JP2004312094A - Support structure for microphone unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a support structure for a microphone unit for utilizing a magnetic force so as to support the microphone unit in a floating state, thereby enhancing the S/N of an output of a microphone through the interruption of surrounding vibration and noise from the microphone unit. <P>SOLUTION: The support structure for the microphone unit 1 stored inside a case 2 is structured such that a magnet 3 or a magnetic material 4 is fixed to a tip side or a rear end side of the microphone unit 1 in a direction matched with the principal axis direction of the microphone, arranged opposite to an opposed part in the case 2 at a prescribed air gap D, a flexible string 5 without extensibility in the axial line direction is fixed between a base end of the case 2 and the rear end side or the tip side of the microphone unit 1, and the microphone unit 1 is supported in a floating state by balancing an attractive force produced between the magnet 3 and the magnetic material 4 with a tension of the string 5. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a structure for holding a microphone unit of a microphone for a normal voice call.
[0002]
[Prior art]
Generally, in a microphone, the holding structure of the microphone unit is an important subject in designing a microphone so that external vibration and noise can be cut off as much as possible and good S / N communication can be performed. However, as shown in FIG. 7 in particular, a mobile microphone which is attached to a motorcycle or a helmet and used to transmit a voice for a rider to talk while traveling is subjected to various contrivances, for example, (JP-B 7-9506). 8) As shown in FIGS. 8 and 9, examples of which are shown in FIGS. 8 and 9, a suspender Su is provided between a microphone unit 1 and a case 2 which are coaxially housed in a case 2 having acoustic transparency. Is interposed to block vibration. The suspender Su is made of an elastic body such as rubber, and is flexible in the main axis direction by cantilevers Sua, Sub, and Suc installed in three stages from the inner peripheral surface of the case 2 to the outer peripheral surface of the microphone unit 1 in a continuous manner. And is held so as to be swingable. In FIG. 7, M is a mobile microphone, C is a clip, P is a plug, H is a helmet, S is a speaker, Sc is a speaker cord, and Pc is a connection cord.
[0003]
[Problems to be solved by the invention]
In the above-described conventional microphone unit holding structure, the suspender Su, which is the main body of the holding structure, is an object made of a material having physical properties such as compressibility and density, and has flexibility and elasticity. There is a drawback that noise and vibration are transmitted to the microphone unit by the mechanical intrinsic impedance to generate noise. Further, in the holding structure shown in FIGS. 8 and 9, since the microphone is supported at one point at the center of the microphone, the microphone is positioned in front of the microphone unit about a vertical axis with respect to the main axis at the one supporting point at the center. This causes a so-called rolling phenomenon in which the rear end portion vibrates in the opposite phase, which causes noise, which is a problem to be solved.
[0004]
Therefore, in the present invention, by solving the above-mentioned problem, almost eliminating a holding means by a structure having a possibility of transmitting vibration and noise, and holding the microphone unit in a floating state using magnetic force, An object of the present invention is to provide a microphone unit holding structure capable of improving the S / N of an output of a microphone by blocking ambient vibration and noise.
