JP2011192429A - Plasma display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a PDP for actualizing a short-persistence time for a green phosphor, in particular, while suppressing the deterioration of initial brightness and brightness life. <P>SOLUTION: The plasma display panel includes a front substrate 11 and a back substrate 17 arranged opposing each other, discharge cells 24 formed by partition walls 22, and phosphor layers 23 provided in the discharge cells 24. The phosphor layers 23 include a green phosphor layer 23b including at least a Zn<SB>2</SB>SiO<SB>4</SB>: Mn phosphor having a 1/10 persistence time of 4 msec or shorter. The Zn<SB>2</SB>SiO<SB>4</SB>: Mn phosphor has metal oxide films applied onto part of the surfaces of phosphor particles, and includes hydrogen gas as discharge gas in spaces of the discharge cells 24. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a plasma display panel having a phosphor layer containing a phosphor excited by vacuum ultraviolet rays, and in particular, by providing a green phosphor having a short afterglow value and a wide color gamut, the responsiveness of a moving image is improved. The present invention relates to a plasma display panel.

  In recent years, plasma display panels (hereinafter referred to as PDPs) are attracting attention as color display devices that can be large, thin, and lightweight as color display devices used for image display in computers and televisions.

The PDP performs full color display by additively mixing the so-called three primary colors of red, green, and blue. In order to perform this full-color display, a phosphor layer that emits each of the three primary colors is provided. The phosphor particles constituting the phosphor layer are excited by ultraviolet light emitted in the PDP discharge cell to generate visible light of each color. Conventionally, (Y, Gd) BO ₃ : Eu is used as a red phosphor, Zn ₂ SiO ₄ : Mn and (Y, Gd) BO ₃ : Tb are used as a green phosphor, and BaMgAl ₁₀ is used as a blue phosphor. O ₁₇ : Eu and the like are known.

  Here, the moving image quality of the PDP greatly depends on the afterglow characteristics of the red, green, and blue phosphors. If the phosphor has a 1/10 afterglow time (hereinafter simply referred to as afterglow time) of 8 msec or more, it is visually recognized that the light emission has a tail, and the display image quality deteriorates. Further, if it is 4 msec or less, the afterglow becomes difficult to be seen by human eyes, and the display image quality is improved.

  In addition, even in a stereoscopic image display television using active liquid crystal shutter-type 3D glasses that has been developed and standardized in recent years, a stereoscopic image display television with excellent image quality can be realized by setting the afterglow time to 4 msec or less. It is said.

Of the phosphors used in PDP, BaMgAl ₁₀ O ₁₇ : Eu, which is usually used as a blue phosphor, has no problem because it has an afterglow time of 1 msec or less. Further, in the red phosphor, the afterglow time of (Y, Gd) BO ₃ : Eu that is usually used is as long as about 10 msec. Therefore, it is necessary to reduce the afterglow time by changing to (Y, Gd) (P, V) O ₄ : Eu or Y ₂ O ₃ : Eu having a shorter afterglow time or mixing them. is there.

On the other hand, in the green phosphor, the afterglow time of commonly used Zn ₂ SiO ₄ : Mn and (Y, Gd) BO ₃ : Tb is as long as 10 msec or more, so (Y, Gd) Al having a short afterglow time. ₃ (BO ₃ ) ₄ : mixing Tb is disclosed in Patent Document 1.

Further, as a method for shortening the afterglow time of Zn ₂ SiO ₄ : Mn itself, increasing the concentration of Mn, which is the emission center, is disclosed in Patent Document 2 and the like.

Furthermore, in order to increase the luminance maintenance ratio of Zn ₂ SiO ₄ : Mn, an example using a phosphor coated with a metal oxide film by attaching a metal alkoxide to the surface of the phosphor and firing it is disclosed in Patent Literature. 3 is disclosed.

