JP2010010255A - Electromagnetic wave shield member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic wave shield member that strikes a balance between the thickness reduction and the increase of electromagnetic wave shielding effect of a large screen thin-type display device such as a plasma display device. <P>SOLUTION: The electromagnetic wave shield member having an annular part formed by winding fabric metal fiber one or more turns and an extension formed by extending the metal fiber from the annular part is disposed between a part to which no conductive front filter is applied and a cabinet at an end of the display panel to conduct the cabinet. The extension is conductively connected to a metal end of the conductive front filter to conduct the front filter and the cabinet, thereby shielding the electromagnetic waves while preventing breakage of surface glass on a plasma display panel. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electromagnetic wave shielding member applied to a large-screen thin display device such as a plasma display device.

  2. Description of the Related Art Self-luminous display devices such as a plasma display device and a CRT display (Cathode-Ray Tube display) device are widely used because a natural image can be obtained without dependency on a viewing angle. In particular, plasma display devices are rapidly spreading because they are thin and optimal for constructing a large screen.

  The plasma display device is mainly composed of a plasma display module section having a plasma display panel and a shield casing surrounding the module. This plasma display panel is a display that generates visible light by exciting phosphors provided in each discharge cell by ultraviolet rays generated by gas discharge to generate display light, and includes a plurality of electrodes (display electrode pairs and address electrodes). ) Are arranged in a grid pattern, and an image is formed by selectively emitting light from discharge cells that intersect each electrode. Due to this principle, a large current for driving flows through the electrodes, and an electromagnetic field is generated by this current from the plasma display module.

  Proposals have been made on the configuration of a plasma display device for shielding an electromagnetic field generated in this way (see, for example, Patent Document 1).

  The configuration of a conventional plasma display device will be described with reference to FIG. 10A and 10B are schematic diagrams for explaining the configuration of a conventional plasma display device. FIG. 10A is a front view, and FIG. 10B is an AA line AA in FIG. It is sectional drawing.

A conductive filter 20 is directly attached to the front surface of the plasma display panel 10. The filter 20 is electrically connected to the conductive cabinet 17 via an electromagnetic wave shielding member 21 disposed on the filter 20. Further, the conductive back cover 16 on the back side and the conductive cabinet 17 are also electrically connected by screws or the like (not shown). With the above configuration, the plasma display module is surrounded by a conductive member, and the generated electromagnetic field is electromagnetically shielded.
JP 2006-091844 A

  The electromagnetic wave shielding member 21 often has a configuration in which metal fibers are attached to the surface of an elastic material such as a sponge (referred to as a gasket).

  However, when the plasma display device is further reduced in thickness, it is assumed that the gap allowed between the conductive cabinet 17 and the conductive filter 20 (that is, the gap into which the electromagnetic wave shielding member 21 is inserted) becomes extremely narrow. Is done.

  For example, when the gap is 1 mm or less, the minimum gap is reduced to about 0.2 mm due to variations in the member dimensions of the apparatus and assembly tolerances. It is assumed that it is physically difficult to insert the conventional electromagnetic wave shielding member 21 into such a narrow gap. Further, even if the electromagnetic wave shielding member 21 is inserted into the narrow gap, the repulsive force due to the excessive compression of the elastic material becomes larger than necessary, and the possibility that the surface glass of the plasma display panel 10 will break increases. There are challenges.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an electromagnetic wave shielding member capable of achieving both the thinning of a thin display device having a large screen such as a plasma display device and the electromagnetic wave shielding effect. .

  In order to solve the above-described conventional problems, an electromagnetic wave shielding member of the present invention has an annular portion in which a cloth-like metal fiber is wound one or more times, and an extension portion in which the metal fiber extends from the annular portion. It is placed between the part of the panel where the conductive front filter is not attached and the cabinet and conducts to the cabinet, and the extension is conductively connected to the metal end of the conductive front filter. I do.

  According to the electromagnetic wave shielding member of the present invention, electromagnetic wave shielding can be performed while preventing the surface glass of the plasma display panel from being broken when the plasma display device is further thinned.

  Hereinafter, embodiments of a plasma display device and the like to which an electromagnetic wave shielding member of the present invention is applied will be described with reference to the drawings. In the embodiment, components that perform the same operation may be denoted by the same reference numerals and the description thereof may be omitted.

(Embodiment 1)
First, the plasma display device according to the first embodiment will be described. FIG. 1 is a schematic diagram of a configuration of a plasma display device according to Embodiment 1 of the present invention, FIG. 1 (a) is a front view, and FIG. 1 (b) is a line AA in FIG. 1 (a). It is sectional drawing. FIG. 1 shows only components that are deeply related to unwanted electromagnetic radiation in the present invention. FIG. 2 is a perspective view of the plasma display module in the plasma display apparatus according to Embodiment 1 of the present invention.

