JP6118669B2 - Condenser microphone - Google Patents

Description

  The present invention relates to a condenser microphone, and more particularly to a side-entry condenser microphone provided with a square (rectangular or square) microphone unit.

  Condenser microphones include end address type microphones and side entry type microphones in terms of the direction in which sound waves are captured.

  Although not shown, in the end address type microphone, the microphone unit is housed in a cylindrical unit case, and sound waves are mainly taken into the microphone unit from the front end portion of the unit case.

  On the other hand, in the side entry type microphone, as shown in FIG. 4, the microphone unit 1 is arranged almost vertically in a cylindrical unit cover 2 made of, for example, a metal net, and the cylinder of the unit cover 2 is arranged. A sound wave is taken into the microphone unit 1 from a direction orthogonal to the axis.

  In the side entry type microphone, the unit cover 2 is attached to the upper part of the microphone base 3, and the microphone unit 1 is supported by the microphone base 3 via a mount member (not shown). A circuit board having an audio signal output circuit (not shown) is accommodated in the microphone base 3, and an output connector portion 4 is provided at the lower part of the microphone base 3.

  By the way, also in the side entry type microphone, in many cases, as shown in FIG. 4, a circular microphone in which a diaphragm 1b is stretched around a circular diaphragm ring 1a as a microphone unit 1 as in the end address type microphone. A unit is used (see, for example, Patent Document 1).

  According to this, since the surface of the unit cover 2 that collects the sound wave is rectangular, the microphone unit 1 is circular, so the utilization rate of the area of the sound collection surface is not so good.

  Therefore, as shown in FIG. 5, by using a rectangular (rectangular) microphone unit 5 having a rectangular diaphragm 5b stretched on a diaphragm ring 5a having a rectangular frame as the microphone unit, the sound collection area can be reduced. Utilization efficiency is increased, and a microphone having a small size, high sensitivity, and high signal-to-noise ratio can be realized.

JP 2006-101305 A

  However, when the diaphragm ring 5a is a rectangular frame, the frame is deformed inward by the tension of the diaphragm 5b stretched on the diaphragm ring 5a, and the tension of the diaphragm 5b changes. In particular, since the long side is more easily deformed than the short side, the tension of the diaphragm 5b between the long sides is reduced.

  Such a change in the tension of the diaphragm 5b due to the deformation of the diaphragm ring 5a also occurs during assembly of the unit in which the microphone unit 5 is mounted on the microphone base 3 via the mount member. Such a problem also occurs when the diaphragm ring is a square frame.

  Accordingly, an object of the present invention is to make it possible to easily adjust the tension of the diaphragm even after the unit is assembled in a condenser microphone including a square (rectangular or square) microphone unit.

In order to solve the above-mentioned problems, the present invention includes a microphone unit in which a diaphragm stretched on a diaphragm ring and a fixed electrode plate supported by an insulating seat are arranged to face each other via a spacer member, In the condenser microphone in which the microphone unit is supported on the microphone body via a mount member including a support frame that surrounds the diaphragm ring,
Both the diaphragm ring and the support frame are formed of a rectangular frame having two pairs of opposed frame portions, and the support frame includes one pair of opposed frame portions on the diaphragm ring side and / or the other of the pair of frame portions. It is characterized in that tension adjusting means for pressing and deforming a pair of opposing frame portions from the outside is provided.

  The present invention includes an aspect in which the quadrangular frame includes a rectangular frame including a pair of long-side frame portions and a pair of short-side frame portions. In this case, the tension adjusting means includes the support frame. It is preferable to be provided in the substantially center part of each long side frame part.

  The present invention also includes another aspect in which the quadrangular frame is formed of a square frame in which the lengths of the four frame portions are equal. In this case, the tension adjusting means is arranged to face at least one of the support frames. What is necessary is just to be provided in the approximate center part of a pair of frame part to do.

  In the present invention, at the time of tensionless adjustment before the tension adjustment by the tension adjusting means, a tension higher than the tension finally adjusted by the tension adjusting means is applied to the diaphragm.

  Further, as the tension adjusting means, it is preferable to use a screw screwed to the support frame so as to be able to advance and retreat with respect to the frame portion of the diaphragm ring.

  The present invention can be applied to all condenser microphones including a square (rectangular or square) microphone unit, and in particular, a mount member including a support frame in which the microphone unit surrounds the diaphragm ring. This is suitable for a side-entry type condenser microphone that is supported substantially vertically on a microphone base as a microphone body.

  According to the present invention, since the tension of the diaphragm can be adjusted after the unit is assembled, it is possible to provide a side-address type condenser microphone using a rectangular diaphragm with little individual difference in directivity frequency response particularly in a low frequency range. it can. In addition, since the diaphragm is rectangular, it is possible to realize a condenser microphone that has a higher sensitivity and a higher signal-to-noise ratio even with the same outer diameter than a circular diaphragm.

