CN220272145U - Noise reduction system, heat dissipation device and electronic equipment - Google Patents

Abstract

A noise reduction system for a heat dissipating device is proposed, comprising: an acoustic sensor for capturing noise generated by the heat sink to generate a first audio signal representative of the noise; a signal conversion unit for converting the first audio signal into a second audio signal having an opposite phase to the first audio signal; and a speaker for generating sound represented by the second audio signal. By superimposing the sound represented by the opposite phase signal with the noise, the noise can be at least partially cancelled, thereby reducing the noise strength, improving the user experience, or improving the system performance.

Description

Noise reduction system, heat dissipation device and electronic equipment

Technical Field

The present utility model relates to a noise reduction system of an electronic device, and more particularly, to a noise reduction system for reducing noise generated by a heat sink, a heat sink including the noise reduction system, and an electronic device using the heat sink.

Background

Electronic devices such as notebook computers and desktop computers generate heat during operation due to the energizing of electronic devices, which may cause damage to the electronic devices and may even cause safety accidents. Therefore, a heat sink containing a key component such as a fan is required to spread out the heat generated by these electronic devices during operation. However, the operation of the fan generates noise, and the intensity of the noise increases with the increase of the rotation speed of the fan.

Currently, there are some schemes to reduce noise generated by high speed rotation of fans. One such solution is to use a larger fan because a larger fan size can achieve the same heat dissipation effect with a lower rotational speed. Larger fan modules necessarily result in higher manufacturing costs and are disadvantageous in miniaturization and slimness of electronic devices, which affect the size of the main board and the battery, which is very disadvantageous for electronic devices such as notebook computers, and cannot achieve an optimal design from a system perspective. Another solution is to configure different fan speeds according to different system temperatures, so as to control noise generated by the fan. The problem with this solution is that the fan is only operated at its maximum rotational speed at higher system temperatures, and most of the time the fan does not exert its maximum performance, nor is it able to reduce the system noise at the maximum rotational speed. This approach reduces fan noise to a limited extent at the expense of fan performance.

Therefore, a more intelligent and efficient noise reduction system becomes particularly important for improving system performance and improving user experience.

Disclosure of Invention

The present utility model proposes an adaptive noise reduction system for a heat sink that is capable of reducing noise of the system without increasing the size of the fan module and without sacrificing fan performance.

According to one aspect of the present utility model, there is provided a noise reduction system for a heat dissipating device, comprising: an acoustic sensor for capturing noise generated by the heat sink to generate a first audio signal representative of the noise; a signal conversion unit for converting the first audio signal into a second audio signal having an opposite phase to the first audio signal; and a speaker for generating sound represented by the second audio signal.

According to another aspect of the present utility model, there is provided a heat dissipating device for an electronic apparatus, including: a fan; and a noise reduction system provided by the utility model.

According to another aspect of the present utility model, an electronic device is provided, which includes the heat dissipating device provided by the present utility model.

Noise consists of a spectrum that can be completely cancelled out if a sound can be found that is exactly the same as the noise to be cancelled, but just in exactly opposite phase (180 deg. out of phase).

In accordance with the principles of the present utility model, noise generated by a heat sink is collected by an acoustic sensor to generate a noisy first audio signal. The signal conversion unit is capable of converting the first audio signal into a second audio signal having an opposite phase to the first audio signal. Since the second audio signal has an opposite phase to the first audio signal, the sound represented by the second audio signal is able to or at least partially cancel the noise represented by the first audio signal.

The utility model provides an adaptive noise reduction system which can effectively reduce noise of a fan under the condition that the rotation speeds of the fans are the same. The noise reduction system can allow higher fan speeds without significantly increasing noise, thereby achieving better heat dissipation.

Drawings

FIG. 1 illustrates a block diagram of a noise reduction system for a heat sink in accordance with one embodiment of the present utility model;

FIG. 2 illustrates a block diagram of a noise reduction system for a heat sink in accordance with another embodiment of the present utility model;

FIG. 3 illustrates a block diagram of a noise reduction system for a heat sink in accordance with another embodiment of the present utility model;

FIG. 4 shows a schematic diagram of a heat sink according to one embodiment of the utility model;

FIG. 5 shows a schematic diagram of an electronic device according to one embodiment of the utility model; and is also provided with

Fig. 6 shows a schematic view of a heat sink according to another embodiment of the utility model.

