JP2000223036A - Electromagnetic wave shielding transparent plate and plasma display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic wave shielding transparent plate which has sufficient transparency, can significantly reduce the occurrence of moire fringes in a wide angle range, and has excellent visibility over a wide angle range. Provided is a plasma display device using a plate. SOLUTION: In an electromagnetic wave shielding transparent plate in which a conductive grid pattern 3 is provided on a transparent substrate, the grid interval d of the conductive grid pattern 3 is set to 130 μm or less, or the conductive grid pattern 3 is formed. The width m of the line is 35 μm or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic wave shielding transparent plate which is used by being disposed on the front of a display panel of a computer, a television, or the like, or a display panel of a plasma display, and a plasma display device using the same. is there.

[0002]

2. Description of the Related Art Various computer displays,
2. Description of the Related Art A large amount of electromagnetic waves are generated from displays such as game consoles and televisions, and in recent years, there has been a problem that the electromagnetic waves may interfere with other devices.

Therefore, in recent years, in order to shield such electromagnetic waves, it has been widely practiced to mount or dispose an electromagnetic wave shielding transparent plate on the front surface of the display panel.

Incidentally, an electromagnetic wave shielding transparent plate used as a front panel of such a display panel must have transparency in addition to a function of shielding electromagnetic waves. As such an electromagnetic wave shielding transparent plate,
For example, a material in which a conductive material is formed in a lattice shape on a transparent substrate or a material in which a transparent conductive film is laminated on a transparent substrate are known.

[0005]

As the former electromagnetic wave shielding transparent plate, there is, for example, a transparent plate in which conductive fibers are knitted in a lattice shape and integrated on a transparent substrate. The transparent plate has an excellent electromagnetic wave shielding function, but has a low light transmittance, and thus has a problem that a screen on a display equipped with the transparent plate becomes dark.
On the other hand, if the lattice spacing is increased to increase the light transmittance, there is a problem that moire fringes are generated due to interaction with the pixels of the display, and the visibility is significantly reduced. That is, in the conventional electromagnetic wave shielding transparent plate, generation of moiré fringes when mounted on an object such as a display or the like cannot be prevented at all, or an angle range (such as a display or the like) in which moiré fringes can be prevented from being generated. The angle in a plane parallel to the target surface (see FIG. 4) is extremely small, and if even slightly deviated from the proper mounting position (angle) during or after mounting, moire fringes are observed and visibility deteriorates. was there.

The present invention has been made in view of such a technical background, and has sufficient transparency, can significantly reduce the occurrence of moire fringes in a wide angle range, and has excellent visibility. It is an object of the present invention to provide a transparent electromagnetic wave shielding plate and a plasma display device having such characteristics and excellent in electromagnetic wave shielding properties.

[0007]

Means for Solving the Problems In order to achieve the above-mentioned object, the present inventors have made intensive studies and, as a result, designed the conductive grid-like pattern so that the lattice spacing falls within a specific range, or obtained the conductive pattern. By defining the widths of the lines constituting the conductive lattice pattern within a specific range, it has been found that the desired electromagnetic wave shielding transparent plate can be obtained, and the present invention has been completed.

That is, in the electromagnetic wave shielding transparent plate according to the present invention, in the electromagnetic wave shielding transparent plate in which the conductive lattice pattern is provided on the transparent substrate, the lattice spacing of the conductive lattice pattern is 130 μm or less. It is a feature. By setting the lattice spacing to 130 μm or less,
Since the angle range in which moire does not occur or hardly occurs can be widened, visibility can be improved.

Further, another electromagnetic wave shielding transparent plate according to the present invention is an electromagnetic wave shielding transparent plate in which a conductive lattice pattern is provided on a transparent substrate, wherein a line constituting the conductive lattice pattern has a width of 35 μm. It is characterized by the following. By setting the line width to 35 μm or less,
Since the angle range in which moire does not occur or hardly occurs can be widened, visibility can be improved.

In any of the above electromagnetic wave shielding transparent plates, the aperture ratio of the conductive lattice pattern is 70% or more and 100% or more.
% Is preferable, whereby the effect of improving the visibility is sufficiently ensured, and the screen at the time of mounting is bright.

In the case where the conductive lattice pattern is formed by etching a conductive thin film such as a metal foil previously laminated on a transparent substrate, fine lines can be formed with sufficient accuracy. Sufficient quality can be ensured even if the design is such that a fine wire can be formed.

