JP2004349043A - Plasma display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce noise in an area located high above sea level by converting frequency components offensive to the ear into high-frequency waves, in a plasma display device. <P>SOLUTION: This plasma display device is composed by oppositely arranging a pair of substrates so as to form a space between them, by sealing the peripheral parts thereof by a sealing member 14, and by forming barrier ribs 15 for partitioning the space into a plurality of areas. The plasma display device is so structured that each barrier rib 15 is disposed by making the height of its center part different from those of end parts thereof; and the inside of a panel is prevented from being easily swollen at a high altitude by applying this structure. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a plasma display device known as a large-screen, thin, and lightweight display device.
[0002]
[Prior art]
2. Description of the Related Art In recent years, a plasma display device has attracted attention as a display panel (thin display device) having excellent visibility, and higher definition and a larger screen are being promoted.
[0003]
This plasma display device is roughly classified into an AC type and a DC type in terms of driving, and a discharge type includes a surface discharge type and a facing discharge type. At present, an AC type surface discharge type plasma display device has become the mainstream because of high definition, large screen, and easy manufacturing.
[0004]
4 to 7 show an example of a panel structure in such a plasma display device. FIG. 4 is a perspective view with a part cut away, FIG. 5 is a schematic sectional view of the entire panel, and FIG. 7 shows a cross-sectional view taken along line AA ′ in FIG. 7, and FIG. 7 shows a cross-sectional view taken along line BB ′ in FIG. As shown in FIGS. 4 to 7, on a transparent front substrate 1 such as a glass substrate, a plurality of pairs of stripe-shaped display electrodes 4 formed by scanning electrodes 2 and sustain electrodes 3 are formed. A light-shielding layer 5 is arranged and formed between adjacent display electrodes 4 on 1. The scanning electrode 2 and the sustaining electrode 3 are respectively composed of transparent electrodes 2a, 3a and buses 2b, 3b made of silver or the like electrically connected to the transparent electrodes 2a, 3a. Further, a dielectric layer 6 is formed on the front substrate 1 so as to cover a plurality of pairs of electrode groups, and a protective layer 7 is formed on the dielectric layer 6.
[0005]
On a rear substrate 8 opposed to the front substrate 1, a plurality of stripe-like data covered with a base dielectric layer 9 are arranged in a direction orthogonal to both the display electrodes 4 of the scanning electrodes 2 and the sustain electrodes 3. An electrode 10 is formed. A plurality of stripe-shaped partitions 11 are arranged in parallel with the data electrodes 10 on the underlying dielectric layer 9 between the respective data electrodes 10, and between the partitions 11, side surfaces 11 a of the partition and the underlying dielectric layer 9 is provided with a phosphor layer 12.
[0006]
The front substrate 1 and the rear substrate 8 are opposed to each other with a small discharge space interposed therebetween so that both the display electrodes 4 of the scan electrodes 2 and the sustain electrodes 3 are orthogonal to the data electrodes 10, and the periphery thereof is formed. One of helium, neon, argon, and xenon or a mixed gas is sealed as a discharge gas in the discharge space. The discharge space is divided into a plurality of sections by the partition walls 11, so that a plurality of discharge cells 13 located at the intersections of the display electrodes 4 and the data electrodes 10 are provided. The respective phosphor layers 12 are sequentially arranged one by one so that the three colors of blue and blue are individually emitted. In FIG. 5, reference numeral 14 denotes a sealing member such as a glass frit for sealing the periphery of the front substrate 1 and the back substrate 8.
[0007]
Electrode array in this panel, as shown in FIG. 8, a matrix arrangement of discharge cells with M rows × N columns, scanning electrodes _SCN 1 of the M rows in the row direction ～SCN _M and sustain electrodes _SUS 1 _{~SUS M} are arranged, and N columns of data electrodes D _{1 to DN} are arranged in the column direction (see Patent Document 1).
[0008]
[Patent Document 1]
JP 2001-189135 A
[Problems to be solved by the invention]
As shown in FIG. 5, the panel body of the plasma display device has a front substrate 1 and a rear substrate 8 bonded together with a partition wall therebetween, and a discharge gas mainly composed of neon sealed at about 500 Torr inside. Normally, the front substrate 1 is pressed against the partition 11 of the rear substrate 8 by atmospheric pressure.
[0010]
However, in areas where the outside air pressure is low, especially at high altitudes, the adhesion between the front substrate and the rear substrate is weak, and a gap is created between the partition walls formed on the rear substrate and the front substrate, causing audible noise during panel operation. There was a problem that occurred. This noise is audible to the human perception and becomes quite annoying when the sound pressure exceeds 30 dB.
[0011]
The present invention has been made to solve such a problem, and an object of the present invention is to reduce noise in a high altitude area by increasing a frequency component that sounds unpleasant.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, a plasma display device according to the present invention is arranged such that a pair of substrates are opposed to each other so that a space is formed therebetween, and a peripheral portion is sealed with a sealing member, and the space is partitioned into a plurality of spaces. The partition is arranged so that the height is different between the center and the end thereof. By this configuration, the inside of the panel does not easily expand at high altitude. Things.