Detailed Description

Although the present utility model is described with reference to a heat sink including a fan, it should be understood that the use of the noise reduction system of the present utility model is not limited to a heat sink including a fan. For example, the noise reduction system of the present utility model can be used to reduce noise generated by water flow in a water cooling system.

Fig. 1 illustrates a block diagram of a noise reduction system 100 for a heat sink in accordance with one embodiment of the present utility model. The noise reduction system 100 comprises an acoustic sensor 101 for capturing noise generated by a heat sink to generate a first audio signal representative of the noise. The acoustic sensor 101 is capable of listening for noise and converting the noise into an electrical signal. For example, the acoustic sensor 101 is a microelectromechanical system (MEMS) microphone, which has advantages of miniaturization, stable performance, and the like. These advantages of MEMS microphones are particularly applicable to electronic devices that do not occupy excessive space within the device while enabling accurate collection of noise.

The noise reduction system 100 further comprises a signal conversion unit 102 for converting the first audio signal into a second audio signal having an opposite phase to the first audio signal. The signal conversion unit 102 may receive the electric signal generated by the acoustic sensor 101 and perform an inversion process on the electric signal to obtain a signal having an opposite phase. When the sound represented by the opposite phase signal is co-present with noise, the superposition of the two will cancel or at least partially cancel the noise, thereby achieving a reduction in noise intensity.

In one embodiment, the signal conversion unit 102 may be implemented by a hardware scheme. For example, the signal conversion unit may be a phase inversion circuit. The phase inversion circuit may be integrated on a Digital Signal Processing (DSP) chip, such as an audio Codec chip.

The implementation of the signal conversion unit 102 by a hardware solution is advantageous in that the hardware solution enables phase inversion with a short response time, which enables to ensure the simultaneous occurrence and superposition of sound and noise represented by signals of opposite phases in a low cost manner for the purpose of noise reduction.

In another embodiment, the signal conversion unit 102 may be implemented by a software scheme, which may be embodied as an application program. The software solution requires a high-speed processor running a corresponding application to effect the conversion from the first audio signal to the second audio signal. For example, when the noise reduction system 100 is applied to a heat sink of a notebook computer, a CPU of the notebook computer itself may be used to run a corresponding application program to convert a first audio signal generated by the acoustic sensor 101 into a second audio signal having an opposite phase. The software solution requires that the processor has sufficient performance to enable high-speed conversion of the signals to ensure that sound represented by the second audio signal of opposite phase can occur almost synchronously with the noise of the first audio signal and be superimposed.

The noise reduction system 100 further comprises a loudspeaker 103 for generating sound represented by said second audio signal. The speaker 103 may receive the second audio signal generated by the signal conversion unit 102 and convert the electrical signal into a corresponding sound. The sound is played through the speaker 103 into a space where noise is present at the same time, so that the noise is eliminated or at least partially eliminated, thereby reducing the intensity of the noise.

In one embodiment, the second audio signal has the same amplitude as the first audio signal. This means that the sound waveform of the second audio signal is exactly opposite to the sound waveform of the first audio signal, i.e. opposite in phase and identical in amplitude. This allows the sound represented by the second audio signal to completely cancel the noise.

In another embodiment, the amplitude of the second audio signal may not be exactly equal to the amplitude of the first audio signal. In this case, even if the sound represented by the second audio signal cannot completely cancel the noise, at least a part of the noise can be canceled, and thus the effect of reducing the noise intensity is also achieved, achieving the purpose of improving the user experience.

Such active noise cancellation actually uses the principle of superposition of acoustic waves. Thus, the sound generated by the speaker 103 may be superimposed not only with noise but also with any other sound, which is disadvantageous in some cases. For example, when the noise reduction system 100 is applied to an electronic device, sound generated by the speaker 103 may also affect normal operation sound of the electronic device. For example, in the application scenario of a notebook computer, the notebook computer may play video, music or perform voice call, and of course, other working sounds exist. The video sound, music sound, and conversation sound generated during this period all belong to working sounds that are not expected to be affected by any.

