JP2605535Y2 - Line microphone anti-vibration structure - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a line microphone which is a narrow directional microphone.
The present invention relates to an anti-vibration structure for a line microphone having a narrow directivity by fitting an acoustic tube to a microphone unit.

[0002]

2. Description of the Related Art As microphones mounted on video cameras and the like, among condenser microphones, those having unidirectionality and sharp directivity are widely used. In the case of a video camera for general home use, a unidirectional condenser microphone is usually used due to the problem of miniaturization of the appearance, and in the case of a video camera for business use such as creation of a broadcast program, a condenser microphone having a sharp directivity. Is often used.

[0003] Among these microphones required to have directivity, there is a microphone having a narrow directivity called a line microphone. In this line microphone, one end of a leaky acoustic tube is fitted to the front acoustic terminal of the microphone unit, and sound waves from angles other than the main sound collection axis are subjected to acoustic resistance from the front end face and the side opening of the acoustic tube. The material enters the sound tube through the material, and attenuates the sound wave of the main sound pickup axis by the phase difference to obtain sharp directivity.

A conventional line microphone of this type is:
The microphone unit includes a microphone unit having a front acoustic terminal and a rear acoustic terminal, and an acoustic tube having a slit formed on the peripheral surface. One end of the acoustic tube is fitted to the front acoustic terminal side of the microphone unit, and the rear acoustic terminal side of the microphone unit is located in a free sound field. An acoustic resistance material made of nonwoven fabric such as felt or nylon mesh is provided on the outer peripheral surface or inner peripheral surface of the acoustic tube.

[0005] By the way, a video camera has a large number of rotating parts, and its rotation may reach a microphone as sound waves or vibrations, and may be picked up. Therefore,
With this kind of microphone. A front acoustic terminal of a microphone unit is firmly coupled to a rear portion of the acoustic tube, and vibration is prevented by covering the entire acoustic tube and the microphone unit with an elastic body such as rubber.

[0006]

However, the above-described vibration isolation not only increases the number of components but also complicates the assembly and increases the cost.

[0007] Therefore , the purpose of the present invention is to eliminate vibration noise
Another object of the present invention is to provide an anti-vibration structure for a line microphone that is effective against so-called wind noise and that can be easily assembled at low cost.

[0008]

To achieve the above Symbol object, according to an aspect of this invention has a front end is opened, the rear acoustic on the rear end side
Acoustic tube consisting of a cylindrical tube of predetermined length with terminal openings
And the front end of the rear acoustic terminal opening in the acoustic tube.
Unidirectional microphone unit stored in side position
And the ventilation arranged before and after the microphone unit
Compliant front elastic ring and rear elastic ring.
Above the the microphone unit of that line microphone
In the vibration isolation structure of a line microphone fixed in an acoustic tube in a vibration isolation state, the microphone unit is
A unit holder having a cylindrical recess to be housed therein;
Coaxially and integrally provided in front of the knit holding part,
Opening for the resonator that introduces sound waves into the microphone unit
A cylindrical holding member made of an elastic body having a mouth and
The holding member and the sound
Forward sound of the above microphone unit between the inside of the sound tube and
No. that secures a gap for communication between the sound terminal and the rear sound terminal
One projection is formed, and the axial direction of the holding member is
Second protrusions for each of the above elastic rings are formed at both ends.
And the microphone unit is
The first and second projections are housed in the holding portion.
That it is elastically supported in the acoustic tube through
Features.

[0009] According to this arrangement, is held by inserting the microphone unit in the unit holding portion of the holding member, the coercive member only attached to the acoustic tube, are disposed on the inner surface and the axial direction of the acoustic tube member ( Front elastic ring and rear bullet
Projection of the holding member with respect to sex ring) contacts respectively,
Resiliently it can fix the microphone unit in the acoustic tube, which allows vibration-damping support of the microphone unit. Further, since the microphone unit is held with a fixed distance between the acoustic tube wall, front acoustic terminal and a rear acoustic terminal of the microphone unit is coupled with an acoustic pipe with an acoustic impedance Rutotomoni, resonator unit that functions as a high-frequency resonator Can be integrally formed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention shown in the drawings will be described below. FIG. 1 shows a main part of the entire line microphone. The line microphone 1 is fitted to an acoustic tube 2 made of metal such as aluminum and the like through a holding member 4 in a rear end portion of the acoustic tube 2. Microphone unit 3
It is composed of

As shown in the sectional view of FIG. 2 and the right side view of FIG. 3, the holding member 4 has a substantially cylindrical shape and is integrally formed of, for example, neoprene rubber having a hardness of 30 degrees. The holding member 4 is provided with cylindrical openings having different diameters along the axis. A large-diameter opening on the right side in FIG. 2 is a unit holding portion 5 for holding a microphone unit, and a small-diameter opening on the left side. The resonator 6 communicates with the unit holder 5 and functions as a high-frequency resonator.
At the outer periphery of the holding member 4, three projections 7 are integrally provided at two locations in the axial direction at every 120 degrees in the circumferential direction, and three locations at both ends are shifted from the projections by 60 degrees. Are provided with projections 8 and 9, respectively. In addition, as a molding material of the holding member 4, any material may be used as long as it is an elastic material having characteristics equivalent to neoprene rubber, and the material is not particularly limited.

