JPS6228157Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a microphone whose structure is simplified using an acoustic conversion unit, and the acoustic conversion unit can also be used as a headphone or a speaker.

In the conventional microphone shown in FIG. 1, a voice coil 6 connected to a diaphragm 5 is loosely fitted into a gap 4A of a magnetic circuit composed of a yoke 1, a magnet 2, a pole 3, and a plate 4. Also,
The hole 1A on the bottom surface of the yoke 1, the hole 1B on the side surface, and the hole 7A of the inertance ring 7 that fixes the pole 3 in the yoke 1 are connected to resistors 8A and 8B, respectively.
and 8C, and the hole 4B of the plate 4 formed on the back surface of the diaphragm 5 is open. An equalizer 9 having a sound entrance hole 9A is attached to the front of the diaphragm 5, and a back cavity case 10 forming a rear chamber is attached to the rear of the yoke 1.
The resistors 8A, 8B, and 8C are made of felt or papillon paper, and the resistance value of the resistor 8A is greater than that of the resistors 8B and 8C.

The microphone configured in this way has a plurality of resistors 8A, 8B, and 8C installed at the boundary between the external acoustic space and the internal acoustic space.
It is difficult to adjust the sound quality because it has to be adjusted so that it has a predetermined acoustic characteristic. Also, because the resistance of the acoustic circuit was large, large magnets had to be used to increase sensitivity. Furthermore, since the structure is complicated, it has disadvantages such as not being able to be used as a speaker or headphone.

This invention was developed in consideration of the above points, and provides a microphone whose structure is simplified by using an acoustic conversion unit. This invention will be explained below based on the drawings.

FIG. 2 is a schematic cross-sectional view showing one embodiment of this invention.

In FIG. 2, 11 is a yoke, 12 is a magnet, 13 is a plate, and 14A is the yoke 1.
1, a first hole 14B passing through a magnetic circuit composed of a magnet 12 and a plate 13 is a gap in the magnetic circuit, into which a voice coil 16 connected to a diaphragm 15 is loosely fitted. Reference numeral 17 denotes an equalizer that also serves as a protector and has a sound entrance hole 17A, and the above-mentioned numerals 11 to 17 constitute an acoustic conversion unit. 1
Reference numeral 8 denotes a back cavity case which is attached to the rear of the yoke 11 and forms a rear chamber, and is provided with an opening 18A for orientation on its side surface, which is closed with a resistor 19 made of felt, papillon paper, or the like. Also,
A second hole 11A is provided in a portion of the yoke 11 facing between the voice coil 16 and the edge of the diaphragm 15.

The microphone constructed in this manner has an opening 18A in the back cavity case 18, and the first and second holes 14A, 11A communicate with the opening 18A, thereby making it possible to reduce the resistance of the acoustic circuit. Furthermore, by adjusting the aperture 18A for adjusting the directivity with the resistor 19, high sensitivity can be achieved in the middle and low frequency ranges. Furthermore, since the resistor 19 is attached to only the opening 18A to adjust the resistance value of the acoustic circuit, this can be easily done without affecting the sensitivity. Furthermore, since the high frequency range can be compensated for by the equalizer 17, the sensitivity is also improved.

FIG. 3 is a characteristic diagram showing the sensitivity of the microphone shown in FIG. 2.

In FIG. 3, curves a, b, and c are characteristics in the 0°, 90°, and 180° directions, respectively.

Note that four openings 18A were provided, and No. 4 Papillon paper was used as the resistor 19.

Although the above embodiment has been described with respect to a microphone, this structure has the effect that the acoustic conversion unit portion and the back cavity case 18 can be easily separated, so that the acoustic conversion unit can be used as a speaker or a headphone.

As explained above, the microphone of this invention has the first and second holes in the acoustic transducer, and the opening provided in the back cavity and the first and second holes.
Since the overall resistance of the acoustic circuit is reduced by communicating with the holes in the acoustic circuit, adjustment is facilitated, and the resistance value of the acoustic circuit can be reduced, which has the advantage of increasing sensitivity. Further, since the acoustic conversion unit can be used alone as a speaker or headphone, there is an effect that the cost can be reduced.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional schematic diagram showing a conventional microphone.
FIG. 2 is a schematic cross-sectional view showing an embodiment of this invention, and FIG. 3 is a characteristic diagram of the embodiment of FIG. In the figure, 11 is a yoke, 11A is a second hole, 12
is a magnet, 13 is a plate, 14A is a first hole, 15 is a diaphragm, 16 is a voice coil, 17 is an equalizer, 18 is a back cavity case, 1
8A is an opening, and 19 is a resistor.

Claims (1)

[Scope of utility model registration request] A microphone is constituted by an acoustic conversion unit in which an equalizer having predetermined holes is arranged on the front side of an acoustic conversion section consisting of a yoke, a magnet, a plate, and a diaphragm, and a back cavity case provided on the back side of this acoustic conversion unit, A space formed on the back side of the diaphragm by penetrating the plate and the magnet in the microphone, and a space at the edge of the diaphragm penetrating the yoke part are respectively connected to the space of the back cavity case. first and second holes are provided that communicate with each other, and the back cavity case has an opening that communicates between the inside and outside;
A microphone characterized in that it is provided with an acoustic resistor that adjusts the amount of air flowing through the opening.