[0005]
[Means for Solving the Problems]
The structure of the microphone unit holding structure of the present invention for achieving the object will be described with reference to the reference numerals shown in FIGS. 1 to 6 corresponding to the embodiments. This is a holding structure of the stored microphone unit 1, wherein a magnet 3 or a magnetic body 4 is fixed to a front end side or a rear end side of the microphone unit 1 so as to coincide with a main axis direction of the microphone. A magnetic body 4 or a magnet 3 is disposed facing the front end side or the rear end side with a predetermined gap D therebetween, and the base end side of the case 2 and the rear end side of the microphone unit 1 or A flexible string-shaped body 5 that is inextensible in the axial direction, has a large mechanical internal loss and is flexible is fixed between the microphone unit 1 and the microphone unit 1 and the microphone unit 1. The cord 7 is electrically connected by the lead wire 6, and the suction force generated between the magnet 3 and the magnetic body 4 and the tension of the string 5 are balanced to make the microphone unit 1. Is held in a floating state. Further, the second invention of the present application is a string-shaped member having flexibility and conductivity, which has no extensibility in the axial direction, has a large mechanical internal loss, and is replaced with the string-shaped member 5 in the first invention. The body 5a is fixed and the lead wire 6 is omitted, and the suction force generated between the magnet 3 and the magnetic body 4 is balanced with the tension of the string-like body 5a, so that the microphone unit 1 is floated. A microphone unit holding structure characterized by being held.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
To implement the microphone unit holding structure of the present invention having such a configuration, the microphone unit 1 has a structure in which the microphone element 11 is housed in the unit case 15. The microphone element 11 is an electroacoustic transducer and may be of any structure and type. However, the electret condenser type microphone element 11 is preferable because of its simple structure, light weight and low cost. In particular, a system in which the FET serving as the preamplifier 17 is incorporated in the vicinity of the diaphragm is advantageous in terms of weight, acoustic performance, price, and the like. In addition, the microphone element 11 may be a piezoelectric electroacoustic transducer. A terminal plate 12 is attached to the rear end of the unit case 15, and a terminal 13 is attached to the terminal plate 12. A sound introduction hole 14 is formed in the unit case 15, but if the sound introduction hole 14 is formed on one surface side of the microphone element 11 mounted inside the unit case 15, and the back surface is sealed. It becomes a non-directional unit, and if the sound wave introduction holes 14 are formed on both sides, it becomes a uni-directional unit or a bi-directional unit.
[0007]
The case 2 protects and appropriately holds the microphone unit 1 in use. Any structure may be used, but a non-magnetic metal plate generally formed by deep drawing a so-called perforated plate having a large number of small air holes 25 formed in a bottomed cylindrical shape is generally used. is there. Such a case 2 has a function as an electrostatic shield in addition to a function of protecting and holding the microphone unit 1. A base 24 for coupling to the flexible conduit tube 8 is fixed to a cylindrical rear open end, that is, a base end side, and a base end portion is provided at a portion of the base 24 facing the inside of the case 2. A side terminal plate 22 is attached, and a terminal 23 is attached to the base end side terminal plate 22. Normally, the case 2 is covered with a windshield 21 made of a material such as a porous and air-permeable foamed resin.
[0008]
The microphone unit 1 is housed inside the case 2, and the state is such that either the magnet 3 or the magnetic body 4 is aligned with the main shaft direction of the microphone at the front end side or the rear end side of the microphone unit 1. A magnetic body 4 or a magnet 3 is fixed to a facing portion on the distal end side or a facing portion on the base end side of the case 2 with a predetermined gap D therebetween. And there is no extensibility in the axial direction between the base end side of the case 2 and the rear end side of the microphone unit 1, or between the front end side of the case 2 and the front end side of the microphone unit 1, In addition, the string-shaped body 5 having flexibility is fixed, and the suction force generated between the magnet 3 and the magnetic body 4 is balanced with the tension of the string-shaped body 5 so that the microphone unit 1 is in a floating state. It is held by. The shape of the magnet 3 and the magnetic body 4 may be cylindrical or prismatic, but by forming one or both of the opposing surfaces into a conical or pyramidal shape, the magnetic force lines φ are concentrated and the attractive force is increased. And the microphone unit 1 can be stably held. Further, by making the gap D narrow, a large attractive force can be obtained even with a small magnet.
[0009]
As described above, the string-shaped body 5 may be any object as long as it has flexibility or flexibility and lacks extensibility in the length direction. However, the standing wave is difficult to mechanically or acoustically ride. It is desirable to use, for example, a fishing line, a kite line, or a fiber material having properties equivalent thereto. Alternatively, the microphone unit 1 is held in a floating state by using a string 5a made of a conductive wire such as a litz wire, which is extremely flexible, has no extensibility, and is conductive instead of the string 5. At the same time, the microphone element 11 and the microphone cord 7 can be electrically connected. When the above-mentioned fiber material is used as the cord body 5, it goes without saying that the microphone element 11 and the microphone cord 7 must be separately connected by the lead wire 6. Further, the lead wire 6 used for this purpose may be the same as the conductive wire used as the string-shaped body 5a, but if such a conductive wire is formed in a spiral shape, the vibration isolation is improved.
