JP2000324423A - Video display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a video display device which is low in cost does not require soldering for fixing the device to the video signal outputting circuit substrate to facilitate fixing and is given a measure against an unnecessary radiation radio by a grounding component having a function of preventing the vibration and loosening of the video signal output circuit substrate. SOLUTION: A grounding component 4 formed of a rectangular parallelepiped conductive rubber is fixed onto the ground pattern of a video signal outputting circuit substrate 1, and the substrate 1 is fixed to a case video. At the time of housing the case video in a rear plate, the component 4 is in area-contact with the inner wall surface of the rear plate with elasticity to reliably fix the potential of the pattern 14 of the circuit 1 to ground potential through a wide range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video display device, and more particularly to a video display device provided with a color cathode ray tube and taking measures against unnecessary radiation waves.

[0002]

2. Description of the Related Art Generally, a color cathode ray tube (hereinafter referred to as CRT)
The video display device includes a video amplifier that amplifies the video signal and a video signal output circuit board that outputs the video signal amplified by the video amplifier. In addition, a variety of unnecessary radiation waves are generated. The source of the unnecessary radiated radio waves is a video amplifier that amplifies the video signal, and it is thought that the video signal output circuit board is affected via the printed wiring and the relay wire connecting the boards. .

FIG. 12 is an exploded view showing a video display device 90 having a video amplifier (not shown) for amplifying a video signal and a video signal output circuit board 1 for outputting a video signal amplified by the video amplifier. It is a perspective view, CRT3
1. A metal box-shaped case video 41 and a case video 4 that house a video amplifier and shield unnecessary radiation waves
1, a metal box-shaped external shield (referred to as a rear plate) 69 for housing the antenna 1 and shielding unnecessary radiation waves is shown. Although the actual configuration of the video display device 90 is more complicated and includes a wide variety of components, sparse components related to the present invention are omitted for simplification.

In the video display device 90, the CRT 31
The terminal 312 of the electron source (also referred to as a neck) 311 constituting the CRT 31 is inserted into the socket 11 of the video signal output circuit board 1 provided so as to cover the opening 411 of the case video 41. It is arranged as follows. Then, the case video 41 is stored in the rear plate 69,
It is configured to prevent unnecessary radiation from reaching the outside. The rear plate 69 is configured to be grounded by a configuration not shown.

FIG. 13 shows a state in which the video signal output circuit board 1 is mounted on the case video 41. As shown in FIG. 13, the video signal output circuit board 1 is disposed so as to cover the opening 411 of the case video 41, but is soldered to the ground pattern of the video signal output circuit board 1 and is electrically connected. Ground video (using braided wire, etc.) 13 is case video 41
It is configured to be screwed to. A grounding component (called a spring) 36 made of phosphor bronze and having a spring rigidity is attached to a grounding pattern (disposed on a side facing the rear plate 69) of the video signal output circuit board 1.

Here, FIG. 14 shows a video signal output circuit board 1.
1 shows an example of a ground pattern. In FIG. 14, a region indicated by hatching is a ground pattern 14, and a predetermined circuit pattern is provided in a region surrounded by the ground pattern 14, but is not shown. The spring 36 is fixed to the region 15 indicated by a broken line on the ground pattern 14 by soldering or the like.

When the case video 41 is stored in the rear plate 69, the spring 36 elastically contacts the inner wall surface of the rear plate 69, and ensures the potential of the ground pattern of the video signal output circuit board 1. This has the effect of fixing the ground potential.

[0008] Such a configuration is employed because the dimensional accuracy of the CRT 31 in the direction of the electron source 311 includes some errors and the video signal output circuit board 1 is warped due to the grounding of the video signal output circuit board 1 itself. Pattern the rear plate 69
This is because it is difficult to make direct contact with the object.

As described above, connecting the ground pattern portion of the video signal output circuit board 1 to the rear plate 69 and grounding it is taken as a measure to suppress the influence of unnecessary radiated radio waves.

As a countermeasure against high-frequency unnecessary radiated radio waves, it is necessary to make the potential of each part as close as possible to the same potential by grounding not only one place but also a plurality of places. , The ground line 13 is connected to the case video 41 (the same potential as the rear plate 69).

