Head-mounted device

Abstract

The invention provides a head-mounted device which comprises a head-mounted device body, a noise reduction box and a fan, the noise reduction box is installed in the head-mounted device body, the fan is installed in the noise reduction box, the noise reduction box is provided with an air outlet structure, the air outlet structure is arranged in the direction of an air outlet of the fan, and the fan is installed in the noise reduction box. The air outlet structure is provided with a first air outlet channel and a second air outlet channel, the length of the second air outlet channel is 4M + 3 times that of the first air outlet channel, M is a natural number, and through the length design of the air outlet channels, sound waves at the intersection of the first air outlet channel and the second air outlet channel can be mutually counteracted, so that the air outlet effect is improved. And the effect of weakening or eliminating specific frequency noise is achieved.

Description

Technical Field

[0001] This application relates to a head-mounted device, and more particularly to a head-mounted device for reducing fan noise. Background Art

[0002] As a consumer electronic product, a head-mounted device is installed by wearing it on the head. The head-mounted device can provide users with multiple sensory experiences such as vision and hearing, and can provide users with an immersive experience. Currently, the head-mounted device is developing rapidly, mainly driven by computer technology and virtual reality (VR) technology. The popularization of smartphones has also injected vitality into the consumer electronics industry.

[0003] Generally speaking, a head-mounted device can be worn on the head and can implement functions such as vision, hearing, gesture, body sensing, 3D motion tracking, and depth sensing. Generally, a virtual reality head-mounted device mainly consists of a display screen and a camera. The head-mounted device can add appropriate sensors to the wearing part according to different application requirements to achieve specific functions. With the increase in application requirements, the amount of calculation required by the head-mounted device also becomes larger. The processor will generate a large amount of heat when completing the calculation and rendering of the virtual reality scene. In the prior art, the head-mounted device needs to be equipped with a cooling fan for heat dissipation, but the working noise of the cooling fan always affects the immersive experience of the user as noise.

[0004] In the prior art, there is a method of adapting the rotation speed of the cooling fan according to the temperature. By appropriately reducing the fan speed to keep the noise of the cooling fan not exceeding the threshold, the use experience of the user is not affected as much as possible. Reducing the fan speed will weaken the heat dissipation effect. During the use of the head-mounted device, the user is in direct contact with the head-mounted device. If the heat generated during the long-term use of the head-mounted device cannot be effectively dissipated, it will cause the temperature of the user's face to rise. In particular, the skin around the human eyes is sensitive to temperature, and the head-mounted device especially needs to reduce the temperature of the area corresponding to the human eyes. Now, a new heat dissipation structure is needed to achieve less noise when the fan is working for heat dissipation. Now, a head-mounted device that can reduce the noise generated by the working of the cooling fan is also needed to solve at least one problem in the prior art. Summary of the Invention

[0005] In view of the above problems, the present application provides a head-mounted device, including a head-mounted device body; a soundproof box, which is installed in the head-mounted device body; a fan, which is installed in the soundproof box. The soundproof box has an air outlet structure, and the air outlet structure is arranged in the air outlet direction of the fan. The air outlet structure has a first air outlet channel and a second air outlet channel. The length of the second air outlet channel is 4M + 3 times the length of the first air outlet channel, where M is a natural number. By designing the lengths of the air outlet channels, the sound waves at the intersection of the first air outlet channel and the second air outlet channel can be cancelled out each other, achieving the effect of weakening or eliminating noise at specific frequencies.

[0006] Through the understanding of the subsequent description and the drawings, the further objectives and advantages of the present application will be fully reflected. Description of the Drawings

[0007] By describing the embodiments of the present application in more detail in conjunction with the drawings, the above-mentioned and other objectives, features, and advantages of the present application will become more obvious. The drawings are used to provide a further understanding of the embodiments of the present application, and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application, and do not constitute a limitation to the present application. In the drawings, the same reference numerals generally represent the same components or steps.

[0008] Figure 1 The schematic structural diagram of the head-mounted device according to an embodiment of the present application is shown.

[0009] Figure 2 The schematic structural diagram of the fan and the soundproof box according to an embodiment of the present application is shown.

[0010] Figure 3 The schematic structural diagram of the fan and the soundproof box according to an embodiment of the present application is shown.

[0011] Figure 4 The schematic diagram of the noise cancellation process according to an embodiment of the present application is shown.

[0012] Figure 5 The schematic diagram of the noise cancellation process of the soundproof box according to an embodiment of the present application is shown.

[0013] Figure 6 The schematic structural diagram of the soundproof box according to another embodiment of the present application is shown.

[0014] Figure 7 The schematic structural diagram of the head-mounted device according to another embodiment of the present application is shown.

[0015] Figure 8 The schematic structural diagram of the head-mounted device according to another embodiment of the present application is shown. Detailed Embodiments

[0016] Hereinafter, example embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments of the present invention. It should be understood that the present invention is not limited by the example embodiments described herein.

[0017] In the description of the present invention, it should be noted that for orientation terms, such as the terms "center", "horizontal", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating orientation and positional relationships are based on the orientations or positional relationships shown in the accompanying drawings. This is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and should not be construed as limiting the specific protection scope of the present invention.

[0018] It should be noted that the terms "first", "second", etc. in the description and claims of this application are used to distinguish similar objects and do not necessarily have to be used to describe a specific order or sequence.

