JP3062982B2 - Microphone sound quality adjustment mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microphone sound quality adjusting mechanism which can obtain good results when applied to a microphone which is used for sharing speech and vocals.

[0002]

2. Description of the Related Art A microphone includes a microphone body provided with a diaphragm and a converter for converting the vibration of the diaphragm into a sound current. A back air chamber is provided at the back of the microphone unit, and an acoustic resistance when the diaphragm vibrates is obtained by the function of the back air chamber. By changing the acoustic resistance, the low-frequency characteristics change.

[0003] Although the low-frequency characteristics can be changed by changing the acoustic resistance in this way, it is practically difficult to change the acoustic resistance in a microphone body having a fixed volume. Therefore, conventionally, a series circuit of a choke coil and a switch is connected in parallel to the electrical output circuit of the microphone unit, and by switching this switch, the choke coil is connected to the microphone unit in parallel or disconnected. , To change the low frequency characteristics.

[0004]

Such a device that electrically changes the acoustic characteristics is not preferable because the impedance changes accordingly, and also increases the number of electric components, which causes a high cost.

[0005] The present invention has been made in view of this point, and solves the above-mentioned problems of the prior art by mechanically changing the acoustic characteristics.
Is intended to improve the operability of the device.

[0006]

According to the present invention, there is provided a microphone unit in which a yoke is arranged on an outer peripheral portion of a magnet to constitute a magnetic circuit, and a back air chamber of the microphone unit is provided. Maikuhe rotation shutter mechanism with a window that opens and closes between the external and
Inside the arm and around the yoke,
The switching ring of the shutter mechanism is installed outside the microphone head.
In addition, the opening degree of the rotary shutter mechanism changes the degree of communication between the back air chamber and the outside, changes the acoustic resistance, and controls the low-frequency characteristics.

Further, a plurality of back air chambers of the microphone unit are provided, and a valve mechanism for changing the degree of communication between the back air chambers is provided between the plurality of back air chambers. It is configured to change the acoustic resistance.

[0008]

With such a configuration, by operating the rotary shutter mechanism or the valve mechanism to change the opening thereof,
Since the back air chamber of the microphone unit communicates with the outside or changes the overall volume, a part of the acoustic resistance for adjusting the speed component is variable, and the low-frequency characteristics can be controlled.

[0009]

FIG. 1 shows an embodiment of the present invention. Reference numeral 1 denotes a microphone body, which is a metal cylinder. A connection terminal is attached to a lower end (not shown) of the microphone body 1 so as to be connected to a plug of a cord. A female screw is engraved on the microphone body 1, and a male screw portion of the unit holder 2 is screwed and attached to the female screw portion.

The unit holder 2 is a bottomed cylindrical body as shown in the drawing, and accommodates a tail portion 3 of a microphone unit described later via a cushion 4 therein.
An external thread is engraved on the upper outer peripheral portion of the unit holder 2, and a mounting ring 6 of a microphone head 5, which is entirely formed of a net, is screwed onto the external thread. Exposed from the microphone head 5 of the unit holder 2
A concave portion 7 is provided in the above-mentioned portion, and a switching ring 8 is mounted in this concave portion 7, and this portion will be described later.

The above-mentioned tail part 3 is supported by the unit holder 2 via a cushion 9 at the lower end.
The microphone unit 11 is supported on the upper part by a bolt 10 penetrating the central part. Microphone unit 11
Are magnet 12, yoke 13, ring yoke 14, diaphragm
15, a voice coil 16, a protector 17, a case 18 surrounding the whole, and the like. A hole 19 for passing sound waves is provided at a front portion of the protector 17, and a hole 20 for acoustic resistance is provided at a side portion of the case 18.
A damper member 21 is attached to the hole 20.

The bottom of the yoke 13 is provided with a hole 22 through which a tail portion 3 is attached via a damper material 23 attached thereto.
It communicates with the inside. That is, the yoke 13
The inside of the tail part 3 and the inside of the tail part 3 form one volume via the damper material 23, and constitute an acoustic resistance for adjusting the velocity component on the back of the diaphragm 15. Since the acoustic resistance can be changed by changing the degree of communication of the back of the diaphragm 15 to the outside, the present invention employs the following structure.

As described above, the unit holder 2 is provided with the concave portion 7, and the switching ring 8 is mounted in the concave portion 7. The unit holder 2 is provided with a hole 24 communicating with the recess 7, and a projection 25 formed on a part of the switching ring 8 penetrates the hole 24 and enters the inside of the unit holder 2. The lower end of the arm 28 of the switching sleeve 27 is engaged with the projection 25 via the cushion 26. The switching sleeve 27 includes a ridge 29 provided on the outer periphery of the tail portion 3 and a case.
It is supported between 18 and pivots at that position.