In order to avoid as much as possible the influence of the sound generated by the loudspeaker 103 on the normal operating sound of the electronic device, in an embodiment the noise reduction system further comprises a switching unit. The switching unit is used for enabling the noise reduction system to switch between different working modes. Some examples of the operation modes are described below, which can be used to explain how to avoid the influence on the normal operation sound of the electronic device.

In the first mode, the amplitude of the second audio signal may be so large as to be exactly the same as the amplitude of the first audio signal to maximize noise cancellation. The first mode is preferably selected without the electronic device emitting any working sound. The amplitude of the audio signal represents the intensity of the sound, with larger amplitudes producing stronger sounds. In the first mode, there is no operating sound of the electronic device. Therefore, there is no fear that the stronger sound interferes with the working sound.

In the second mode, the amplitude of the second audio signal is smaller than the amplitude of the first audio signal. The second mode is preferably selected in case the electronic device emits an operating sound but does not perform a critical task. For example, a user may be playing movies or music using a notebook computer. At this time, the amplitude of the second audio signal may be set to be slightly smaller, so as to minimize the interference to the sound played by the notebook computer, and at the same time, still maintain a certain noise reduction function.

In the third mode, the speaker 103 may be completely turned off, thereby temporarily stopping the noise reduction function. This is necessary in cases where the electronic device needs to emit a working sound to complete a critical task. For example, a user may be using a notebook computer to conduct an important online meeting. At this time, the talking voice played by the notebook computer is not expected to be interfered by any other sound, so as to avoid losing any key voice information.

Of course, the switchable modes are not limited to the above three modes. For example, a plurality of modes may be set, each of which sets a plurality of amplitude values between a maximum amplitude (noise amplitude) and a minimum amplitude (0).

Different modes may be implemented by different conversion circuits. The switching unit may be implemented as a switching circuit, which may be used to switch between different switching circuits. These switching circuits and switching circuits may be integrated on the same chip.

Alternatively, the different modes may be implemented by different software modules. These software modules may be included in the same application program, and a user may manually select icons representing different modes on the application program interface to switch between the different modes.

Fig. 2 illustrates a block diagram of a noise reduction system 200 for a heat sink in accordance with another embodiment of the present utility model. In addition to the acoustic sensor 101, the signal conversion unit 102, and the speaker 103 described with reference to fig. 1, the noise reduction system 200 includes a band-pass or low-pass filter 104. The filter 104 is used to filter noise collected by the acoustic sensor 101.

The inventors of the present utility model have appreciated that although the human ear is able to perceive sound in the frequency range of 20Hz to 20kHz, humans are typically very sensitive to noise in the frequency range of 300Hz to 5kHz, while noise outside the frequency range of 300Hz to 5kHz is typically less influential to humans. Therefore, the method can only generate the inverse sound in the frequency range from 300Hz to 5kHz to offset the noise in the frequency range from 300Hz to 5kHz, so that the purposes of noise elimination or partial elimination can be realized, the cost can be reduced, and the user experience can be better enhanced.

In one embodiment, the filter 104 may be a band pass filter having a passband of 300Hz to 5kHz, or a low pass filter having a cutoff frequency of 5kHz, which filters noise collected by the acoustic sensor 101 so that noise signals in a frequency range of only 300Hz to 5kHz, or in a frequency range of only less than 5kHz, can be transmitted to the signal conversion unit 102 for phase conversion. Accordingly, the speaker 103 is also only able to receive the converted signal in the frequency range of 300Hz to 5 kHz. This can reduce interference of the sound generated by the speaker 103 with other sounds (e.g., the operation sound of the electronic device such as a notebook computer described above) so that other sounds outside the frequency range of 300Hz to 5kHz can be protected from the sound.

Furthermore, the inventors of the present utility model have realized that not all noise over the frequency range will increase significantly with increasing fan speed, but that noise only in the frequency range of 300Hz to 1.6kHz will increase significantly with increasing fan speed.