The spring 36 has a case video 41
When the video signal output circuit board 1 is stored in the rear plate 69, the video signal output circuit board 1 is pressed against the case video 41 to prevent the video signal output circuit board 1 from vibrating and loosening.

[0012]

As described above,
In the conventional video display device 90, the spring 36 made of phosphor bronze is used as one means for fixing the potential of the ground pattern of the video signal output circuit board 1 to the ground potential.

[0013] Phosphor bronze is a material whose rigidity is not easily lost due to aging and is also effective in terms of conductivity. However, it is very expensive in price, and its attachment is performed by soldering. So the work cost is high,
It was a measure against expensive unnecessary radiation waves.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is inexpensive in terms of cost, and does not use soldering for attachment to a video signal output circuit board, and is easy to attach. It is another object of the present invention to provide a video display device in which an unnecessary radiation wave countermeasure is taken by a grounding component having a function of preventing vibration and loosening of a video signal output circuit board.

[0015]

According to a first aspect of the present invention, there is provided an image display apparatus having a predetermined ground pattern, a video signal output circuit board for outputting a video signal, and a video signal output circuit board. A ground plate disposed at an interval and fixed to the ground potential, and a ground component disposed on the ground pattern and contacting the ground plate to fix the potential of the ground pattern to the ground potential. The grounding component is formed of a conductive member other than metal, and has elasticity at least in a direction perpendicular to the grounding pattern.

According to a second aspect of the present invention, the grounding component is made of conductive rubber.

According to a third aspect of the present invention, in the image display device, the grounding component is formed of a spongy conductive material.

According to a fourth aspect of the present invention, the shape of the grounding component is a rectangular parallelepiped or a cube.

According to a fifth aspect of the present invention, in the video display device, the grounding component includes at least one bent portion and has a shape having elasticity in a predetermined direction, and the predetermined direction corresponds to the ground pattern. It is disposed on the ground pattern so as to coincide with the vertical direction.

According to a sixth aspect of the present invention, in the video display device according to the first aspect, the grounding component contacts a main surface of the video signal output circuit board opposite to a side on which the ground pattern is formed. A body, a second structure that contacts the ground pattern, and a third structure that extends from the second structure to an opposite side of the first structure. The second structure is fixed across the periphery of the opening provided in the video signal output circuit board, and the third structure is in contact with the ground plate.

According to a seventh aspect of the present invention, in the video display device, the grounding component includes a resin material having at least one bent portion and having elasticity in a predetermined direction, and covering a surface of the resin material. And a conductive film disposed on the ground pattern so that the predetermined direction coincides with a direction perpendicular to the ground pattern.

[0022] In the video display device according to the present invention, the grounding component includes a sponge body and a sheet-like conductive rubber disposed so as to wrap the sponge body.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS <A. First Embodiment><A-1. Apparatus Configuration and Effects> FIG. 1 shows a video signal output circuit that outputs a video signal amplified by a video amplifier (not shown) that amplifies a video signal in video display apparatus 100 according to the first embodiment of the present invention. A means for fixing the potential of the ground pattern to the ground potential provided on the substrate and the ground pattern of the video signal output circuit board;
FIG. 4 is a perspective view showing a grounding component 4 which is one of the components.

The video display device 100 has a CRT, a case video, a rear plate, and the like, like the video display device 90 described with reference to FIG. 12, and the video signal output circuit board 1 has an opening for the case video. It is arranged to cover,
In order to clarify the features, the same reference numerals are given to the same configurations as those in the related art, and overlapping drawings and descriptions are omitted.
The same applies to the video display devices 200, 300, and 400 in the second, third, and fourth embodiments described below.

In FIG. 1, a grounding component 4 made of a rectangular parallelepiped conductive rubber is mounted on a grounding pattern 14 of the video signal output circuit board 1. The material of the grounding component 4 is, for example, a material containing silicone rubber as a main component and a conductive material for imparting conductivity, and has an electric resistivity of about 15 × 10 ⁻³ Ωm. The electric resistivity of phosphor bronze is 0.18 × 10 ⁻⁶ Ω.
m.

