JP2011176612A - Condenser microphone unit and condenser microphone - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a condenser microphone unit and a condenser microphone, easily discharging moisture even in case the moisture infiltrates into the inside when dew condensation or the like occurs, and thereby preventing the generation of noise caused by the leakage of electric charges by the moisture. <P>SOLUTION: The condenser microphone unit 1 is composed by at least housing built-in components including: a diaphragm 2 spread on a diaphragm support 4; a fixed pole 3 whose front surface side is arranged facing the diaphragm 2; and an insulation seat 9 which faces the back surface side of the fixed pole 3 and supports it inside a bottomed cylindrical unit case 7. The insulation seat 9 is equipped with: a receiving surface 9e for receiving the back surface of the fixed pole 3; and a peripheral wall part 9c projected from the outer peripheral edge of the receiving surface 9e to the side of the fixed pole 3. On the surface facing the diaphragm support 4 of the peripheral wall part 9c, a recessed and projected part 9a is provided. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a condenser microphone unit including a diaphragm and a fixed electrode in a unit case, and more specifically, a condenser microphone unit configured to easily remove moisture when moisture is condensed inside by moisture, and the condenser microphone. The present invention relates to a condenser microphone provided with a unit.

  For example, as in the invention described in Patent Document 1, the condenser microphone unit includes a capacitor element composed of a diaphragm and a fixed pole in a unit case formed in a bottomed cylindrical shape by a conductive metal such as brass. The electroacoustic conversion is performed by extracting the capacitance change of the capacitor element from the fixed pole, sending it to the impedance converter, converting it to a low impedance by the impedance converter, and outputting it. In this case, the fixed pole is arranged in the unit case by being supported by the insulating seat while surrounding the peripheral wall portion with the insulating seat so as not to be electrically connected to the unit case side.

  As shown in FIGS. 2 and 3, the condenser microphone unit 1 has a sound hole on the front side (upper side in FIGS. 2 and 3) and an opening surface on the rear side (lower side in FIGS. 2 and 3). A bottomed cylindrical unit case 7, the diaphragm 2 stretched on the diaphragm support 4 and disposed on the sound hole side in the unit case 7, and the front side thereof (upper side in FIGS. 2 and 3) Are provided with a fixed pole 3 facing the diaphragm 2 with a certain space, and an insulating seat 9 for supporting the peripheral edge of the back side of the fixed pole 3 (the lower side in FIGS. 2 and 3).

  A female screw 11 is engraved on the inner peripheral surface of the unit case 7 in the vicinity of the opening surface, and the insulating seat 9 can be advanced and retracted via a lock ring 5 screwed with the female screw 11. ing. Therefore, the built-in member including the insulating seat 9 is held in the unit case 7 under the pressure generated according to the degree of the locking state of the lock ring 5. Further, a front mesh 10 that prevents dust and the like from entering the unit case 7 is disposed inside the sound hole of the unit case 7. An electrode rod 8 for extracting a signal from the fixed pole 6 is disposed through the insulating seat 9. The insulating seat 9 includes a peripheral wall portion 9c that protrudes toward the fixed pole 6 on the peripheral side thereof, and faces the back surface (lower surface in FIG. 3) of the fixed pole 3 inside the peripheral wall portion 9c. A receiving portion 9e for receiving the fixed pole 3 is formed. The fixed pole 6 is bonded to the receiving portion 9 e of the insulating seat 9. The fixed pole 6 is held on the insulating seat 9 side while being supported by the receiving portion 9e so as to be fitted into the peripheral wall portion 9c. On the diaphragm support 4, the surface 9 b facing the diaphragm support 4 of the peripheral wall portion 9 c of the insulating seat 9 is in surface contact with the fixed surface of the diaphragm 2, and the diaphragm 2 and the fixed pole 3 are in contact with each other. A minute gap is formed in the diaphragm, and the diaphragm 2 and the fixed pole 3 constitute a capacitor.

  When the condenser microphone using the condenser microphone unit 1 configured as described above is placed in a high humidity environment, the gap A between the diaphragm support 4 shown in FIG. 2 and the peripheral wall 9c of the insulating seat 9 is shown. Moisture may enter and penetrate. Due to the penetration of moisture, the insulation between the diaphragm 2 and the fixed pole 3 is lowered, the capacitance of the capacitor formed by the diaphragm 2 and the fixed pole 3 is lowered, and noise is generated by the change in the capacitor capacity. . In particular, in a condenser microphone of a type that supplies a polarized power supply from the outside, power is supplied from the outside as soon as the capacitor capacity is reduced, and on the other hand, the operation of reducing the capacity is repeated, and noise is continuously generated.

