO ₃ : Mn phosphor. The method of claim 6, wherein the red fluorescent film is (Y, Gd) BO ₃ : Eu Plasma display panel further comprises a phosphor. The method of claim 6, wherein the red fluorescent film is MnO and MgF ₂ Plasma display panel further comprises a phosphor.

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