Noise reduction circuit, audio device and electric equipment

By using a noise reduction circuit in the speech recognition system, the speech signal of the first pickup component is amplified in reverse and superimposed with the signal of the second pickup component to offset it, thus solving the problem of background noise affecting the pickup effect and achieving the accuracy of speech recognition and the reliability of electrical equipment.

CN223488388UActive Publication Date: 2025-10-28TCL AIR CONDITIONER ZHONGSHAN CO LTD
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Patent Information

Application Number
CN202422268144.7
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2024-09-14
Publication Date
2025-10-28
Estimated Expiration
2034-09-14

AI Technical Summary

Technical Problem

During the speech recognition process, the sounds from the surrounding environment will cause the collected speech to be mixed with a large amount of background noise, affecting the sound pickup effect.

Method used

A noise reduction circuit is used to achieve the purpose of noise reduction by inverting and amplifying the voice signal obtained by the first sound pickup component and then superimposing and canceling it with the voice signal obtained by the second sound pickup component, thereby alleviating the impact of sound pickup on the audio device.

Benefits of technology

It effectively alleviates the impact of background noise on voice recognition, avoids the problem of erroneous information broadcast or false triggering of electrical equipment, and ensures the accuracy of voice pickup.

✦ Generated by Eureka AI based on patent content.

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Abstract

The utility model discloses a noise reduction circuit, an audio device and electric equipment, and the noise reduction circuit comprises a first audio module which is used for being connected with a first pickup assembly and outputting a first voice differential signal after a first voice signal collected by the first pickup assembly is subjected to inverted amplification; the noise reduction module is connected with the first audio module, and the noise reduction module is used for being connected with a second pickup assembly, superposing the first voice signal collected by the second pickup assembly with the first voice differential signal and then outputting a second voice signal; the second audio module is connected with the noise reduction module, and the second audio module is used for converting the second voice signal into a second voice differential signal; according to the invention, noise reduction of the audio signal can be realized.
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Description

Technical Field

[0001] This application relates to the field of electronic circuit technology, specifically to a noise reduction circuit, an audio device, and an electrical appliance. Background Technology

[0002] With the development of technology, speech recognition is increasingly being applied to electrical devices. During the speech recognition process, ambient sounds can introduce a large amount of background noise into the collected speech, which, if not processed, will affect the sound pickup effect.

[0003] Therefore, the technology still needs to be improved and enhanced. Utility Model Content

[0004] This application provides a noise reduction circuit, an audio device, and an electrical device that can effectively alleviate the problem of background noise affecting speech recognition.

[0005] This application provides a noise reduction circuit, which includes:

[0006] The first audio module is used to connect to the first pickup component and to amplify the first speech signal acquired by the first pickup component by inverting and outputting the first speech differential signal.

[0007] The noise reduction module is connected to the first audio module and is used to connect to the second pickup component. The noise reduction module superimposes the first speech signal collected by the second pickup component with the first speech differential signal and outputs the second speech signal.

[0008] The second audio module is connected to the noise reduction module and is used to convert the second speech signal into a second speech differential signal.

[0009] In some embodiments of the noise reduction circuit, the first audio module includes a first resistor, a second resistor, and a first operational amplifier. One end of the first resistor is connected to a first pickup component, the other end of the first resistor is connected to the inverting input terminal of the first operational amplifier, one end of the second resistor is connected to the output terminal of the first operational amplifier, the output terminal of the first operational amplifier is connected to the noise reduction module, and the non-inverting input terminal of the first operational amplifier is powered on.

[0010] In some embodiments of the noise reduction circuit, the noise reduction module includes a third resistor and a fourth resistor. One end of the third resistor is connected to the output of the first operational amplifier, and the other end of the third resistor is connected to the second audio module. One end of the fourth resistor is connected to the second pickup component, and the other end of the fourth resistor is connected to the other end of the third resistor.

[0011] In some embodiments of the noise reduction circuit, the second audio module includes a fifth resistor, a first capacitor, and a second operational amplifier. The inverting input terminal of the second operational amplifier is connected to the other end of the third resistor. One end of the fifth resistor and one end of the first capacitor are both connected to the inverting input terminal of the second operational amplifier. The other end of the fifth resistor and the other end of the first capacitor are connected to the output terminal of the second operational amplifier. The non-inverting input terminal of the second operational amplifier is powered on.

