CN111200779A

CN111200779A - Electret microphone and electronic device

Info

Publication number: CN111200779A
Application number: CN201911309921.5A
Authority: CN
Inventors: 陈智崇; 吴立德
Original assignee: Goertek Microelectronics Inc
Current assignee: Goertek Microelectronics Inc
Priority date: 2019-12-18
Filing date: 2019-12-18
Publication date: 2020-05-26
Anticipated expiration: 2039-12-18
Also published as: CN111200779B

Abstract

The invention provides an electret microphone, which comprises a polar plate and a vibrating diaphragm, wherein the vibrating diaphragm and the polar plate form a parallel plate capacitor structure; and a shielding layer for shielding light is arranged inside the diaphragm and/or on the surface of the diaphragm. By using the invention, the interference of external laser or light such as light source can be shielded by the shielding layer.

Description

Electret microphone and electronic device

Technical Field

The present invention relates to the field of acoustic technologies, and in particular, to an electret microphone and an electronic device having the same.

Background

An electret microphone (also called electret microphone) generally consists of two parts, namely, an acoustoelectric conversion part and an impedance conversion part. The key element of the sound-electricity conversion is an electret vibrating membrane which is an extremely thin membrane, and a metal thin film is arranged on one surface of the membrane; a capacitor structure is formed between the electret diaphragm and the metal plate. When the electret diaphragm encounters sound wave vibration, the electric field at two ends of the capacitor is caused to change, so that alternating voltage changing along with the change of the sound wave is generated, and a corresponding sound signal is generated.

At present, a common voice control system does not need to carry out user identity authentication, so a hacker can easily crack the system under the condition of not needing a password or a PIN code. For example, a laser pen, a laser actuator, an audio power amplifier, and other devices are used to intrude an intelligent device with a built-in microphone based on a light instruction, and then the voice assistant function is started.

In the conventional microphone, a diaphragm is disposed in the sound wave vibration, and the vibration of the diaphragm generates a current, so as to convert the sound into an electronic signal. If laser or LED light is used for irradiating the diaphragm, energy can be provided for the diaphragm to generate current, noise or misoperation of the microphone is easily caused, and the safety and stability of the product are affected.

Disclosure of Invention

In view of the above problems, an object of the present invention is to provide an electret microphone and an electronic device, so as to solve the problem that the conventional microphone is easily interfered by external light, and the safety and stability of the product are affected.

The invention provides an electret microphone, which comprises a polar plate and a vibrating diaphragm which forms a parallel plate capacitor structure with the polar plate; and a shielding layer for shielding light is arranged inside the diaphragm and/or on the surface of the diaphragm.

In addition, the preferable structure is that the diaphragm includes an electret layer and a metal layer; the shielding layer is disposed between the electret layer and the metal layer.

In addition, the preferred structure is that the shielding layer is a black glue layer or a light-absorbing glue layer; the metal layer and the electret layer are fixedly connected through the shielding layer.

In addition, the preferable structure is that the diaphragm includes an electret layer and a metal layer; the shielding layer is arranged on one side of the electret layer close to the polar plate.

In addition, it is preferable that the shielding layer is a black thin film layer or a light absorbing layer.

In addition, the shielding layer is preferably coated or bonded on the electret layer.

In addition, it is preferable that the electrode plate is provided with through holes regularly distributed.

In addition, it is preferably provided that at least one edge support and at least one intermediate support are arranged between the pole plate and the diaphragm.

In addition, the preferred structure is that, in the static state, the vibrating diaphragm and the polar plate are arranged in parallel, and an air gap is arranged between the vibrating diaphragm and the polar plate.

In addition, the invention also provides an electronic device which comprises the electret microphone.

According to the technical scheme, the electret microphone is characterized in that the shielding layer for shielding interference light is arranged in the vibrating diaphragm and/or on the surface of the vibrating diaphragm, and the shielding layer absorbs or reflects the interference of external light to prevent the microphone from being started by mistake or interfered, so that the safety and the reliable and stable performance of the product are ensured.