[0019] The terms "comprising" and "having" and any variations thereof in the description and claims of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products, or devices.

[0020] In the description of the present invention, it should also be noted that unless otherwise clearly specified and defined, the terms "set", "installed", "connected", "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or a contact connection or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] Appendix Figure 1An embodiment of a head-mounted device 1 according to the present application is shown. The head-mounted device 1 includes a head-mounted device main body 30 and a wearing component 40. The wearing component 40 is disposed on one side of the head-mounted device main body 30. The wearing component 40 can be implemented as an elastic restraint element such as a strap. The head-mounted device main body 30 includes a display structure, further includes electronic components for processing information, and further includes a processor chip for computing, etc. Therefore, in the present application, the head-mounted device main body 30 is the main heat-generating device. After the heat accumulates in the head-mounted device main body 30 after long-term use, the temperature of the head-mounted device main body 30 will rise, thereby affecting the wearing experience of the user. Especially the skin around the human eye is sensitive to temperature, and it is particularly necessary to reduce the temperature of the head-mounted device main body 30 corresponding to the area around the human eye. In the prior art, a cooling fan is used for heat dissipation processing.

[0022] Still referring to the attached Figure 1 As shown, the head-mounted device 1 in the present application further includes a fan 20 and a soundproof box 10. The fan 20 is installed in the soundproof box 10. In the present application, the fan 20 can be used to dissipate heat from the head-mounted device main body 30. In the prior art, head-mounted devices of the virtual reality (VR) type are designed to allow users to experience the fun of virtual reality immersively. However, if the working noise of the fan 20 is too large, it will undoubtedly reduce the user's experience. The greater the working noise of the fan 20, the more likely it is to affect the user's immersive experience.

[0023] The fan 20 in the present application can be a miniaturized fan driven by rotation in the prior art. Those skilled in the art should know that there are mainly two types of fans in the prior art: radial flow fans and axial flow fans. The blades of an axial flow fan push air to flow in the same direction as the rotation axis, so it is called an axial flow fan. When a radial flow fan works, the blades push air to flow in a direction perpendicular to the axis (i.e., the radial direction), so it is called a radial flow fan. More importantly, since the air pressure of an axial flow fan is not generated in the central part of the fan, but appears due to the rotation of the fan blades. Therefore, no matter how high its rotation speed is, there will be no wind blowing down below the axis of the fan. Therefore, the axis of the axial flow fan is exactly where the heat generation core is located. This situation causes an inherent defect of the axial flow fan. Blocked by the motor, the air flow cannot reach the central part smoothly, resulting in a heat dissipation blind area. The existence of the heat dissipation blind area leads to a relatively high temperature in the core area, affecting the overall heat dissipation effect. In the present application, in order to adapt to the structure and function of the soundproof box 10, the fan 20 in the present application is selected as a radial flow fan, so that the air generated by the fan 20 can flow along the direction perpendicular to the axis by the blades pushing the air, so that the air generated by the fan 20 can enter the soundproof box 10, so that the soundproof box 10 can conveniently eliminate the sound of the air generated by the fan 20. The blowing direction of the fan 20 in the present application is parallel to the installation surface of the fan 20, and the air intake direction of the fan 20 is perpendicular to the installation surface of the fan 20.

[0024] The inventor found that when the fan 20 in this application is selected as a radial-flow fan, the frequency of the noise of the fan 20 is determined by the following formula (1);

[0025] F = K ∙ N ∙ n / 60…………………(1)

[0026] In formula (1):

[0027] N - the number of blades of the fan, which is a positive integer;

[0028] n - the rotational speed of the fan (number of revolutions of the fan per minute);

[0029] n / 60 - the rotational speed of the fan (number of revolutions of the fan per second, which is considered as the unit of frequency in this application and is the rotational frequency of the fan (unit: hertz, Hz));

[0030] K is a constant, which can take values of 1, 2, 3..., and is determined by the fitting coefficient after fitting according to the actual noise and other parameters;

[0031] F - the main noise frequency generated by the fan;

[0032] Those skilled in the art should know that the turbulence generated by the air flow vortices during the operation of the fan will cause broadband noise with a wide distribution range. However, this broadband noise may have multiple frequencies that are relatively low or decibels that are relatively low, and it is not easy for users to clearly feel it. However, the fan will cause noise within a certain reference frequency range. The noise within this reference frequency range is generally the part with a larger decibel and is also the main noise frequency generated by the fan.

[0033] In this application, the inventor also found that there is a relationship between the wavelength (λ) of the noise generated by the fan, the speed of sound (v), and the frequency (f) as follows: λ = v / f…………………(2)

[0034] Among them, the speed of sound v is the speed of propagation in a certain medium, generally considered to be 340 m / s (in this application, the unit meter per second, m / s) is adopted. The frequency f refers to the number of vibrations of sound waves per unit time, and the unit is usually hertz (Hz). In this application, the frequency f is the number of revolutions of the fan per second, and it is considered that the number of revolutions of the fan per second is the unit of frequency in this application.

[0035] Therefore, the higher the frequency, the higher the pitch of the sound, and the lower the frequency, the lower the pitch of the sound. In other words, there is also a simple relationship between frequency and wavelength: f = v / λ.