[0013]
Further, in the plasma display device of the present invention, in the above configuration, the height of the partition wall is gradually increased from the end of the partition wall toward the center of the panel, and the height of the partition wall is increased so that the panel central portion expands. The height of the panel is higher than the end of the panel, so that the panel is sealed in such a manner as to fit along the substrate at the time of sealing, thereby making it difficult for the inside of the panel to expand at high altitudes.
[0014]
Further, in the plasma display device of the present invention, in the above configuration, the height of the partition wall is increased from the panel central portion toward the terminal end portion of the partition wall, and the height of the partition wall is set so that the panel central portion sinks. By making the height lower than the terminal end, the sealing is performed in such a manner as to fit the substrate at the time of sealing, thereby making it difficult for the inside of the panel to expand at high altitude.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a plasma display device according to an embodiment of the present invention will be described with reference to FIGS.
[0016]
FIG. 1 shows a panel structure of a plasma display device according to an embodiment of the present invention, and FIG. 2 shows a configuration of the entire device. The panel includes a front panel and a rear panel. The front panel includes transparent electrodes 2a and 3a made of a transparent conductive material such as ITO or tin oxide (SnO ₂ ) as display electrodes on a front substrate 1, a silver (Ag) thick film (thickness: 2 μm to 10 μm), and aluminum. (Al) Busbars 2b and 3b composed of a thin film (thickness: 0.1 μm to 1 μm) or a Cr / Cu / Cr laminated thin film (thickness: 0.1 μm to 1 μm) are sequentially laminated and formed so as to cover the display electrodes. , as a main component (an example of lead oxide (PbO) or bismuth oxide _(Bi 2 _{O 3)} or phosphorus oxide (PO _4), lead oxide (PbO) 70 wt%, boron oxide _{(B 2} O 3) 15 wt%, the dielectric layer 6 made of low melting glass (thickness 20Myuemu～50myuemu) to silicon oxide _(SiO 2) 15 wt%) screen printing method (the form in die printing or film lamination Possible), and then, in order to protect the dielectric layer 6 from damage by plasma, a protection layer 7 (thickness: 100 nm to 1000 nm) made of MgO is formed by an electron beam evaporation method or a sputtering method. Have been. As an example, when the busbars 2b and 3b are composed of silver electrodes, they are formed by uniformly applying a silver electrode ink containing an ultraviolet-sensitive resin by a screen printing method, drying, and then patterning and baking by exposure and development. .
[0017]
On the other hand, on the back panel side, first, a silver (Ag) thick film (thickness: 2 μm to 10 μm), an aluminum (Al) thin film (thickness: 0.1 μm to 1 μm) or a Cr / Cu / Cr laminated thin film is formed on the back substrate 8. (Thickness: 0.1 μm to 1 μm) A data electrode 10 is formed in a direction intersecting the display electrode, and lead oxide (PbO) or bismuth oxide (Bi ₂ O ₃ ) or An underlying dielectric layer 9 made of a low-melting glass (thickness: 5 μm to 20 μm) containing phosphorus oxide (PO ₄ ) as a main component is formed.
[0018]
Further, partitions 15 mainly composed of glass are formed on the base dielectric layer 9 at a predetermined pitch, and a red phosphor (R) and a green phosphor (G) are formed in each space sandwiched by the partitions 15. ), A phosphor layer 12 of a blue phosphor (B) is formed, thereby constituting a back panel. Here, the partition 15 has a shape whose height gradually increases from the end of the partition 15 toward the center of the panel.
[0019]
Note that the base dielectric layer 9 is for improving the adhesion to the partition walls 15, and does not mean that the plasma display panel does not operate without it. Further, the phosphor layer 12 is formed by mixing a vehicle with powders of red phosphor (R), green phosphor (G), and blue phosphor (B), and applying a paste to form the paste by an ink discharge method. . The partition 15 formed on the rear substrate 8 is mainly formed by die coating printing, and is formed by performing exposure and development. Here, since the central portion must be formed to be higher, for example, a method of performing etching several times, or a method of drying and polishing the partition wall 15 and then polishing the same, as shown in FIG. The partition 11 having a high center can be formed.
[0020]
Next, the front panel and the rear panel manufactured in this manner are bonded together using the sealing member 14, and the inside of the discharge cells 13 partitioned by the partition walls 15 is evacuated to a high vacuum (1 × 10 ⁻⁴ Pa). After that, a discharge gas having a predetermined composition is sealed at a predetermined pressure to produce a plasma display panel. As an example, the mixed gas of neon gas and xenon gas is 95% and 5% by volume, respectively, and the pressure is 66.5 kPa (500 Torr).
[0021]
Until now, not a small amount of space has been created between the front panel and the rear panel during sealing, and both panels have been forcibly joined together by reducing the internal pressure of the panel to a pressure lower than the atmospheric pressure in the exhaust process. Therefore, at high altitudes, the external pressure applied to the front panel (the pressure difference between the inside and outside of the panel) is weakened, and the elasticity of the front panel is increased, so that a gap is generated and noise is generated.
