JP2009094850A - Microphone and pop noise generation preventing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce pop noise without deteriorating frequency response of a microphone or changing the design of the microphone itself. <P>SOLUTION: The microphone 10 constituted by storing a microphone unit in a head case 12 having a protective cover that sound waves can pass through includes an air current generating means 20 (preferably, a bimorph vibrator 21) disposed outside the head case 12 and generating an air current A from a direction nearly perpendicular to the axis X-X of sound absorption of the microphone unit. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a microphone and a pop noise generation prevention device, and more particularly to a technique for effectively reducing pop noise output from a microphone due to a plosive sound or the like emitted from a speaker.

  The plosive sound generated by momentarily opening a closed lip, such as p, b, t, d, k, g, etc., is accompanied by a sudden change in airflow, so it bursts from the speaker very close to the microphone. When sound is emitted, a sudden air current flows into the microphone and pop noise is generated. This pop noise becomes a problem particularly when picking up sound in a studio or the like.

  In order to reduce the pop noise, conventionally, an instrument called “pop filter” in which a mesh material having elasticity like a stocking is attached to a ring-shaped frame is arranged in front of the microphone.

  In order to reduce pop noise by using a pop filter, there are a method of increasing the density of the filter so that an air flow accompanying a plosive sound is not easily applied to the microphone, and a method of increasing the distance between the microphone and the pop filter.

  However, when the density of the filter is increased, the acoustic resistance value is increased correspondingly, so that the frequency response may be deteriorated.

  In addition, if the distance between the microphone and the pop filter is increased, the microphone and the sound source are separated more than necessary, so that the use of the proximity effect can be limited (the sound creation using the proximity effect is limited). Therefore, it is not preferable.

  Apart from this, in the invention described in Patent Document 1, the generation of pop noise is reduced by housing a porous filter element having a surface shape covering all front acoustic terminals in the unit case of the microphone unit. Like to do.

  According to this, since the pop filter is not used, the overall size is reduced. However, in order to suppress the pop noise to a lower level, it is necessary to increase the density of the filter, and the frequency response may be deteriorated.

In addition, since the porous filter element is stored in the unit case, it is necessary to secure the storage space in the unit case and to take into account the characteristics of the porous filter element. There is also a problem that it cannot be applied to a microphone.
JP 2004-297765 A

  Therefore, an object of the present invention is to reduce pop noise without deteriorating the frequency response of a microphone and without requiring a design change of the microphone itself.

  In order to solve the above-described problems, the present invention provides a microphone in which a microphone unit is housed in a head case having a protective cover through which a sound wave can pass, and is disposed outside the head case, and the sound collecting shaft of the microphone unit. Is provided with an air flow generation means for generating an air flow from a direction substantially perpendicular to the above.

  In the present invention, as described in claim 2, it is preferable to use a bimorph vibrator for the airflow generating means.

  According to a third aspect of the present invention, it is preferable that a wind noise preventing filter made of a net is disposed between the airflow generating means and the head case.

  The present invention also includes a pop noise generation prevention device used for a microphone in which a microphone unit is housed in a head case having a protective cover through which a sound wave can pass. The pop noise generation preventing device includes a bimorph vibrator that is disposed outside the head case and generates an air flow from a direction substantially perpendicular to the sound collection axis of the microphone unit.

  According to the present invention, since the air flow is generated from the direction substantially perpendicular to the sound collecting axis of the microphone unit by the air flow generating means arranged outside the head case, the sudden burst accompanying the burst sound generated by the speaker is generated. As a result, at least a part of the typical airflow is pushed away by the airflow generated by the airflow generation means, and the sudden airflow caused by the plosive sound reaching the microphone unit is reduced, thereby reducing the pop noise without degrading the frequency response. can do. Further, since the airflow generation means may be arranged outside the microphone, it can be applied to an existing microphone.

  In addition, a blower having a fan may be used as the airflow generation means, but according to the bimorph vibrator, no wind noise is generated by the fan, so that generation of extra noise can be suppressed.

  Further, if a wind noise prevention filter made of a net is disposed between the airflow generation means and the head case, wind noise generated by the wind generated by the airflow generation means can be prevented.

  Next, an embodiment of the present invention will be described with reference to FIGS. 1 and 2, but the present invention is not limited to this. FIG. 1 is a schematic diagram showing an embodiment of the present invention, and FIG. 2 is a schematic diagram showing a bimorph vibrator used as an airflow generating means.