[0010]
In the holding structure of the microphone unit 1 described above, the microphone unit 1 is positioned inside the case 2, and the distal end portion thereof is positioned by an attractive force generated by the magnet 3 and the magnetic body 4 and coinciding with the main axis direction of the microphone. The rear end side is positioned by the tension of the flexible strings 5 and 5a, which are inextensible in the axial direction and have large mechanical internal loss and are flexible, so that the microphone unit 1 The suction force is balanced with the tension of the string-shaped body, and is held in a floating state with respect to the case 2. Therefore, the transmission coefficient of the vibration of the holding structure at the front end and the rear end of the microphone unit 1 is extremely small, and the vibration and noise transmitted from the case 2 are almost shut off. Further, unlike the holding structure of the conventional example, the magnetic attraction force and the tension of the cord-like body 5 determine the position of the microphone unit 1 along the main axis of the microphone at two points, the front end and the rear end. Therefore, rolling vibration around an axis perpendicular to the main axis and passing through the middle of the microphone unit 1 is prevented, and no noise is generated from the microphone unit 1 itself. Further, since the mass of the magnet 3 or the magnetic body 4 is large, the natural frequency of the microphone unit 1 is sufficiently low with respect to external vibrations. Therefore, the S / N of the microphone output is remarkable due to the combination of both functions. Be improved.
[0011]
【Example】
FIG. 1 shows a longitudinal sectional shape of a first embodiment of the present invention. The microphone unit 1 has a microphone element 11 housed in a unit case 15. The microphone element 11 is an electret condenser type. As is well known, a preamplifier 17 composed of an FET is incorporated near the diaphragm. A terminal plate 12 having two terminals 13 is attached to the rear end of the unit case 15, and the microphone element 11, that is, the input / output lead 16 of the preamplifier 17 is connected to the terminal 13. The unit case 15 is provided with a sound wave introduction hole 14, but in this embodiment, since the sound wave introduction hole 14 is formed on the front surface of the microphone element 11 and the back surface is closed, it is omnidirectional. .
[0012]
The case 2 is formed by deep drawing a so-called perforated plate (made of aluminum) having a large number of small ventilation holes 25 into a bottomed cylindrical shape. A base 24 for coupling to the flexible conduit tube 8 is fixed to a rear open end, that is, a base end side of the bottomed cylindrical shape. A terminal terminal plate 22 is attached, and a terminal 23 is attached to the base end terminal plate 22. Further, a windshield 21 made of an open-cell foamed resin is placed on the outside of the case 2.
[0013]
The stored state of the microphone unit 1 inside the case 2 is such that the magnet 3 is fixed to the tip end side of the microphone unit 1 so as to coincide with the main axis direction of the microphone, and the opposed portion in the case 2, that is, the case in the first embodiment. A magnetic body 4 is arranged at a bottom of the bottomed cylindrical shape, that is, at a tip end side of the microphone, with a predetermined gap D therebetween. Then, a string-like body 5 made of a fiber material similar to a fishing line is fixed at both ends between the terminal plate 22 on the base end side of the case 2 and the rear end side terminal plate 12 of the microphone unit 1. The microphone unit 1 is held in a floating state by balancing the suction force generated between the magnetic body 4 and the tension of the string-shaped body 5. Also, the terminals 23, 23 of the base end side terminal plate 22 of the case 2 and the terminals 13, 13 of the rear end side terminal plate 12 of the microphone unit 1 are connected by leads 6, 6, so that the microphone element 11 The microphone cord 7 is electrically connected. The lead wire 6 uses a litz wire formed into a spiral shape. The core wire 71 of the microphone cord 7 and the shield conductor 72 are connected to the terminals 23 of the base terminal plate 22.