[0036] In other words, the wavelength and frequency of the noise generated by the fan are interrelated. When the frequency increases, the wavelength decreases; when the frequency decreases, the wavelength increases. Although the situation of the noise generated by the fan during operation cannot be directly obtained, the trend related to the fan can be qualitatively analyzed for the noise. In this application, the vibration of gas molecules caused by the fan will actually drive the vibration of the structural members, thus generating noise. However, in fact, the volume of the vibration of the structural members is not high, and the main influence that the user can hear is still the direct vibration of the gas molecules. Therefore, in this application, the noise within a certain reference frequency range caused by the fan 20 in this application is mainly solved, and the influence of the main noise generated by the fan is reduced, that is, the influence of the airflow noise caused by the fan 20 is mainly reduced, and the influence of the noise of the fan 20 in this application can be reduced.

[0037] Appendix Figure 2 and Appendix Figure 3 shows a structural diagram of a sound-absorbing box 10 and a fan 20 of this application. In this application, the sound-absorbing box 10 includes a fan installation structure 100 and an air outlet structure 101. The fan 20 is disposed within the fan installation structure 100. The shape of the fan installation structure 100 is a semi-circular structure. In this application, the fan 20 is a common circular fan in the prior art, and the circular fan can fit the space of the fan installation structure 100. In this application, the fan installation structure 100 further includes an air intake grille 1001 and a first installation groove 1002. The air intake grille 1001 further includes three barrier strips 10011 disposed on the surface and an air intake channel 10012 formed on the surface. In this application, the three barrier strips 10011 are arranged in a circumferential array and are approximately 120° apart from each other. The hollowed-out part between every two barrier strips 10011 serves as the air intake channel 10012, and the hollowed-out part forms the air intake channel 10012. The air intake channel 10012 can achieve the effect of intake air for the fan 20. In this application, the fan installation structure 100 further includes a first installation groove 1002, and the first installation groove 1002 is a circular installation area adapted to the fan 20, so as to better fix the fan 20.

[0038] Refer to Appendix Figure 2 , Appendix Figure 3 and Appendix Figure 5As shown, it is worth mentioning that in this application, the shape of the first installation groove 1002 is a semi-circular groove. The first installation groove 1002 has a first installation groove center 10021, which is set in the central area of the first installation groove 1002. In this application, the fan 20 also has a fan center 201, which is set in the central area of the fan 20. The fan center 201 and the first installation groove center 10021 in this application are not aligned. Thus, the fan 20 is offset and arranged in the first installation groove 1002, that is, the fan 20 is arranged at a non-centered position of the semi-circular structure of the fan installation structure 100. Specifically, the center of the fan 20 is offset relative to the center of the first installation groove 1002. The first installation groove center 10021 is offset 0.3 cm - 0.9 cm in one direction relative to the fan center 201, and the diameter of the circle of the semi-circular structure of the fan 20 installation structure is 3 cm. That is to say, the offset distance of the first installation groove center 10021 relative to the center of the fan 20 installation structure in one direction is equivalent to 10% - 30% of the diameter of the circle of the semi-circular structure of the fan 20 installation structure. The inventor found that when the intervals are equal, if the fan 20 interferes with one or several fixed obstacles, noises of airflow collision with structural members with relatively close frequencies will be generated. In this case, offsetting the fan 20 can generate discrete-frequency noises. Therefore, noise concentration can be prevented, and a significant effect of discrete noise frequency distribution can be achieved. It will also make the basic frequency range of the fan 20 noise wider, and it is less likely for the frequencies of the fan 20 noise to become consistent. The superposition of noises with the same frequency is likely to generate noises with too large a volume. In addition, increasing the gap between the outer circle of the fan 20 and the fixed obstacle can also reduce this kind of noise. Generally, this gap should not be less than 10 - 15% of the outer diameter of the fan 20 to reduce the loss and noise of the fan 20. It is easier to understand that if the fan 20 is arranged at an equal distance from the adjacent structural members, since the airflow generated by each blade of the fan 20 in this application will collide with the equidistant structural end faces, the structural end faces will collide with the airflow to form some noise frequencies that may be very close. Therefore, when the noises generated by the collision of the structural end faces are the same, the volume of the noises generated by the collision will be enhanced, which may cause obvious discomfort to the user when some frequency noises are enhanced. Once the volume generated by the collision is too large, a considerable part of the noise will be the noise of the airflow colliding with the structural end faces, which exceeds the main noise generated by the rotation of the fan itself. And this application mainly aims to reduce the noise of the main airflow generated by the rotation of the fan itself. If the noises of other frequencies are too large, additional methods may need to be set for optimization. Simply put, in this application, the method of offsetting the fan 20 relative to the first installation groove 1002 can prevent the situation where the noises generated by gas collision and the noises generated by gas vibration are superimposed too much, thus discretizing the noise distribution.

[0039] When the solution of offsetting and setting the fan 20 in the present application is adopted, since the airflow generated by the blades of the fan 20 is at unequal distances from different structural surfaces, the noises generated by the airflow colliding with the end faces of the structures are all different. The frequency distributions of these collision-generated noises are at different levels. Obviously, through this design of the present application, the superposition of noises of the same frequency will not occur, and the situation where the fundamental frequencies of the noises are too concentrated will not occur. Therefore, it is possible to prevent the noise from being too strong at a certain frequency intensity from the user's hearing and prevent the occurrence of "local" abnormal noises.