  As shown in FIG. 1, the plasma display device 1 mainly includes a plasma display module 2, a conductive front filter 20, a conductive cabinet 17, a back cover 16, and an electromagnetic wave shielding member 30.

  As shown in FIGS. 1 and 2, the plasma display module 2 has a plasma display panel on the non-display surface side of the plasma display panel 10 having scan / sustain electrodes 14 parallel to the longitudinal direction and address electrodes 15 parallel to the short direction. A chassis conductor 11, which is a holding plate 10, is disposed via a heat conductive sheet 18.

  The scan / sustain electrode drive circuit board 12 a, the address electrode drive circuit board 12 b, the relay circuit board 12 c, and the discharge control circuit board 12 d are arranged on the back side of the chassis conductor 11. The scan / sustain electrode drive circuit board 12a generates a drive signal and transmits the drive signal to the scan / sustain electrode 14 of the plasma display panel 10 through the flexible cable 13a. Then, the discharge control circuit board 12d generates a high frequency signal for display control, transmits it to the relay circuit board 12c by the flexible cable 13d, and transmits it to the address electrode drive circuit board 12b by the flexible cable 13c. The address electrode drive circuit board 12b generates a drive signal and transmits the drive signal to the address electrode 15 of the plasma display panel 10 through the flexible cable 13b.

  The chassis conductor 11 is made of a metal plate such as aluminum or copper having high thermal conductivity and electrical conductivity. The plasma display panel 10 is attached to one surface (front surface) of the chassis conductor 11 via a heat conductive sheet, and each drive circuit board and the like are parallel to the chassis conductor 11 on the other surface (back surface). Are connected to the ground of each drive circuit board. For this reason, the chassis conductor 11 not only functions as a strength member that holds the plasma display panel 10 and each drive circuit board and maintains these strengths, but also functions as an electrical ground for each drive circuit board and the like. For example, the signal ground of the scan / sustain electrode drive circuit board 12a is the Ga point, the signal ground of the address electrode drive circuit board 12b is the Gb point, the signal ground of the relay circuit board 12c is the Gc point, and the discharge control circuit board. The signal ground 12d is grounded to the chassis conductor 11 which is a frame ground at the point Gd.

  A back cover 16, a conductive cabinet 17, a conductive front filter 20, and an electromagnetic wave shielding member 30 are disposed outside the plasma display module 2, and a shield housing of the plasma display module 2 is configured by these configurations. . Details of the structure and arrangement method of the electromagnetic wave shielding member 30 will be described later.

  Next, the plasma display panel 10 according to Embodiment 1 will be described. 3A and 3B are schematic views of the electrode structure of the plasma display panel in the plasma display device according to the first exemplary embodiment of the present invention. FIG. 3A is a perspective view and FIG. 3B is a cross-sectional view. As shown in FIG. 3, the plasma display panel 10 has a structure in which a front glass plate 101 and a rear glass plate 102 are bonded together, and a dielectric layer 103 is formed on the front glass plate 101 to form a scanning electrode 14a. A plurality of scanning / sustaining electrodes 14 including the sustain electrodes 14 b are formed so as to be protected by the dielectric layer 103. A dielectric layer 103 is also formed on the rear glass plate 102, and a large number are formed so that the address electrodes 15 are protected.

  A portion sandwiched between the scan / sustain electrode 14 and the address electrode 15 at the intersection of the scan / sustain electrode 14 and the address electrode 15 is a discharge cell 104, which is helium (He), neon (Ne), xenon (Xe). A discharge gas containing a rare gas such as) is enclosed. The discharge cell 104 is formed by being partitioned by a partition wall 105, and each of the discharge cells is coated with red, blue, and green phosphors 106a to 106c.

  Next, the conductive front filter 20 according to Embodiment 1 will be described. FIG. 4 is a perspective view of the conductive front filter in the plasma display device according to the first embodiment of the present invention. As shown in FIG. 4, the conductive front filter 20 includes a shock absorbing layer 201 that reduces external shock, a conductive layer 202 formed of metal mesh such as copper or metal sputter on the shock absorbing layer 201, and a conductive layer 202. And a protective film 204 formed on the conductive layer 202 with a transparent insulating resin. Since the metal end portion 203 is not covered with the protective film 204, it functions as an electrical connection location. The conductive front filter 20 is directly attached to the front surface of the plasma display panel 10.

  As the conductive layer 202, a copper mesh is used as a metal mesh, and a silver sputter is used as a metal sputter. Since the metal mesh has a lower resistivity than metal sputtering, a high shielding effect can be obtained.

  The shock absorbing layer 201 is provided to protect the plasma display panel 10 from an impact from the outside, and requires a predetermined thickness for protecting the glass, specifically, a thickness of about 0.5 mm. Things are used.