JP-A-10-195428 JP 2006-274137 A JP 2006-528712 A

However, in the method described in Patent Document 1, since (Y, Gd) Al ₃ (BO ₃ ) ₄ : Tb has a narrow color gamut and an afterglow time of about 4 msec, Zn ₂ SiO has a long afterglow time. ₄ : No matter how much Mn (usually 8 to 14 msec) is mixed, the color gamut becomes narrow, and the afterglow time does not become 4 msec or less.

In the method described in Patent Document 2, when the Mn concentration is increased, the color gamut is deteriorated and the ion sputtering rate is increased to deteriorate the luminance life. This is considered to occur because the probability that the luminescent center is ion-sputtered increases by increasing the Mn concentration. As a result, the brightness is lowered during panel aging, and the panel initial brightness after aging is lowered. Even if the crystallinity of Zn ₂ SiO ₄ : Mn is increased, these problems due to an increase in the Mn concentration are unavoidable in principle, and this is a big problem for realizing a stereoscopic image display.

  Furthermore, in the method described in Patent Document 3, the metal alkoxide is a compound containing an organic substance, and a carbon-based compound remains on the phosphor surface unless firing is sufficiently performed. This carbon compound is decomposed by electric discharge. In particular, when used for a long time, the decomposed carbon-based compound is discharged into the discharge space, and the discharge becomes unstable.

  An object of the present invention is to solve such a problem and to provide a PDP that realizes a short afterglow time of a green phosphor and suppresses deterioration of initial luminance and luminance life.

In order to achieve the above object, the PDP according to the present invention has at least one partition wall for partitioning a plurality of discharge spaces and disposing a pair of substrates transparent at least on the front side so as to form a discharge space between the substrates. An electrode group is disposed on the substrate so that a discharge is generated in a discharge space partitioned by a partition wall, and a phosphor layer that emits light by discharge is provided. / 10 afterglow time 4msec following _Zn 2 _SiO 4: comprising a green phosphor layer containing Mn _phosphor, Zn 2 _SiO 4: Mn phosphor metal oxide film is coated on a part of the surface of the phosphor particles In addition, hydrogen gas is contained as a discharge gas in the discharge space.

  According to such a configuration, it is possible to realize a PDP that has no afterimage even in stereoscopic image display and suppresses deterioration of initial luminance and luminance life.

Further, the Zn ₂ SiO ₄ : Mn phosphor desirably has a Mn / Zn composition ratio of 0.09 to 0.12. According to such a configuration, the afterglow time of the green phosphor can be reliably set to 4 msec or less, and high image quality without an afterimage can be realized in stereoscopic image display.

  Furthermore, it is desirable that the metal oxide film is at least one of magnesium oxide, aluminum oxide, gadolinium oxide, lanthanum oxide, and yttrium oxide. According to such a configuration, the luminance life of the green phosphor having a short afterglow time can be improved.

  Furthermore, it is desirable to mix 0.001% or more and 1% or less of hydrogen gas in the discharge gas. According to such a configuration, the luminance life can be further improved.

  As described above, according to the PDP of the present invention, it is possible to realize a PDP that has no afterimage even in stereoscopic image display and suppresses deterioration of initial luminance and luminance life.

It is a disassembled perspective view which shows the structure of PDP in embodiment.

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

(Embodiment)
FIG. 1 is an exploded perspective view showing the structure of the PDP in the embodiment. As shown in FIG. 1, the PDP 10 includes a front substrate 11 and a back substrate 17. On the glass front substrate 11, a plurality of display electrode pairs 14 are formed in parallel with each other with the scanning electrodes 12 and the sustain electrodes 13. Scan electrode 12 and sustain electrode 13 are formed in a pattern that repeats in the arrangement of scan electrode 12 -sustain electrode 13 -sustain electrode 13 -scan electrode 12. The scanning electrode 12 is formed on a wide transparent electrode 12a made of a conductive metal oxide such as indium tin oxide (ITO), tin oxide (SnO ₂ ), or zinc oxide (ZnO), in order to increase conductivity. A narrow bus electrode 12b containing a metal such as (Ag) is stacked. Similarly, the sustain electrode 13 is formed by laminating a narrow bus electrode 13b on a wide transparent electrode 13a.