  A portion that maintains the insulation between the diaphragm 2 and the fixed pole 3 is a surface 9b facing the diaphragm support 4 that is the front surface (upper surface in FIG. 2) of the peripheral wall portion 9c of the insulating seat 9 shown in FIG. Only. Since the facing surface 9b is a flat surface and is in surface contact with the diaphragm support 4, the creepage distance between the facing surface 9b and the diaphragm support 4, that is, the minimum distance along the surfaces of the members facing each other is short. Become. Accordingly, the surface area that contributes to the insulation between the facing surface 9b and the diaphragm support 4 is reduced, and when moisture enters as described above, the electric charge between the diaphragm 2 and the fixed electrode 3 leaks and noise is easily generated. Become. In such a case, for example, it is conceivable to return the condenser microphone unit 1 to an environment where the relative humidity is low. However, since the water entering the gap A is difficult to evaporate, it takes time to evaporate again.

JP 2009-77008 A

  In the present invention, even in a high humidity environment, the insulating property is lowered by devising the structure so that moisture does not easily permeate between the opposing surfaces of the diaphragm support and the diaphragm support of the peripheral wall portion of the insulating seat. It is an object of the present invention to provide a condenser microphone unit and a condenser microphone using the same, which can prevent the occurrence of noise caused by charge leakage by preventing charge leakage between the diaphragm and the fixed pole. To do.

  The condenser microphone unit according to the present invention has a diaphragm stretched on a diaphragm support, a fixed pole whose front side faces the diaphragm, and a rear side of the fixed pole that faces and supports the diaphragm. A condenser microphone unit including a built-in component including an insulating seat in a bottomed cylindrical unit case, the insulating seat receiving a back surface of the fixed pole, and the receiving surface A peripheral wall portion projecting from the outer peripheral edge of the peripheral wall portion toward the fixed pole side, and an uneven surface is provided on a surface of the peripheral wall portion facing the diaphragm support. .

  The condenser microphone according to the present invention is characterized in that the condenser microphone unit according to the present invention is used as a condenser microphone unit and is housed in a microphone case.

  According to the present invention, unevenness is provided on the surface of the peripheral wall portion of the insulating seat that comes into contact with the diaphragm support so as to face the diaphragm support so that the creepage distance, i.e., the surface of the diaphragm support and the insulating seat facing the surface. Since the distance along the surface of the member can be increased, moisture does not easily permeate between the diaphragm support and the insulating seat even in a high humidity environment. Can be avoided, and the deterioration of the insulation between the diaphragm and the fixed pole can be prevented. Therefore, it is possible to prevent the occurrence of noise due to the above-described deterioration of the insulation, and further, the use of a condenser microphone unit that can reduce the cost because a spacer can be unnecessary in structure, and the same is used. A condenser microphone can be provided.

It is an expanded sectional view showing an important section of an example of a condenser microphone unit concerning the present invention. It is an expanded sectional view which shows the principal part of the prior art example of a condenser microphone unit. It is sectional drawing which shows the prior art example of a condenser microphone unit.

  Embodiments of a condenser microphone unit and a condenser microphone according to the present invention will be described below with reference to the drawings. It should be noted that the present invention is not limited to the configuration of the illustrated embodiment, and the design can be changed without departing from the technical scope described in the claims. The main feature of the present invention lies in the configuration of the contact portion between the insulating seat of the condenser microphone unit and the diaphragm support, and the overall configuration of the condenser microphone to which it is applied is appropriate based on the concept of technical design. Can be selected. The configuration of the conventional condenser microphone unit shown in FIGS. 2 and 3 is the same as that of the conventional condenser microphone unit shown in FIGS. 2 and 3, except for the configuration of the contact portion between the insulating seat of the condenser microphone unit and the diaphragm support. The same components as those described above are denoted by the same reference numerals.

  In FIG. 1, a condenser microphone unit 1 includes a diaphragm support 4 formed in a ring shape, a diaphragm 2 stretched on the back side (lower side in FIG. 1) of the diaphragm support 4, and a front surface. The side (upper side in FIGS. 1 and 3) faces the diaphragm 2 facing the diaphragm 2 with a certain space, and the back side of the fixed pole 3 (lower side in FIGS. 1 and 3). It has a built-in component including an insulating seat 9 that supports it, and these built-in components are incorporated in a bottomed cylindrical unit case 7.

