JP2822304B2 - Exterior structure of audio equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio equipment such as an audio amplifier and, more particularly, to an exterior structure of an audio equipment for obtaining good sound quality.

[0002]

2. Description of the Related Art Acoustic equipment is always required to have better sound quality, and improvements are being made from various viewpoints.

The causes that affect the sound quality of audio equipment are not limited to elements directly related to the audio signal, such as the circuit system and circuit components, but are also indirect, such as the structure and material of the exterior body of the audio equipment. It is already known that components cannot be ignored.

However, in audio equipment, it is often difficult to express the quality of sound quality in measurement data even though there is a difference when heard by ear. For example, the deterioration of sound quality due to the passage of a switch is caused by the difference in the material of the contact portion, which is said to be excellent in gold, but it is difficult to express the fact by measurement. In addition, although the sound quality changes even when the purity of the wire material of the electric wire is increased, quantitative measurement cannot be performed for this as well. However, none of them, in theory, without various losses gives good results in most cases.

Conventionally, it has been said that there are many cases where the outer case of an audio device such as an audio amplifier is made of aluminum and has better sound quality than the case where the outer case is made of iron. . It has been known that the sound quality can be further improved by listening to the music after removing the cover of the outer case.

The cause of such a change in sound quality (deterioration) is as follows.
It is generally said that the loss is caused by eddy current generated in the exterior member of the device. It is said that iron material has poor sound quality, aluminum material is good, thin aluminum vapor deposition layer and foil have further improved sound quality, and it is said that the best is that such outer material is not used This is because they can explain the facts well.

The eddy current is proportional to μ ² / R, where μ is the magnetic permeability of the material and R is the resistance of the material. Therefore, in the case of iron having a large μ, this becomes effective in the square, so that the loss due to the eddy current is large and the sound quality is extremely deteriorated. On the other hand, for aluminum, μ is 1
, And not very large. Furthermore, in the case of an aluminum vapor-deposited layer or foil, the value of R becomes larger, so that it goes in a better direction. Ultimately, if there is no such constituent material, the eddy current becomes 0 and the effect is not exerted. .

[0008]

SUMMARY OF THE INVENTION
It is preferable that the structure of the exterior material of the audio equipment does not generate eddy current. To this end, it is conceivable that an electrically conductive member such as iron or aluminum is not used, and an insulating member such as wood or plastic is used, or the exterior member is omitted.

However, omitting the outer case member is difficult to implement because it does not constitute a form of an acoustic device, or secures electrical safety. Also, if the exterior material is made of an insulating material, the shielding effect cannot be obtained,
Interference from radios and radios, or pulling hum from the power supply causes noise and causes practical problems.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an acoustic device having excellent sound quality performance by obtaining an exterior structure of the acoustic device which has a shielding effect and does not generate eddy current loss.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides a structure in which a part or the whole of an exterior member such as an exterior case for housing audio equipment is independent of each other, that is, is provided with an electrically conductive layer adjacent to the exterior. The present invention is characterized in that a conductive member layer having a pattern formed of a group of strip-shaped strips that are separated and adjacent to each other is used.

Further, according to the present invention, the pattern composed of a group of fine wires which are independent and close to each other is formed by printed wiring on a printed wiring board. Alternatively, it is also characterized in that a conductive member is formed on the surface of the insulating member by vapor deposition or printing.

Further, according to the present invention, the printed wiring board or the insulating member having the pattern of the thin line groups which are independent and close to each other also serves as a part or all of the outer case of the audio equipment. And

Further, the present invention is characterized in that the line width of the pattern of the thin line group of the conductive member is 5 mm or less.

[0015]

As described above, according to the present invention, the conductive layer of the exterior member accommodating the audio equipment is formed of strip-shaped thin wires arranged independently and in close proximity to each other. Therefore, they are electrically connected at the minimum points.

