JP2008271391A - Sound collection apparatus for microphone - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sound collection apparatus for a microphone to obtain an ideal frequency response property even when a frequency is extremely high or low. <P>SOLUTION: A sound collection apparatus for a microphone comprises a housing unit, a diaphragm in which a coil is stretched on its surface and which is mounted in the housing unit and two magnetic units which are disposed within the housing unit so as to face both sides of the diaphragm, respectively, and constitute magnetic circuits, respectively. When the diaphragm vibrates, a current is generated in the coil by the two magnetic circuits constituted by the two magnetic units. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a microphone sound collector, and more particularly to a microphone sound collector that can obtain an ideal frequency response characteristic even if it is not a capacitor type using a bias power supply.

  In a dynamic microphone, for example, as described in Patent Document 1, a voice coil integrally attached to a diaphragm is arranged in a magnetic gap formed in a magnetic circuit, and current is supplied to the voice coil by vibration of the diaphragm. In order to improve the sensitivity, the second permanent is magnetized on the part facing the center pole piece so that the same pole as the first permanent magnet faces each other. By arranging magnets, measures were taken to reduce leakage magnetic flux. However, since the ratio of the voice coil to the diaphragm is not small in weight, an ideal frequency response characteristic cannot be obtained when the frequency is extremely high or low as shown in FIG. There is also.

Further, since the condenser microphone does not use a voice coil, an ideal frequency response characteristic can be obtained even if the frequency becomes extremely high or low as shown in FIG. 2, but the vibration is changed to an electric signal. In order to obtain the bias voltage, a bias power source is required.
Japanese Published Patent No. 2005-354571

  In view of the problems of the dynamic microphone and the condenser microphone, an object of the present invention is to provide a microphone sound collecting device that can obtain an ideal frequency response characteristic even when the frequency is extremely high or low.

  In order to achieve the above object, the present invention provides a housing unit, a diaphragm having a coil mounted on the surface thereof and mounted in the housing unit, and a predetermined magnetic gap between both surfaces of the diaphragm. The magnetic circuit is arranged in the housing unit so as to form a closed magnetic circuit with the magnetic gap interposed therebetween. When the diaphragm vibrates, the magnetic circuit formed by the two magnetic units causes the coil to move to the coil. Provided is a microphone sound collector characterized by generating a current.

In the microphone sound collector, the two magnetic units are preferably configured such that the polarities of the permanent magnets facing the diaphragm are the same.
Further, in the microphone sound collecting device, the two magnetic units are connected to the columnar permanent magnet arranged so that one pole thereof faces the diaphragm, and the other pole of the permanent magnet, A yoke arranged in a ring around a magnetic gap having a predetermined width around the one pole, and the magnetic flux generated from the permanent magnet forms the magnetic circuit closed through the yoke. it can.

  In this case, the housing unit is provided with openings corresponding to both sides of the diaphragm so that external air vibrations can be transmitted to the diaphragm, and the yoke and the permanent magnet are formed on the two magnetic units. It is preferable that each of the through holes penetrating the magnet is formed.

The coil is preferably stretched concentrically on a surface of the diaphragm substantially along a plane by a conductive material.
Further, in the microphone sound collector, the two magnetic units are formed in a tubular shape and are arranged so that an axial center line thereof is orthogonal to the diaphragm, and one end of the permanent magnet is the other of the permanent magnets. And a yoke formed to face the diaphragm through a magnetic gap so that the other end faces one of the poles of the permanent magnet, and the magnetic flux generated from the permanent magnet is transferred to the yoke. It can be configured to conduct and form the magnetic circuit.

  Further, in the microphone sound collecting device, the two magnetic units are arranged such that one of the two permanent magnetic units is arranged so that one end face of the two magnetic units faces the diaphragm, and the other pole side of the permanent magnet And an annular yoke with a flange arranged to face the diaphragm annularly through a magnetic gap so as to face one pole of the diaphragm side, and the other two magnets A unit is formed in a tubular shape and is connected to a permanent magnet disposed so that an axis thereof is orthogonal to the diaphragm, and an end face on the other pole side of the permanent magnet, and a magnetic gap having a predetermined width in a tube of the permanent magnet And a yoke that extends in a columnar shape through the magnetic flux generated by each of the permanent magnets can be conducted through the yoke to form the magnetic circuit.