As shown in FIG. 2, the upper portion of the switching sleeve 27 is located on the outer periphery of the yoke 13, and the switching sleeve 27 is provided with a plurality of windows 30 at appropriate intervals .
On the other hand, a hole 31 for a phase shift circuit is provided on the side of the case 18 so as to face the window 30. Damper material in hole 31
32 is stuck. The window 30 and the hole 31 are opposed to each other to form a rotary shutter mechanism. When the switching sleeve 27 is rotated by the switching ring 8, the case is closed.
The degree of communication between the back air chamber inside 18 and the outside, that is, the acoustic resistance, changes. This rotary shutter mechanism
It is configured inside the microphone head 5 and outside the microphone head 5.
It can be operated by the switching ring 8 of the section.

The microphone having the above-described configuration also uses the sound wave arriving from the front of the diaphragm 15 to generate the sound.
Vibrates, and the basic principle that voice current is induced in the voice coil 16 that vibrates in the magnetic circuit is no different from the conventional one. When the diaphragm 15 vibrates,
A back pressure is generated in the back air chamber inside the case 18, which affects low frequency characteristics. Here microphone head
When the degree of polymerization of the plurality of windows 30 provided on the switching sleeve 27 and the holes 31 for the phase shift circuit provided on the side of the case 18 is changed by operating the switching ring 8 provided outside Case
Since the degree of communication between the back air chamber inside 18 and the outside changes and air flows as shown by the arrow in FIG. 1 and the acoustic resistance changes, the low-frequency characteristics can be changed.

FIG. 3 shows this, in which a hole 31 is shown.
Is the case where four are opened, and similarly is the case where two are opened. Furthermore, this is the characteristic when all four are closed. Increasing the number of open holes in this way makes it easier to output low frequencies, making it suitable for singing with karaoke, etc.When closed, the low frequencies are attenuated, so that clear speech can be made. Become. In general, when measuring the characteristics of the microphone, the measurement is performed at a position where the top of the microphone head 5 is in contact with the mouth or not, but the characteristics in FIG.
It has been confirmed that the same tendency appears even when the microphone head 5 is separated from the mouth.

FIG. 4 shows a main part of another embodiment of the present invention, and the same members as those in FIG. 1 are denoted by the same reference numerals. In this embodiment, the inside of the yoke 13 serving as the back air chamber and the inside of the tail portion 3 are connected only by the passage 33 without providing the shutter mechanism provided in FIG.
Inside, a valve mechanism 34 for changing the degree of communication between these back air chambers is provided. The direction of the valve mechanism 34 can be changed by operating the switching knob 35, and the acoustic resistance can be changed according to the direction. In this embodiment, the valve mechanism 34 is a rotary type. However, the present invention is not limited to this, and a slide type valve mechanism may be used.

[0018]

Since the present invention is a sound quality adjusting mechanism for a microphone constructed as described above, the attenuation of the low-frequency characteristic can be freely changed by a simple operation simply by turning a switching ring or a switching knob. be able to. Since the structure is simple, it can be implemented without making significant changes to the conventional microphone, which is advantageous in cost.
Further, since the low-frequency characteristics are acoustically controlled, no choke coil is required, and the output impedance does not fluctuate. And in the structure with a switching ring,
A switching ring is provided outside the microphone head and this switching ring
The rotating shutter mechanism inside the microphone head
Operation, which greatly improves its usability.
You.

[Brief description of the drawings]

FIG. 1 is a sectional view of one embodiment of the present invention.

FIG. 2 is a perspective view showing a rotary shutter mechanism in FIG.

FIG. 3 is a graph illustrating an effect when the one in FIG. 1 operates.

FIG. 4 is a sectional view of a main part of another embodiment of the present invention.

[Explanation of symbols]

1 Microphone body 2 Unit holder 3 Tail 5 Microphone head 7 Recess 8 Switching ring 11 Microphone unit 12 Magnet 13 Yoke 18 Case 19 Sound wave passage hole 20 Acoustic resistance hole 24 Hole 27 Switching sleeve 30 Window 31 Hole 33 Passage 34 Valve mechanism

────────────────────────────────────────────────── ─── Continuation of the front page (56) References Japanese Utility Model 60-150881 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) H04R 1/38 H04R 1/04

Claims (2)

(57) [Claims] 1. A microphone unit in which a yoke is arranged on an outer peripheral portion of a magnet to form a magnetic circuit, wherein a rotary shutter mechanism having a window for opening and closing between a back air chamber of the microphone unit and the outside is provided . internal
At the outer periphery of the yoke and the rotary shutter mechanism.
The switching ring is provided outside the microphone head, and the opening degree of the rotary shutter mechanism changes the degree of communication between the back air chamber and the outside, changes the acoustic resistance, and controls low-frequency characteristics. A sound quality adjustment mechanism for a microphone. 2. A plurality of back air chambers of a microphone unit are provided, and a valve mechanism for changing the degree of communication between the back air chambers is provided between the plurality of back air chambers. A sound quality adjustment mechanism for a microphone, characterized in that the sound resistance is changed.