  As shown in FIG. 1, the microphone in this embodiment is a side address type (side entry type) microphone 10 used in a studio or the like, and includes a microphone housing 11 formed in a cylindrical shape from, for example, brass alloy, A head case 12 having a protective cover through which sound waves can pass is provided in the upper half portion of the microphone casing 11.

  Although not shown, a microphone unit (in this example, a condenser microphone unit) is accommodated in the head case 12. Since it is a side address type, the diaphragm is arranged vertically, and therefore its sound collection axis XX is horizontal in FIG. A ribbon microphone unit may be used as the microphone unit.

  In order to reduce the pop noise caused by the sudden airflow B caused by the burst sound emitted from the speaker H, the microphone 10 includes an airflow generating means (blower means) 20 disposed outside the head case 12.

  The airflow generation means 20 is disposed at a height higher than, for example, the head case 12 via a support member (not shown), and generates an airflow A from a direction substantially perpendicular to the sound collection axis XX of the microphone unit therefrom. Let

  According to this, at least a part (preferably all) of the sudden air flow B accompanying the plosive sound etc. emitted from the speaker H is made into the two-dot chain line in FIG. As shown in the figure, the pop noise caused by the sudden airflow B is reduced because the microphone is pushed downward and does not reach the microphone unit directly.

  A fan having a fan may be used as the airflow generating means 20, but this type of fan is likely to generate wind noise of the fan. Therefore, in this embodiment, the bimorph vibrator 21 that hardly generates wind noise or the like is used in the airflow generation means 20.

  As schematically shown in FIG. 2, the bimorph vibrator 21 used in this embodiment has two diaphragms 211 and 212 made of piezoelectric ceramics bonded together in the same polarization direction, and one end of the diaphragm is joined to a base 213. The vibrator is held and supported, and one is displaced in the contracting direction and the other is displaced in the extending direction depending on the polarity of the applied voltage.

  Therefore, when the connection is made as shown in FIG. 2 and the AC voltage V is applied, the tip end side is continuously reciprocated, so that as described above, from the direction substantially perpendicular to the sound collection axis XX of the microphone unit. Airflow A can be generated. The bimorph vibrator has an advantage that it has low electromagnetic noise and low noise, and the applied voltage may be small.

  Although the bimorph vibrator 21 itself has low noise, an air flow A (wind) is generated in the vicinity of the head case 12, and therefore the wind noise may be generated by the air flow A.

  In order to prevent this wind noise, it is preferable to arrange a wind noise prevention filter 30 made of a mesh body between the bimorph vibrator 21 (airflow generating means 20) and the head case 12, as shown in FIG. .

  As an example of the wind noise prevention filter 30, an acoustic filter in which a net body 31 made of a SUS mesh having a wire diameter of φ0.1 mm and a mesh degree of # 100 is attached to the frame body 32 is preferably employed.

  In the above embodiment, the airflow generation means 20 (preferably the bimorph vibrator 21) is arranged at a higher height outside the head case 12, but with respect to the sound collection axis XX of the microphone unit. If the airflow A can be obtained from a substantially vertical direction, the airflow generation means 20 may be disposed on the side of the head case 12 (position perpendicular to the paper surface in FIG. 1) or below the head case 12.

  Further, the microphone 10 is not necessarily a side address type (side entry type), and the microphone 10 may be a handheld condenser microphone or a dynamic microphone.

The schematic diagram which shows one Embodiment of this invention. The schematic diagram which shows the bimorph vibrator | oscillator used as an airflow generation means.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Microphone 11 Microphone housing | casing 12 Head case 20 Airflow generation means (blowing means)
21 Bimorph vibrator 211, 212 Diaphragm 30 Wind noise prevention filter A Airflow by airflow generation means B Airflow by plosives X Sound collection axis

Claims (4)

In a microphone in which a microphone unit is housed in a head case having a protective cover through which sound waves can pass,
A microphone provided with an air flow generating means that is disposed outside the head case and generates an air flow from a direction substantially perpendicular to a sound collecting axis of the microphone unit.   The microphone according to claim 1, wherein a bimorph vibrator is used as the airflow generation unit.   The microphone according to claim 1 or 2, wherein a wind noise prevention filter made of a net is disposed between the airflow generating means and the head case. In a pop noise generation preventing device used for a microphone in which a microphone unit is housed in a head case having a protective cover through which sound waves can pass,
A pop noise generation preventing apparatus, comprising: a bimorph vibrator disposed outside the head case and generating an air flow from a direction substantially perpendicular to a sound collecting axis of the microphone unit.

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