[0014]
FIG. 2 shows a longitudinal sectional shape of a second embodiment of the present invention. In this embodiment, the positional relationship between the magnetic body 4 and the magnet 3 in the holding structure of the microphone unit 1 is different from that of the first embodiment, and the magnetic body 4 coincides with the tip side of the microphone unit 1 in the main axis direction of the microphone. The magnet 3 is disposed at a facing portion in the case 2, that is, at the bottom of the case 2 in the embodiment, facing a predetermined gap D. The electret condenser type microphone element 11 used in this embodiment has a transducer part covered with a sub case 11a, a sound wave introduction hole 14 provided at the tip end side, and the element itself is a non-directional microphone element. It has become. Then, in order to easily attach the magnetic body 4, the side surface of the unit case 15 of the microphone unit 1 is extended to the distal end side, the magnetic body 4 is fitted and attached, and the magnetic body 4 and the microphone element 11 are connected. A gap is formed therebetween, and a separate sound wave introduction hole 14 is formed in a portion corresponding to the gap on the side surface of the unit case 15.
[0015]
FIG. 3 shows a vertical cross-sectional shape of a third embodiment of the present invention. In this embodiment, a piezoelectric element is used as the microphone element 11 and, unlike the first embodiment in which the shape of the magnetic body 4 in the holding structure of the microphone unit 1 is basic, the surface facing the magnet 3 has a conical surface. Formed and pointed. The positional relationship between the magnetic body 4 and the magnet 3 is the same as in the second embodiment. This embodiment is characterized in that the required attractive force can be obtained even with a small volume magnet since the magnetic force lines φ are concentrated on the pointed head. The structure of other parts is the same as that of the first embodiment.
[0016]
FIG. 4 shows a vertical cross-sectional shape of a fourth embodiment of the present invention. In this embodiment, the shape of the magnet 3 in the holding structure of the microphone unit 1 is different from that of the first embodiment in the basic shape, and the surface facing the magnetic body 4 forms a flat surface. The positional relationship between the magnetic body 4 and the magnet 3 is the same as in the second embodiment. The microphone element 11 is attached so that the vibrating surface is parallel to the main axis of the microphone, and the sound wave introducing holes 14 are formed in two side surfaces of the unit case 15 to form a unidirectional unit. This embodiment has a feature that the magnetic body 4 and the magnet 3 are inexpensive because their shapes are simple. In the fourth embodiment, the structure of other parts is the same as that of the first embodiment.
[0017]
FIG. 5 shows a longitudinal sectional shape of a fifth embodiment of the present invention. In this embodiment, the structures of the microphone unit 1 and the string-shaped body 5a are different from those of the second embodiment, and the microphone unit 1 is provided with a sound wave introduction hole 14 at the front and rear surfaces of the built-in microphone element 11, respectively. It is a unidirectional unit. Further, in the drawing, the string-shaped body 5a indicated by reference numeral 5a is formed by simply twisting two thin litz wires. In this embodiment, since the microphone element 11 is a unidirectional unit, the S / N of a call is improved, and the string 5a is formed only of a litz wire. This is characterized in that it is inexpensive as compared with a holding structure in which the lead wire 6 and the string-like body 5 are combined. The structure of other parts is the same as that of the first embodiment.
[0018]
FIG. 6 shows a longitudinal sectional shape of a sixth embodiment of the present invention. In this embodiment, the holding structure of the microphone unit 1 is different from that of the other embodiments, and the magnet 3 is provided on the rear end side of the microphone unit 1 and the conical magnetic body 4 is provided on the base end side of the case 2. A string-like body 5 is attached and astride the distal end side of the microphone unit 1 and the bottom of the distal end side of the case 2, and the attraction force of the magnet 3 and the magnetic body 4 and the string-like body 5 are fixed. And the microphone unit 1 is held. The microphone unit 1 uses the ceramic type omnidirectional microphone element 11 as it is. Since the microphone unit 1 is omnidirectional, the small air holes 25 of the case 2 are provided only at the front end of the case 2. The light is incident only from the front. In the holding structure of the microphone unit 1, the magnet 3 and the magnetic body 4 have the above-described positional relationship and shape because manufacture is relatively easy. Needless to say, the structure may be the same as that of each of the first to fifth embodiments. In the figure, reference numeral 26 denotes a wire net for protecting the front end.
[0019]
As described above, the embodiments which are considered to be representative of the present invention have been described. However, the present invention is not necessarily limited to the structures of the embodiments, but includes the above-mentioned constituent features of the present invention, and The above-mentioned object can be achieved, and can be carried out with appropriate modifications within a range having the following effects.