To the accomplishment of the foregoing and related ends, one or more aspects of the invention comprise the features hereinafter fully described. The following description and the annexed drawings set forth in detail certain illustrative aspects of the invention. These aspects are indicative, however, of but a few of the various ways in which the principles of the invention may be employed. Further, the present invention is intended to include all such aspects and their equivalents.

Drawings

Other objects and results of the present invention will become more apparent and more readily appreciated as the same becomes better understood by reference to the following description taken in conjunction with the accompanying drawings. In the drawings:

fig. 1 is a schematic partial structure diagram of an electret microphone according to a first embodiment of the invention;

fig. 2 is a schematic partial structure diagram of an electret microphone according to a second embodiment of the invention.

Wherein the reference numerals include: the vibrating diaphragm comprises a vibrating diaphragm 1, a metal layer 11, a shielding layer 12, an electret layer 13, a polar plate 2 and a through hole 21.

The same reference numbers in all figures indicate similar or corresponding features or functions.

Detailed Description

In order to describe the structure of the electret microphone of the present invention in detail, specific embodiments of the present invention will be described below with reference to the accompanying drawings.

Fig. 1 shows a partial schematic structure of an electret microphone according to a first embodiment of the invention.

As shown in fig. 1, an electret microphone according to an embodiment of the present invention includes a pole plate 2 and a diaphragm 1 forming a parallel-plate capacitor structure with the pole plate 2, and in order to ensure stability of the diaphragm 1 and prevent an external signal from interfering with the diaphragm 1, in the electret microphone according to the present invention, a shielding layer 12 for shielding an interfering light is disposed inside the diaphragm 1 and/or on a surface of the diaphragm 1.

In the first embodiment, the diaphragm 1 includes an electret layer 13 disposed close to the polar plate 2 and a metal layer 11 disposed far from the polar plate 2, the shielding layer 12 is disposed between the electret layer 13 and the metal layer 11, and the metal layer 11 and the electret layer 13 are fixedly connected through the shielding layer 12. This shielding layer 12 can adopt structural layers such as black glue layer or extinction glue layer, not only can realize the firm connection of metal level 11 and electret layer 13 through black glue or extinction glue, can also effectively absorb the interference such as the radium-shine or LED light source of laser that enters into electret microphone inside, prevents that external light from influencing the performance of vibrating diaphragm 1.

It can be known that the shielding layer 12 in this embodiment may also adopt other dark glue layers or structural layers having light absorption or reflection functions, so as to shield the interference of the laser pen, the laser actuator, the audio power amplifier and other devices to the diaphragm.

In one embodiment of the present invention, through holes 21 are regularly distributed on the plate 2, at least one side support member (not shown) and at least one middle support member (not shown) are disposed between the plate 2 and the diaphragm 1, and the plate 2 and the diaphragm 1 are supported and connected by the side support member and the middle support member.

Under electret microphone unoperated state or vibrating diaphragm are in quiescent condition, vibrating diaphragm 1 and polar plate 2 parallel arrangement, form the air-gap between vibrating diaphragm 1 and polar plate 2, when vibrating diaphragm 1 receives the acoustic pressure effect and warp, its deformation can cause the capacitance value of parallel plate capacitor structure to change, read the circuit and can change the capacitance change into voltage output, realize the conversion of sound and electronic signal, it can effectively shield external interference signal to set up shielding layer 12 in vibrating diaphragm 1, reduce vibrating diaphragm 1 and receive external environment's influence, ensure vibrating diaphragm 1 reliable stable performance.

Fig. 2 shows a partial schematic structure of an electret microphone according to a second embodiment of the invention.

As shown in fig. 2, an electret microphone according to a second embodiment of the present invention includes a pole plate 2 and a diaphragm 1 forming a parallel-plate capacitor structure with the pole plate 2, and in order to ensure stability of the diaphragm 1 and prevent an external signal from interfering with the diaphragm 1, in the electret microphone according to the present invention, a shielding layer 12 for shielding light is disposed inside the diaphragm 1 and/or on a surface of the diaphragm 1.

