JP2001216850A - Wiring cable for audio unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wiring cable for audio units that can suppress propagation of mechanical vibration between mutual audio units or electric components inside an audio unit and realize reproduced sound infinitely close to the original sound. SOLUTION: In the wiring cable 5 there are equipped with central conductor 20 for audio units a plurality of mass increasing metals 21 made of a body to increase mass per unit length to be higher than that at the central conductor 20 thereon repeated at a prescribed separation interval. Here, the mass increasing metal 21 is for instance made of a body with cross section for the unit length larger than the central conductor. Each mass increasing metal 21 is formed by attaching to periphery of the central conductor 20 as shown in Figs. 2 and 4. In place of each mass metal 21, a mass increasing portion 31 may be formed integrally with the central conductor 20, as shown in Fig. 6 or 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio wiring cable used between various audio devices or for internal wiring of audio devices.

[0002]

2. Description of the Related Art In a conventional audio wiring cable, there are some ideas regarding measures against mechanical vibrations, in particular, measures against longitudinal wave vibrations. (Hereinafter, this is referred to as a conventional example; see, for example, Japanese Patent Application Laid-Open No. H10-66231). Also, there is no sufficient countermeasure against sound quality deterioration due to contact between the conductor and the covering member. In particular, no countermeasure has been taken for longitudinal waves and shear waves at the same time.

[0003]

As described above, in the conventional audio wiring cable, there is hardly any one that takes measures against mechanical vibrations into consideration, and attention is paid only to electrical phenomena and electromagnetic phenomena, and the sound quality is reduced. I was trying to improve it.
In addition, even for wiring materials with vibration countermeasures, a method is adopted in which a heavy metal is fixed in the middle of the conductor and the metal is fixed to the base etc. through a cushioning material, so the use site is limited. There was a problem such as being done.

[0004] However, even if the above-mentioned conventional audio wiring cable is used to reproduce an audio signal with high fidelity, the sound quality is significantly degraded due to mechanical vibration or the sound quality grade is stabilized. There was a problem that I could not keep it.

An object of the present invention is to solve the above problems and suppress transmission of mechanical vibration between audio devices or between electric components inside the audio device, thereby realizing a reproduced sound that is as close as possible to the original sound. It is an object of the present invention to provide an audio wiring cable capable of performing the above-mentioned operations.

[0006]

According to a first aspect of the present invention, there is provided an audio wiring cable according to the first aspect of the present invention, which is an audio wiring cable provided with a conductor, wherein the mass per unit length is repeated on the conductor at a predetermined interval. And a plurality of mass increasing members made of an object that increases the number of wires above the conducting wire.

According to a second aspect of the present invention, there is provided an audio wiring cable according to the first aspect, wherein each of the mass increasing members has an object which increases a sectional area per unit length more than the conductive wire. It is characterized by becoming.

[0008] Further, according to a third aspect of the present invention, in the audio wiring cable according to the first or second aspect, each of the mass increasing members is formed by being added around the conductor. And

According to a fourth aspect of the present invention, there is provided an audio wiring cable according to the first or second aspect, wherein each of the mass increasing members is formed integrally with the conductor. I do.

According to a fifth aspect of the present invention, there is provided an audio wiring cable according to any one of the first to fourth aspects, wherein the audio wiring cable is formed around the conductor and is made of an electrically insulating material. The covering member for covering the conductor, the conductor and each of the mass increasing members, formed so as to be interposed between the covering member, made of an electrically insulating material, and contacting the conductor and the covering member. A contact preventing member for preventing the contact, wherein a space is interposed between the conductive wire and the contact preventing member.

Further, the audio wiring cable according to claim 6 is the audio wiring cable according to claim 5, wherein the contact preventing member is made of cotton or silk.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

<Embodiment> FIG. 1 is a block diagram of an audio system for explaining an audio shield cable 4 and an audio single cable 5 which are audio distribution cables according to an embodiment of the present invention. The form when these cables 4 and 5 are used for connection between audio devices is shown.

As shown in FIG. 1, the audio system comprises an audio signal reproducing apparatus 1, a main amplifier 2 called a so-called main amplifier, and a speaker 3, wherein the audio signal reproducing apparatus 1 and the main amplifier 2 are connected by a shielded audio cable 4, and the main amplifier 2 and the speaker 3 are connected by a pair of single audio cables 5.