  The insulating seat 9 includes a main body portion 9d, a receiving portion 9e that faces the back surface of the fixed pole 3, and receives the fixed pole 3, and a peripheral wall portion 9c that protrudes from the peripheral side of the main body portion 9d toward the fixed pole 3 side. ing. The front end of the peripheral wall portion 9c is a facing surface 9f facing the back surface of the diaphragm support 4, and unevenness 9a is formed on the facing surface 9f. The fixed pole 3 is fitted in a recess on the inner peripheral side of the peripheral wall portion 9c of the insulating seat 9, and is fixed to the facing surface 9f while being supported by the facing surface 9f of the insulating seat 9, and is held by the insulating seat 9. ing. The fixing means for the fixed pole 3 is optional, and may be fixed by, for example, adhesion.

  The unit case 7 has a bottomed cylindrical shape, has a sound hole in the bottom located on the front side, and has an open end on the back side. A female screw 11 is engraved on the inner peripheral surface in the vicinity of the open end of the unit case 7, and the insulating seat 9 can be pressed by a lock ring 5 screwed with the female screw 11. . Therefore, the built-in member including the insulating seat 9 is held in the unit case 7 by receiving pressure generated according to the degree of screwing of the lock ring 5.

  The unevenness 9a provided on the surface 9f facing the back surface of the diaphragm support 4 of the insulating seat 9 is formed in a ring shape concentric with the circular insulating seat 9, and in the longitudinal section shown in FIG. It is wavy. A plurality of the ring-shaped convex portions, two in the illustrated example, are formed inside and outside, and a concave portion is formed in the middle. The peripheral wall portion 9 c of the insulating seat 9 protrudes toward the diaphragm support 4 from the front surface of the fixed pole 3. Therefore, a space is generated between the fixed pole 3 and the diaphragm 2. By forming the unevenness 9a on the surface 9f of the insulating seat 9 facing the back surface of the diaphragm support 4, the creeping distance between the insulating seat 9 and the diaphragm support 4, that is, the diaphragm support 4 and the insulating seat 9 is obtained. It is possible to increase the distance along the surface of the member on the surface opposite to the surface, and by increasing the insulation distance, it is possible to prevent deterioration of insulation due to condensation even in a high humidity environment, and it is difficult for condensation to occur. The influence of the subsequent drying residue can be avoided. Further, since the contact area between the diaphragm support 4 and the insulating seat 3 can be reduced, it becomes difficult for moisture to permeate between the diaphragm support 4 and the insulating seat 3, and the diaphragm 2 due to the penetration of moisture. And the discharge of electric charge between the fixed electrode 3 and the fixed electrode 3 can be avoided.

  In the embodiment shown in FIG. 1, the convex portion on the outer peripheral side of the two convex portions formed on the surface 9 f facing the back surface of the diaphragm support 4 of the insulating seat 9 is formed in the horizontal direction (with the surface of the diaphragm 2. The insulating seat 9 is formed in a shape that is cut along the line B in the parallel direction. When the insulating seat 9 is formed in such a shape, a gap is formed between the facing surface 9f and the diaphragm support 4, and the concave portion adjacent to the convex portion on the inner peripheral side communicates with the outside air and is insulated by condensation or the like. Even if moisture enters between the facing surface 9f of the seat 9 and the diaphragm support 4, the moisture can be evaporated from the gap at a relatively early time. The unevenness 9a of the facing surface 9f may have two convex portions and one concave portion as shown in FIG. 1, or may increase the number of convex portions. For example, the number of convex portions may be three and the number of concave portions may be two. In this case, the convex portion on the outermost peripheral side may be formed in a shape cut as described above.

  In the embodiment shown in FIG. 1, the fixed pole 3 is bonded to the receiving portion 9 e of the insulating seat 9, and the opposing surface 9 f of the insulating seat 9 is brought into contact with the vibrating plate support 4, thereby making the diaphragm support A gap is formed between the diaphragm 2 and the fixed pole 3 that are stretched on the base plate 4, and a conventionally used spacer is not interposed between the diaphragm and the fixed pole. That is, the spacer can be omitted from the structure, and the cost can be reduced. However, a spacer may be interposed between the diaphragm and the fixed pole, and a gap may be provided between the diaphragm and the fixed pole. Even in the capacitor microphone unit having such a configuration, the diaphragm support 4 of the insulating seat 9 may be provided. Unevenness 9a is formed on the surface 9f facing the back surface. Thereby, the same effect as the embodiment shown in FIG. 1 can be obtained. Regardless of the configuration, the unevenness 9a may be formed in a concentric ring shape, or may be in other shapes. For example, among the unevenness 9 a in FIG. 1, a plurality of columnar convex portions may be arranged in the circumferential direction of the insulating seat 9 in place of the ring-shaped convex portion on the outermost periphery side of the insulating seat 9. .