Further, a dielectric layer 15 and a protective layer 16 made of magnesium oxide (MgO) are formed so as to cover the display electrode pair 14. The dielectric layer 15 is made of bismuth oxide (Bi ₂ O ₃ ) -based low melting glass or zinc oxide (ZnO) -based low melting glass having a thickness of about 40 μm. The protective layer 16 is a thin film layer made of an alkaline earth metal oxide mainly composed of magnesium oxide (MgO) having a film thickness of about 0.8 μm. The protective layer 16 protects the dielectric layer 15 from ion sputtering and discharge start voltage. Is provided to stabilize the discharge characteristics.

A plurality of parallel data electrodes 18 made of a highly conductive material mainly composed of silver (Ag) or the like are formed on the glass back substrate 17, and a base dielectric layer is formed so as to cover the data electrodes 18. 19 is formed. The underlying dielectric layer 19 may be bismuth oxide (Bi ₂ O ₃ ) -based low-melting glass similar to that of the dielectric layer 15, but titanium oxide (TiO ₂₎ so as to also serve as a visible light reflecting layer. ) A material in which particles are mixed may be used.

  On the base dielectric layer 19, barrier ribs 22 formed in a grid pattern are formed by vertical barrier ribs 22 a and horizontal barrier ribs 22 b. A red phosphor layer 23a, a green phosphor layer 23b, and a blue phosphor layer 23c are formed.

  The partition wall 22 is formed to a height of about 0.12 mm using, for example, a low-melting glass material. In the embodiment, the height of the partition wall 22 is 0.1 mm to 0.15 mm and the pitch of the adjacent partition walls 22 is 0.15 mm in accordance with a full high-definition television having a screen size of 42 inches.

The front substrate 11 and the rear substrate 17 are arranged so that the display electrode pair 14 and the data electrode 18 intersect with each other, and the outer periphery thereof is sealed by a sealing material (not shown) such as a frit and discharged inside. A space is formed. A discharge gas containing xenon (Xe) or the like is sealed in the discharge space at a pressure of about 6 × 10 ⁴ Pa. The discharge space is partitioned into a plurality of sections by partition walls 22, and discharge cells 24 are formed at the intersections between the display electrode pairs 14 and the data electrodes 18. These discharge cells 24 discharge and emit light to display an image. The structure of the PDP 10 is not limited to that described above, and the shape of the partition wall 22 may be a stripe shape.

Here, a BaMgAl ₁₀ O ₁₇ : Eu blue phosphor having a short afterglow time is used for the blue phosphor layer 23c. For the red phosphor layer 23a, (Y, Gd) (P, V) O ₃ : Eu or Y ₂ O ₃ : Eu having a short afterglow time is used. The green phosphor uses a phosphor mainly composed of Zn ₂ SiO ₄ : Mn whose afterglow time is adjusted. Moreover, 0.001% or more and 1% or less of hydrogen gas is mixed in the discharge gas.

Next, a method for producing a Zn ₂ SiO ₄ : Mn green phosphor having a short afterglow time will be described in detail. The Zn ₂ SiO ₄ : Mn phosphor is composed of a silicon source typified by silicon dioxide, a zinc source typified by zinc oxide, and a manganese source typified by manganese carbonate, which are slightly silicon components than the stoichiometric composition. Is mixed at a blending ratio that causes excess. Then, it manufactures by baking at about 1200 degreeC in air | atmosphere or a reducing atmosphere. In this embodiment, in order to adjust the afterglow time, the Mn / Zn composition ratio is changed from 0.09 to 0.12, and the 1/10 afterglow time becomes 4 msec to 2.5 msec. Adjusted as follows.

