CN111526443B

CN111526443B - Ear return earphone circuit, ear return earphone and ear return system

Info

Publication number: CN111526443B
Application number: CN202010296610.6A
Authority: CN
Inventors: 黄停; 常智; 朱辰
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2020-04-15
Filing date: 2020-04-15
Publication date: 2021-07-09
Anticipated expiration: 2040-04-15
Also published as: CN111526443A

Abstract

This application is applicable to earphone technical field, provides an ear returns earphone circuit, ear and ear returns earphone and ear and returns system, and the ear returns earphone circuit and includes: the device comprises a microphone, a key, an earphone, a coder-decoder, a differential module and a feedback module; the coder-decoder is respectively connected with the differential module, the feedback module and the earphone, the feedback module is connected with the differential module and the earphone, and the microphone and the keys are arranged between the differential module and the earphone. The first feedback impedance and the second feedback impedance which are connected in series are arranged between the ground potential and the feedback boosting resistor in the feedback module, and the second end of the first blocking capacitor in the differential module is connected between the first feedback impedance and the second feedback impedance, so that a differential input mode can be adopted, interference signals in collected voice data are reduced through the potential between the first feedback impedance and the second feedback impedance, and the loudness of the ear return earphone is improved on the premise of preventing the ear return earphone from generating squeaking self-excitation.

Description

Ear return earphone circuit, ear return earphone and ear return system

Technical Field

The application belongs to the technical field of earphones, and particularly relates to an ear return earphone circuit, an ear return earphone and an ear return system.

Background

The ear return earphone can collect the sound emitted by the user and feed the collected sound back to the user, so that the user can hear the sound emitted by the user. The ear return earphone is generally applied to scenes of singing, holding at night and the like, for example, a user can hear own voice through the ear return earphone when singing.

Because the ear return earphone is influenced by internal components, part of sound played by the left and right sound channels of the ear return earphone reversely flows into the microphone, so that the reversely flowing sound is amplified and then played through the ear return earphone again, and finally howling self-excitation is caused. In order to avoid the problem of self-excitation of howling, the output gain of the ear return earphone can be reduced, and the loudness of the anti-string sound is reduced when the anti-string sound is played again, so that the anti-string sound can not appear after multiple anti-string plays.

However, reducing the output gain results in a lower loudness of the sound played by the ear return headphones, and the user may not be able to listen to the sound played by the ear return headphones.

Disclosure of Invention

The embodiment of the application provides an ear return earphone circuit, an ear return earphone and an ear return system, and the problem that the loudness of sound played by the ear return earphone is small can be solved.

In a first aspect, an embodiment of the present application provides an ear return earphone circuit, including: the device comprises a microphone, a key, an earphone, a coder-decoder, a differential module and a feedback module;

the coder-decoder is respectively connected with the differential module, the feedback module and the earphone, the feedback module is respectively connected with the differential module and the earphone, and the microphone and the key are both arranged between the differential module and the earphone;

the feedback module comprises a first feedback impedance, a second feedback impedance and a feedback boost resistor; the first end of the feedback boosting resistor is connected with the earphone power supply end of the coder-decoder, and the second end of the feedback boosting resistor is connected with the feedback end of the coder-decoder; the feedback boost resistor is used for adjusting the potential corresponding to the first end of the first feedback impedance, and the first feedback impedance and the second feedback impedance are connected in series between the feedback end of the codec and the ground potential;

the differential module comprises a first blocking capacitor and a second blocking capacitor, a first end of the first blocking capacitor and a first end of the second blocking capacitor are both connected with a data receiving end of the coder-decoder, a second end of the first blocking capacitor is connected between the first feedback impedance and the second feedback impedance, and a second end of the second blocking capacitor is respectively connected with the microphone and the key; the potential of the second end of the first blocking capacitor is set according to the potential of the second end of the second blocking capacitor, the potential of the second end of the first blocking capacitor is used for reducing interference signals of the potential of the second end of the second blocking capacitor on voice data collected by the microphone, and the first feedback impedance and the second feedback impedance are used for adjusting the potential of the second end of the first blocking capacitor.