[0012] In some embodiments of the noise reduction circuit, the noise reduction circuit further includes a voltage divider module, which is connected to the first audio module and the second audio module respectively; the voltage divider module is used to provide a reference voltage to the first audio module and the second audio module according to the power supply voltage.

[0013] In some embodiments of the noise reduction circuit, the noise reduction circuit further includes:

[0014] A first isolation module is connected in series between the first pickup component and the first audio module; the first isolation module is used for signal isolation between the first pickup component and the first audio module.

[0015] The second isolation module is connected in series between the second pickup component and the noise reduction module; the second isolation module is used for signal isolation between the second pickup component and the noise reduction module.

[0016] In some embodiments of the noise reduction circuit, the voltage divider module includes a sixth resistor and a seventh resistor. One end of the sixth resistor is connected to the power supply voltage, the other end of the sixth resistor is connected to one end of the seventh resistor and the first audio module, and the other end of the seventh resistor is grounded.

[0017] In some embodiments of the noise reduction circuit, the first isolation module includes a second capacitor, and the second isolation module includes a third capacitor; one end of the second capacitor is connected to the first pickup component, and the other end of the second capacitor is connected to the first audio module; one end of the third capacitor is connected to the second pickup component, and the other end of the third capacitor is connected to the second audio module.

[0018] This application also provides an audio device, which includes a first pickup component, a second pickup component, and the aforementioned noise reduction circuit; both the first pickup component and the second pickup component are connected to the noise reduction circuit.

[0019] This application also provides an electrical device, which includes the audio device described above.

[0020] This application provides a noise reduction circuit, an audio device, and an electrical appliance. The noise reduction circuit inverts and amplifies the first speech signal acquired by the first pickup component, and then superimposes and cancels it with the second speech signal acquired by the second pickup component to achieve noise reduction and alleviate the impact on the audio device's sound pickup, thus preventing the electrical appliance from broadcasting incorrect information or triggering false alarms. Attached Figure Description

[0021] The following detailed description of the specific embodiments of the present application in conjunction with the accompanying drawings will make the technical solutions and other beneficial effects of the present application apparent.

[0022] Figure 1 This is a structural block diagram of the first embodiment of the noise reduction circuit provided in this application.

[0023] Figure 2 This is a structural block diagram of the second embodiment of the noise reduction circuit provided in this application.

[0024] Figure 3 A circuit diagram of the noise reduction circuit provided in the embodiments of this application. Detailed Implementation

[0025] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Features thus defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0027] Please see Figure 1This embodiment provides a noise reduction circuit 30, which includes a first audio module 31, a noise reduction module 32, and a second audio module 33. The first audio module 31 is connected to the first pickup component 10 and is used to amplify the first speech signal collected by the first pickup component 10 by inverting it and outputting a first speech differential signal. The noise reduction module 32 is connected to the first audio module 31 and is used to connect to the second pickup component 20. The noise reduction module 32 superimposes the first speech signal collected by the second pickup component 20 with the first speech differential signal and outputs a second speech signal. The second audio module 33 is connected to the noise reduction module 32 and is used to convert the second speech signal into a second speech differential signal.

[0028] In this embodiment, the noise reduction circuit 30 amplifies the first voice signal acquired by the first pickup component 10 by inverting it and then superimposes and cancels it with the second voice signal acquired by the second pickup component 20 to achieve noise reduction and alleviate the impact on the audio device's sound pickup, thus preventing the electrical equipment from broadcasting incorrect information or triggering falsely.

[0029] Please refer to the following: Figure 2 In some embodiments, the noise reduction circuit 30 further includes a voltage divider module 34, which is connected to the first audio module 31 and the second audio module 33 respectively. The voltage divider module 34 is used to provide a reference voltage to the first audio module 31 and the second audio module 33 according to the power supply voltage, so as to facilitate the amplification processing of the input audio signal by the first audio module 31 and the second audio module 33.