  In this case, it is preferable that the coils formed on the diaphragm form two coils respectively corresponding to the magnetic units on the one pole side and the other pole side.

According to the above configuration, the present invention increases the magnetic flux density passing through the coil formed on the diaphragm by disposing the magnetic units forming the magnetic circuit on both sides of the diaphragm, and the two magnetic units are opposed to each other. Therefore, the leakage of magnetic flux can be reduced, so that the sensitivity of the microphone sound collector of the present invention can be improved.
Furthermore, since the coil used in the microphone sound collector of the present invention is formed so as to be thinly stretched on the surface of the diaphragm, the weight thereof is much lighter than the conventional one, and therefore the sensitivity of the sound collector of the present invention. Is further improved.

  Hereinafter, the configurations of Examples 1 to 3 of a preferred embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 3 is a cross-sectional view showing the configuration of the microphone sound collecting apparatus according to the first embodiment of the present invention. As shown in the drawing, the sound collecting device includes a housing unit 1, a diaphragm 31 with a coil 32 stretched on the surface thereof, and mounted in the housing unit 1, and a housing unit so as to face both surfaces of the diaphragm 31. 1 is provided with upper and lower two magnetic units 20 and 20 arranged in one.

  Each of the magnetic units 20 and 20 is connected to columnar permanent magnets 21 and 21 arranged so that the N pole faces the diaphragm 31 and the S pole of the permanent magnet 21, and has a predetermined width around the S pole. It is provided with a yoke 22 formed in a cup shape so as to have an annular arrangement in which a magnetic gap G is interposed, and the magnetic flux generated from the N pole of the permanent magnet 21 forms a closed magnetic circuit 211 via the yoke 22.

  The coil 32 formed on the surface of the diaphragm 31 corresponds to the position of the magnetic circuit 211 generated by the upper and lower two magnetic units 20 and 20 and the magnetic gap G thereof, and is substantially along the plane on the surface of the diaphragm 31. While being thinly stretched, it is formed so as to be spirally wound concentrically with a predetermined interval. The material and the forming method for forming the coil 32 can be formed by using a conductive material such as copper or aluminum and using a plating method such as a chemical vapor deposition method or a printed circuit board manufacturing technique.

  Further, as shown in the figure, the housing unit 1 has openings 13 and 13 corresponding to both surfaces of the diaphragm 31, respectively, and the two magnetic units 20 and 20 have yokes 22 and 22 and permanent magnets 21 and 21, respectively. Through holes 24 and 24 are formed so as to allow external air vibrations to be transmitted to the diaphragm 31. Further, as shown in FIGS. 4, 5, 6, and 7, the diaphragm 31 is formed with a plurality of concentric or leaf-like uneven portions 311 and 312 on the surface, thereby reducing stress concentration due to vibration. Unnecessary resonance can be eliminated.

Then, the magnetic fluxes generated by the upper and lower two magnetic units 20 and 20 each become a closed magnetic path, and pass through the coil 32 formed on the surface of the diaphragm 31 in the same direction. Due to the vibration, a current due to electromagnetic induction is generated in the coil 31 along with this.
Incidentally, the arrangement of the N and S poles of the permanent magnets 21 and 21 in the magnetic units 20 and 20 can be arranged such that the S pole faces the diaphragm 31 and the N pole is connected to the yoke 22. .

  FIG. 8 is a cross-sectional view showing a configuration of a microphone sound collecting apparatus according to Embodiment 2 of the present invention. As shown in the drawing, the sound collecting device is similar to the first embodiment, the housing unit 1, the diaphragm 31 with the coil 32 stretched on the surface and attached to the inside of the housing unit 1, and both surfaces of the diaphragm 31. The upper and lower two magnetic units 40 and 40 are disposed in the housing unit 1 so as to face each other.