In the audio system configured as described above, for example, an audio signal (audio signal) which is a low-frequency signal reproduced by an audio signal reproducing apparatus 1 such as a record player, a compact disk (CD) player, a DVD player, and an MD player. Also called a signal.)
Are output to the main amplifying device 2 via the shielded audio cable 4, and the main amplifying device 2 amplifies the input audio signal and outputs the amplified audio signal to the speaker 3 via the single audio cable 5, Converts an input audio signal into an audible sound and reproduces it.

In the audio system shown in FIG. 1, for the sake of simplicity, the case of reproducing one-channel audio signal is shown. However, in the case of reproducing right and left channel stereo signals, each channel is reproduced. An audio shielded cable 4 and a pair of single audio cables 5 are provided, and an audio signal is transmitted for each channel via the audio shielded cable 4 and the single audio single cable 5. Although the audio system of FIG. 1 shows a case of an analog audio signal, it may be a digital audio signal. Furthermore, the cable according to the present embodiment can be applied to connection of various audio devices including video devices that also reproduce audio signals.

As described above, even if the aim is to reproduce an audio signal with a high fidelity using the conventional audio wiring cable, the sound quality is significantly degraded due to the mechanical vibration or the sound quality grade is stabilized. There was a problem that it could not be kept. According to experiments and considerations by the present inventors, the cause of this is that the electronic components in the audio signal reproducing apparatus 1 vibrate during reproduction of an audio signal, and the vibration is generated via the center conductor of the audio wiring cable. It has been found that the sound is transmitted in the form of longitudinal vibration and convolved with the electric signal of each device, deteriorating the quality of reproduced sound. In order to prevent this phenomenon, in the embodiment according to the present invention, as means for attenuating longitudinal wave vibration transmitted through the center conductor,
In the middle of the center conductor 20 and the conductor 30, the conductors 20,
A method of forming a mass increasing conductor 21 or a mass increasing portion 31 larger than the mass per unit length of 30 and reflecting and attenuating vibration by rapidly changing mechanical impedance is used.

<First Embodiment> FIG. 2 is a partially cutaway side view showing a structure of a shielded audio cable 4 according to a first embodiment of the present invention, and FIG.
FIG. 4 is a vertical cross-sectional view showing a cross section of the A ′ plane, and FIG.
It is a longitudinal cross-sectional view which shows the cross section of B 'side.

In FIG. 2, for example, a center conductor 20, which is made of a metal such as copper, gold or silver, and is a conductor having a predetermined length,
A plurality of, for example, spherical mass-increasing conductors 21 made of a metal such as lead or copper are repeated at predetermined intervals in the longitudinal direction of the center conductor 20, caulked and fixedly attached. Here, in each mass increasing conductor 21,
As shown in FIG. 4, a through-hole 21 a is formed to pass through the center thereof, the center conductor 20 is passed through the through-hole 21 a, and the mass increasing conductor 21 is swaged from the outside to the inside of the mass increasing conductor 21. 21 is fixed to the center conductor 20. A covering member 23 that functions as a longitudinal vibration absorbing lining member and that is made of a natural insulating material such as cotton or silk is provided on the outer periphery of the center conductor 20 and the mass increasing conductor 21 via a space 22. Is wound. further,
On the outer periphery of the covering member 23, for example, a metal such as copper, gold, or silver is formed, for example, a net-shaped ground conductor 24 is formed,
Further, an outer cover member 25 made of an electrically insulating material such as a synthetic resin such as vinyl is formed on the outer periphery of the ground conductor 24 at the outermost side of the audio shield cable 4.

Here, the space 22 and the covering members 23 and 25 located inside the ground conductor 24 are
The configuration is such that the zero and the mass increasing conductor 21 are not tightened, that is, the mechanical vibration in the center conductor 20 and the mass increasing conductor 21 is not forcibly suppressed. This will be described in detail below. Even if any material is used as the covering member in the present embodiment, deterioration in sound quality is inevitable, and it is best to use a bare wire. In particular, if the central body 20 is strongly tightened with a petroleum-based insulating tube, the sound quality is significantly deteriorated, but it is essential to electrically insulate it from other conductors, and it is not practical with bare wires. Therefore, in the present embodiment, by taking into account the thicknesses of the covering member 23 and the grounding conductor 24, by using the covering member 25 having an inner diameter slightly larger than the outer diameter of the mass increasing member 21, the fastening by the covering member 25 is performed. In order to prevent the mass increasing conductor 21 from directly contacting the grounding conductor 24 and the covering member 25, the covering member 25 and the grounding conductor 2
The inner surface of No. 4 is lined with an electrically insulating material made of a natural material such as cotton or silk to prevent a contact vibration between the covering member 25 which is a jacket and the mass increasing conductor 21.