[0030] In some embodiments, the noise reduction circuit 30 further includes a first isolation module 35 and a second isolation module 36. The first isolation module 35 is connected in series between the first pickup component 10 and the first audio module 31, and the second isolation module 36 is connected in series between the second pickup component 20 and the noise reduction module 32. The first isolation module 35 is used to isolate the signal between the first pickup component 10 and the first audio module 31, and the second isolation module 36 is used to isolate the signal between the second pickup component 20 and the noise reduction module, thereby improving the reliability of the noise reduction circuit 30.

[0031] Please refer to the following: Figure 3In one embodiment, the first pickup component 10 and the second pickup component 20 can be microphones such as M1 and M2. The first audio module 31 includes a first resistor R1, a second resistor R2, and a first operational amplifier U1. One end of the first resistor R1 is connected to the first pickup component 10, and the other end of the first resistor R1 is connected to the inverting input terminal of the first operational amplifier U1 and one end of the second resistor R2. The other end of the second resistor R2 is connected to the output terminal of the first operational amplifier U1. The output terminal of the first operational amplifier U1 is connected to the noise reduction module 32, and the non-inverting input terminal of the first operational amplifier U1 is powered on. The first voice signal picked up by the first pickup component 10 is differentially amplified by the first operational amplifier U1 and then output inverted. According to the characteristics of the operational amplifier, the inverted output U0 of the first operational amplifier U1 can be calculated as U0 = R2 / R1(U1--U1+).

[0032] As one embodiment, the noise reduction module 32 includes a third resistor R3 and a fourth resistor R4. One end of the third resistor R3 is connected to the output terminal of the first operational amplifier U1, and the other end of the third resistor R3 is connected to the second audio module 33. One end of the fourth resistor R4 is connected to the second pickup component 20, and the other end of the fourth resistor R4 is connected to the other end of the third resistor R3. After the inverted output of the first operational amplifier U1, the voice signal picked up by the second pickup component 20 is added together with the fourth resistor R4 to cancel out the noise, thereby achieving the purpose of noise cancellation.

[0033] In one embodiment, the second audio module 33 includes a fifth resistor R5, a first capacitor C1, and a second operational amplifier U2. The inverting input terminal of the second operational amplifier U2 is connected to the other end of the third resistor R3. One end of the fifth resistor R5 and one end of the first capacitor C1 are both connected to the inverting input terminal of the second operational amplifier U2. The other end of the fifth resistor R5 and the other end of the first capacitor C1 are connected to the output terminal of the second operational amplifier U2. The non-inverting input terminal of the second operational amplifier U2 is energized. The second operational amplifier U2 is used to invert and amplify the noise-reduced speech signal, i.e., the second speech signal, and output a second speech differential signal as an effective speech signal output.

[0034] As one embodiment, the voltage divider module 34 includes a sixth resistor R6 and a seventh resistor R7. One end of the sixth resistor R6 is connected to the power supply voltage, and the other end of the sixth resistor R6 is connected to one end of the seventh resistor R7 and the first audio module 31. The other end of the seventh resistor R7 is grounded. In this embodiment, the power supply voltage is divided by two resistors to obtain the corresponding voltage divider resistors as the reference voltages for the first operational amplifier U1 and the second operational amplifier U2, so as to realize differential amplification processing of the voice signal.

[0035] In one embodiment, the first isolation module 35 includes a second capacitor C2, and the second isolation module 36 includes a third capacitor C3. One end of the second capacitor C2 is connected to the first pickup component 10, and the other end of the second capacitor C2 is connected to the first audio module 31. One end of the third capacitor C3 is connected to the second pickup component 20, and the other end of the third capacitor C3 is connected to the second audio module 33. Based on the function of capacitors to pass AC and block DC, a capacitor is correspondingly provided at the inverting input terminals of both the first operational amplifier U1 and the second operational amplifier U2. This allows for the isolation of the input signal based on the characteristic of capacitors blocking DC and passing AC. Simultaneously, the relatively high low-frequency impedance of the small capacitor can effectively prevent the entry of low-frequency interference signals, thereby improving the reliability of the noise reduction circuit 30.

[0036] The noise reduction circuit 30 in this application uses components such as resistors, capacitors and operational amplifiers to perform noise reduction processing on audio, which can ensure the accuracy of sound pickup while having a simple circuit structure, which is conducive to low-cost implementation.