As described above, the grounding component 4 made of conductive rubber is placed on the grounding pattern 14 of the video signal output circuit board 1.
When the video signal output circuit board 1 is attached to the case video 41 (see FIG. 12) and the case video is stored in the rear plate 69 (see FIG. 12),
The grounding component 4 elastically comes into surface contact with the inner wall surface of the rear plate (grounding plate), so that the potential of the grounding pattern 14 of the video signal output circuit board 1 is reliably fixed to the grounding potential over a wide range. it can.

Also, since the grounding component 4 has elasticity, when the case video is stored in the rear plate, the video signal output circuit board 1 is pressed against the case video to vibrate the video signal output circuit board 1. And loosening can be prevented.

The grounding component 4 can be attached by applying a conductive adhesive (conductive silicone adhesive) to the surface of the grounding component 4 facing the ground pattern 14, compared to soldering. Work costs can be reduced.

<A-2. Modification 1> Instead of the adhesive, a projection may be provided on the grounding component 4, and the projection may be fitted into a hole provided on the video signal output circuit board 1.

FIG. 2 shows a grounding component 4A having a fitting projection 41 and a video signal output circuit board 1 having a fitting hole 16.
A is shown in a perspective view. The projection 41 of the grounding component 4A is provided on the surface facing the grounding pattern 14, and its tip is a conical wedge 411. The diameter of the fitting hole 16 of the video signal output circuit board 1A is slightly smaller than the diameter of the largest portion of the conical wedge 411 of the projection 41. When the projection 41 is inserted into the fitting hole 16, the diameter is easily reduced. Does not come off.

The length of the base 412 of the protrusion 41 is substantially the same as the thickness of the video signal output circuit board 1. When the protrusion 41 is inserted into the fitting hole 16, the grounding component 4 A is connected to the ground pattern 14. Will be in close contact with

By attaching the grounding component 4A to the video signal output circuit board 1A using a conductive adhesive, the adhesion can be further improved, and the potential can be fixed more reliably.

<A-3. Modification 2> In the above description, an example is shown in which only one relatively large grounding component 4 is used, but a plurality of grounding components may be provided.

That is, the image display device 100 shown in FIG.
As shown in A, a plurality of grounding parts 5 may be arranged on the grounding pattern 14 of the video signal output circuit board 1.

The grounding component 5 has a rectangular parallelepiped shape or a cubic shape, and is disposed on the grounding pattern 14 with an interval.

Thus, the relatively small grounding component 5 is
It is suitable when the shape of the ground pattern 14 is complicated and a large area cannot be obtained, and the material cost can be reduced.

The shape of the grounding component 5 is not limited to a rectangular parallelepiped or a cube, but may be a cylinder or a trapezoid.

<A-4. Modification 3> In the above description, an example in which the grounding component is made of a conductive rubber has been described. However, when the rubber itself has a high hardness or when a material having no elasticity is used, the structural It may have a resilient shape.

For example, the grounding component 6 shown in FIG. 4 has a substantially S-shaped cross section, and has a structure that bends when it receives a force in the direction of arrow A. Therefore, by arranging the main surface 61 or 62 of the grounding component 6 so as to abut on the grounding pattern 14, the length of the grounding component 4 shown in FIGS. And 5 (corresponding to the case where the dimension of the grounding component 6 in the B direction is shortened)
The same operation and effect as those described above can be obtained.

Although the grounding component 6 shown in FIG. 4 has a structure having two bent portions having opposite directions and a substantially S-shaped cross section, it is necessary to have a structural elasticity. A structure having only one bent portion, for example, a U-shaped or J-shaped cross section may be used.

<A-5. Modification 4> In the above description, an example was described in which the grounding component was formed of conductive rubber. However, the grounding component may be formed of conductive sponge instead of conductive rubber. As the material of the conductive sponge, a porous material obtained by combining conductive glass fibers in a mesh shape can be used.

The rigidity and resistivity of the conductive sponge are the same as those of the conductive rubber, but the sponge-like structure (sponge-like structure) of the conductive sponge has a large surface area. Since the high-frequency current flows only on the surface of the conductor due to the skin effect, the effect of eliminating the influence of the high-frequency unnecessary radiation can be obtained in the same manner as when a metal is used as the grounding component.