[0040] Still referring to the attached Figure 2 and the attached Figure 3 and, the present application provides a head-mounted device 1 including a head-mounted device main body 30, a soundproof box 10, and a fan 20. The soundproof box 10 is installed in the head-mounted device main body 30, the fan 20 is installed in the soundproof box 10, and the soundproof box 10 is provided with an air outlet structure 101, wherein the air outlet structure 101 is arranged in the air outlet direction of the fan 20. Referring to the attached Figure 5 As shown, the air outlet structure 101 includes a first air outlet channel 1011 and a second air outlet channel 1012. The length of the second air outlet channel 1012 is 4M + 3 times the length of the first air outlet channel 1011, where M is a natural number. By designing the lengths of the air outlet channels, it is possible to cancel out the sound waves at the intersection of the first air outlet channel 1011 and the second air outlet channel 1012, achieving the effect of weakening or eliminating noises of specific frequencies.

[0041] Still referring to the attached Figure 2 and the attached Figure 3, in this application, the muffler box 10 is provided with an air outlet structure 101. The air outlet structure 101 is arranged inside the muffler box 10 and on the air outlet side of the fan 20. Thus, the air blown out by the fan 20 can enter the air outlet structure 101. In this application, the air outlet structure 101 further includes a first baffle 1014, a second baffle 1015 and a third baffle 1016. The first baffle 1014 is arranged between the second baffle 1015 and the third baffle 1016. The first baffle 1014 is composed of two vertical strip-shaped baffles. Thus, the first baffle 1014 forms a first air outlet channel 1011, and the first air outlet channel 1011 has a straight-through structure to facilitate the flow of the air generated by the rotation of the fan 20 in the first air outlet channel 1011. The first baffle 1014 is arranged in the middle area of the fan 20. In this embodiment, the first baffle 1014 is arranged in one side direction of the fan 20. The second baffle 1015 is arranged on one side of the first baffle 1014, and the third baffle 1016 is arranged on the other side of the first baffle 1014. The second baffle 1015 is arranged to have an arc-shaped baffle structure, and the second baffle 1015 forms the second air outlet channel 1012. The third baffle 1016 is also arranged to have an arc-shaped baffle structure, and the third baffle 1016 forms the third air outlet channel 1013. The third baffle 1016 is symmetrical with the second baffle 1015 with respect to the first baffle 1014. Thus, the size of the muffler box 10 of this application can be reduced in a symmetrical design manner.

[0042] Still referring to the attached Figure 2 and the attached Figure 3, wherein the second retaining wall 1015 includes a first section 10152, a first arcuate section 10153, a second section 10154, a second arcuate section 10155, and a third section 10156. The first section 10152 is arranged in the direction close to the fan 20. The first section 10152 has two parts in the vertical direction and the horizontal direction. The channel formed by the first section 10152 faces the fan 20 directly, so that the air flow generated by the fan 20 can enter the first air outlet channel 1011. A first arcuate section 10153 is connected to one side of the first section 10152. The first arcuate section 10153 has an arcuate retaining wall structure. The first arcuate section 10153 can turn the air outlet channel to other directions. In this embodiment, the first arcuate section 10153 bends the horizontal channel of the first section 10152 to the vertical direction. A second section 10154 is connected to one side of the first arcuate section 10153. The first section 10152 extends along the horizontal direction, and the second section 10154 then extends in the vertical direction, so that the length of the ventilation channel can be further increased. A second arcuate section 10155 is connected to one side of the second section 10154. The second arcuate section 10155 further turns the horizontal channel into a vertical channel. A third section 10156 is connected to one side of the second arcuate section 10155. The third section 10156 includes multiple parts in the first vertical direction, the horizontal direction, and the second vertical direction. The third section 10156 can turn the second arcuate section 10155 to the horizontal direction and then to the vertical direction. The outlet of the third section 10156 intersects with the outlet of the first air outlet channel 1011, so that the vibrating gas is transmitted through the tortuous second air outlet channel 1012 of this embodiment. The interaction between the vibrating air and the structural members during the flow process can cancel out part of the air vibration energy. More importantly, the air wave can intersect with the air wave emitted from the first air outlet channel 1011 through the tortuous second air outlet channel 1012. Through a special length design, the two air waves can cancel each other out at the intersection, thereby reducing the air noise. In this application, the second retaining wall 1015 and the third retaining wall 1016 can be made of rubber material. When the sound wave propagates in the air as vibration energy, the vibrating air will force the rubber to move and vibrate, so that the vibration energy of the sound wave dissipates, reducing the kinetic energy of the sound wave and the volume of the noise.

[0043] Briefly speaking, in this application, the second retaining wall 1015 sequentially includes a first section 10152, a first arc section 10153, a second section 10154, a second arc section 10155, and a third section 10156 along the wind direction. The first section 10152 has two parts in the vertical direction and the horizontal direction. One side of the first section 10152 is connected to the first arc section 10153. The first arc section 10153 has an arc-shaped retaining wall structure. The first arc section 10153 can turn the direction of the second air outlet channel 1012 to other directions. One side of the first arc section 10153 is connected to the second section 10154. The second section 10154 extends along a direction. One side of the second section 10154 is connected to the second arc section 10155. One side of the second arc section 10155 is connected to the third section 10156. The third section 10156 includes a continuous section from the vertical direction to the horizontal direction and then to the vertical direction. This design enables the second retaining wall 1015 in this application to meet the long-strip design of the sound insulation box and saves design space through the meandering air outlet channel.