Optionally, the ear return headphone circuit further includes: a first end of the switch module is arranged between a feedback end of the codec and a first end of the first feedback impedance, a second end of the switch module is arranged between the first feedback impedance and the second feedback impedance, and a third end of the switch module is connected with a second end of the first blocking capacitor;

when the ear return earphone is in an ear return mode, the third end of the switch module is communicated with the second end of the switch module; when the ear return earphone is in a key mode, the third end of the switch module is communicated with the first end of the switch module.

Optionally, the ear return headphone circuit further includes: the source electrode and the drain electrode of the MOS tube are respectively arranged at two ends of the first feedback impedance, the grid electrode of the MOS tube is connected with the control end of the ear return earphone, and a level signal sent by the control end is related to an ear return mode and a key mode;

when the ear return earphone is in an ear return mode, the MOS tube is switched off; when the ear return earphone is in a key mode, the MOS tube is conducted.

Optionally, the differential module further includes a voltage dividing resistor, a first end of the voltage dividing resistor is connected to a microphone power supply end of the codec, and a second end of the voltage dividing resistor is connected to the second end of the second dc blocking capacitor, the microphone, and the key, respectively.

Optionally, the earphone comprises a left channel earphone and/or a right channel earphone, and the earphone further comprises a common impedance and a ground resistance;

the first end of the left channel earphone and the first end of the right channel earphone are both connected with the earphone power supply end of the codec, and the second end of the left channel earphone and the second end of the right channel earphone are both connected with the first end of the common impedance;

and the second end of the grounding resistor is connected with the ground potential, and the first end of the grounding resistor is respectively connected with the second end of the second feedback impedance and the second end of the common impedance.

Optionally, the codec includes: the system comprises an analog-to-digital converter, a digital-to-analog converter and a feedback operational amplifier;

the input end of the analog-to-digital converter is respectively connected with the first end of the first blocking capacitor and the first end of the second blocking capacitor, the output end of the analog-to-digital converter is connected with the input end of the digital-to-analog converter, and the output end of the digital-to-analog converter is connected with the earphone;

the input end of the feedback operational amplifier is connected with the first end of the first feedback impedance, and the output end of the feedback operational amplifier is connected with the output end of the digital-to-analog converter.

Optionally, the codec further includes: an operational amplifier disposed between the digital-to-analog converter and the earphone;

the input end of the operational amplifier is respectively connected with the output end of the digital-to-analog converter and the output end of the feedback operational amplifier, and the output end of the operational amplifier is connected with the earphone.

Optionally, the digital-to-analog converter includes a left digital-to-analog converter and a right digital-to-analog converter, the feedback operational amplifier includes a left feedback operational amplifier and a right feedback operational amplifier, and the operational amplifier includes a left operational amplifier and a right operational amplifier;

the earphone comprises a left channel earphone and a right channel earphone, the left digital-to-analog converter, the left feedback operational amplifier and the left operational amplifier correspond to the left channel earphone, and the right digital-to-analog converter, the right feedback operational amplifier and the right operational amplifier correspond to the right channel earphone.

In a second aspect, an embodiment of the present application provides an ear return earphone, including the ear return earphone circuit as described in any one of the first aspect.

In a third aspect, an embodiment of the present application provides an ear return system, which includes a terminal device and the ear return earphone according to the second aspect, where the terminal device is connected to the ear return earphone.

According to the embodiment of the application, the first feedback impedance and the second feedback impedance which are connected in series are arranged between the ground potential and the feedback boosting resistor in the feedback module, the second end of the first blocking capacitor in the difference module is connected between the first feedback impedance and the second feedback impedance, so that a difference input mode can be adopted, interference signals in collected voice data are reduced through the potential between the first feedback impedance and the second feedback impedance, and the loudness of the ear return earphone is improved on the premise of preventing the ear return earphone from howling and self-excitation.