The front view which shows the microphone unit with which the condenser microphone of this invention is provided. AA sectional view taken on the line AA of FIG. The schematic diagram for demonstrating the procedure which obtains a diaphragm assembly from a mother film. The typical front view which shows the conventional side entry type | mold microphone. The typical front view which shows another prior art example of a side entry type | mold microphone.

  Next, an embodiment of the present invention will be described with reference to FIGS. 1 to 3, but the present invention is not limited to this.

  As shown in FIGS. 1 and 2, the condenser microphone according to this embodiment includes a square (rectangular) microphone unit 10 as in the side entry type microphone described in FIG.

  The microphone unit 10 is configured by disposing a diaphragm 11 stretched on a diaphragm ring 12 and a fixed electrode plate 13 supported by an insulating seat 14 so as to face each other through a separator ring 15. In the present invention, the diaphragm ring 12 is formed as a rectangular frame.

  That is, the diaphragm ring 12 includes a pair of long side frame portions 12a and 12a parallel to each other and a pair of short side frame portions 12b and 12b parallel to each other. The diaphragm ring 12 is made of metal, and may be formed of, for example, an aluminum material or a brass alloy.

  The diaphragm 11 is a synthetic resin thin film having a metal vapor deposition film on one surface. As the diaphragm assembly, the diaphragm 11 is attached to the diaphragm ring 12 through an adhesive or the like on the metal vapor deposition film side.

  The separator ring 15 is also formed as a rectangular frame like the diaphragm ring 12. The separator ring 15 is made of an electrically insulating synthetic resin film.

  Since the diaphragm 11 is rectangular, the fixed electrode plate 13 is also formed in a rectangular shape. For example, an aluminum plate is used for the fixed electrode plate 13, and in this embodiment, a plurality of sound holes 13a are formed. Note that an electret film may be attached to the surface of the fixed electrode plate 13 facing the diaphragm 11 to form a back electret condenser microphone.

  The insulating seat 14 is made of an electrically insulating synthetic resin material. In this embodiment, the insulating seat 14 includes a concave portion 14 a for forming an air chamber 16 having a predetermined volume on the back surface side of the fixed electrode plate 13. An acoustic resistance material (not shown) such as a nonwoven fabric may be accommodated in the air chamber 16. The insulating seat 14 may be a ceramic material.

  The microphone unit 10 is disposed in the unit cover 2 in a state of being erected substantially vertically on the microphone base 3 through a mount member including a support frame 20 surrounding the diaphragm ring 12 as shown in FIG. The

  Since the diaphragm ring 12 is a rectangular frame, in this embodiment, the support frame 20 also includes a pair of long side frame portions 20a and 20a parallel to each other and a pair of short side frame portions 20b and 20b parallel to each other. Is a rectangular frame containing

  The support frame 20 includes tension adjusting means 21 that adjusts the tension of the diaphragm 11 by pressing and deforming a predetermined frame portion on the diaphragm ring 12 side from the outside. The support frame 20 may be made of metal or synthetic resin, but preferably has higher rigidity than the diaphragm ring 12.

  In order to obtain the diaphragm assembly, as shown in FIG. 3, the mother film 1M of the diaphragm 11 is placed on the columnar pedestal 6, and a weight 7 is applied over the entire circumference to uniformly distribute the mother film 1M. In a state where tension is applied, the rectangular diaphragm ring 12 is attached via an adhesive, and then the peripheral portion of the frame is cut off with a cutter knife or the like.

  At the time of separation, particularly the long side frame portions 12a and 12 are easily deformed by the tension of the diaphragm 11, whereby the tension of the diaphragm 12 is partially higher than the initial tension applied to the mother film 1M. To drop.

  In addition, when the microphone unit 10 is mounted on the microphone base 3 via the support frame 20 of the mount member, stress is applied to the diaphragm ring 12 and the tension of the diaphragm 12 changes.

  Therefore, in the present invention, when the diaphragm assembly is obtained as described above, the mother film 1M has a tension that is, for example, about 10 to 20% higher than the design value tension that is finally applied to the diaphragm 11. Give. Then, the tension of the diaphragm 11 can be adjusted to be lower after the unit is assembled.

  For this reason, in this embodiment, the tension adjusting means 21 is provided at approximately the center of the long side frame portions 20a, 20 of the support frame 20 so as to be able to advance and retract relative to the long side frame portions 12a, 12a of the diaphragm ring 12. Combined screws 21a, 21a are provided.