<B. Second Embodiment><B-1. Device Configuration and Effects> FIG. 5 shows a video signal output circuit for outputting a video signal amplified by a video amplifier (not shown) for amplifying a video signal in video display device 200 according to the second embodiment of the present invention. FIG. 2 is a perspective view showing a substrate 1B and a grounding component 7 which is provided on a grounding pattern 14 of the video signal output circuit board 1B and is one of means for fixing the potential of the grounding pattern 14 to a ground potential.

In FIG. 5, the video signal output circuit board 1B
The grounding pattern 14 is provided with an opening 17 for inserting the grounding component 7. Here, the shapes of the grounding component 7 and the opening 17 will be described with reference to FIG.

FIG. 6 is a perspective view showing a state before the grounding component 7 is inserted into the opening 17. As shown in FIG. 6, the shape of the grounding component 7 includes a substantially H-shaped main portion 71 for sandwiching the video signal output circuit board 1 </ b> B, and a main portion 71 provided integrally with the main portion 71. Parallel structures 711 and 712
It has a shape having a base 72 (third structure) extending in a direction perpendicular to the (first and second structures). The grounding component 7 is made of an elastic conductive material such as conductive rubber.

The opening 17 has an opening 171 having a width L1 equal to or slightly smaller than the dimension of the structure 711 of the main part 71 of the grounding component 7 in the direction indicated by the arrow S.
1 and an opening 172 having a width L2 equivalent to the dimension of the structure 713 in the direction indicated by the arrow S between the structures 711 and 712 of the main portion 71.

Therefore, by inserting the structure 711 into the opening 171 as shown in FIG. 6 and moving the grounding component 7 so that the structure 713 engages with the opening 172, the structure shown in FIG. In this state, the periphery of the opening 172 of the video signal output circuit board 1B is sandwiched between the structures 711 and 712, and the structure 712 comes into contact with the ground pattern 14. The grounding component 7 is firmly fixed by making the distance between the structures 711 and 712, that is, the length of the structure 713 substantially equal to the thickness of the video signal output circuit board 1B.

FIG. 7 schematically shows a state in which the grounding component 7 attached to the video signal output circuit board 1B is in contact with the rear plate 69 (grounding plate). As shown in FIG. 7, the base 72 of the grounding component 7 is bent, and its side surface is in elastic contact with the inner wall surface of the rear plate 69, and the potential of the ground pattern 14 of the video signal output circuit board 1 is changed to the ground potential. Can be fixed.

Further, since the grounding component 7 has elasticity, the video signal output circuit board 1B can be pressed against the case video to prevent vibration and loosening of the video signal output circuit board 1B.

<B-2. Modification> As a configuration of sandwiching a substrate, a grounding component 8 as shown in FIG. 8 can be used in addition to the grounding component 7 described above.

The grounding component 8 includes a conical wedge 81 (a first structure), a flange 82 (a second structure) disposed at an interval from the conical wedge 81, and a flange 82. Provided integrally,
A base 83 (third base) extending in a direction perpendicular to the flange 82
). The conical wedge 81
There is a structure 84 between the and the flange 82.

The shape of the opening of the video signal output circuit board into which the grounding component 8 is inserted is a circle whose diameter is slightly smaller than the diameter of the largest portion of the conical wedge 81. When inserted, the video signal output circuit board is sandwiched between the conical wedge 81 and the flange 82, and the flange 82 comes into contact with the ground pattern.

When the grounding component 8 comes into contact with the rear plate, the base 83 is bent, and the side surface thereof elastically contacts the inner wall surface of the rear plate, as in the grounding component 7 of the second embodiment. .

<C. Third Embodiment><C-1. Device Configuration and Effects> FIG. 9 shows a video signal output circuit for outputting a video signal amplified by a video amplifier (not shown) for amplifying a video signal in video display device 300 according to the third embodiment of the present invention. A means for fixing the potential of the ground pattern to the ground potential provided on the substrate and the ground pattern of the video signal output circuit board;
FIG. 2 is a perspective view showing a grounding component 9 which is one of them.