Drawings

Fig. 1 is a system diagram of an ear return system related to an ear return headphone according to an embodiment of the present application;

fig. 2 is a schematic structural diagram of an ear return earphone circuit provided in an embodiment of the present application;

fig. 3 is a schematic structural diagram of another ear return earphone circuit provided in an embodiment of the present application;

fig. 4 is a schematic structural diagram of another ear return earphone circuit provided in the embodiment of the present application;

fig. 5 is a schematic structural diagram of a further ear return earphone circuit provided in an embodiment of the present application;

fig. 6 is a schematic structural diagram of another ear return earphone circuit provided in an embodiment of the present application.

Detailed Description

The terminology used in the following examples is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the specification of this application and the appended claims, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, such as "one or more", unless the context clearly indicates otherwise. It should also be understood that in the embodiment of the present application, "and/or" describes an association relationship of associated objects, indicating that three relationships may exist; for example, a and/or B, may represent: a alone, A and B together, and B alone, wherein A, B may be singular or plural. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.

Fig. 1 is a system schematic diagram of an ear return system related to an ear return headphone provided in an embodiment of the present application, and referring to fig. 1, the ear return system may include: an ear return earphone 100 and a terminal device 200.

The ear-return earphone 100 may be connected to the terminal device 200, for example, the ear-return earphone 100 may be connected to the terminal device 200 in a wired connection manner, or may be connected to the terminal device 200 in a wireless connection manner, and the connection manner between the ear-return earphone 100 and the terminal device 200 is not limited in this embodiment of the application.

Further, the ear return headphone 100 can include an ear return headphone circuit for capturing and playing user sounds emitted by the user.

When the ear return system operates, the ear return earphone 100 can receive the voice data sent by the terminal device 200 and play the voice data, so that the user can perform different actions according to the played voice data in different scenes. The ear return earphone 100 can also collect user voice sent by the user and play the collected user voice to the user, so that the user can adjust the voice sent by the user.

For example, the presenter may wear the ear return headphone 100, and the ear return headphone 100 may receive the reminding information sent by the terminal device 200, so that the presenter can conveniently and quickly perform the presenter's work. Or, the singer may wear the ear return earphone 100, and the ear return earphone 100 may receive the accompanying music sent by the terminal device 200, and may further collect the voice sung by the singer and play the singing voice to the singer, so that the singer may sing according to the accompanying music and adjust the voice during singing according to the played singing voice.

Fig. 2 is a schematic structural diagram of an ear return earphone circuit according to an embodiment of the present application. By way of example and not limitation, referring to fig. 2, the ear return headphone circuit may include: a microphone 210, keys 220, an earpiece 230, a codec 240, a differencing module 250, and a feedback module 260.

The codec 240 is connected to the difference module 250, the feedback module 260, and the earphone 230, respectively. The feedback module 260 is also connected to the difference module 250 and the earphone 230, respectively. The microphone 210 and the keys 220 are disposed between the differential module 250 and the earphone 230, i.e., the microphone 210 and the keys 220 are connected to the differential module 250 and the earphone 230.

The microphone 210 is used to collect user sounds made by the user. The difference module 250 is used to eliminate the interference signal in the collected user voice. The codec 240 is used to encode the collected user sound so that the user sound can be played to the user through the headset. The feedback module 260 is used to feed back the effect played by the earphone to the codec 240, so that the codec 240 can adjust the played sound.

In addition, the button 220 can adjust the working state of the ear returning earphone. For example, the key 220 may turn on or off the ear return device, or may control the ear return device or a terminal device connected to the ear return device, such as adjusting the volume of the ear return device, switching a played song, pausing/playing a song, and the like.

When the user uses the ear return earphone, the user can operate the key 220 to control the ear return earphone or the terminal device. When the user operates the key 220, the key 220 is closed, the key 220 is connected in parallel with the microphone 210, and the impedance of the key 220 is much smaller than that of the microphone 210, so that the current in the ear return earphone no longer flows through the microphone 210 but flows through the key 220; the ear return earphone is in a key mode at the moment. When the user does not operate the key, the key 220 is turned off, the key 220 is short-circuited, the current flows through the microphone 210, and the ear return earphone is in the ear return mode. It should be noted that the ear return earphone in the key mode is also an earphone with an ear return function. The key mode described in the embodiments of the present application is only used to illustrate that the ear return earphone is in a state where the key is operated.