When the conductive grid pattern is formed by printing a conductive paste in a grid pattern on a transparent substrate, the printing using the paste is sufficient to form fine lines. Sufficient quality can be ensured even with a design that can be performed with precision and forms a fine line.

Further, it is preferable that a metal layer is laminated on the surface of the conductive lattice pattern, whereby the electromagnetic wave shielding property is further improved.

The above-mentioned electromagnetic wave shielding transparent plate has sufficient transparency, and is capable of significantly reducing the occurrence of moire fringes in a wide angle range and has excellent visibility over a wide angle range. It is particularly suitable as a front plate of a plasma display device requiring high visibility,
The plasma display device in which this electromagnetic wave shielding transparent plate is mounted on the front surface of the display panel has a sufficient electromagnetic wave shielding function, prevents the occurrence of moiré fringes, has excellent visibility, and has a bright, high-quality image. Can be formed.

[0015]

FIG. 1 is a sectional view of an electromagnetic wave shielding transparent plate according to an embodiment of the present invention. The electromagnetic wave shielding transparent plate (1) of this embodiment is formed by laminating and integrating a conductive lattice pattern (3) on a transparent substrate (2). FIG. 2 is an enlarged view of a main part of the conductive lattice pattern (3).
Shown in In FIG. 2, (d) is the lattice spacing,
(M) is the width of the line constituting the pattern.

In the present invention, the conductive grid pattern (3) may be provided directly on the surface of the transparent substrate (2) (FIG. 1), or as shown in FIG. 3) A transparent film (4) provided on the surface is laminated and integrated on a transparent substrate (2) (that is, a conductive grid pattern (4) is formed on the transparent substrate (2) via the transparent film (4)). 3) may be provided, or a configuration in which a conductive grid pattern (3) is interposed and integrated between two transparent substrates (2) and (2) may be used. In short, a conductive lattice pattern (3) is provided on a transparent substrate (2).

Materials constituting the transparent substrate (2) include:
The material is not particularly limited as long as it is a transparent material, and examples thereof include glass and synthetic resin. Examples of the synthetic resin include an acrylic resin, a polycarbonate resin, a polyester resin such as polyethylene terephthalate, a polyolefin resin such as polyethylene and polypropylene, and a polyether sulfone. Among them, glass, an acrylic resin, or a polycarbonate resin is preferable as a material constituting the transparent substrate (2) because of its excellent transparency. Such a transparent substrate (2) may be a single plate composed of one layer or a laminated plate composed of two or more same or different layers.

The thickness of the transparent substrate (2) is not particularly limited, but is generally in the range of 0.5 to 20 mm, preferably in the range of 1 to 10 mm. When the object is a display, for example, the size (area) of the transparent substrate (2) may be appropriately set according to the screen size of the display.

The transparent substrate (2) may contain additives and the like. For example, when the electromagnetic wave shielding transparent plate (1) is used as a front plate of a plasma display panel, the transparent substrate (2) is generated from the front of the panel. A near-infrared absorbing agent for absorbing near-infrared rays is often included.

When a synthetic resin is used as a material constituting the transparent substrate (2), a hard coat layer may be provided on the surface of the substrate (2) from the viewpoint of improving the surface hardness.

In the case where the structure shown in FIG. 3 is adopted, the material constituting the transparent film (4) is not particularly limited as long as it is a transparent material. Examples include polyester resins such as polyethylene terephthalate, polyolefin resins such as polyethylene and polypropylene, and acrylic resins. The thickness of the transparent film (4) is not particularly limited, but is usually in a range of 0.04 to 0.3 mm.

The transparent substrate (2) and the transparent film (4) may be colored with a coloring agent such as a dye or a pigment. Such coloring is often performed for the purpose of improving the visibility of the display.

On the other hand, the conductive grid pattern (3) provided on the transparent substrate (2) needs to be formed so that the grid spacing (d) or the width (m) of the constituent lines is within a specific range. There is. That is, the conductive grid pattern (3) is formed so that the grid spacing is 130 μm or less, or the width of a line forming the conductive grid pattern (3) is 35 μm.
m. With such a configuration, it is possible to widen an angle range where moiré does not occur or almost does not occur, and thus it is possible to achieve excellent visibility over a wide angle range.

Above all, the lattice spacing of the conductive lattice pattern (3) is more preferably in the range of 60 to 130 μm, and by setting such a range, the visibility can be further improved over a wide angle range. Can be. Also,
The width of the line constituting the conductive grid pattern (3) is 10
The thickness is more preferably in the range of 30 μm to 30 μm, whereby visibility can be further improved over a wide angle range.