  The conductive cabinet 17 is disposed so as to be in electrical contact with the metal end portion 203 of the conductive front filter 20 via the conductive member 21. Further, the conductive cabinet 17 is also in contact with the back cover 16 via screws or the like (not shown).

  The back cover 16 is formed by press-molding a conductive metal plate, and is fixed to the conductive cabinet 17 so as to cover the back surface of the plasma display panel 10 and each drive circuit board, etc. It plays a role of shielding electromagnetic waves radiated from each drive circuit board and the like.

  Here, details of the structure and arrangement method of the electromagnetic wave shielding member 30 of the present invention will be described with reference to FIGS.

  5A and 5B are diagrams showing a first structure of the electromagnetic wave shielding member in the plasma display device according to Embodiment 1 of the present invention, in which FIG. 5A is a perspective view and FIG. 5B is a bottom view. The electromagnetic wave shielding member 30 of the present invention is obtained by winding one or more turns of cloth-like metal fibers 30b plated on polyester fibers around an elastic body 30a (for example, a sponge such as urethane foam) having a substantially rectangular cross section. The end portion is not wound around a proper amount. That is, the metal fiber 30b is composed of an annular portion wound around the sponge one or more times and an extended portion extending from the annular portion. By adopting such a configuration, the conductive portion of the electromagnetic wave shielding member 30 is composed of an integral metal fiber, so that the conductivity is not discontinuous and the electromagnetic wave shielding effect is enhanced.

  As shown in FIG. 5B, fixing adhesive materials 30 c and 30 d are disposed on the bottom surface of the electromagnetic wave shielding member 30. Among these, the adhesive material 30d has conductivity by an acrylic adhesive material in which metal particles are dispersed. Further, the adhesive material 30c does not necessarily have conductivity. In addition, a very thin and weak elastic anti-dust material 30e (for example, sponge) for preventing dust from entering the plasma display device is disposed on the opposite side of the adhesive 30d at the end of the metal fiber 30b.

  FIG. 6 is a layout view of the electromagnetic wave shielding member in the plasma display device according to Embodiment 1 of the present invention, and is an enlarged view of a portion B in FIG. In order to facilitate understanding, the actual scale is not consistent.

  In the first embodiment of the present invention, the conductive front filter 20 is formed with a small amount on the top, bottom, left, and right with respect to the outer dimensions of the plasma display panel 10 and is attached. The conductive front filter 20 is larger than the area obtained by adding the area of the metal end 203 of the conductive front filter 20 to the area of the opening of the conductive cabinet 17, and the two electromagnetic shielding members 30 from the area of the plasma display panel 10. The size is smaller than the area obtained by subtracting the area of the minute. By adopting such a configuration, even when the gap between the conductive cabinet 17 and the conductive front filter 20 is extremely narrow (for example, 0.2 mm), the gap between the end of the plasma display panel 10 and the conductive cabinet 17 is small. It is possible to secure a larger thickness by the thickness of the conductive front filter 20 (for example, 0.5 mm).

  The electromagnetic wave shielding member 30 is fixed to the end portion of the plasma display panel 10 to which the conductive front filter 20 is not attached by an adhesive material 30c. Then, the metal fiber 30b extending from the elastic body 30a of the electromagnetic wave shielding member 30 is connected and fixed to the metal end 203 of the conductive front filter 20 by the adhesive material 30d. Further, when the conductive cabinet 17 is put on the plasma display panel 10, the elastic body 30 a of the electromagnetic wave shielding member 30 is appropriately compressed, and conduction between the conductive cabinet 17 and the electromagnetic wave shielding member 30 is ensured. As a result, the conductive layer 202 of the conductive front filter 20 is secured to the conductive cabinet 17 via the electromagnetic wave shielding member 30.

  With the above configuration, even when the gap between the conductive front filter and the conductive cabinet attached to the front surface of the plasma display panel becomes extremely narrow, the front side of the plasma display panel can be continuously and conductively enclosed. Therefore, a sufficient electromagnetic wave shielding effect can be obtained. Further, since the elastic body is not excessively compressed, the pressure applied to the plasma display panel can be made appropriate.

  In this embodiment, the cross section of the elastic body 30a of the electromagnetic wave shielding member 30 is substantially rectangular. However, the cross section of the elastic body 30a has a small area on the conductive cabinet 17 side as shown in FIGS. A trapezoidal shape or a substantially semicircular shape may be used. FIG. 7 is a diagram showing a second structure of the electromagnetic wave shielding member in the plasma display device according to the first embodiment of the present invention, and FIG. 8 shows the second structure of the electromagnetic wave shielding member in the plasma display device according to the first embodiment of the present invention. FIG.