Next, a method of coating the above-described Zn ₂ SiO ₄ : Mn phosphor with a metal oxide will be described. Here, the case where magnesium oxide is coated will be described. Magnesium nitrate is dissolved in water or an aqueous alkaline solution at a concentration of 0.8% by weight. Next, a Zn ₂ SiO ₄ : Mn phosphor having a Mn / Zn composition ratio changed from 0.09 to 0.12 is added to the solution to prepare a mixed solution, which is stirred while being heated. At this time, when the heating temperature is less than 30 ° C., the metal salt is precipitated in the solution. At a temperature exceeding 60 ° C., Zn ₂ SiO ₄ : Mn is dissolved by acid or alkali. For this reason, it heats in the temperature range of 30 degreeC or more and 60 degrees C or less. By this stirring, the magnesium cation in the solution is brought into close contact with Zn ₂ SiO ₄ : Mn having negative chargeability, whereby a magnesium oxide (MgO) coating film is formed. The mixed solution is filtered and dried, and then fired in the air at 400 ° C. to 800 ° C., whereby a Zn ₂ SiO ₄ : Mn green phosphor coated with magnesium oxide on the surface can be produced.

In addition, aluminum oxide (Al ₂ O ₃ ), gadolinium oxide (Gd ₂ O ₃ ), lanthanum oxide (La ₂ O ₃ ), yttrium oxide (Y ₂ O ₃ ), and the like are similarly used using these water-soluble raw materials. It can be coated on a Zn ₂ SiO ₄ : Mn phosphor.

Incidentally, Zn 2 _SiO as a green phosphor 4: For another green phosphor used in a mixture in _Mn phosphor produced as follows. That is, (Y, Gd) ₃ Al ₅ O ₁₂ : Tb, (Y, Gd) ₃ Al ₅ O ₁₂ : Ce, (Y, Gd) Al ₃ (BO ₃ ) ₄ : Tb, etc. are yttrium oxide (Y ₂ O ₃ ), gadolinium oxide (Gd ₂ O ₃ ), aluminum oxide (Al ₂ O ₃ ), boron oxide (B ₂ O ₃ ) and other oxides that form a base crystal, terbium oxide (Tb ₂ O ₃ ), After mixing with the activating oxide which forms the luminescent center of cerium oxide (CeO ₂ ), it is manufactured by firing at 1000 ° C. to 1400 ° C. in a weakly reducing atmosphere. These afterglow times were adjusted by controlling the amount of the activated oxide (terbium oxide or cerium oxide). _{(Y, Gd) 3 Al 5} O 12: Tb and _{(Y, Gd) Al 3 (} BO 3) 4: realized 4msec~5msec in _{Tb, (Y, Gd) 3} Al 5 O 12: In Ce 0. 1 msec to 0.3 msec is realized.

Such a PDP 10 in which a metal oxide was coated on the surface and the afterglow time was shortened and a Zn ₂ SiO ₄ : Mn green phosphor was used and hydrogen gas was mixed with the discharge gas was manufactured. These PDPs were subjected to a sustain discharge for 1000 hours, and then the luminance change of the green phosphor and the green afterglow state were observed. The results are shown in Table 1.

Examples 1 to 9 in Table 1 use a green phosphor in which a metal oxide is coated on a Zn ₂ SiO ₄ : Mn phosphor having an afterglow time of 4 msec or less, and a discharge gas (Xe-Ne). This is a PDP added with 0.001% to 1% of hydrogen (H ₂ ) gas. In these PDPs, the luminance maintenance ratio after sustain discharge for 1000 hours was as high as 84% to 89%, and afterglow could not be visually confirmed even in afterglow observation.

On the other hand, Comparative Example 1 is a PDP that uses a Zn ₂ SiO ₄ : Mn phosphor having an afterglow time of 3.5 msec without a metal oxide coating, and in which no hydrogen gas is added to the discharge gas. Comparative Example 2 is a PDP using the same phosphor as Comparative Example 1 and adding 0.01% hydrogen gas to the discharge gas. From the results of Comparative Example 1 and Comparative Example 2, the luminance maintenance rates after 1000 hours of sustain discharge are reduced to 80% and 77%, respectively.

In Comparative Example 3, the afterglow time of 3.5msec _Zn 2 _SiO 4: Use the phosphors MgO coated Mn phosphor, the PDP without the addition of hydrogen gas, the luminance maintenance rate of 80% and less.