Correspondingly, in the process of the ear return earphone working, the ear return earphone can be turned on according to the operation triggered by the user on the key 220, and if the ear return earphone is in the ear return mode. The microphone 210 may collect a sound emitted by the user and transmit the collected user sound to the difference module 250; denoising the user sound by adopting a differential input mode through a differential module 250 to obtain the user sound without interference; the denoised user sound is then sent to the codec 240, and the user sound is decoded and re-encoded by the codec 240, so that the re-encoded user sound is sent to the headset, and the headset 230 can play the sound emitted by the user.

During the playing process, the feedback module 260 may feed back to the codec 240 according to the sound played by the earphone 230, so that the codec 240 may adjust the re-encoded user sound according to the feedback, thereby adjusting the user sound played by the earphone 230, and improving the sound heard by the user.

It should be noted that the codec 240 may include: analog-to-digital converter (ADC), digital-to-analog converter (DAC), feedback operational amplifier and microphone supply terminal A. The output end of the ADC is connected with the input end of the DAC, and the output end of the feedback operational amplifier is connected with the input end of the DAC. Also, the output terminal of the DAC may be the earphone power supply terminal B of the codec 240, the input terminal of the feedback operational amplifier may be the feedback terminal C of the codec 240, and the input terminal of the ADC may be the data receiving terminals D1 and D2 of the codec 240.

Further, referring to fig. 3, the difference module 250 may include: a first blocking capacitor 2501, a second blocking capacitor 2502 and a voltage dividing resistor 2503.

The first terminal of the first dc blocking capacitor 2501 and the first terminal of the second dc blocking capacitor 2502 may be connected to the data receiving terminals D1 and D2 in the codec 240. A second terminal of the first dc blocking capacitor 2501 is connected to the feedback module 260. The second end of the second dc blocking capacitor 2502 is connected to the microphone 210 and the earphone button 220, respectively. A first end of the voltage dividing resistor 2503 is connected to the microphone power supply end a of the codec 240, and a second end of the voltage dividing resistor 2503 is connected to a second end of the second dc blocking capacitor 2502, the microphone 210, and the button 220, respectively.

For example, the capacitive reactance of the first dc blocking capacitor 2501 and the second dc blocking capacitor 2502 may be 100nf (nanofarad), and the resistance of the voltage dividing resistor 2503 may be 2200 ohms.

Correspondingly, the feedback module 260 may include: a first feedback impedance 2601, a second feedback impedance 2602, and a feedback boost resistor 2603.

A first end of the first feedback impedance 2601 is connected to the feedback end C of the codec 240, and a second end of the first feedback impedance 2601 is connected to a first end of the second feedback impedance 2602. A second end of the second feedback impedance 2602 is connected to the earpiece 230. A first end of the feedback boost resistor 2603 is connected to the earphone power supply terminal B of the codec 240, and a second end of the feedback boost resistor 2603 is connected to the feedback terminal C of the codec 240.

Also, the second terminal of the first dc blocking capacitor 2501 in the differential module 250 may be connected to the second terminal of the first feedback impedance 2601 or the first terminal of the second feedback impedance 2602.

In addition, the earphones 230 may include a left channel earphone 2301 and/or a right channel earphone 2301, and may further include a common impedance 2302 and a ground resistor 2303.

Wherein, the first end of the left/right channel earphone 2301 can be connected with the earphone power supply terminal B of the codec 240. The second end of the left/right channel headphones 2301 may be connected to the first end of the common impedance 2302, the microphone 210 and the keys 220, respectively. A second terminal of the common impedance 2302 is connected to a first terminal of a ground resistor 2303. A second terminal of the ground resistor 2303 is connected to ground potential.

Also, a second terminal of the second feedback impedance 2602 is connected to a second terminal of the common impedance 2302 or a first terminal of a ground resistor 2303.