  7 and FIG. 8, the effect is that the elastic body 30a has a trapezoidal shape or a substantially semicircular cross section. However, since the pressure is concentrated on the side in contact with the conductive cabinet 17, the conductive cabinet 17 In addition, the contact resistance between the electromagnetic wave shielding member 30 and the electromagnetic wave shielding member 30 can be further reduced. Conversely, the pressure contacting the plasma display panel 10 is dispersed, and the pressure load on the plasma display panel 10 can be reduced.

  In the present embodiment, the elastic body 30a is used for the electromagnetic wave shielding member 30, but the elastic body 30a may not be used as shown in FIG. FIG. 9 is a diagram showing a fourth structure of the electromagnetic wave shielding member in the plasma display device according to Embodiment 1 of the present invention. In that case, the metal fiber 30b is made more than one turn to form a metal transition ring. And the annular ring of the metal fiber 30b is compressed appropriately, and the conduction | electrical_connection of the conductive cabinet 17 and the electromagnetic wave shielding member 30 is ensured.

  The effect of not using the elastic body 30a as shown in FIG. 9 is that, even when the gap between the plasma display panel 10 and the conductive cabinet 17 is only about the metal fiber 30b, the front side of the plasma display panel 10 is Since the conductor can be continuously surrounded, a sufficient electromagnetic shielding effect can be obtained. Further, since the electromagnetic wave shielding member 30 is not excessively compressed, the pressure applied to the plasma display panel 10 can be made appropriate.

  Note that the specific numerical values and the like used in the above embodiment are merely examples, and can be appropriately set to optimal values according to the characteristics of the display device and the specifications of the image display device. Is possible.

  As described above, the electromagnetic wave shielding member according to the present invention is useful as an electromagnetic wave shielding member applied to a plasma display device and the like for the purpose of further thinning and a device having an extremely small gap.

BRIEF DESCRIPTION OF THE DRAWINGS Schematic of the plasma display device according to the first embodiment of the present invention, (a) front view, (b) AA sectional view 1 is a perspective view of a plasma display module in a plasma display device according to Embodiment 1 of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS Schematic diagram of electrode structure of plasma display panel in plasma display apparatus according to Embodiment 1 of the present invention, (a) perspective view, (b) cross-sectional view The perspective view of the electroconductive front filter in the plasma display apparatus concerning Embodiment 1 of this invention The figure which shows the 1st structure of the electromagnetic wave shielding member in the plasma display apparatus which concerns on Embodiment 1 of this invention, (a) Perspective view, (b) Bottom view Arrangement diagram of electromagnetic wave shielding member in plasma display device according to Embodiment 1 of the present invention Arrangement diagram of second electromagnetic wave shielding member in plasma display device according to embodiment 1 of the present invention Arrangement of third electromagnetic wave shielding member in plasma display apparatus according to embodiment 1 of the present invention Arrangement of fourth electromagnetic wave shielding member in plasma display device according to embodiment 1 of the present invention. Schematic diagram of conventional plasma display device, (a) front view, (b) AA sectional view

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plasma display apparatus 2 Plasma display module 10 Plasma display panel 11 Chassis conductor 12a Scan / sustain electrode drive circuit board 12b Address electrode drive circuit board 12c Relay circuit board 12d Discharge control circuit board 13a, 13b, 13c, 13d Flexible cable 14 Scan / sustain electrode 15 Address electrode 16 Back cover 17 Conductive cabinet 18 Thermal conductive sheet 19 Front cabinet 20 Conductive front filter 21 Conventional electromagnetic wave shielding member 30 Electromagnetic wave shielding member (first structure)
31 Electromagnetic wave shielding member (second structure)
32 Electromagnetic wave shielding member (third structure)
DESCRIPTION OF SYMBOLS 101 Front glass plate 102 Back glass plate 103 Dielectric 104 Discharge cell 105 Bulkhead 106a, 106b, 106c Phosphor 201 Shock absorption layer 202 Conductive layer 203 Metal edge 204 Protective film

Claims (4)

An annular portion wound with one or more rounds of cloth-like metal fibers;
The electromagnetic wave shielding member provided with the extension part which the said metal fiber extended from the said annular part. The electromagnetic wave shielding member according to claim 1, further comprising an elastic body in the annular portion. The electromagnetic wave shielding member according to claim 2, wherein a cross section of the elastic body is trapezoidal or semicircular. A display panel;
A conductive layer pasted on the front surface of the display panel, formed of a metal mesh or metal sputter, and a conductive front filter having a metal edge formed at the periphery of the conductive layer;
An electromagnetic wave shielding member having an annular portion in which one or more rounds of cloth-like metal fibers are wound, and an extension portion in which the metal fibers extend from the annular portion;
A conductive cabinet surrounding the display panel;
The electromagnetic wave shielding member is disposed between the cabinet and the portion where the annular front portion is not attached to the conductive front filter at the end of the display panel, and the extension portion is electrically conductive. A display panel device characterized by being conductively connected to a metal end of a filter.

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