  The positional relationship between the permanent magnets and the yokes in the magnetic units 40 and 40 is opposite to that in the first embodiment, the permanent magnets 41 and 41 are formed in a tubular shape, and their axis is perpendicular to the diaphragm 31, and the diaphragm The yokes 42, 42 are arranged so that the end facing the 31 is an N pole, the yoke 42, 42 is connected to the end of the S pole of the permanent magnet 41, and the inside of the permanent magnet 41 from the disk platform 421 Are provided with a column base part 422 extending in a columnar shape through a magnetic gap G of a predetermined width, and a disk base part 421 and a through hole 43 that penetrates the column base part 422 and transmits external air vibrations to the diaphragm 31. Thus, the magnetic flux generated from the N pole of the permanent magnet 41 is conducted through the yoke 42 to form a magnetic circuit.

  Since the configuration, forming material, and method of the diaphragm 31 and the coil 32 are the same as those in the first embodiment, the detailed configuration is omitted. In the second embodiment, the upper and lower two magnetic units 40, Each of the magnetic fluxes generated by 40 becomes a closed magnetic path and passes through the coil 32 formed on the surface of the diaphragm 31 in the same direction, and the diaphragm 21 vibrates due to air vibration caused by sound waves. Thus, a current is generated in the coil 31 by electromagnetic induction.

  FIG. 9 is a sectional view showing the structure of a microphone sound collecting apparatus according to Embodiment 2 of the present invention. As shown in the figure, the sound collecting device is similar to the first embodiment, the housing unit 1, the diaphragm 31 with the coils 33 and 34 stretched on the surface and attached in the housing unit 1, and both surfaces of the diaphragm 31. The upper and lower two magnetic units 50 and 60 are disposed in the housing unit 1 so as to face each other.

  The magnetic unit 50 disposed on the upper side of the diaphragm 31 has the same configuration as the magnetic unit 40 in the second embodiment, the permanent magnet 51 is formed in a tubular shape, and its axis is orthogonal to the diaphragm 31. The yoke 52 is arranged so that the end facing the diaphragm 31 is an N pole, and the yoke 52 is connected to the end of the S pole of the permanent magnet 51, and the inside of the permanent magnet 51 from the disk base 521. And a circular column base part 522 extending in a columnar shape through a magnetic gap G of a predetermined width, and a disk base part 521 and a through hole 53 that transmits the external air vibration to the diaphragm 31 through the cylindrical base part 522. Thus, the magnetic flux generated from the N pole of the permanent magnet 51 is conducted by the yoke 52 to form a magnetic circuit.

  The magnetic unit 60 disposed below the diaphragm 31 has the same configuration as that of the magnetic unit 20 in the first embodiment, that is, a column-like permanent disposed so that the N pole faces the diaphragm 31. A magnet 61, a yoke 62 connected to the S pole of the permanent magnet 61 and formed in a cup shape so as to have an annular arrangement with a magnetic gap G of a predetermined width around the S pole, and the permanent magnet 61 and the yoke 62 The magnetic flux generated from the N pole of the permanent magnet 61 is conducted by the yoke 62 to form a magnetic circuit, whereby the magnetic flux generated from the N pole of the permanent magnet 61 is conducted by the yoke 62. Configured to form a magnetic circuit.

  In the third embodiment, the direction of the magnetic circuit generated by the magnetic unit 50 disposed above the diaphragm 31 and the magnetic unit 60 disposed below the diaphragm 31 is reversed. The direction of the generated current is also reversed, and it is necessary to form coils 33 and 34 corresponding to the upper and lower magnetic units 50 and 60 on the diaphragm 31 and not connected to each other. About the material and formation method which form the coils 33 and 34, the same thing as Example 1 can be used.

  Incidentally, in each of the above-described embodiments, the N and S poles of the permanent magnet can be arranged so that the S pole faces the diaphragm and the N pole is connected to the yoke.

  According to the above configuration, the present invention increases the magnetic flux density passing through the coil formed on the diaphragm by disposing the magnetic units forming the magnetic circuit on both sides of the diaphragm, and the two magnetic units are opposed to each other. Therefore, the leakage of magnetic flux can be reduced, so that the sensitivity of the microphone sound collector of the present invention can be improved.

  Furthermore, since the coil used in the microphone sound collector of the present invention is formed so as to be thinly stretched on the surface of the diaphragm, its weight is much lighter than the conventional one, so that the frequency is extremely high or low, for example. Even so, the sound collecting device of the present invention can obtain an ideal frequency response characteristic.