[0044] Refer to the attached Figure 3 As shown, the width of the first air outlet channel 1011 near the fan 20 in this application is W 1 , and the width of the second air outlet channel 1012 near the fan 20 is W 2 , and the width of the third air outlet channel 1013 near the fan 20 is W 3 , satisfying the following relational expressions:

[0045] 2*W 2 ≤W 1 ≤6*W 2 ;

[0046] 2*W 3 ≤W 1 ≤6*W 3 ;

[0047] 0.9*W 3 ≤W 2 ≤1.1*W 3 .

[0048] This application uses multiple air outlet channels for heat dissipation. When the ratio is met, it can ensure that the first air outlet channel 1011 serves as the main heat dissipation channel, and rapid heat dissipation can occur where the air flows in the first air outlet channel 1011. There are arc-shaped sections in the second air outlet channel 1012 and the third air outlet channel 1013, so there will be a certain loss in the air flow velocity, resulting in a lower heat dissipation efficiency than that of the first air outlet channel 1011. When the ratio of the formula is met, it can ensure that the air flow in the first air outlet channel 1011 is the main one, and the air flow in the second air outlet channel 1012 and the third air outlet channel 1013 can assist in heat dissipation. More importantly, the air in the second air outlet channel 1012 and the third air outlet channel 1013 will converge at the first air outlet 1017, the second air outlet 1018, and the third air outlet 1019. Through a special length design, the air waves can cancel each other out at the convergence point, thereby reducing air noise. The first air outlet channel 1011, as a straight-through air outlet channel, can dissipate heat over a large area. In this application, the second air outlet channel 1012 and the third air outlet channel 1013, as winding air outlet channels, will weaken the air kinetic energy, thus affecting the heat dissipation effect.

[0049] Refer to the attached Figure 5 As shown, the length of the first air outlet channel 1011 in this application is L 1 , the length of the second air outlet channel 1012 is L 2 , and the length of the third air outlet channel 1013 is L 3 . As mentioned above, the main noise frequency in the noise generated by the fan 20 in this embodiment satisfies F = K·N·n / 60. Generally speaking, the sounds in nature are all generated by the vibration of objects. Assuming the default sound speed is 340 m / s, the noise generated by the fan 20 in this embodiment can be simply expressed as:

[0050] λ = v / f

[0051] f = (K·N·n) / 60

[0052] λ = v / (K·N·n / 60)…………………(3)

[0053] The length of the first air outlet channel 1011 is L 1 , and the length of the second air outlet channel 1012 is L 2 , satisfying the following relational expression:

[0054]

[0055]

[0056] where V is the speed of sound (unit: meters per second, m / s), H is the rotation frequency of the fan at H (unit: hertz, Hz), N is the number of fan blades of the fan (N is a positive integer), and M 1 is a coefficient (M 1 is a positive integer), M 2 is a coefficient (M 2 is a positive integer).

[0057] Under the relationships of the above various formulas, the inventor found that after the number of fan blades of the fan 20 is determined, changing the parameters of other fans 20 will basically not cause a large change in the coefficient K. Through the relative design of the first air outlet channel 1011, the second air outlet channel 1012, and the third air outlet channel 1013, the factor of the coefficient K can be offset. In this embodiment, the length L of the first air outlet channel 1011 1 satisfies the M times multiple of 340 / (H*N) / 4, and the lengths L of the second air outlet channel 1012 and the third air outlet channel 1013 1 also satisfy the M times multiple of 340 / (H*N)*3 / 4 2 and L 3 also satisfies the M times multiple of 340 / (H*N)*3 / 4 1Sub-multiple, so the length of the second air outlet channel 1012 in this application is 3 times the length of the first air outlet channel 1011, and the length of the third air outlet channel 1013 is 3 times that of the first air outlet channel 1011. In the previous description, the wavelength of the sound is λ = v / (K﹒N﹒n / 60) …………………(3). For the noise in this application, the noise generated by the rotation of the fan 20 is the frequency noise of H*N. After Fourier transform, the noise can be simplified and expressed in the form of a sin wave or a cos wave. The wavelength of the noise generated by the rotation of the fan 20 in this application satisfies 340 / (H*N). By designing the length of the first air outlet channel 1011 in this application to satisfy M sub-multiples of 340 / (H*N) / 4, the phase of the noise wavelength at the outlet of the first air outlet channel 1011 is different from the original phase by 1 / 4 wavelength. The air outlet structure 101 in this application further includes a first air outlet 1017, a second air outlet 1018, and a third air outlet 1019. The first air outlet 1017 is arranged at the end of the first air outlet channel 1011, the second air outlet 1018 is arranged at the end of the second air outlet channel 1012, and the third air outlet 1019 is arranged at the end of the third air outlet channel 1013. In this application, the first air outlet 1017 and the second air outlet 1018 are adjacent to each other, and the first air outlet 1017 and the third air outlet 1019 are also adjacent to each other. Thus, the vibrating air emitted through the first air outlet channel 1011, the vibrating air emitted through the second air outlet channel 1012, and the vibrating air emitted through the third air outlet channel 1013 can be converged together. Since the length of the second air outlet channel 1012 is designed to satisfy N sub-multiples of 340 / (H*N)*3 / 4, the phase of the noise wavelength at the second air outlet 1018 is different from the original phase by 3 / 4 wavelength. Thus, the sound at the first air outlet 1017 and the second air outlet 1018 differs by half a wavelength. When two sound waves meet, the two sound waves interfere, and the sound waves with opposite phases will form wave crests and wave troughs that cancel each other out, resulting in the weakening or even disappearance of the sound. In terms of air kinetic energy, due to the collision between air molecules, mainly including the mutual cancellation of noise, after part of the air molecules' vibrations are cancelled, it is converted into the heat of the air. This principle is similar to that of noise-canceling headphones. Noise-canceling headphones achieve the effect of noise cancellation by emitting sound waves opposite to the surrounding noise. In occasions such as concerts or meetings, multiple sets of speakers are also set to emit sound waves with the same frequency but opposite phases to reduce noise interference and improve sound quality. In this application, a similar method is adopted to set the lengths of the first air outlet channel 1011 and the second air outlet channel 1012 into a certain multiple relationship, so that the sound waves at the air outlet are superimposed and cancelled at 1 / 4 wavelength and 3 / 4 wavelength, thereby eliminating a certain amount of noise.