One end of the center conductor 20 is connected to the center conductor 11a of the pin plug 11, and one end of the ground conductor 24 is connected to the ground conductor 11b of the pin plug 11. On the other hand, the other end of the center conductor 20 is connected to the center conductor 12a of the pin plug 12.
, And one end of the ground conductor 24 is connected to the ground conductor 12 b of the pin plug 12.

In this embodiment, the conductor of the central conductor 20 is, for example, 0.32 mm in diameter and 1000 m in length.
For example, a spherical lead material having a diameter of 5 mm can be used as the mass increasing conductor 21.

In the present embodiment, a plurality of mass-increasing conductors 21 are repeatedly fixedly formed at predetermined intervals on the center conductor 20, but this means that an audio signal is transmitted through the center conductor 20 as described below. Central conductor 2 generated when transmitting
It is used to greatly attenuate the mechanical vibration of longitudinal waves propagating through zero.

It is generally known that when a longitudinal wave propagates through a medium having a different characteristic impedance, reflection occurs at a portion where the characteristic impedance changes, and apparent attenuation occurs. The characteristic impedance Z of the medium is expressed by the following equation.

## EQU1 ## Z = mc

Here, m is the mass of the medium (the conductor 20 and the mass increasing conductor 21 in the present embodiment) per unit length, and c is the speed of sound in the medium. Further, using the density ρ of the medium and the cross-sectional area A, it is expressed by the following equation.

## EQU2 ## Z = ρA

A longitudinal wave such as a sound wave is transmitted from the first medium having the characteristic impedance Z ₁ to the characteristic medium having the characteristic impedance Z _2.
The amplitude reflectance r when propagating to the second medium is expressed by the following equation.

R = (Z ₁ −Z ₂ ) / (Z ₁ + Z ₂ )

In this case, the amount of attenuation R of the propagating signal is expressed by the following equation.

R = 10 × log (1 / (1-r ² )) [dB]

According to the equations for calculating the amplitude reflectance r and the attenuation R, when the characteristic impedance Z ₂ of the _second medium becomes 14 times or more larger than the _first characteristic impedance Z ₁ ,
The amount of attenuation R is 6 dB. 6 dB is a general value that can be effectively heard by a person, and the effect of the vibration isolator of the present invention can be determined. When the characteristic impedance Z2 of the _second medium is 62 times or more the characteristic impedance Z1 of the _first medium, the attenuation R becomes 12 dB.
It is needless to say that the attenuation R is more preferably 18 dB or more in terms of audibility.
In this case, the characteristic impedance Z ₂ of the _second medium is
Is about 250 times that of the medium of the characteristic impedance Z ₁ of the.
In the present embodiment, the attenuation R is preferably 18 dB.
The above is necessary, and more preferably, from 10 dB to 10
It must be 0 dB.

In general, the characteristic impedance is equal to the product of the mass per unit length of the medium and the propagation velocity as described above, and the propagation velocity is related to the density and Young's modulus of the medium. A medium having a density and a speed of sound several times higher than that of (for example, copper) is not realistic, so that the cross-sectional area is actually changed. That is, as shown in FIGS. 2 to 4, the cross-sectional area of the mass increasing conductor 21 is set to be larger than the cross-sectional area of the center conductor 20, thereby changing the characteristic impedance and reducing the vibration of the longitudinal wave. Attenuated.

As described above, the mass-increasing conductor 21 according to the present embodiment is not a one-point-concentrated type which has been tried in some prior arts, but a small-sized mass-increasing conductor that can be inserted into the covering members 23 and 25. A so-called dispersion method in which the conductors 21 are repeatedly and continuously fixed at predetermined intervals on the center conductor 20 is employed. This small mass-increasing conductor 21 has a small amount of attenuation of longitudinal waves per one, but a large amount of attenuation can be obtained as a whole by repeating it continuously over multiple stages.

In consideration of the thicknesses of the covering member 23 and the grounding conductor 24, by covering with a covering member 25 having an inner diameter slightly larger than the outer diameter of each mass-increasing conductor 21, stability of electric insulation at the time of wiring is stabilized. Thus, it is possible to provide a highly convenient audio wiring cable that can be cut at an arbitrary length while ensuring the audio performance.