[0020]
【The invention's effect】
As is apparent from the above description, in the microphone unit holding structure of the present invention, the microphone unit balances the attractive force of the magnet at the front end side with the tension of the string-shaped body provided at the rear end side, and attaches the microphone unit to the case. On the other hand, it is kept floating. Therefore, the transmission level of the vibration caused by the holding structure at the front end and the rear end of the microphone unit is extremely small, and the vibration and noise transmitted from the case are almost cut off, and the S / N of the microphone output is significantly improved. Also, unlike the holding structure of the conventional example, the attractive force of the magnet and the tension of the cord-like body hold the microphone unit at two points, the front end and the rear end, so that the rolling vibration of the microphone unit is prevented, No noise is generated from the microphone unit itself, and the clarity of the call is further improved.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view along a main axis of a first embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of the second embodiment along a main axis.
FIG. 3 is a longitudinal sectional view of the third embodiment along a main axis.
FIG. 4 is a longitudinal sectional view along a main axis of the fourth embodiment.
FIG. 5 is a longitudinal sectional view of the fifth embodiment along a main axis.
FIG. 6 is a longitudinal sectional view along a main axis of the sixth embodiment.
FIG. 7 is a schematic explanatory view showing a usage example of a mobile microphone.
FIG. 8 is a front view of a conventional microphone unit holding structure of a mobile microphone.
FIG. 9 is a sectional side view taken along the line AA in FIG. 8;
[Explanation of symbols]
Reference Signs List 1 microphone unit 11 microphone element 12 rear end terminal plate 13 terminal 14 sound wave introduction hole 15 unit case 16 preamplifier input / output lead wire 17 preamplifier 2 case 21 windshield 22 base end side terminal plate 23 terminal 24 base 25 small air hole 3 Magnet 31 Tip 4 Magnetic body 41 Tip 5 String 5a String 6 also serving as lead wire Lead wire 7 Microphone cord 71 Core wire 72 Shield conductor 8 Flexible conducting tube D Air gap between magnet and magnetic material M Mobile microphone C Clip P Plug H Helmet S Speaker Sc Speaker cord Pc Connection cord Su Suspenders Sua, Sub, Suc Cantilever of suspender

Claims (4)

A holding structure of a microphone unit (1) stored inside a case (2), wherein a magnet (3) or a magnetic body (4) is mounted on a mobile terminal at a front end side or a rear end side of the microphone unit (1). The microphone (4) or the magnet (3) is fixed at a position facing the front end or the rear end in the case (2) with a predetermined gap (D) therebetween. They are arranged to face each other, and there is no extensibility in the axial direction between the base end side of the case (2) and the rear end side or the front end side of the microphone unit (1), and mechanical internal loss is large. And a flexible cord-like body (5) is fixed, the microphone unit (1) and the microphone cord (7) are electrically connected by a lead wire (6), and the magnet (3) is fixed. The microphone unit (1) is held in a floating state by balancing a suction force generated between the magnetic body (4) and a tension of the cord-like body (5). Unit holding structure. A holding structure of a microphone unit (1) stored inside a case (2), wherein a magnet (3) or a magnetic body (4) is mounted on a mobile terminal at a front end side or a rear end side of the microphone unit (1). The microphone (4) or the magnet (3) is fixed at a position facing the front end or the rear end in the case (2) with a predetermined gap (D) therebetween. They are arranged to face each other, and there is no extensibility in the axial direction between the base end side of the case (2) and the rear end side or the front end side of the microphone unit (1), and mechanical internal loss is large. And the string (5a) having flexibility and conductivity is fixed, and the microphone unit (1) and the microphone cord (7) are electrically connected by the string (5a). Said ma The microphone unit (1) is held in a floating state by balancing the suction force generated between the net (3) and the magnetic body (4) with the tension of the cord-like body (5a). Characteristic microphone unit holding structure. 3. The microphone unit holding structure according to claim 1, wherein one or both of the magnet (3) and the magnetic body (4) are flat surfaces. 3. The microphone unit holding structure according to claim 1, wherein one or both of the magnet (3) and the magnetic body (4) has a conical surface.

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