  When the diaphragm assembly is cut out from the mother film 1M, the tension of the diaphragm 11 between the long side frame portions 12a and 12a is several due to the deformation of the long side frame portions 12a and 12a of the diaphragm ring 12 having a low tensile strength. % But decreases. On the other hand, the tension on the short side frame portions 12b and 12b side of the diaphragm ring 12 hardly changes.

  Therefore, in this embodiment, after the unit is assembled, the screws 21 a and 21 a as the tension adjusting means 21 are advanced with respect to the long side frame portions 12 a and 12 a of the diaphragm ring 12, so that the long side frame of the diaphragm ring 12 is The portions 12a and 12a are deformed from the outside to the inside, and the tension of the diaphragm 11 in the direction of the long side frame portions 12a and 12a is adjusted to a further lower direction. The tension is adjusted to the design value tension to be applied to the diaphragm 11.

  Thus, according to the present invention, since the tension of the diaphragm 11 can be adjusted after the unit is assembled, the side address type condenser microphone using the rectangular diaphragm with little individual difference in the directivity frequency response particularly in the low frequency range. Can be provided.

  In addition, since the diaphragm is rectangular, it is possible to realize a condenser microphone that has a higher sensitivity and a higher signal-to-noise ratio even with the same outer diameter than a circular diaphragm.

  In the above embodiment, the long side frame portions 12a, 12a of the diaphragm ring 12 are deformed inward, but the screws 21a, 21a as the tension adjusting means 21 are connected to the short side of the support frame 20. It may be arranged at the substantially central portion of the frame portions 20b, 20b so that the tension of the long side frame portions 12a, 12a and the short side frame portions 12b, 12b of the diaphragm ring 12 can be adjusted. Included in the invention.

  In the case where the screws 21a and 21a are provided at substantially the center of the long side frame portions 20a and 20a of the support frame 20 as in the above embodiment, the microphone unit is centered on the axes of the screws 21a and 21a in the support frame 20. For example, a rotation-preventing screw, a claw, or the like may be provided on the short side frame portions 20b and 20b of the support frame 20 so that the 10 does not rotate.

  When the diaphragm ring 12 is a square frame, the support frame 20 is preferably a square frame surrounding the diaphragm ring 12, and a tension adjusting screw 21a is provided at the center of each frame portion of the support frame 20. However, what is necessary is just to be provided in the approximate center part of at least one pair of opposing frame parts.

  The present invention is suitable for the side entry type condenser microphone described in the above embodiment, but may be a condenser microphone including a square (rectangular) microphone unit other than the side entry type. The base 3 is read as a microphone body.

2 Unit Cover 3 Microphone Base 10 Microphone Unit 11 Diaphragm 12 Diaphragm Ring 12a Long Side Frame 12b Short Side Frame 13 Fixed Electrode Plate 14 Insulator 15 Spacer Ring 20 Support Frame 20a Long Side Frame 20b Short Side Side frame 21 Tension adjusting means 21a Screw

Claims (8)

A microphone unit in which a diaphragm stretched on a diaphragm ring and a fixed electrode plate supported by an insulating seat are arranged to face each other via a spacer member, and the microphone unit surrounds the diaphragm ring. In the condenser microphone supported by the microphone body through the mount member including the frame,
Both the diaphragm ring and the support frame are formed of a rectangular frame having two pairs of opposed frame portions, and the support frame includes one pair of opposed frame portions on the diaphragm ring side and / or the other of the pair of frame portions. A condenser microphone, comprising tension adjusting means for pressing and deforming a pair of opposing frame portions from the outside.   2. The condenser microphone according to claim 1, wherein the quadrangular frame is a rectangular frame including a pair of long-side frame portions and a pair of short-side frame portions.   3. The condenser microphone according to claim 2, wherein the tension adjusting means is provided at a substantially central portion of each long side frame of the support frame.   The condenser microphone according to claim 1, wherein the quadrangular frame is a square frame in which the lengths of the four frame portions are equal.   5. The condenser microphone according to claim 4, wherein the tension adjusting means is provided at a substantially central portion of at least one pair of opposed frame portions of the support frame.   At the time of no tension adjustment before the tension adjustment by the tension adjustment means, a tension higher than the tension finally adjusted by the tension adjustment means is applied to the diaphragm. The condenser microphone according to any one of claims 1 to 5.   The condenser microphone according to any one of claims 1 to 6, wherein the tension adjusting means includes a screw screwed to the support frame so as to be movable back and forth with respect to the frame portion of the diaphragm ring.   8. The side entry type, wherein the microphone unit is a side entry type supported substantially vertically on a microphone base as a microphone body via a mount member including a support frame surrounding the diaphragm ring. The condenser microphone according to any one of the above.

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