The aperture ratio of the conductive lattice pattern (3) is preferably set to 70% or more and less than 100%. By setting such a range, the brightness of the screen at the time of mounting can be improved. The aperture ratio (%) is a value obtained by the following equation.

Aperture ratio (%) = (dm) ² ÷ d ² × 100 (d: lattice spacing, m: width of a line constituting the pattern)

In order to set the aperture ratio to 70% or more and less than 100%, in the above equation, the aperture ratio is set to a desired value.
In the range of d ≦ 130 μm or m ≦ 35 μm, d
And m may be determined. Among them, the aperture ratio is 70-9
More preferably, it is 0%. If it exceeds 90%, the electromagnetic wave shielding property tends to decrease.

The method of forming the conductive grid pattern (3) is not particularly limited as long as it can form a predetermined grid interval and line width.

For example, a method in which conductive fibers are woven in a lattice shape (for example, a woven cloth having a metal surface plated on the fibers) is bonded and integrated on a transparent substrate (2), or Two transparent substrates (2) woven in a lattice
(2) A method of interposing and integrating between them, and the like.

As a preferable method for forming a grid pattern having a line width of 35 μm or less, a method in which a conductive thin film such as a metal foil laminated on a transparent substrate (2) is processed into a grid by etching. A method of printing a conductive paste in a grid pattern on the transparent substrate (2).
Examples of the conductive thin film include thin films of metals such as copper and aluminum, and ITO (indium-tin oxide) thin films. Examples of the conductive paste include silver paste and copper paste. In both of the former method and the latter method, fine lines can be formed with sufficient accuracy, and sufficient quality can be ensured even in a design that forms fine lines. Among them, the intaglio offset printing method is particularly preferable.

The thickness of the conductive grid pattern (3) is not particularly limited, but is preferably in the range of 3 to 35 μm. When the thickness is less than 3 μm, electromagnetic wave shielding properties cannot be sufficiently obtained, and thus it is not preferable. When the thickness is more than 35 μm, formation of a lattice pattern tends to be difficult, which is not preferable. Among them, the thickness of the conductive lattice pattern (3) is more preferably in the range of 4 to 20 μm.

The conductive grid pattern (3) may be colored black from the viewpoint of improving the visibility when the display is mounted. A known method can be used as a method for blacking the conductive grid pattern in this way. For example, a method using plating such as black nickel plating, chromate plating, black alloy plating,
In the case where the conductive grid pattern is formed by a printing method, a method of printing a conductive paste into which a black dye or pigment has been kneaded in advance may be used.

It is preferable that a metal layer such as copper or nickel is laminated on the surface of the conductive grid pattern (3), so that the electromagnetic wave shielding property can be further improved. The lamination of the metal on the pattern (3) can be performed by, for example, a plating method. In addition,
When the metal is laminated on the pattern (3) in this manner, the line width after the metal lamination tends to increase. Therefore, the lattice shape before the metal lamination is adjusted so that the predetermined line width is obtained after the metal lamination. It is necessary to set the wire diameter of the pattern (3).

The electromagnetic wave shielding transparent plate (1) of the present invention may be provided with various functions according to the characteristics, form, use environment and the like of the display to be mounted.
As a method for imparting various functions as described above, for example, a method of laminating a functional film on at least one surface of the transparent substrate (2) and the like can be mentioned. As the functional film, an antireflection film provided with an antireflection layer for preventing light reflection on the film surface, a colored film colored by a coloring agent or an additive, a near-infrared shielding film that absorbs or reflects near-infrared light, Examples include an antifouling film that prevents contaminants such as fingerprints from adhering to the surface, and a film on which a transparent conductive film is formed.

Electromagnetic wave shielding transparent plate (1) according to the present invention
Is suitably used, for example, as a front panel for various displays, but is not particularly limited to this use. Among them, it is particularly suitably used as an electromagnetic wave shielding front plate for a plasma display panel which is a large display device requiring excellent visibility. The plasma display device in which the electromagnetic wave shielding transparent plate (1) of the present invention is mounted on the front surface of the display panel has a sufficient electromagnetic wave shielding function, is free from moiré fringes, has excellent visibility, and is bright and high quality. Image can be formed.

[0036]

EXAMPLES Next, specific examples of the present invention will be described, but the present invention is not limited to these examples.