One purpose of the heat sink to reduce noise is not to significantly increase the intensity of noise when the fan speed of the heat sink is increased to enhance heat dissipation. Since noise outside the frequency range of 300Hz to 1.6kHz does not significantly vary with an increase in the rotational speed of the fan, only the inverse sound in the frequency range of 300Hz to 1.6kHz can be generated to cancel noise in the frequency range of 300Hz to 1.6kHz.

In one embodiment, the filter 104 may be a band pass filter having a passband of 300Hz to 1.6kHz, or a low pass filter having a cutoff frequency of 1.6kHz, which filters noise acquired by the acoustic sensor 101 such that only noise signals in the frequency range of 300Hz to 1.6kHz, or only noise signals in the frequency range of less than 1.6kHz, can be transmitted to the signal conversion unit 102 for phase conversion. Accordingly, the speaker 103 is also only capable of receiving a converted signal in the frequency range of 300Hz to 1.6kHz. This can reduce interference of the sound generated by the speaker 103 with other sounds (e.g., the operation sound of the electronic device such as a notebook computer described above) so that other sounds outside the frequency range of 300Hz to 1.6kHz can be protected from the sound.

Fig. 3 illustrates a block diagram of a noise reduction system 300 for a heat sink in accordance with another embodiment of the present utility model.

The function of the acoustic sensor 101 is to accurately collect noise emitted by the heat sink, and any other sound that can be collected by the acoustic sensor 101 is undesirable and affects the accurate collection of noise by the acoustic sensor 101. For example, the speaker 103 itself can generate sound in anti-phase with the noise based on the collected noise, and the sound is also likely to be collected as an echo 11 by the acoustic sensor 101. Therefore, the acoustic sensor 101 of the noise reduction system 300 preferably further comprises an echo cancellation unit 10. The echo cancellation unit 10 can be used to cancel sound from the loudspeaker 103 from sound collected by the acoustic sensor 101.

In one embodiment, the echo cancellation unit 10 may be a linear adder circuit that may numerically invert the signal representing the echo and linearly add to the sound signal acquired by the acoustic sensor 101, thereby canceling the echo from the sound acquired by the acoustic sensor 101. Since the sound of the speaker is generated from the signal generated by the signal conversion unit 102, the echo signal is known to the noise reduction system, and thus, no other component is required to determine the echo signal. For example, the signal conversion unit 102 may feed back the signal generated by it to the echo cancellation unit 10 for echo cancellation while transmitting the signal to the speaker 103.

In addition to the echoes described above, the acoustic sensor 101 may also collect undesirable ambient sound 21. For example, music played by a notebook computer may also be captured by the acoustic sensor 101, thereby affecting the accurate capture of noise by the acoustic sensor 101. Therefore, it is preferable that the acoustic sensor 101 of the noise reduction system 300 further includes the ambient sound eliminating unit 20. The ambient sound removing unit 20 can be used to remove ambient sound from the outside from sound collected by the acoustic sensor 101.

Similar to the echo cancellation unit 10, the echo cancellation unit 10 may be a linear adder circuit that may numerically invert a signal representing the ambient sound and linearly add to the sound signal acquired by the acoustic sensor 101, thereby canceling the ambient sound from the sound acquired by the acoustic sensor 101.

Unlike echo cancellation, the noise reduction system itself cannot determine the ambient sound signal. Therefore, information on the environmental sound signal needs to be acquired from other components.

In a scenario integrated into a notebook computer, the ambient sound may be sound that the notebook computer is able to expect. For example, a processor of a notebook computer can read a music signal to be played by the notebook computer from a storage medium of the notebook computer. The signal may be transmitted to the ambient sound removing unit 20 by a wired or wireless manner to be removed.

Ambient sound may also be unexpected sound. For example, during use of a notebook computer, the user's speech sounds with others may be captured as ambient sounds by an acoustic sensor. In this case, the system microphone (or other external microphone) of the notebook computer may collect unintended sounds such as talking sounds. The collected unintended sound signal may be transmitted to the ambient sound removal unit 20 by a wired or wireless manner to be removed.