[0022]
Therefore, by forming the height of the partition wall 15 such that the center of the panel becomes higher in advance as in the present invention, the elastic force acting on the front panel in the sealing / exhausting process can be reduced and noise can be suppressed. can do.
[0023]
Here, when the shape of the panel after sealing and the shape of the panel after evacuation were measured, it was found that a gap of approximately 20 μm was opened between the top of the partition wall 15 and the dielectric layer 6 toward the center of the panel. Do you get it. Therefore, a rear panel having a height of the partition wall 15 of a maximum of 30 μm to a height of several μm was prepared, and an experiment was performed. As a result, the best results could be obtained when the height difference was 15 μm to 25 μm. Was.
[0024]
Such a plasma display device can suppress the bulge of the panel even in an area having a high altitude, and can suppress noise generated from a peripheral portion of the panel.
[0025]
Next, the overall configuration of a plasma display device incorporating such a panel will be described with reference to FIG. In FIG. 2, a housing for accommodating the panel main body 21 is composed of a front frame 22 and a metal back cover 23, and an opening of the front frame 22 is made of glass or the like which also serves as an optical filter and protects the panel main body 21. Is disposed. The front cover 24 is coated with, for example, silver to suppress unnecessary radiation of electromagnetic waves. Further, the back cover 23 is provided with a plurality of ventilation holes 23a for releasing heat generated in the panel body 21 and the like to the outside.
[0026]
The panel body 21 is held by being bonded to a front surface of a chassis member 25 made of aluminum or the like via a heat conductive sheet 26, and a plurality of panels for driving the panel body 21 for display are provided on the rear surface side of the chassis member 25. A circuit block 27 is attached. The heat conductive sheet 16 is for efficiently transmitting the heat generated in the panel main body 21 to the chassis member 25 to radiate heat. The circuit block 27 includes an electric circuit for driving the display of the panel main body 21 and controlling the display main body 21, and the four edges of the chassis member 25 are connected to the electrode extraction portions extended to the edge of the panel main body 21. It is electrically connected by a plurality of flexible wiring boards (not shown) extending beyond.
[0027]
A boss 25a for attaching the circuit block 27 and fixing the back cover 23 is formed on the rear surface of the chassis member 25 by integral molding using die casting or the like. Note that the chassis member 25 may be configured by fixing a fixing pin to an aluminum flat plate.
[0028]
FIG. 3 is a cross-sectional view showing a panel structure in a plasma display device according to another embodiment of the present invention. In this embodiment, instead of the partition wall 15 of the above-described embodiment, from the center of the panel to the terminal portion. A partition wall 28 that becomes higher is provided. That is, in the present embodiment, as shown in FIG. 3, the height of the partition wall 28 is provided so as to increase in the vertical direction from the center. At this time, by setting the height of the sealing member 14 to be higher than the height of the partition wall 28, a force for urging the front panel inward is applied to the entire panel, and a structure that does not easily expand even at high altitude is adopted. Can be. When noise measurement of this prototype panel was performed at an altitude of 2000 m, the noise was able to be suppressed to 30 dB or less.
[0029]
At this time, the height difference of the partition wall 28 of the plasma display panel was 10 μm to 20 μm. As a result, the noise level could be suppressed most at 15 μm. The height of the sealing member 14 was designed to be about 5 μm higher than the partition wall 28. Thereby, there is no sinking of the panel at the sealing member 14, and the sealing can be performed along the partition wall 28.
[0030]
Such a plasma display device has an effect that no resonance frequency is generated in the audible range and no noise is generated even in an actual operation at a high altitude where the atmospheric pressure is low.
[0031]
【The invention's effect】
As is clear from the above description, according to the plasma display device of the present invention, it is possible to obtain an effect that noise can be suppressed in an actual operation in an area or a place where the atmospheric pressure is low.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a panel structure in a plasma display device according to an embodiment of the present invention; FIG. 2 is an exploded perspective view showing an entire configuration of the plasma display device; FIG. FIG. 4 is a sectional view showing a panel structure of a plasma display device according to the present invention. FIG. 4 is a perspective view showing an example of a panel structure of a general plasma display device. FIG. 5 is a schematic sectional view showing the panel structure. FIG. 7 is a cross-sectional view taken along the line BB ′ of FIG. 4. FIG. 8 is an explanatory view showing the electrode arrangement of the panel body of the plasma display device.
DESCRIPTION OF SYMBOLS 1 Front substrate 2 Scanning electrode 3 Sustain electrode 4 Display electrode 5 Light shielding layer 6 Dielectric layer 7 Protective layer 8 Back substrate 9 Underlayer dielectric layer 10 Data electrode 12 Phosphor layer 13 Discharge cell 14 Sealing member 15, 28 Partition wall

Claims (3)

A pair of substrates are arranged so as to face each other so that a space is formed therebetween, and the peripheral portion is sealed with a sealing member, and a partition for dividing the space into a plurality is provided, and the partition is configured by: A plasma display device characterized in that the central portion and the end portion have different heights. 2. The plasma display device according to claim 1, wherein the height of the partition wall gradually increases from the end of the partition wall toward the center of the panel. 2. The plasma display device according to claim 1, wherein the height of the partition wall increases from the center of the panel toward the terminal end.

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