Further, Comparative Example 4 is a PDP in which a phosphor that is obtained by coating MgO on a Zn ₂ SiO ₄ : Mn phosphor having an afterglow time value of 3.5 msec and adding 1.1% of hydrogen gas to the discharge gas. From this result, when the hydrogen gas is mixed in excess of 1%, the luminance maintenance rate is decreased.

Comparative Example 5 is a PDP that does not add a hydrogen gas using a Zn ₂ SiO ₄ : Mn phosphor that does not cover a metal oxide and has an afterglow value of 10 ms, and has a luminance maintenance ratio of 83%. Although it was almost equivalent to Example 9, afterglow was visually confirmed in afterglow observation.

Comparative Example 6 is a PDP to which 0.01% of hydrogen gas using a Zn ₂ SiO ₄ : Mn phosphor having an afterglow time of 10 ms and coated with MgO is added, and the luminance maintenance ratio is 84%. Although it is equivalent to 1-9, afterglow was visually confirmed in afterglow observation.

As a result, as in Examples 1 to 9 in the present embodiment, as a green phosphor, a fluorescent material in which a Zn ₂ SiO ₄ : Mn phosphor having a persistence time of at least 4 ms or less is coated with a metal oxide. By adding 0.001% to 1% of hydrogen gas to the PDP discharge gas, a PDP with improved luminance retention and afterglow characteristics can be realized.

Furthermore, as in Example 6 to Example 9, Zn ₂ SiO ₄ : Mn phosphor coated with a metal oxide and having an afterglow time of 4 ms or less, (Y, Gd) ₃ Al ₅ O ₁₂ : Tb, ( By mixing at least one of Y, Gd) ₃ Al ₅ O ₁₂ : Ce and (Y, Gd) Al ₃ (BO ₃ ) ₄ : Tb, it is possible to further suppress a decrease in luminance due to sustain discharge. .

  As described above, according to the PDP in the embodiment, it is possible to provide a PDP with high-quality moving image display quality and good luminance and luminance life.

  According to the PDP of the present invention, a PDP that realizes high-quality moving image display quality is provided, which is useful for a large-screen stereoscopic image display device and the like.

10 PDP
DESCRIPTION OF SYMBOLS 11 Front substrate 12 Scan electrode 12a, 13a Transparent electrode 12b, 13b Bus electrode 13 Sustain electrode 14 Display electrode pair 15 Dielectric layer 16 Protective layer 17 Rear substrate 18 Data electrode 19 Base dielectric layer 22 Partition 22a Vertical partition 22b Horizontal partition 23 Phosphor layer 23a Red phosphor layer 23b Green phosphor layer 23c Blue phosphor layer 24 Discharge cell

Claims (4)

At least a pair of substrates transparent at least on the front side are disposed opposite to each other so that a discharge space is formed between the substrates, and a partition for partitioning the discharge space into a plurality is disposed on at least one substrate, and is partitioned by the partition A plasma display panel in which an electrode group is arranged on a substrate so that discharge occurs in a discharge space and a phosphor layer that emits light by discharge is provided, and the phosphor layer has at least 1/10 afterglow time of 4 msec or less. A green phosphor layer containing Zn ₂ SiO ₄ : Mn phosphor is provided, and the Zn ₂ SiO ₄ : Mn phosphor is coated with a metal oxide film on a part of the surface of the phosphor particles, and discharge in the discharge space. A plasma display panel comprising hydrogen gas as a gas. The plasma display panel according to claim 1, wherein the Zn ₂ SiO ₄ : Mn phosphor has a Mn / Zn composition ratio of 0.09 to 0.12. The plasma display panel according to claim 1, wherein the metal oxide film is at least one of magnesium oxide, aluminum oxide, gadolinium oxide, lanthanum oxide, and yttrium oxide. The plasma display panel according to claim 1, wherein 0.001% or more and 1% or less of the hydrogen gas is mixed in the discharge gas.

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