As a result, eddy currents induced by magnetism in a transformer or the like of an acoustic device are generated in a thin wire portion made of a conductive member. It will be slight. The loss due to the eddy current generated in the coupling member can be suppressed to a range where the adverse effect on the sound quality can be ignored. Moreover, if the conductive layer is a thin layer such as a conductive pattern of a printed wiring board,
The resistance value is higher than that of a conventional metal case or the like, and the eddy current can be reduced from this point as well.

Further, according to the present invention, since the pattern made of the fine wire-shaped conductive member is formed adjacently, if this pattern is grounded, the same shielding effect as the conventional one can be obtained with respect to noise due to external hum and the like. Can be

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments. FIG. 1 is a perspective view showing an embodiment having an exterior structure of an audio device according to the present invention. The figure shows an assembled state of the audio amplifier 1. The audio amplifier 1 houses therein circuit components such as a circuit board, a transformer, and a switch, and various switches and knobs are mounted on a front operation panel 2. The rear surface is composed of a rear panel 3 provided with connection terminals for various devices, and the front and rear operation panels 2 and the side surfaces of the rear panel 3 are formed by side panels 4.

Further, a top plate 5 and a bottom plate 6 are attached to the top and bottom portions of the audio amplifier 1 by known means such as screws, respectively, and these panels constitute an exterior case. Reference numeral 10 denotes a screw hole for mounting the top plate 5 and the bottom plate 6.

The top plate 5 and the bottom plate 6 are made of a printed wiring board 7 made of glass epoxy resin, and a copper foil portion 8 on the board is formed by etching a predetermined pattern by the same means as used for forming a normal printed circuit. Have been. As shown in FIG. 2, the dividing line 9 formed by this etching has a fishbone-like shape in which a large number of straight thin lines are formed adjacent to and parallel to the surface of the substrate 7, and these thin lines and one straight thin line are perpendicular to the thin lines. Has a pattern.

Therefore, the copper foil portion 8 of the substrate 7 is divided into a certain strip-shaped thin line by the dividing line 9 by etching. Then, this substrate 7 is connected to the audio amplifier 1
If the screw is used, the copper foil portion 8 remains on the outer periphery of the substrate 7, and is grounded to the chassis of the audio amplifier 1 via the screw hole 10, so that a shielding effect can be obtained.

Next, an experiment was conducted on the change in sound quality. In the experiment, the pattern of the top plate 5 and the bottom plate 6 was changed using the audio amplifier 1 having the structure shown in FIG. As a comparative example, a case where the top plate 5 and the bottom plate 6 were removed, and a case where the copper foil portion 8 was formed on the entire surface of the top plate 5 and the bottom plate 6 before pattern formation were prepared and auditioned. Next, the copper foil part 8 was cut by a cutter into the copper foil part 8 so that the pattern shown in FIG. 2 was obtained, and the copper foil part 8 was divided into strip-shaped thin wire groups. By this division, the width of the pattern thin line indicated by L in FIG.
mm, and then put the dividing line 9 in the middle so that the fine line becomes a half width, that is, 5 mm, and increase it. Finally, further subdivide the L so that it becomes 2.5 mm, and listen to each sample. Done.

The sample was heard without the top plate 5 and the bottom plate 6 and used as a reference. Next, when the whole surface on which no pattern was formed was covered with copper foil and the sound was heard and compared, it was found that the sound was bad and the difference was immediately recognized. Next, when the width of the thin line is 10
When listening to a sample with a diameter of mm, the deterioration of the sound quality was reduced, but the deterioration is still apparent. Further, when the width of the thin line was set to 5 mm, the change was extremely small as to whether or not the sound changed, and when the width was 2.5 mm, it was impossible to determine at all.

From the above, it has been found that when the width L of the fine line is set to 5 mm or less, a product having no difference in sound quality from that obtained by removing the panel can be obtained. The width of the insulating portion formed by etching or cutting is not particularly limited because the object of the present invention can be achieved by dividing the adjacent conductive pattern. However, if the width is increased, the shielding effect is reduced. Therefore, the width may be set in consideration of the shielding effect.