Referring to fig. 3, a potential corresponding to the second terminal of the left/right channel headphone 2301 may be set as a first potential (V1), a potential corresponding to the feedback terminal of the codec 240 may be set as a second potential (V2), a potential corresponding to the second terminal of the voltage-dividing resistor 2503 may be set as a third potential (V3), and a potential between the first feedback impedance 2601 and the second feedback impedance 2602 may be set as a fourth potential (V4).

Due to the presence of the ground resistor 2303 and the common impedance 2302 in the ear return earphone, a voltage is present at the second end of the left/right channel earphone 2301, thereby interfering with the user's voice picked up in the microphone 210. The embodiment of the application can modulate the resistance values of the first feedback resistor 2601 and the second feedback resistor 2602 in a differential input manner, so that the potentials of V4 and V3 are the same, thereby eliminating the interference generated by V3.

In adjusting the resistance values of the first and

second feedback impedances

2601 and 2602, the total resistance values of the first and

second feedback impedances

2601 and 2602 may be determined according to a headphone crosstalk (crosstalk) technique such that V1 is equal to V2; the resistances of the first feedback resistor 2601 and the second feedback resistor 2602 are adjusted according to V3, so that V4 is the same as V3, thereby eliminating V3.

However, in practical applications, the potential of V3 will vary depending on the mode of the ear return earphone. When the ear return earphone is in the ear return mode, the button 220 is turned off, the current flows through the microphone 210, and partial voltage division exists at two ends of the microphone 210, and the voltage level corresponding to V3 is low, and similarly, the required voltage level of V4 is also low. However, if the button 220 is closed, the impedance of the branch where the button 220 is located is much smaller than the impedance of the microphone 210, the current flows through the button 220, and only a small voltage is generated across the button 220, and at this time, the voltage corresponding to V3 is high, and the required voltage of V4 is also high.

Because different V3 require different V4, V4 can be adjusted to be the average value of two V3 according to the corresponding V3 of the key 220 under different states, thereby reducing partial interference caused by V3, improving the gain of the ear return earphone, and improving the loudness of the ear return earphone.

For example, when the ear return headphone is in the ear return mode, V3_-MICX1 × V1. Wherein, V3_-MICThe voltage level of V3 in the ear return mode, V1 is V1, X1 is the ratio of the voltage of the microphone 210, and X1 can be 1/3. V3 when the ear return speaker is in the button 220 mode, that is, when the button 220 is in the closed state_-HOOKX2 × V1. Wherein, V3_-HOOKThe voltage level is V3 in the key 220 mode, V1 is V1, X2 is the voltage ratio of the key 220, and X2 can be 1. In addition, the ear return earphone can also be in a test mode, in which V3_-KMICX3 × V1, wherein V3_-KMICIn the test mode, V3 is the voltage corresponding to V1, V1 is the voltage corresponding to V1, X3 is the voltage ratio of the test equipment, and X3 can be 2/3.

Correspondingly, the potential corresponding to V4 may be determined according to V3 corresponding to the ear return mode and V3 corresponding to the key 220 mode, and then V4 is equal to (V3)_-MIC+V3_-HOOK) V1/2 (X1+ X2). Furthermore, V4 is V2 ═ Ry2+ Re)/(Ry1+ Ry2+ Re) based on the branch corresponding to the feedback module 260.

Further, since the headphone Crosstalk (Crosstalk) can be adjusted for the ear return headphones, so that Crosstalk is-20 log { (V2-V1)/(Vr-V1) }, then V2-V1 ═ Vr ═ C ═ V1 × Rr/Rx. Wherein Crosstalk is a Crosstalk parameter, and the larger the absolute value of the parameter is, the better the isolation of the left and right channel earphones 2301 is; v2 is a potential corresponding to V2, V1 is a potential corresponding to V1, Vr is a potential corresponding to the right channel headphone 2301, Rr is an equivalent impedance corresponding to the right channel headphone 2301, Rx is an equivalent impedance corresponding to the common impedance 2302, and C is a percentage of Crosstalk conversion.