<Example 1> A black polyester woven fabric having a copper / nickel plating on the fiber surface (with a lattice spacing of 78 μm)
m, wire diameter 28 μm) is sandwiched between two upper and lower transparent acrylic plates (1.5 mm in thickness, “SUMIPEX 000” manufactured by Sumitomo Chemical Co., Ltd.), and then hot-pressed (press conditions: temperature 130 ° C., pressure) (40 kg / cm ² , press time 30 minutes)
To obtain an electromagnetic wave shielding transparent plate.

<Example 2> As a polyester / black woven cloth plated with copper / nickel, a lattice spacing of 102 μm was used.
m, and an electromagnetic wave shielding transparent plate was obtained in the same manner as in Example 1 except that a wire having a wire diameter of 36 μm was used.

<Example 3> As a black woven cloth made of polyester plated with copper and nickel, a lattice spacing of 127 μm was used.
m, and an electromagnetic wave shielding transparent plate was obtained in the same manner as in Example 1, except that a material having a wire diameter of 31 μm was used.

<Example 4> As a polyester-black woven cloth plated with copper and nickel, a lattice spacing of 188 μm was used.
m, and a transparent plate for shielding electromagnetic waves was obtained in the same manner as in Example 1, except that a wire having a wire diameter of 34 μm was used.

Example 5 A transparent acrylic plate (thickness 3 m)
m, 200 mm × 200 mm, Sumitomo Chemical Co., Ltd. “Sumipex 000”), copper foil laminated PET film (200 mm × 200 mm, 50 μm thick PET film, 18 μm thick copper foil laminated and integrated with adhesive Were laminated and integrated via an adhesive with the PET surface facing the acrylic plate. Next, a resist was applied on the copper foil and exposed through a mask having a predetermined mesh pattern, and then unnecessary portions of the resist were removed. Further, an etching process was performed to remove an unnecessary portion of the copper foil, and then the resist on the remaining copper foil pattern was peeled off to form a conductive lattice pattern. The lattice interval of the lattice pattern of the obtained copper foil was 195 μm, and the line width was 18 μm. In forming the conductive grid pattern, the direction of the constituent lines of the grid and the direction of the constituent sides of the obtained electromagnetic wave shielding transparent plate intersect at an angle of 45 degrees.

Example 6 Glass substrate (1.1 m thick)
m, 300 mm × 400 mm), and a silver paste was printed in a grid pattern at a thickness of 4 μm using an intaglio offset printing method. At this time, the lattice spacing was 254 μm and the line width was 27 μm. Next, the surface of the lattice pattern made of the silver paste was blackened by performing copper plating and further black nickel plating to obtain an electromagnetic wave shielding transparent plate. The grid spacing of the obtained conductive grid pattern was 254 μm, and the line width was 33 μm. In forming the conductive grid pattern, the direction of the constituent lines of the grid was parallel to the direction of the constituent sides of the obtained electromagnetic wave shielding transparent plate.

<Comparative Example 1> As a polyester / black woven cloth plated with copper / nickel, a lattice spacing of 423 μm was used.
m and a wire diameter of 55 μm, except that an electromagnetic wave shielding transparent plate was obtained in the same manner as in Example 1.

<Comparative Example 2> A copper-nickel-plated polyester black woven fabric was used, with a lattice spacing of 254 μm.
m, and an electromagnetic wave shielding transparent plate was obtained in the same manner as in Example 1 except that a wire having a wire diameter of 44 μm was used.

Each of the electromagnetic wave shielding transparent plates manufactured as described above was evaluated according to the following evaluation method. Table 1 shows the results. Examples 1 to 4 and Comparative Examples 1 and 2
In the above, a sample obtained by cutting out the obtained electromagnetic wave shielding transparent plate into a size of 300 mm × 280 mm was used as a sample for evaluation. At this time, the directions of the constituent lines of the lattice,
The sample was cut out so that the direction of the constituent side of the sample became parallel.

<Evaluation Method of Moire Elimination Angle Range> As shown in FIG. 4, the obtained electromagnetic wave shielding transparent plate (1) is brought into close contact with the plasma display front surface (9) while being in close contact with the display front surface (9). It was rotated in the plane, and at that time, an angle region where moiré disappeared was visually observed. Then, the total value of the angle range in which the moiré disappeared when the electromagnetic wave shielding transparent plate (1) was rotated 90 degrees was described as the moiré disappearance angle range (α).