FIG. 3 shows another embodiment of the present invention, and shows a pattern formed on the surface of the printed wiring board 7. In this embodiment, the copper foil portion 8 of the substrate 7 including the outer peripheral portion is removed by etching, and the copper foil portion 8 which is a conductive pattern is left in a fishbone shape, contrary to the one shown in FIG. Even in such a form, since the conductive layers are in the form of strips independent of each other, eddy current can be similarly reduced and a shielding effect can be obtained. However, in the case of this embodiment, since the grounding of the conductive pattern cannot be performed through the screw hole 10 simply by attaching the substrate 7 to the amplifier, a lead wire is connected to any part of the conductive pattern and this lead wire is connected to the audio. It is necessary to electrically connect to the ground portion of the amplifier 1 to perform grounding.

FIG. 4 shows another embodiment of the fine line pattern of the conductive layer formed on the surface of the insulating member.
Is formed by appropriately dividing the dividing line 9 in the vertical and horizontal directions.
FIG. 2B shows a state in which the dividing lines 9 are provided in parallel in an oblique direction. FIG. 4C shows a case where the dividing line 9 is formed in a branch shape in the vertical and horizontal directions from the intersecting diagonal straight line.

In the embodiment of the present invention, the audio amplifier 1 has a top plate 5 and a bottom plate 6 each having a predetermined pattern formed on a printed circuit board 7 made of glass epoxy resin.
The present invention is not limited to such a form,
It is also possible to use one in which a predetermined conductive pattern is formed on the surface of the insulating member by vapor deposition, or one in which a predetermined pattern is printed with conductive ink.

In the embodiment, the printed wiring board 7 is used as a panel for the top plate 5 and the bottom plate 6 which have a large occupied area in the outer case. It is also possible to use for the part. Furthermore, a structure in which a predetermined conductive pattern is formed on the surface of a sheet-shaped edge member, instead of using a printed wiring board, may be attached to the inner surface or the like of an acoustic device exterior member made of wood or plastic.

[0029]

As described above, according to the present invention, in an audio equipment, while having a shielding effect of the equipment,
An exterior body structure that prevents deterioration of sound quality due to eddy current loss can be obtained.

In addition, since the exterior structure can use an existing printed wiring board or the like, it is possible to obtain effects such as maintenance of mechanical strength, versatility, and low production cost.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an assembly structure of an audio amplifier according to the present invention.

FIG. 2 is a plan view showing a structure of a top plate or a bottom plate of an outer case used in the present invention.

FIG. 3 is a plan view of another embodiment showing a structure of a top plate or a bottom plate of an exterior case used in the present invention.

FIG. 4 is a plan view showing another embodiment of the conductive layer pattern of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Audio amplifier 2 Operation panel 3 Back panel 4 Side panel 5 Top plate 6 Bottom plate 7 Substrate 8 Copper foil part 9 Split wire 10 Screw hole

Claims (5)

(57) [Claims] 1. A sound characterized by using a conductive member layer having a pattern consisting of a group of fine wires that are independent and close to each other on a part or the entire surface of an exterior member for housing an audio device. Equipment exterior structure. 2. The exterior body structure of an audio device according to claim 1, wherein the pattern composed of a group of fine lines which are independent and close to each other is formed by printed wiring of a printed wiring board. 3. A pattern comprising a group of fine lines which are independent and close to each other is formed by depositing or printing a conductive member on the surface of an insulating member.
The exterior body structure of the audio equipment according to the above. 4. A printed wiring board or an insulating member having a pattern consisting of a group of fine wires which are independent and close to each other,
The exterior body structure of an audio equipment according to claim 1, wherein the exterior body structure is a part or all of a panel of an exterior case of the audio equipment. 5. The exterior body structure of an acoustic device according to claim 1, wherein the line width of the conductive member layer pattern of the thin wire group is 5 mm or less.