Based on the above formulas, Ry2 ═ Ry (X1+ X2)/2 × (C × Rr + Rx)/Rx can be derived, where Ry ═ Ry1+ Ry2, so that Ry1 ═ Ry-Ry2, that is, impedances corresponding to the first feedback impedance 2601 and the second feedback impedance 2602, respectively, can be derived.

During the operation of the ear-return earphone, the microphone 210 can collect the sound emitted by the user and input the sound to the ADC of the codec 240 through the second dc blocking capacitor 2502. Although the input user sound has interference corresponding to V3, V4 can be input to the ADC through the first blocking capacitor 2501, so that V3 and V4 cancel each other in a differential input mode, thereby obtaining a user sound with less interference, reducing the generated howling self-excitation, and further improving the loudness of the ear return headphone.

It should be noted that fig. 3 illustrates only a single channel headphone 2301 as an example. In practical applications, the ear return headphones generally include two left and right channel headphones 2301. Referring to fig. 4, fig. 4 shows an ear return headphone including a left channel headphone 2301l and a right channel headphone 2301r, and shows the connection manner of the respective components in the codec 240.

Among them, the codec 240 may include: an analog-to-digital converter 2401, a left digital-to-analog converter 2402l, a right digital-to-analog converter 2402r, a left operational amplifier 2403l, a right operational amplifier 2403r, a left feedback operational amplifier 2404l, a right feedback operational amplifier 2404r, and respective voltage dividing resistors 2405.

Referring to fig. 4, the microphone 210 may collect a user voice emitted from a user and transmit the user voice to the ADC in the codec 240 through the second dc blocking capacitor 2502. The first dc blocking capacitor 2501 may input a voltage corresponding to V4 to the ADC2401, thereby forming a differential input, and reducing interference corresponding to V3 included in the input user voice.

The ADC2401 in the codec 240 may subtract V3 from the user's voice according to V4, convert the user's voice into a digital signal, and transmit the user's voice in the form of a digital signal to DACs corresponding to the left/right channel headphones, respectively. The DAC can convert the user voice into the user voice in the form of analog signals, then the operational amplifiers corresponding to the left/right channel earphones amplify the user voice in the form of analog signals respectively, and finally the operational amplifiers transmit the amplified user voice in the form of analog signals to the left/right channel earphones respectively, so that the left/right channel earphones play the user voice respectively, and the process of collecting and feeding back the user voice is completed.

In the process of playing the user sound, the user sound output by the operational amplifier can be adjusted by the operational amplifier according to the feedback signal through the feedback operational amplifier corresponding to the left/right channel earphone respectively and the feedback of the operational amplifier corresponding to the left/right channel earphone respectively.

In the above embodiment, by adjusting the potential V4 between the first feedback impedance 2601 and the second feedback impedance 2602, the V4 can reduce the interference caused by V3 to some extent; a switch module may be further disposed at two ends of the first feedback impedance 2601, so that the potentials of V2 and V4 may be changed according to different connection modes of the switch module. Therefore, the V4 can be switched between different modes of the ear return earphone, so that the V4 can be matched with the corresponding V3 in different modes, interference caused by the V3 can be eliminated, and self-excited howling of the ear return earphone can not occur under the condition of improving the loudness of the ear return earphone.

Referring to fig. 5, on the basis of the ear return earphone shown in fig. 3, the ear return earphone shown in fig. 5 may further include: a switch module 270. The switch module 270 may be disposed across the first feedback impedance 2601 and connected to a second end of the first dc blocking capacitor 2501. The switch module 270 has a first terminal, a second terminal, and a third terminal.

Specifically, a first terminal of the switch module 270 may be connected to a feedback terminal of the codec 240 or a first terminal of a first feedback impedance 2601. A second terminal of the switching module 270 may be connected to a second terminal of the first feedback impedance 2601 or a first terminal of the second feedback impedance 2602. The third terminal of the switch module 270 is connected to the second terminal of the first dc blocking capacitor 2501.