Since the ambient sound removing unit 20 needs to receive signals from other components, the ambient sound removing unit 20 also needs to be configured with an additional wired or wireless receiving module.

Those skilled in the art will appreciate that although the echo cancellation unit 10 and the ambient sound cancellation unit 20 are shown as different units in fig. 3, the echo cancellation unit 10 and the ambient sound cancellation unit 20 may also be implemented in the same unit. For example, the same linear adder circuit may implement the functions of both the echo cancellation unit 10 and the ambient sound cancellation unit 20 at the same time. Further, although the noise reduction system 300 of fig. 3 includes both the echo cancellation unit 10 and the ambient sound cancellation unit 20, the noise reduction system 300 may include only one of the echo cancellation unit 10 and the ambient sound cancellation unit 20. Fig. 4 shows a schematic view of a heat sink 400 according to an embodiment of the utility model. The heat sink 400 includes a noise reduction system according to any of the embodiments described above. In addition, the heat sink 400 includes a fan 410 for discharging heat. Preferably, an acoustic sensor of the noise reduction system is placed near the fan 410 so that noise generated by the operation of the fan 410 can be accurately collected. This is not necessary and the acoustic sensor may be placed in any suitable location in order to optimize the system configuration so long as it accurately captures the noise generated by the operation of the fan 410. In addition, the signal conversion unit may be placed at different locations, such as near the fan or far from the fan, depending on the specific system configuration.

In one embodiment, there is an enclosed cavity 420 (represented by the dashed box) defined by at least the speaker 103 and the fan 410. The air outlet 40 of the fan 410 and the sound outlet 30 of the speaker 103 should be directed towards the inside of the closed cavity such that the noise generated by the fan 410 and the sound generated by the speaker 103 are directed into the closed cavity 420 for superposition. Since the intensity of the noise is higher in the direction in which the air outlet 40 of the fan 410 is directed, such a design can ensure that the noise having higher intensity can be offset, thereby improving the noise reduction effect. Meanwhile, neither the noise generated by the fan 410 nor the sound generated by the speaker 103 is desired to be propagated to the outside of the apparatus to disturb the user or to disturb other sounds (for example, the operation sound of the notebook computer described above). Such a design may advantageously cancel as much as possible the noise generated by the fan 410 and the sound generated by the speaker 103 in the enclosed cavity 420 to avoid that it affects other sounds outside the device.

The heat sink 400 can also include a heat pipe 430 and heat fins 440. When the heat sink 400 is installed in an electronic device, the heat pipe 430 is capable of conducting heat generated by the electronics of the electronic device to the heat sink fins 440. The heat dissipation fins 440 dissipate heat in the form of convection by the air flow generated by the fan 410. These components of the heat sink 400 may cooperate with the speaker 103 and the fan 410 to define an enclosed cavity 420. As shown in fig. 4, the closed cavity 420 is defined by the speaker 103, the fan 410, the heat pipe 430, and the heat sink fins 440.

Those skilled in the art will appreciate that the enclosed cavity 420 can be defined by any suitable component and is not limited to the component shown in fig. 4. For example, a recess may be formed in the heat sink fin 440 and both the sound outlet of the speaker 103 and the air outlet of the fan 410 may be aligned with the recess in the heat sink fin 440 to form a closed cavity defined by the speaker 103, the fan 410 and the heat sink fin 440.

Fig. 5 shows a schematic diagram of an electronic device 500 according to an embodiment of the utility model. The electronic device 500 includes a motherboard 501, and a heat dissipating device according to any of the embodiments described above may be mounted on the motherboard 501. The noise reduction system in the heat sink may be mounted on the motherboard 501 as an integral module with critical heat dissipation components such as fans, heat pipes, heat fins, or the individual components in the noise reduction system may be mounted on the motherboard 501 independent of the critical heat dissipation components. For example, the acoustic sensor, the signal conversion unit, the filter, and the speaker of the noise reduction system may be mounted at different positions of the main board 501, respectively.