In FIG. 9, the grounding component 9 has a substantially J-shaped cross-sectional shape, and a metal deposition film (for example, aluminum deposition film) 91 is formed on the surface thereof. Although the base material of the grounding component 9 is a resin, it has a spring rigidity by being formed in a substantially J-shape, and a strength is obtained by increasing the thickness as compared with a case where the ground component is made of a metal plate. Like that.

The grounding component 9 having such a structure is formed by using a conductive double-sided tape, for example, a double-sided pressure-sensitive adhesive tape made of aluminum foil as a base material, and a conductive adhesive, for example, a conductive silicone adhesive. Attach it on the ground pattern 14, attach it to the case video 41 (see FIG. 12), and attach the case video to the rear plate 69 (FIG. 12).
(See FIG. 1), the grounding component 9 elastically comes into surface contact with the inner wall surface of the rear plate (grounding plate) to fix the potential of the grounding pattern 14 of the video signal output circuit board 1 to the ground potential. be able to.

<D. Fourth Embodiment><D-1. Device Configuration and Operation / Effect> FIG. 10 shows a video signal output circuit for outputting a video signal amplified by a video amplifier (not shown) for amplifying a video signal in video display device 400 according to the fourth embodiment of the present invention. A substrate 1 and a ground pattern of the video signal output circuit board 1,
FIG. 3 is a view showing a grounding component 10 which is one of means for fixing a potential of a grounding pattern to a grounding potential, and a rear plate 69. FIG. 11 shows an assembly drawing of the grounding component 10.

As shown in FIG. 11, the grounding component 10 is composed of a cylindrical sponge body 101 and a conductive rubber sheet 102 disposed so as to wind the sponge body 101. Sponge body 101 and conductive rubber sheet 10
2 is joined by an adhesive means such as a double-sided tape. The grounding component 10 is mounted on the grounding pattern of the video signal output circuit board 1 with a conductive double-sided tape, for example, a double-sided adhesive tape having aluminum foil as a base material, and a conductive adhesive, for example, a conductive silicone adhesive. .

When the video signal output circuit board 1 to which the grounding component 10 having such a configuration is mounted is mounted on the case video 41 (see FIG. 12) and the case video is housed in the rear plate 69 (grounding plate), FIG. As shown in
The grounding component 10 elastically comes into surface contact with the inner wall surface of the rear plate 69, so that the potential of the ground pattern of the video signal output circuit board 1 can be fixed to the ground potential.

Usually, conductive rubber is more expensive than general rubber in terms of cost. Therefore, this embodiment, which requires less conductive rubber, is advantageous in terms of product cost.

In the above description, the grounding component 10
Is a cylindrical shape, but it goes without saying that it may be a rectangular parallelepiped.

[0062]

According to the image display device of the first aspect of the present invention, since the grounding component is formed of a conductive member other than metal, the mounting to the grounding pattern is performed using, for example, a conductive adhesive. By doing so, there is no need to perform soldering, and the working cost can be reduced. In addition, since the grounding component has elasticity, the video signal output circuit board is pressed in a direction opposite to the ground plate by bringing the ground component attached to the video signal output circuit board into contact with the ground plate. This can eliminate the influence of the unnecessary radiated radio wave and prevent the vibration and loosening of the video signal output circuit board.

According to the image display device of the second aspect of the present invention, since the grounding component is made of conductive rubber, the degree of freedom of the shape of the grounding component is high. By fitting it into an opening provided in the video signal output circuit board, a grounding component can be attached.

According to the third aspect of the present invention, since the grounding component is made of a spongy conductive material, its surface area is large. Since the high-frequency current flows only on the surface of the conductor due to the skin effect, the effect of eliminating the influence of the high-frequency unnecessary radiation can be obtained in the same manner as when a metal is used as the grounding component.

According to the video display device of the fourth aspect of the present invention, since the shape of the grounding component is a rectangular parallelepiped or a cube, the contact area with the grounding pattern and the grounding plate can be increased. In addition, since the structure is simple, the cost for manufacturing can be reduced.

According to the image display device of the fifth aspect of the present invention, since the grounding component includes at least one bent portion and has a shape having elasticity in a predetermined direction, the member itself has elasticity. Even if such a material is not used, the video signal output circuit board can be pressed in the direction opposite to the ground plate, and vibration and loosening of the video signal output circuit board can be prevented.