[0058] In this application, the air outlet structure further includes a third air outlet passage 1013, and the length of the third air outlet passage 1013 is 4M times the length of the first air outlet passage 1011 2 + 3 times, where M 2 is a natural number, and the length of the third air outlet passage 1013 is L 3 , L 3 satisfies the following relationship:

[0059]

[0060] M 3 is a coefficient (M 3 is a positive integer).

[0061] It is worth mentioning that in this application, the length of the third air outlet passage 1013 is also set to be M times of 340 / (H*N)*3 / 4. Thus, the length of the third air outlet passage 1013 in this application is 3 times the length of the first air outlet passage 1011. Therefore, the sound at the outlet of the first air outlet passage 1011 and the outlet of the third air outlet passage 1013 differs by half a wavelength. Referring to the attached 3 figure, the specific frequency air sound wave at the outlet of the first air outlet passage 1011 can be as shown in the upper figure of the attached Figure 5 figure, and the specific frequency air sound wave at the outlet of the second air outlet passage 1012 can be as shown in the middle figure of the attached Figure 5 figure. In the foregoing, the lengths of the first air outlet passage 1011 and the second air outlet passage 1012 are specially designed, so that air at the adjacent first air outlet 1017 and the second air outlet 1018, and air at the adjacent first air outlet 1017 and the third air outlet 1019 will all experience a situation similar to the half-wave loss shown in the lower middle figure of the attached Figure 5 figure, thereby reducing the transmission of vibration waves from the air outlet to the outside, so as to prevent noise from affecting the outside or noise from entering the user's ears through the outside air. Figure 5 The attached

[0062] attached Figure 4 figure shows that the aerodynamic noise generated by the fan 20 is the noise generated by the interaction during the fluid flow process, or the interaction between the gas and the solid medium. From the mechanism of noise generation, it is mainly composed of rotational noise (pressure pulsation) and vortex noise (turbulent noise). However, as described in the foregoing content in this application, the rotational noise can be considered related to the structure of the fan 20 itself, the rotation frequency of the fan 20 and its related factors, and the frequency and wavelength of the rotational noise caused by the fan 20 can be analyzed in a quantitative manner. The attached Figure 4Shown in the figure is a sine wave, whose wavelength λ is the propagation distance of the sound wave within a complete cycle. The wavelength can be obtained through consecutive peaks or any two corresponding points within a cycle. This method is also applicable to other periodic waves, not just sine waves. By subjecting sound waves of certain frequencies to Fourier transformation into a frequency-domain graph, sound waves of certain frequencies become very regular periodic waves. In this application, by designing the fan 20 and controlling the noise generated by the fan 20 within the designed frequencies, and then through the design of the length of the air outlet channels, the sound waves of different air outlet channels achieve noise reduction at the total air outlet, such that the sound waves of the airflow at the total air outlet have lower noise. For example, in the appendix Figure 4 The upper figure in the appendix shows the waveform of the air sound wave of a specific frequency at the outlet of the first air outlet channel 1011. The wave on the figure is a solid line wave, while in the appendix Figure 4 The middle figure in the appendix shows the waveform of the air sound wave of a specific frequency at the outlet of the second air outlet channel 1012. The wave on the figure is a dashed line wave. Since in this embodiment, the length of the second air outlet channel 1012 is three times that of the first air outlet channel 1011, it is possible to achieve a difference of one-quarter wavelength between these two waveforms, thereby enabling the peaks and valleys of the sound waves to cancel each other out, ultimately achieving the situation shown in the appendix Figure 4 The lower figure in the appendix shows the situation where the dashed line wave and the solid line wave can be superimposed. Obviously, this superimposed wave can cancel out the peaks and valleys, thereby achieving the effect of noise reduction.

[0063] The noise reduction principle of this application can be simply understood as follows: when two sound waves meet, the two sound waves interfere, and the sound waves with opposite phases will form peaks and valleys that cancel each other out, resulting in the weakening or even disappearance of the sound. Through the solution of this application, it is possible to make the phases of the sound waves opposite at the 1 / 4 wavelength and 3 / 4 wavelength positions, and let the sound waves at the 1 / 4 wavelength and 3 / 4 wavelength positions be superimposed and cancelled, thereby eliminating the noise of the same frequency generated by the fan 20.