It is a graph which shows the frequency response characteristic of the conventional dynamic microphone. It is a graph which shows the frequency response characteristic of the conventional condenser microphone. It is sectional drawing which shows the structure of the sound collector for microphones of Example 1 of this invention. It is explanatory drawing which shows the structural example of the uneven | corrugated | grooved part formed in the diaphragm in this invention. FIG. 5 is a cross-sectional view of a configuration example of the diaphragm shown in FIG. 4. It is explanatory drawing which shows another structural example of the uneven | corrugated | grooved part formed in the diaphragm in this invention. It is sectional drawing of the structural example of the diaphragm shown in FIG. It is sectional drawing which shows the structure of the sound collector for microphones of Example 2 of this invention. It is sectional drawing which shows the structure of the sound collector for microphones of Example 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Housing unit 13 Opening 20 Magnetic unit 21 Permanent magnet 22 Yoke 24 Through-hole 31 Diaphragm 32 Coil 33, 34 Coil 40 Magnetic unit 41 Permanent magnet 42 Yoke 43 Through-hole 50, 60 Magnetic unit 51 Permanent magnet 52 Yoke 53 Through-hole 61 Permanent magnet 62 Yoke 63 Through hole 211 Magnetic circuit 311, 312 Uneven portion 421 Disc base portion 422 Column base portion 521 Disc base portion 522 Column base portion

Claims (9)

A housing unit,
A diaphragm having a coil stretched on its surface and mounted in the housing unit;
Two magnetic units arranged in the housing unit so as to face each other with a predetermined magnetic gap on both surfaces of the diaphragm, and forming a closed magnetic circuit across the magnetic gap;
A microphone sound collector, wherein when the diaphragm vibrates, a current is generated in the coil by the magnetic circuit formed by the two magnetic units.   2. The microphone sound collector according to claim 1, wherein the two magnetic units are configured such that the polarities of the poles of the permanent magnets facing the diaphragm are the same. The two magnetic units have columnar permanent magnets arranged so that one pole thereof faces the diaphragm;
A yoke connected to the other pole of the permanent magnet and arranged annularly around the one pole via a magnetic gap of a predetermined width, and the magnetic flux generated by the permanent magnet is closed via the yoke 3. The microphone sound collecting device according to claim 2, wherein the sound collecting device comprises the magnetic circuit.   The microphone according to claim 1, wherein the housing unit has openings corresponding to both surfaces of the diaphragm so that external air vibration can be transmitted to the diaphragm. Sound collector.   4. The through hole penetrating the yoke and the permanent magnet is formed in each of the two magnetic units so that external air vibration can be transmitted to the diaphragm. Microphone sound collector.   The sound collecting device for a microphone according to claim 1, wherein the coil is stretched concentrically on a surface of the diaphragm substantially along a plane by a conductive material. The two magnetic units are formed in a tubular shape, and a permanent magnet disposed so that an axial center line thereof is orthogonal to the diaphragm;
A yoke having one end connected to the other pole of the permanent magnet and the other end facing the diaphragm via a magnetic gap so that the other end faces the one pole of the permanent magnet, The microphone sound collector according to claim 2, wherein the magnetic circuit is formed by conducting magnetic flux generated from a permanent magnet through the yoke. The two magnetic units are:
One is connected to the columnar permanent magnet arranged so that the end face on one pole side faces the diaphragm, and the end face on the other pole side of the permanent magnet, and is opposed to one pole on the diaphragm side. And an annular yoke with a flange arranged annularly facing the diaphragm via a magnetic gap,
The other two magnetic units are formed in a tubular shape and connected to a permanent magnet disposed so that the axis thereof is orthogonal to the diaphragm, and to the other pole side end face of the permanent magnet, and in the tube of the permanent magnet A yoke extending in a columnar shape through a magnetic gap of a predetermined width,
3. The microphone sound collector according to claim 2, wherein the magnetic circuit is formed by conducting magnetic flux generated by each permanent magnet through each yoke.   9. The microphone sound collector according to claim 8, wherein the coil formed on the diaphragm is formed with two coils corresponding respectively to the magnetic units on the one-pole side and the other-pole side.

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