The switch module 270 may communicate any two of the first, second, and third terminals of the switch module 270. If the third terminal of the switch module 270 is connected to the first terminal, V2 can be input to the codec 240 through the first dc blocking capacitor 2501, so that V3 corresponding to the key 220 mode is subtracted through V2. If the third terminal of the switch module 270 is connected to the second terminal, V4 may be input to the codec 240 through the first blocking capacitor 2501, so that V3 corresponding to the earreturn mode is subtracted through V4.

The calculation of the resistance values of the first feedback resistor 2601 and the second feedback resistor 2602 is similar to that of the above embodiment, and is not repeated herein.

For example, the ear return speaker may detect the mode in which the ear return speaker is located, i.e. whether the button 220 of the ear return speaker is pressed. If the button 220 is pressed, it indicates that the ear return earphone enters the button mode, and the third end of the switch module 270 may be controlled to communicate with the first end, so as to reduce the voltage V3 with a higher voltage level through the voltage V2. If the button 220 is not detected to be pressed, it indicates that the ear return earphone is in the ear return mode, and the third end and the second end of the switch module 270 may be controlled to be communicated, so as to reduce the voltage V3 with a lower voltage through the voltage V4.

Further, the switch module 270 may be simplified, for example, the switch module 270 may be replaced by a MOS transistor 280(metal oxide semiconductor field effect transistor). Whether the first feedback impedance 2601 is short-circuited or not can be controlled by turning on or off the MOS transistor 280, so that the potential corresponding to V4 is switched, and matching of V4 with V3 corresponding to different modes is achieved.

Referring to fig. 6, on the basis of the ear-return earphone shown in fig. 3, the source and the drain of the MOS transistor 280 are respectively connected to two ends of the first feedback impedance 2601. If the MOS transistor 280 is turned off when the MOS transistor 280 is turned off, the current flows through the first feedback resistor 2601 and then flows into the second feedback resistor 2602, the potential of V4 is low, and the V4 at this time can be matched with the V3 corresponding to the ear-return mode, thereby reducing the V3.

When the MOS transistor 280 is closed, the first feedback impedance 2601 is short-circuited, the current flows into the second feedback impedance 2602 through the MOS transistor 280, and no longer flows through the first feedback impedance 2601, the potential of V4 is raised, the potential corresponding to V4 is substantially the same as the potential corresponding to V2, and then V4 at this time can be matched with V3 corresponding to the key 220 mode, so that V3 is subtracted.

For example, similar to the above example, the ear return speaker may detect the mode in which the ear return speaker is located, i.e. whether the button 220 of the ear return speaker is pressed. If the button 220 is pressed, it indicates that the ear return earphone enters the button 220 mode, and the MOS transistor 280 can be controlled to be turned on, so as to reduce the V3 with higher potential through the V4 with raised potential. If the button 220 is not detected to be pressed, the ear return earphone is in the ear return mode, the MOS tube 280 can be controlled to be disconnected, and the V3 with the lower potential is reduced through the V4.

It should be noted that the gate of the MOS 280 is connected to the control terminal of the ear-return circuit, and the level signal output by the control terminal is related to the mode of the ear-return circuit. When the MOS transistor 280 is an N-type MOS transistor 280, if the ear return earphone is in the key 220 mode, the control terminal may output a high level to turn on the MOS transistor 280, and if the ear return earphone is in the ear return mode, the control terminal may output a low level to turn off the MOS transistor 280. On the contrary, when the MOS transistor 280 is a P-type MOS transistor 280, if the ear return earphone is in the key 220 mode, the control terminal may output a low level to turn on the MOS transistor 280, and if the ear return earphone is in the ear return mode, the control terminal may output a high level to turn off the MOS transistor 280.

To sum up, the ear headphone provided in the embodiment of the present application sets the first feedback impedance and the second feedback impedance connected in series between the ground resistance and the feedback boost resistance in the feedback module, and connects the second end of the first blocking capacitor in the differential module between the first feedback impedance and the second feedback impedance, so that a differential input mode can be adopted, interference signals in the collected voice data are reduced through the potential between the first feedback impedance and the second feedback impedance, and then the loudness of the ear headphone is improved on the premise of preventing the ear headphone from howling and self-exciting.