Further, the inner surfaces of the covering member 25 and the grounding conductor 24 are lined with a covering member 23 made of a natural material such as cotton or silk, so that the mass increasing conductor 21 directly contacts the grounding conductor 24 and the covering member 25. Is prevented, mechanical vibration of the mass increasing conductor 21 itself can be damped, and the fidelity of signal transmission can be further improved.

<Second Embodiment> FIG. 5 is a partially cutaway side view showing the structure of a single audio cable 5 according to a second embodiment of the present invention. This audio single cable 5 is the audio shield cable 4 shown in FIG.
Compared to the first embodiment, a single wire structure is employed without forming the ground conductor 24. At both ends of the single audio cable 5, the center conductor 20 is drawn out in the form of a bare wire and connected to a predetermined terminal. The audio single cable 5 configured as described above has the same operational effects as the audio shielded cable 4 according to the first embodiment, except for the electromagnetic shielding effect.

<Third Embodiment> FIG. 6 is a side view showing the structure of a single audio cable 6 according to a third embodiment of the present invention. The single audio cable 6 includes a conductor 30 and a mass increasing portion 31 formed integrally therewith, and does not form a covering member.

In the present embodiment, the conductor 3 is a conductor.
It is manufactured by repeatedly forming a plurality of mass-increasing members 31 which are bump-like ridges at a predetermined interval on the upper surface of the lens. Since the single audio cable 6 can be cut to an arbitrary length in accordance with the distance between the components to be connected, it can be applied to a portion that does not require insulation. As the conductor of the conductor 30, for example, a diameter of 0.32
mm in a conductor of an arbitrary length, and as the mass increasing portion 31,
For example, a bump having a diameter of 3 mm may be used. However, these are merely examples, and various changes can be made in accordance with the use situation.

Therefore, according to the present embodiment, the mass increasing portion 31 repeatedly formed at predetermined intervals on the conductor 30 is not used as an external additional member as in the first embodiment, and the conductor 30 itself is locally bumped. By forming in the shape, the same operation and effect as in the first embodiment can be obtained. This audio single cable 6 can be used as well as general wiring materials.

<Fourth Embodiment> FIG. 7 is a partially cutaway side view showing the structure of a single audio cable 7 according to a fourth embodiment of the present invention. The single audio cable 7 according to this embodiment is different from the single audio cable 6 according to the third embodiment in that the conductor 30 and the mass increasing portion 31 in the single audio cable 6 according to the third embodiment are replaced with the single audio cable 5 according to the second embodiment.
A single audio cable 5
Are formed in place of the conductor 20 and the mass-increasing conductor 21 of FIG. The single audio cable 7 is applicable to a covered wiring cable for connecting components within an audio device. Therefore, according to the present embodiment,
In addition to the effects of the third embodiment, the conductor 30 can be covered and wired.

[0038]

EXAMPLE In the second embodiment, since a plurality of mass increasing conductors 21 are formed at predetermined intervals on the center conductor 20, the attenuation R per one mass increasing conductor 21 is 6 dB. By forming the two mass-increasing conductors 21, the attenuation R can be reduced to 12 dB. However, if the distance is too small, the effect is reduced.

In the experiment of the single audio cable 5 by the present inventor, 19 5gr mass increasing conductors 21 were fixed on a 2m center conductor 20 at intervals of 0.1m on a 2m center conductor 20.
The weight ratio of the center conductor 20 to the mass increasing conductor 21 is set to 70 to 8
It was made 0 times. At this time, it was confirmed that the attenuation R was 12 dB or more per one mass-increasing conductor 21, which cleared 200 dB in the entire length, and that the longitudinal wave vibration was completely cut off.

For example, in the single audio cable 5 according to the second embodiment, the formation interval of the mass-increasing conductor 21 is preferably about 10 to 20 cm, and the audio shield cable 4 according to the first embodiment is preferably used. In this case, an interval of about 5 cm is appropriate and practical.

<Modification> In the first embodiment described above, the ground conductors 24 are connected at both ends of the audio wiring cable 4, but only one end is connected to the ground conductor 2.
4 may be connected. In addition, a plurality of mass increasing conductors 21 are provided inside the grounding conductor 24 and the covering member 24, respectively.
May be accommodated. In this case, a balanced cable in which a pair of center conductors 20 are insulated from the ground conductor 24 or an unbalanced cable in which one center conductor 20 is connected to the ground conductor 24 may be used.