[0037] This application also provides an audio device, which includes a first pickup component, a second pickup component, and a noise reduction circuit. Both the first and second pickup components are connected to the noise reduction circuit. The noise reduction circuit performs noise reduction processing on the audio signal acquired by the second pickup component. The audio device in this embodiment uses two pickup components, such as the first and second pickup components, to simultaneously receive voice signals. One signal is inverted and then summed with the other signal, which cancels out the signals, thus achieving noise reduction. Since the noise reduction circuit has been described in detail above, it will not be repeated here.

[0038] This application embodiment also provides an electrical device, such as an air conditioner or a television set, which includes the aforementioned audio device. Since the noise reduction circuit has been described in detail above, it will not be repeated here.

[0039] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0040] The noise reduction circuit provided in the embodiments of this application has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A noise reduction circuit, characterized in that, The noise reduction circuit includes: The first audio module is used to connect to the first pickup component and to amplify the first speech signal collected by the first pickup component by inverting it and outputting the first speech differential signal. A noise reduction module is connected to the first audio module. The noise reduction module is used to connect to the second sound pickup component and output a second sound signal by superimposing the first speech signal collected by the second sound pickup component with the first speech differential signal. A second audio module is connected to the noise reduction module, and the second audio module is used to convert the second speech signal into a second speech differential signal; The noise reduction circuit also includes a voltage divider module, which is connected to the first audio module and the second audio module respectively; the voltage divider module is used to provide a reference voltage to the first audio module and the second audio module according to the power supply voltage; The noise reduction circuit also includes: A first isolation module is connected in series between the first pickup component and the first audio module; the first isolation module is used for signal isolation between the first pickup component and the first audio module. The second isolation module is connected in series between the second pickup component and the noise reduction module; the second isolation module is used for signal isolation between the second pickup component and the noise reduction module.

2. The noise reduction circuit according to claim 1, characterized in that, The first audio module includes a first resistor, a second resistor, and a first operational amplifier. One end of the first resistor is connected to the first pickup component, the other end of the first resistor is connected to the inverting input terminal of the first operational amplifier and one end of the second resistor, the other end of the second resistor is connected to the output terminal of the first operational amplifier, the output terminal of the first operational amplifier is connected to the noise reduction module, and the non-inverting input terminal of the first operational amplifier is powered.

3. The noise reduction circuit according to claim 2, characterized in that, The noise reduction module includes a third resistor and a fourth resistor. One end of the third resistor is connected to the output terminal of the first operational amplifier, and the other end of the third resistor is connected to the second audio module. One end of the fourth resistor is connected to the second pickup component, and the other end of the fourth resistor is connected to the other end of the third resistor.

4. The noise reduction circuit according to claim 3, characterized in that, The second audio module includes a fifth resistor, a first capacitor, and a second operational amplifier. The inverting input terminal of the second operational amplifier is connected to the other end of the third resistor. One end of the fifth resistor and one end of the first capacitor are both connected to the inverting input terminal of the second operational amplifier. The other end of the fifth resistor and the other end of the first capacitor are connected to the output terminal of the second operational amplifier. The non-inverting input terminal of the second operational amplifier is powered on.

5. The noise reduction circuit according to claim 1, characterized in that, The voltage divider module includes a sixth resistor and a seventh resistor. One end of the sixth resistor is connected to the power supply voltage, and the other end of the sixth resistor is connected to one end of the seventh resistor and the first audio module. The other end of the seventh resistor is grounded.

6. The noise reduction circuit according to claim 1, characterized in that, The first isolation module includes a second capacitor, and the second isolation module includes a third capacitor; one end of the second capacitor is connected to the first pickup component, and the other end of the second capacitor is connected to the first audio module; one end of the third capacitor is connected to the second pickup component, and the other end of the third capacitor is connected to the second audio module.

7. An audio device, characterized in that, The audio device includes a first pickup component, a second pickup component, and a noise reduction circuit as described in any one of claims 1-6; both the first pickup component and the second pickup component are connected to the noise reduction circuit.

8. An electrical appliance, characterized in that, The electrical equipment includes the audio device as described in claim 7.