In this embodiment, the enclosed cavity 520 may also be defined by components of the electronic device 500 in conjunction with a speaker, fan, etc. assembly. For example, the motherboard 501 or a portion of the housing of the electronic device 500 may be used to define an enclosed cavity 520 (represented by a dashed box).

The electronic device 500 also includes a heat sink 50. Typically, the air outlet of the fan needs to be aligned with the heat sink 50 to blow heat out of the heat sink 50.

Fig. 6 shows a schematic diagram of an electronic device 600 according to an embodiment of the utility model. The electronic device 600 includes a motherboard 601, and a heat dissipating device according to any of the embodiments described above may be mounted on the motherboard 601. The noise reduction system in the heat sink may be mounted on the main board 601 together with key heat dissipation components such as fans, heat pipes, heat dissipation fins as an integral module, or the individual components in the noise reduction system may be mounted on the main board 601 independently of the key heat dissipation components. For example, the acoustic sensor, the signal conversion unit, the filter, and the speaker of the noise reduction system may be mounted at different positions of the main board 601, respectively.

On the main board 601, the electronic device 610 of the electronic apparatus 600 is integrated. The electronics 610 may include a Central Processing Unit (CPU) and a Graphics Processing Unit (GPU), which are the primary components that generate heat during operation of the electronic device. As shown in fig. 6, the heat pipe 430 may conduct heat generated by the electronic device 610 to the heat dissipation fins 440, thereby blowing the heat out of the heat dissipation port 60 of the electronic device 600 using a fan.

In one embodiment, in addition to including a primary air outlet directed toward the heat fins 440 and the heat sink 60, the fan 410 includes a lateral air outlet 61 directed toward the electronic device 610, the lateral air outlet 61 directing the air flow generated by the fan toward the electronic device 610 to dissipate heat generated by the electronic device 610 directly.

A sealed cavity 620 (represented by a dashed box) may be formed inside the electronic device 600 by the components of the fan 410, speaker 103, sealing gasket 62, heat pipe 430, motherboard 601, etc. The sound outlet of the speaker 103 and the lateral air outlet 61 of the fan face the inside of the sealed cavity 620, so that the fan noise emitted from the lateral air outlet 61 and the sound generated by the speaker 103 are directed to be superimposed in the sealed cavity 620, thereby realizing the noise reduction function. Since the lateral outlets 61 themselves are designed to be directed towards the electronic device 610, the electronic device 610 may also be located in the closed cavity 620.

In one embodiment, as shown in fig. 6, the sound outlet of speaker 103 faces away from the heat sink 60 of the electronic device 600. In this embodiment, the sound generated by the speaker 103 is directed entirely into the enclosed space inside the electronic device 600, which is advantageous for reducing the influence of the sound generated by the speaker 103 on the sound outside the electronic device 600. The sound outlet of the speaker 103 may be located between the main air outlet of the fan and the heat dissipation port 60 of the electronic device 600 to simultaneously reduce noise emitted from the main air outlet of the fan. Of course, noise from the main air outlet of the fan can be reduced by using another loudspeaker.

In one embodiment, to enhance the heat dissipation function, the heat dissipation device may include a plurality of fans. Fig. 6 shows two fans 410 and 410'. The closed cavity 620 may be defined by both fans 410 and 410 'together, and the sound generated by the speaker 103 may simultaneously reduce noise generated by both fans 410 and 410'. Of course, different speakers may be used to reduce noise generated by different fans, respectively.

Mounting the heat sink according to the present embodiment into the electronic device may include integrating the heat sink completely into the electronic device during manufacturing of the electronic device. Alternatively, during the manufacturing process of the electronic device, the heat sink may not be installed and an interface for installing the heat sink may be reserved to facilitate the user to selectively install the heat sink into the electronic device later. Alternatively, only a portion of the heat sink may be integrated into the electronic device during manufacture of the electronic device. For example, during the manufacturing process of the electronic device, the main heat dissipating components of the heat dissipating device (such as fans, heat pipes, heat dissipating fins, etc.) may be integrated into the electronic device and an interface for installing the noise reduction system is reserved for facilitating the subsequent selective installation of the noise reduction system into the electronic device by a user.