According to the image display device of the sixth aspect of the present invention, since the grounding component is fixed by sandwiching the video signal output circuit board between the first and second structures, a conductive adhesive or the like can be used. This eliminates the need to use the device, thereby reducing the operation cost.

According to the image display apparatus of the present invention, the grounding component has a resin material having an elasticity,
Since it is composed of the conductive film covering the surface, an inexpensive image display device can be obtained.

According to the video display device of the present invention, since the grounding component is composed of the sponge body and the sheet-like conductive rubber disposed so as to wrap the sponge body, An image display device which is inexpensive can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a characteristic portion of a video display device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration of a characteristic portion of a modification of the first embodiment of the video display device according to the present invention.

FIG. 3 is a diagram illustrating a configuration of a characteristic portion of a modification of the first embodiment of the video display device according to the present invention.

FIG. 4 is a diagram illustrating a configuration of a characteristic portion of a modification of the first embodiment of the video display device according to the present invention.

FIG. 5 is a diagram illustrating a configuration of a characteristic portion of a video display device according to a second embodiment of the present invention.

FIG. 6 is a diagram illustrating a configuration of a characteristic portion of a video display device according to a second embodiment of the present invention.

FIG. 7 is a diagram illustrating the operation and effect of the image display device according to the second embodiment of the present invention.

FIG. 8 is a diagram illustrating a configuration of a characteristic portion of a modification of the video display device according to the second embodiment of the present invention.

FIG. 9 is a diagram illustrating a configuration of a characteristic portion of a video display device according to a third embodiment of the present invention.

FIG. 10 is a fourth embodiment of the video display device according to the present invention.
It is a figure explaining composition of a characteristic part.

FIG. 11 is a fourth embodiment of the video display device according to the present invention.
It is a figure explaining the assembling state of the characteristic part of FIG.

FIG. 12 is an exploded perspective view illustrating a configuration of a general video display device.

FIG. 13 is a diagram illustrating a configuration of an unnecessary radiation wave measure of a general video display device.

FIG. 14 is a diagram illustrating a ground pattern of a video signal output circuit board of a general video display device.

[Explanation of symbols]

1, 1A, 1B video signal output circuit board, 4, 4A, 5
To 10 grounding parts, 14 grounding patterns, 91 metallized films, 711, 712 structures, 101 sponge bodies,
102 conductive rubber sheet.

Claims (8)

[Claims] A video signal output circuit board having a predetermined ground pattern and outputting a video signal; a ground plate disposed at an interval from the video signal output circuit board and fixed to a ground potential; A ground component disposed on the ground pattern and contacting the ground plate to fix the potential of the ground pattern to a ground potential, wherein the ground component is a conductive material other than metal. An image display device comprising: an elastic member; and having elasticity at least in a direction perpendicular to the ground pattern. 2. The image display device according to claim 1, wherein said grounding component is made of conductive rubber. 3. The image display device according to claim 1, wherein said grounding component is made of a conductive material having a spongy structure. 4. The image display device according to claim 2, wherein the shape of the grounding component is a rectangular parallelepiped or a cube. 5. The grounding component includes at least one bent portion and has a shape having elasticity in a predetermined direction. The video display device according to claim 2, wherein the video display device is disposed on a display. 6. A first structure that contacts a main surface of the video signal output circuit board opposite to a side on which the ground pattern is formed, and a second structure that contacts the ground pattern. And a third structure extending from the second structure to a side opposite to the first structure, wherein the first and second structures are used to output the video signal output circuit board. The image display device according to claim 2, wherein the third structure contacts the ground plate, and is fixed with the periphery of the opening provided in the second member interposed therebetween. 7. The grounding component includes a resin material having at least one bent portion and having elasticity in a predetermined direction, and a conductive film covering a surface of the resin material, wherein the predetermined direction is provided. 2. The image display device according to claim 1, wherein the image display device is disposed on the ground pattern so as to coincide with a direction perpendicular to the ground pattern. 8. The image display device according to claim 1, wherein the grounding component has a sponge body and a sheet-like conductive rubber disposed so as to wind the sponge body.