  Other configurations are the same as those of the conventional example shown in FIGS. That is, the unit case 7 is made of a conductive metal material such as brass or aluminum. Further, the sound hole of the unit case 7 is a long slit hole portion 7a that radially extends from around the substantially central portion of the front surface of the unit case 7 (the upper surface in FIGS. 1 to 3) to the peripheral side of the unit case 7. And short slit holes 7b are alternately arranged. Further, in order to prevent dust and the like from entering the unit case 7 from the outside through the long slit hole portion 7a and the short slit hole portion 7b inside the unit case 7 where the sound hole is located. Further, a front mesh 10 is provided. The shape of the unit case 7 is not limited to that described above, and any shape can be selected.

  The insulating seat 9 is formed of an appropriate insulating material, and an electrode rod 8 for extracting a signal from the fixed pole 3 penetrates the insulating seat 9 in the central axis direction. The insulating seat 9 has a recessed portion that receives the fixed pole 3, and a receiving portion that includes a front end surface of a step portion formed in the main body portion 9d in order to bond the back surface of the insulating seat 9 received in the recessed portion. 9e and the peripheral wall part 9c which regulates the outer peripheral surface of the insulating seat 9. Furthermore, the insulating seat 9 is provided with a hole 12 (see FIG. 3) for communicating the recessed portion with the outside. The hole 12 forms a rear acoustic terminal. The acoustic resistance material 6 is bonded to the back surface of the insulating seat 9 so as to close the hole 12. The electrode rod 8 is electrically connected to the fixed electrode 3 through an appropriate conductor.

  As described above, the diaphragm holding body 4 with the diaphragm 2 stretched, the fixed pole 3, and the built-in components including the insulating seat 9 are accommodated in the unit case 7. Since the fixed pole 3 is disposed so that the outer peripheral surface thereof does not come into contact with the unit case 7 by the peripheral wall portion 9c of the insulating seat 9, the fixed poles 3 are electrically insulated from each other. The built-in components in the unit case 7 are arranged as described above, and the lock ring 5 is screwed into the female screw 5 of the unit case 7 and rotated in the tightening direction. The built-in component is stably housed and held in the unit case 7 by the pressure generated in this way. That is, the diaphragm 2, the fixed pole 3, and the insulating seat 9 are stably housed and held in the unit case 7 while maintaining a mutually parallel positional relationship.

  The condenser microphone unit according to the present invention can constitute a condenser microphone by incorporating it into a microphone case. A circuit board constituting an appropriate electric circuit can be disposed in the microphone case. The microphone case is provided with a connector for connecting a microphone cable, and the electroacoustic converted signal is input to an external device via the connector and the microphone cable.

  As described above, an example of the embodiment of the present invention has been described. However, the present invention is not limited to the configuration of this example, and the design can be changed without departing from the technical idea described in the claims. That is, the main feature of the present invention is that the configuration of the abutting portion between the insulating seat of the condenser microphone unit and the diaphragm support is the omnidirectional condenser microphone unit other than the unidirectional condenser microphone unit mainly shown in the embodiment. Can be used.

DESCRIPTION OF SYMBOLS 1 Capacitor microphone unit 2 Diaphragm 3 Fixed pole 4 Diaphragm support body 7 Unit case 9 Insulation seat 9a Concavity and convexity 9c Peripheral wall part 9e Receiving part

Claims (6)

A built-in component including a diaphragm stretched on a diaphragm support, a fixed pole whose front side is disposed facing the diaphragm, and an insulating seat that faces and supports the rear side of the fixed pole A condenser microphone unit that is housed in a bottomed cylindrical unit case,
The insulating seat includes a receiving surface that receives the back surface of the fixed pole, and a peripheral wall portion that protrudes from an outer peripheral edge of the receiving surface toward the fixed pole side,
A condenser microphone unit, wherein a surface of the peripheral wall facing the diaphragm support is provided with irregularities.   The condenser microphone unit according to claim 1, wherein the unevenness provided on the peripheral wall portion of the insulating seat is formed in a concentric ring shape.   The condenser microphone unit according to claim 1 or 2, wherein a space is provided between the fixed pole and the diaphragm by projecting the peripheral wall portion of the insulating seat toward the diaphragm supporter with respect to the fixed pole.   The unevenness forming surface of the peripheral wall portion of the insulating seat is formed in a shape in which the convex portion on the outer peripheral side is cut, and a gap is generated between the unevenness forming surface and the diaphragm support. The condenser microphone unit according to any one of the above.   5. The condenser microphone unit according to claim 1, wherein the unevenness forming surface of the insulating seat is in contact with the diaphragm support and a gap is formed between the diaphragm and the fixed pole.   The condenser microphone unit according to claim 1 is housed in a microphone case, and a connector for outputting an audio signal from the capacitor microphone unit to the outside is provided in the microphone case. Condenser microphone.

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