The shielded audio cable 5 and the single audio cables 6, 7, 8 according to the present invention can be widely applied not only to general audio equipment, but also to televisions and medical equipment for processing high-frequency band signals. The same operation and effect can be obtained.

In the above embodiment, the mass increasing conductor 2
1 and the mass increasing portion 31 are made of an object such as a solid, a rigid body, or a rigid body. Here, instead of the mass increasing conductor 21, an object having no conductivity may be used.

[0044]

As described above in detail, according to the audio wiring cable according to the present invention, in the audio wiring cable provided with the conductor, the mass per unit length is repeated on the conductor at a predetermined interval. A plurality of mass-increasing members made of an object to be increased more than the conductive wire are provided. Here, each of the mass increasing members is preferably made of an object having a cross-sectional area per unit length larger than that of the conductive wire.
Further, each of the mass increasing members is formed by being added around the conducting wire, or is formed integrally with the conducting wire.

Therefore, according to the present invention, in the wiring used for at least one of electrical components between audio devices and inside the audio device, each of the mass-increasing members according to the present invention includes a conductor between the devices or inside the device. Longitudinal vibrations transmitted through the loudspeaker are greatly attenuated as compared with the conventional example, vibration transmission between audio devices and inside the audio devices is suppressed, and accurate waveform processing and reproduction are enabled. As a result, the original sound as an audio system is obtained. A reproduction sound that is as close as possible can be realized.

Also, in the audio wiring cable, a covering member formed around the conductor and covering the conductor with an electrically insulating material, the conductor, the mass increasing members, and the covering member A contact preventing member formed of an electrically insulating material and configured to prevent the conductive wire and the covering member from contacting each other, wherein a space is provided between the conductive wire and the contact preventing member. Space intervenes. Here, the contact preventing member is preferably made of cotton or silk.

Therefore, according to the present invention, each of the mass increasing members is prevented from directly contacting the covering member, so that the mechanical vibration of the mass increasing member itself can be buffered, and the signal transmission can be performed. Can be further improved.

[Brief description of the drawings]

FIG. 1 is a block diagram of an audio system for explaining an audio shielded cable 4 and an audio single cable 5 which are audio distribution cables according to an embodiment of the present invention.

FIG. 2 is a partially cutaway side view showing a structure of the shielded audio cable 4 according to the first embodiment of the present invention.

FIG. 3 is a longitudinal sectional view showing a section taken along a line AA ′ in FIG. 2;

FIG. 4 is a longitudinal sectional view showing a section taken along the plane BB ′ of FIG. 2;

FIG. 5 is a partially cutaway side view showing a structure of a single audio cable 5 according to a second embodiment of the present invention.

FIG. 6 is a side view showing a structure of a single audio cable 6 according to a third embodiment of the present invention.

FIG. 7 is a partially cutaway side view showing a structure of a single audio cable 7 according to a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Audio signal reproduction apparatus, 2 ... Main amplification apparatus, 3 ... Speaker, 4 ... Shielded cable for audio, 5, 6, 7, 8 ... Single cable for audio, 11, 12 ... Pin plug, 11a, 12a ... Central conductor 11b, 12b: ground conductor, 20: center conductor, 21: mass increasing conductor, 31: mass increasing portion, 22: space space, 23, 25: covering member, 24: ground conductor, 30: conductor.

Claims (6)

[Claims] 1. An audio wiring cable provided with a conductor, comprising: a plurality of mass increasing members made of an object which is repeated on the conductor at a predetermined interval to increase the mass per unit length more than the conductor. A wiring cable for audio, characterized in that: 2. The audio wiring cable according to claim 1, wherein each of the mass-increasing members is made of an object whose cross-sectional area per unit length is larger than that of the conductor. 3. The audio wiring cable according to claim 1, wherein each of the mass increasing members is formed by being added around the conducting wire. 4. The audio wiring cable according to claim 1, wherein each of the mass increasing members is formed integrally with the conductor. 5. A covering member formed around the conducting wire and made of an electrically insulating material and covering the conducting wire, and formed so as to be interposed between the conducting wire and each of the mass increasing members and the covering member. A contact preventing member made of an electrically insulating material and preventing the conductive wire from contacting the covering member, wherein a space is interposed between the conductive wire and the contact preventing member. The audio wiring cable according to any one of claims 1 to 4, wherein 6. The audio wiring cable according to claim 5, wherein said contact preventing member is made of cotton or silk.