[0064] Referring to the appendix Figure 3 As shown, in this application, the soundproof box 10 has a soundproof body 102. The air outlet structure includes a first air outlet 1017, a second air outlet 1018, and a third air outlet 1019. The first air outlet 1017 is provided at the end of the first air outlet channel 1011. The second air outlet 1018 is provided at the end of the second air outlet channel 1012. The third air outlet 1019 is provided at the end of the third air outlet channel 1013. The first air outlet 1017, the second air outlet 1018, and the third air outlet 1019 converge together, so that when multiple sound waves meet, multiple sound waves can interfere.

[0065] The first air outlet 1017, the second air outlet 1018, and the third air outlet 1019 converge in front of a sound-absorbing body 102. In this application, since the air flowing out of the first air outlet 1017, the second air outlet 1018, and the third air outlet 1019 will cancel each other out, resulting in a weakening or even disappearance of the sound, the kinetic energy of the remaining air will decrease. The air entering the sound-absorbing body 102 will not increase the vibration wave either. Therefore, after the sound-absorbing body 102 is arranged behind the first air outlet 1017, the second air outlet 1018, and the third air outlet 1019, the vibrating air wave still enters the sound-absorbing body 102 in a noise-reducing manner. The sound-absorbing body 102 is in a hollow shape, and an opening is hollowed out on the sound-absorbing body 102 as a sound-absorbing port 1021, so that the sound-absorbing port 1021 becomes an air outlet. The sound-absorbing port 1021 communicates with the external environment. Since the air discharged from the sound-absorbing port 1021 has been noise-reduced, this part of the vibrating air has been noise-reduced, and the impact on the air vibration transmitted to the user's ears or the external environment will be relatively small, achieving the noise-reducing effect.

[0066] In this application, the sound-absorbing body 102 further has a slope surface 1022, and the slope surface 1022 is set as an arc surface with a curvature towards the outside. It is worth mentioning that in this embodiment, the slope surface 1022 is an entire arc surface, and the curvature of the arc surface closer to the outside is larger. Thus, the air is gradually changed in the direction of the air flow by gradually changing the direction through the arc surface, and finally the air exits through the sound-absorbing port 1021. Moreover, the larger the curvature of the arc surface closer to the outside, the more the air flow can be accelerated. The flow area between the arc surface closer to the outside and the total air outlet is smaller, while the flow area between the arc surface farther from the outside and the total air outlet is larger. According to Bernoulli's equation, when the flow area between the arc surface closer to the outside and the total air outlet is smaller, the flow velocity is larger; when the flow area between the arc surface farther from the outside and the total air outlet is larger, the flow velocity is smaller. This way can accelerate the air flow velocity at the total air outlet, and thus can take away the heat faster.

[0067] In the present application, the first baffle wall 1014, the second baffle wall 1015, and the third baffle wall 1016 are all made of metal materials. Due to the use of metal materials, the first baffle wall 1014, the second baffle wall 1015, and the third baffle wall 1016 can all be used as heat sinks for heat dissipation, thereby facilitating the first baffle wall 1014, the second baffle wall 1015, and the third baffle wall 1016 to dissipate heat. In the present application, the first air outlet channel 1011, the second air outlet channel 1012, and the third air outlet channel 1013 can all be used as heat dissipation channels. When air flows in the first air outlet channel 1011, the second air outlet channel 1012, and the third air outlet channel 1013, the air will drive the flow of heat, thereby achieving heat dissipation.

[0068] Reference Figure 2 and attached Figure 3 As shown, it is worth mentioning that in the present application, the first air outlet channel 1011 corresponds to the heat-conducting end surface of the head-mounted device 1, the second air outlet channel 1012 corresponds to the heat-conducting end surface of the head-mounted device 1, and the third air outlet channel 1013 also corresponds to the heat-conducting end surface of the head-mounted device 1. The heat-conducting end surfaces corresponding to the air outlet channels can allow the airflow generated by the fan 20 to take away the heat generated by the head-mounted device 1, so that the heat of the head-mounted device 1 can be driven by the fan 20 to achieve a cooling effect. In short, the silencer box 10 in the present application may include an upper heat conductor 103 and a lower heat conductor 104, wherein the upper heat conductor 103 is arranged above the silencer box 10, and the lower heat conductor 104 is arranged below the silencer box 10. In the present application, the upper heat conductor 103, the lower heat conductor 104 and the first baffle wall 1014 constitute a heat dissipation channel, wherein the air blown out by the fan 20 can flow in the heat dissipation channel, and the air flows through the inner surface of the upper heat conductor 103 and the inner surface of the lower heat conductor 104, thereby the air can drive the heat flow of the upper heat conductor 103 and the lower heat conductor 104, so that the heat of the silencer box 10 can be taken away.