In this embodiment two, vibrating diaphragm 1 is including being close to the electret layer 13 that polar plate 2 one side set up and keeping away from the metal level 11 that polar plate 2 one side set up, shielding layer 12 sets up the one side that is close to polar plate 2 on electret layer 13, metal level 11 and electret layer 13 snap-on, this shielding layer 12 can adopt black thin layer or light-absorbing layer, shielding layer 12 is fixed on electret layer 13 through the mode of coating or laminating, this shielding layer 12 can also adopt other dark thin layer or have light absorption or reflection function's structural layer etc. can shield laser pen, laser ware and devices such as audio power amplifier can to the interference of vibrating diaphragm.

In one embodiment of the present invention, through holes 21 are regularly distributed on the plate 2, at least one side support member (not shown) and at least one middle support member (not shown) are disposed between the plate 2 and the diaphragm 1, and the plate 2 and the diaphragm 1 are connected by the side support member and the middle support member.

When electret microphone does not under operating condition or the vibrating diaphragm is in quiescent condition, vibrating diaphragm 1 and polar plate 2 parallel arrangement, form the air-gap between vibrating diaphragm 1 and polar plate 2, when vibrating diaphragm 1 receives the acoustic pressure effect and warp, its deformation can cause the capacitance value change of parallel plate capacitor structure, read the circuit and can change the capacitance change into voltage output, realize the conversion of sound and electronic signal, it can effectively shield external interference signal to set up shielding layer 12 in vibrating diaphragm 1, reduce vibrating diaphragm 1 and receive external environment's influence, ensure vibrating diaphragm 1 reliable performance and stable.

It should be noted that, in order to improve the shielding effect of the diaphragm, a thin film layer having a shielding function may be disposed inside and on the surface of the diaphragm, and the shielding layer may adopt a black thin film layer, a black glue layer, a light absorbing thin film layer, a light refraction layer, and other various structural layers.

According to the electret microphone and the electronic device provided by the invention, the shielding layer for shielding the light source is arranged in the vibrating diaphragm and/or on the surface of the vibrating diaphragm, and the microphone is prevented from being started by mistake or interfered by absorbing or reflecting external light interference through the shielding layer, so that the safety of the product and the stable and reliable performance are ensured.

The electret microphone and the electronic device proposed according to the present invention are described above by way of example with reference to the accompanying drawings. It will be appreciated by those skilled in the art that various modifications may be made to the electret microphone and electronic device of the invention described above without departing from the scope of the invention. Therefore, the scope of the present invention should be determined by the contents of the appended claims.

Claims

1. An electret microphone comprises a polar plate and a vibrating diaphragm which forms a parallel-plate capacitor structure with the polar plate; it is characterized in that the preparation method is characterized in that,

and a shielding layer for shielding light is arranged inside the diaphragm and/or on the surface of the diaphragm.

2. The electret microphone of claim 1,

the vibrating diaphragm comprises an electret layer and a metal layer;

the shielding layer is disposed between the electret layer and the metal layer.

3. The electret microphone of claim 2,

the shielding layer is a black glue layer or a light absorption glue layer;

the metal layer and the electret layer are fixedly connected through the shielding layer.

4. The electret microphone of claim 1,

the vibrating diaphragm comprises an electret layer and a metal layer;

the shielding layer is arranged on one side of the electret layer close to the polar plate.

5. The electret microphone of claim 4,

the shielding layer is a black film layer or a light absorption layer.

6. The electret microphone of claim 4,

the shielding layer is coated or attached on the electret layer.

7. The electret microphone of claim 1,

through holes are regularly distributed on the polar plate.

8. The electret microphone of claim 1,

at least one side support member and at least one intermediate support member are disposed between the pole plate and the diaphragm.

9. The electret microphone of claim 1,

in a static state, the vibrating diaphragm and the polar plate are arranged in parallel, and an air gap is formed between the vibrating diaphragm and the polar plate.

10. An electronic device comprising an electret microphone according to any one of claims 1 to 9.