Mounting the heat sink into the electronic device may include mounting the heat sink into the electronic device as an integral module. Alternatively, the individual components of the heat sink (e.g., fan, sound sensor, speaker, etc.) may be individually mounted into the electronic device.

Electronic devices according to the present utility model include, but are not limited to: notebook computers, desktop computers, air conditioners, televisions, and gaming machines. Those skilled in the art will recognize that any electronic device that includes a heat sink that may generate noise may be included within the scope of the present utility model.

The noise reduction system, the heat dissipating device, and the electronic apparatus of the present utility model are described above with reference to various embodiments, wherein the embodiments mentioned may include a particular feature, structure, or characteristic, but not every embodiment necessarily includes the particular feature, structure, or characteristic. Furthermore, some embodiments may have some or all of the features described for other embodiments or none of the features described for other embodiments.

Various features of different embodiments or examples may be combined in various ways with some features included, as well as other features excluded, to accommodate a variety of different applications. The figures and the preceding description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may be combined into a single functional element. Alternatively, some elements may be separated into multiple functional elements. Elements from one embodiment may be added to another embodiment. The scope of the embodiments is in no way limited by these specific examples. Many variations, whether explicitly given in the specification or not, such as differences in product composition and structure, are possible.

Claims (15)

1. A noise reduction system for a heat sink, comprising:

an acoustic sensor for capturing noise generated by the heat sink to generate a first audio signal representative of the noise;

the noise reduction system is characterized by further comprising:

a signal conversion unit for converting the first audio signal into a second audio signal having an opposite phase to the first audio signal; and

a speaker for generating sound represented by the second audio signal.

2. The noise reduction system of claim 1, wherein the second audio signal has the same amplitude as the first audio signal.

3. The noise reduction system according to claim 1, wherein the signal conversion unit is a phase inversion circuit.

4. The noise reduction system according to claim 1, further comprising a switching unit for switching between a first mode, a second mode and a third mode of the noise reduction system, wherein,

in the first mode, the amplitude of the second audio signal converted by the signal conversion unit is the same as the amplitude of the first audio signal;

in the second mode, the amplitude of the second audio signal converted by the signal conversion unit is smaller than the amplitude of the first audio signal; and is also provided with

In the third mode, the speaker is turned off.

5. The noise reduction system of any of claims 1-4, further comprising a bandpass filter for filtering the noise collected by the acoustic sensor.

6. The noise reduction system of claim 5, wherein the passband of the bandpass filter is 300Hz to 5kHz or 300Hz to 1.6kHz.

7. The noise reduction system of any of claims 1-4, further comprising a low pass filter for filtering the noise collected by the acoustic sensor.

8. The noise reduction system of claim 7, wherein the cut-off frequency of the low pass filter is 5kHz or 1.6kHz.

9. The noise reduction system of any of claims 1-4, wherein the acoustic sensor comprises an echo cancellation unit for canceling sound generated by the speaker from sound collected by the acoustic sensor.

10. The noise reduction system according to any one of claims 1-4, wherein the acoustic sensor comprises an ambient sound cancellation unit for canceling ambient sound from sound collected by the acoustic sensor.

11. A heat dissipation device for an electronic device, comprising:

a fan; and

the noise reduction system of any of claims 1-10.

12. The heat sink of claim 11, wherein at least the speaker and the fan define a closed cavity, and wherein the sound outlet of the speaker and the air outlet of the fan face the interior of the closed cavity.

13. An electronic device comprising the heat sink according to any of claims 11-12.

14. An electronic device according to claim 13,

the fan comprises a lateral air outlet, and the lateral air outlet faces the electronic device of the electronic equipment;

wherein at least the speaker and the fan define a closed cavity, the sound outlet of the speaker and the lateral air outlet of the fan being directed towards the interior of the closed cavity; and is also provided with

Wherein, the electronic device of the electronic equipment is positioned in the closed cavity.

15. The electronic device of claim 14, wherein the sound outlet of the speaker faces away from a heat sink of the electronic device.