A grill 10 is formed at the distal end of the acoustic tube 2, and a front damper 11 made of an acoustic resistance material that transmits sound waves penetrating through an opening of the grill 10 is provided behind the grill 10. I have. Front damper 11
A wire mesh 12 and a tube damper 13 made of an acoustic resistance material are provided along the inner periphery of the acoustic tube 2 while being held on the inner surface of the acoustic tube 2 by its own shape restoring force. These are adhesively fixed to the inner surface of the acoustic tube 2 at the ends by an adhesive.

The holding member 4 is mounted in the acoustic tube 2 with the microphone unit 3 inserted into the unit holding portion 5 and held in the holding portion 5. The rear end of the holding member 4 holding the microphone unit 3 is located forward of an opening 14 for a rear acoustic terminal formed at the rear of the acoustic tube 2, and is provided with air permeability fitted into the acoustic tube 2. It is in contact with a rear elastic ring 17 made of rubber or foamable synthetic resin. The rear elastic ring 17 has the opening 1
4 is fixed by the edge of the wire mesh 15 inserted into the acoustic tube 2 so as to cover the acoustic tube 4. The other end of the wire net 15 is fixed by a bottom pad 16 inserted into the acoustic tube 2.

[0014] the tip of the resonator portion 6 of the holding member 4, after
Parts of an elastic ring 17 and the same material, the movement is restricted by the front fastener 20 through the front elastic ring 19 at least equal outer diameter to the inner diameter of the acoustic tube 2.
The details of the front fastener 20 are not shown,
It has a ring portion having a diameter smaller than the inner diameter of the acoustic tube 2 and a plurality of legs projecting from the ring portion in the outer diameter direction, and is fixed in the acoustic tube 2 with the air permeability by these legs. . Reference numeral 21 denotes an opening for introducing a sound wave from the side surface of the acoustic tube 2 to the front acoustic terminal.

With this configuration, the microphone unit 3
Is inserted and held in the unit holding portion 5 of the holding member 4,
The assembly can be easily performed simply by sequentially inserting the above members together with the above-described members behind the tube damper 13 of the acoustic tube 2. Moreover, the axial direction is formed by the projections 8 and 9.
The front elastic ring 19 and the rear elastic ring 17 are in contact with each other, and the circumferential direction is in contact with the inner peripheral surface of the acoustic tube 2 by the protrusion 7. Therefore, vibration transmitted from the acoustic tube 2 to the microphone unit 3 is effective. And good assemblability and vibration isolation can be realized at the same time.

In the frequency band above the middle band,
On the resonator section 6 side of the holding member 4 is a front acoustic terminal, but at a low frequency, the front end of the acoustic tube 2 is also a front acoustic terminal, and the opening 14 at the rear end of the acoustic tube 2 which is a rear acoustic terminal. Becomes longer, and an extremely large pressure difference occurs between the two. However, a gap is formed between the holding member 4 and the inner peripheral surface of the acoustic tube 2 due to the projection 7, and the front fastener 20 moves to the front elastic ring 19 and
An air leakage path is formed through the rear elastic ring 17 to the rear acoustic terminal, so that even if there is a pressure difference between the front acoustic terminal and the rear acoustic terminal, air on the high pressure side flows into the low pressure side. The pressure difference is small,
It can also contribute to the reduction of wind noise.

[0017]

As described above, the anti-vibration structure of the line microphone according to the present invention has a unit holder for holding the microphone unit, and communicates along the same axis with the unit holder to introduce sound waves into the microphone unit. An opening, and a substantially cylindrical strip holding member made of an elastic body having a plurality of projections projecting from the outer peripheral surface and both ends in the axial direction and abutting on the inner surface of the acoustic tube, and the unit holding part In a state where the microphone unit is held, the projection is elastically brought into contact with the inner surface of the acoustic tube by the projection, so that a line microphone that can be easily assembled and has excellent vibration proofing properties can be provided at low cost. Further, an opening serving as a resonator functioning as a high-frequency resonator can also be formed integrally with the holding member.

[Brief description of the drawings]

FIG. 1 is a front view showing a cross section of a main part of a line microphone having an acoustic tube according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing only the holding member.

FIG. 3 is a side view of the holding member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Line microphone 2 Acoustic tube 3 Microphone unit 4 Holding member 5 Unit holding part 6 Resonator part 7, 8, 9 Projection

Claims (1)

(57) [Scope of request for utility model registration] A front end is opened and a rear acoustic end is provided on a rear end side.
An acoustic tube comprising a cylindrical tube of a predetermined length having an opening for a child,
Front end side of the rear acoustic terminal opening in the same acoustic tube
A unidirectional microphone unit housed in the
Breathability placed before and after the microphone unit
In the vibration damping system of the front elastic ring and rear elastic ring and La <br/> in microphone on SL line microphone for fixing the vibration-correction state above Symbol acoustic tube the microphone unit comprising comprise, the microphone unit therein Is housed in a cylindrical recess
Unit holding part having a part, and the front of the unit holding part
The microphone unit is coaxially connected to the
With openings for resonators to introduce acoustic waves into the
A cylindrical holding member composed of a body, wherein the holding member
Between the holding member and the inner surface of the acoustic tube
Front acoustic terminal and rear acoustic end of the microphone unit
The first projection is formed to secure a space for communicating with the child.
And at the axial ends of the holding member,
A second projection for the elastic ring is formed, and
The microphone unit is stored in the unit holder
The acoustic tube through the first and second protrusions
An anti-vibration structure for a line microphone, which is elastically supported inside .