Further, through set up switch module or MOS pipe in the ear returns the earphone in the ear for the ear returns the earphone and can returns the mode that the earphone is located according to the ear, also be according to the ear and return the button of earphone and press, adjust the state of switch module or MOS pipe, make the electric potential of the second end of first blocking electric capacity, can match with the electric potential of the second end of second blocking electric capacity under the different modes, thereby can further subdue the interfering signal in the speech data of gathering through assorted electric potential, in order to improve the effect of subduing interfering signal.

In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or illustrated in a certain embodiment.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the embodiments provided in the present application, it should be understood that the disclosed circuit and headset may be implemented in other ways. For example, the above-described system embodiments are merely illustrative, and for example, the division of the modules or units is only one logical division, and there may be other divisions when actually implemented, for example, a plurality of units or components may be combined or may be integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; the modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present application, and are included in the protection scope of the present application.

Claims

1. An ear return headphone circuit, comprising: the device comprises a microphone, a key, an earphone, a coder-decoder, a differential module and a feedback module;

the differential module comprises a first blocking capacitor and a second blocking capacitor, wherein a first end of the first blocking capacitor is connected with one data receiving end (D1) of the coder-decoder, a first end of the second blocking capacitor is connected with the other data receiving end (D2) of the coder-decoder, a second end of the first blocking capacitor is connected between the first feedback impedance and the second feedback impedance, and a second end of the second blocking capacitor is respectively connected with the microphone and the key; the electric potential of the second end of the first blocking capacitor is set according to the electric potential of the second end of the second blocking capacitor, under the condition that the ear return earphone circuit adopts differential input, the electric potential of the second end of the first blocking capacitor is used for reducing interference signals of the electric potential of the second end of the second blocking capacitor on voice data collected by the microphone, and the first feedback impedance and the second feedback impedance are used for adjusting the electric potential of the second end of the first blocking capacitor.

2. The ear return headphone circuit of claim 1, further comprising: a first end of the switch module is arranged between a feedback end of the codec and a first end of the first feedback impedance, a second end of the switch module is arranged between the first feedback impedance and the second feedback impedance, and a third end of the switch module is connected with a second end of the first blocking capacitor;

3. The ear return headphone circuit of claim 1, further comprising: the source electrode and the drain electrode of the MOS tube are respectively arranged at two ends of the first feedback impedance, the grid electrode of the MOS tube is connected with the control end of the ear return earphone, and a level signal sent by the control end is related to an ear return mode and a key mode;

4. The ear return earphone circuit according to any one of claims 1 to 3, wherein the differential module further comprises a voltage dividing resistor, a first end of the voltage dividing resistor is connected to a microphone power supply end of the codec, and a second end of the voltage dividing resistor is connected to a second end of the second DC blocking capacitor, the microphone and the key, respectively.

5. An ear return headphone circuit as claimed in any one of claims 1 to 3, wherein the headphones comprise a left channel headphone and/or a right channel headphone, the headphones further comprising a common impedance and a ground resistance;

6. An ear return headphone circuit as claimed in any one of claims 1 to 3, wherein the codec comprises: the system comprises an analog-to-digital converter, a digital-to-analog converter and a feedback operational amplifier;

7. The ear return headphone circuit of claim 6, wherein the codec further comprises: an operational amplifier disposed between the digital-to-analog converter and the earphone;

8. The ear return headphone circuit of claim 7, wherein the digital-to-analog converter comprises a left digital-to-analog converter and a right digital-to-analog converter, the feedback operational amplifier comprises a left feedback operational amplifier and a right feedback operational amplifier, the operational amplifier comprises a left operational amplifier and a right operational amplifier;

9. An ear return headphone, comprising an ear return headphone circuit as claimed in any one of claims 1 to 8.

10. An ear return system, characterized in that it comprises a terminal device and an ear return headset according to claim 9, said terminal device being connected to said ear return headset.