[0047]

[Table 1]

As is clear from the table, the electromagnetic wave shielding transparent plates of Examples 1 to 6 of the present invention were able to prevent generation of moiré fringes in a wide angle range and were excellent in visibility.

On the other hand, in Comparative Examples 1 and 2, which deviate from the scope of the present invention, the angle range in which the occurrence of moiré fringes can be prevented was narrow, and sufficient visibility could not be obtained.

[0050]

As described above, according to the electromagnetic wave shielding transparent plate of the present invention, the grid spacing of the conductive grid pattern is 130 μm.
As defined below, an angle range where no or almost no moiré is generated can be widened, and visibility can be improved over a wide angle range. Therefore, even when the mounting position (angle) shifts after or after mounting on an object such as a display, moire fringes are not observed, and excellent visibility can be secured. You can do it.

Further, another electromagnetic wave shielding transparent plate according to the present invention has a line width of 35 μm constituting the conductive grid pattern.
As defined below, an angle range where no or almost no moiré is generated can be widened, and visibility can be improved over a wide angle range. Therefore, even when the mounting position (angle) shifts after or after mounting on an object such as a display, moire fringes are not observed, and excellent visibility can be secured. You can do it.

In the above, when the aperture ratio of the conductive lattice pattern is 70% or more and less than 100%, the brightness of the screen at the time of mounting is further improved while sufficiently securing the effect of improving the visibility. Can be done.

In the case where the conductive grid pattern is formed by etching a conductive thin film such as a metal foil previously laminated on a transparent substrate, the formation of fine lines can be performed with sufficient accuracy. Thus, sufficient quality can be ensured even if the design is such that a thin line is formed.

When the conductive grid pattern is formed by printing a conductive paste in a grid pattern on a transparent substrate, the printing using the paste is sufficient to form fine lines. It can be performed with high precision, and sufficient quality can be ensured even if the design is such that a thin line is formed. Further, since no etching treatment is required, waste liquid after the treatment is not discharged, which is preferable from an environmental point of view.

Further, when a metal layer is laminated on the surface of the conductive lattice pattern, the electromagnetic wave shielding property can be further improved.

Further, in the plasma display device according to the present invention, the electromagnetic wave shielding transparent plate is mounted on the front surface of the display panel, so that the electromagnetic wave can be sufficiently shielded and there is no generation of moire fringes. It is possible to form a bright, high-quality image having excellent properties.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an electromagnetic wave shielding transparent plate according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part showing one mode of a conductive lattice pattern.

FIG. 3 is a cross-sectional view illustrating an electromagnetic wave shielding transparent plate according to another embodiment.

FIG. 4 is an explanatory diagram showing a method for evaluating a moiré disappearing angle range.

[Explanation of symbols]

 1: transparent electromagnetic wave shielding plate 2: transparent substrate 3: conductive grid pattern

Continued on the front page F-term (reference) 4F100 AB01B AB01C AB17 AB33B AK25 AK41 BA02 BA03 BA10A BA10C BA32 DC15B DG01 DG12 EH71 EJ15B EJ20 EJ42 GB41 HB08B HB31B JD08 JG01B JL10 JN01A YY00B 5C040 MA08 BB04A08

Claims (7)

[Claims] 1. An electromagnetic wave shielding transparent plate having a conductive lattice pattern provided on a transparent substrate, wherein the lattice spacing of the conductive lattice pattern is 130 μm or less. 2. An electromagnetic wave shielding transparent plate in which a conductive grid pattern is provided on a transparent substrate, wherein a width of a line forming the conductive grid pattern is 35 μm.
An electromagnetic wave shielding transparent plate characterized by the following. 3. The conductive grid-like pattern having an aperture ratio of 7
The electromagnetic wave shielding transparent plate according to claim 1, which is 0% or more and less than 100%. 4. The conductive grid-like pattern is formed by etching a conductive thin film such as a metal foil previously laminated on a transparent substrate.
The electromagnetic wave shielding transparent plate according to any one of the above. 5. The electromagnetic wave shielding transparent plate according to claim 1, wherein the conductive grid pattern is formed by printing a conductive paste in a grid pattern on a transparent substrate. . 6. The electromagnetic wave shielding transparent plate according to claim 1, wherein a metal layer is laminated on the surface of the conductive lattice pattern. 7. A plasma display device, wherein the electromagnetic wave shielding transparent plate according to claim 1 is mounted on a front surface of a display panel.