[0069] In the present application, the metal material selected for the first retaining wall 1014, the second retaining wall 1015, and the third retaining wall 1016 can be made of copper, iron, aluminum, etc. Since the metal material is used, the metal material can have better heat dissipation. Figure 6Illustrates another embodiment of the soundproof box 10 of the present application. In one embodiment of the present application, the first partition wall 1014, the second partition wall 1015, and the third partition wall 1016 may be provided with holes. The first partition wall 1014 may have a first partition wall hole 10141, the second partition wall 1015 may have a second partition wall hole 10151, and the third partition wall 1016 may have a third partition wall hole 10161. Since there are holes in the partition walls, when the vibrating air enters the holes, the air wave will consume energy in the holes after entering the holes, thereby reducing the overall noise volume of the air wave. This method can reduce the overall sound volume of the air wave.

[0070] In the present application, the first partition wall hole 10141 is made of rubber material, the second partition wall hole 10151 is made of rubber material, and the third partition wall hole 10161 is made of rubber material. Since rubber material is used, after the air enters the holes, the air wave will consume energy in the holes due to the cavity in the holes, thereby reducing the high-frequency energy of the air wave. Those skilled in the art should know that since the high-frequency vibration part has greater energy when the sound vibrates, a certain amount of energy can be consumed in the holes. Obviously, the part of the high-frequency vibration that will be consumed in the holes will be relatively small, so more high-frequency sound energy will be consumed. In this case, the decibels of some harsh or high-frequency sounds can be significantly reduced. Because in this polymer material, there is a strong force between molecules. When a molecule is driven by an external force to vibrate, the kinetic energy of the movement is quickly consumed during the transfer between molecules, and the sound vibration energy is quickly converted into the kinetic energy of the in-situ vibration of the molecules. Therefore, it is difficult for sound to pass through this material effectively. In the present application, some holes are also provided. After the sound propagates in, it is continuously reflected in the holes and then gradually absorbed by the inner wall. Finally, only very little sound can escape from it. In this case, it is relatively simple to achieve high-decibel high-frequency noise. These methods all set an obstacle during the propagation of noise to hinder the propagation of noise, so it belongs to passive noise reduction. In the present application, since the high-frequency noise encounters more attenuation when passing through the medium than the low-frequency noise, the vibration speed of the high-frequency sound wave is fast. That is to say, in the same time, the high-frequency sound wave causes more vibrations of air molecules, has more friction with the surrounding air molecules, converts momentum into heat energy faster, and attenuates faster. Therefore, the high-frequency noise situation can be reduced.

[0071] In the present application, the property of the half-wave loss of the wave is mainly utilized. When two waves meet, the resulting effect is the superposition of the two. If two waves with exactly the same amplitude and frequency but opposite vibration directions (that is, a phase difference of 180 degrees) meet, then at the meeting position, the waves will cancel each other out and the sound will disappear.

[0072] As shown in the attached drawings Figure 3 In the head-mounted device 1 of the present application, a multi-channel ventilation passage is integrated at the main air outlet, and sound waves are cancelled at the main air outlet, thereby achieving a noise reduction effect. The inventor found that since sound waves actually represent the vibration energy of particles such as molecules and atoms, in the present application, cancelling the vibration of sound waves at the air outlet will also reduce the vibration speed of air waves. The air waves cancelled in the present application are mainly the noise generated by the rotation of the fan 20. Therefore, the main component of the air waves is the blowing air of the fan 20. The vibration energy of this part of the air waves will be cancelled at the main air outlet, thereby also weakening the kinetic energy of the air, and thus reducing the heat dissipation effect at the main air outlet. In the present application, in order to prevent the heat dissipation effect from being weakened too much, a method of setting an acceleration surface at the main air outlet is adopted to accelerate the air flow rate. In the present application, the acceleration surface adopts a slope surface 1022, and the slope surface 1022 can be a slope surface 1022 with a curved surface. The radian of the arc surface of the slope surface 1022 facing the main air outlet is greater than the arc surface of the slope surface 1022 far from the main air outlet, so that the slope surface 1022 can be used as an acceleration surface to accelerate the air, so that the air can flow out of the main air outlet in an accelerated manner. In this method, the slope surface 1022 is used as the acceleration surface, and the energy accelerated by the slope surface 1022 is actually mainly to increase the speed of the air flow direction, that is, mainly to increase the air flow rate. This method can make the air flow rate faster, thereby increasing the speed of the air flow. This acceleration is obviously not the same frequency as the noise of the fan 20. Therefore, at the main air outlet, the kinetic energy provided by this part of the acceleration will not be weakened due to the opposite wavelength during active noise reduction. In the present application, the air flow rate is increased by the slope surface 1022 to increase the heat dissipation effect. More importantly, it can ensure that the wind speed at the main air outlet can still maintain a certain kinetic energy, so that the wind flowing out of the main air outlet can still achieve a certain heat dissipation effect. This method can solve the problem of the weakened kinetic energy of the air vibration wave caused by active air noise reduction.

[0073] attached Figure 7Another embodiment of the head-mounted device 1 of the present application is shown. In this embodiment, the head-mounted device 1 further includes a heating element 50. In the foregoing content, during the use of the head-mounted device 1, the processor chip will undergo a large number of operations such as computing and rendering. The processor chip will generate heat. After the heat accumulates after long-term use, the temperature of the main body of the head-mounted device 1 will rise, thus affecting the wearing experience of the user. In the present application, the heating surface of the heating element 50 is thermally conductively connected to the sound insulation box 10. Thus, when the sound insulation box 10 dissipates heat through the fan 20, the air flow can take away the heat inside the sound insulation box 10. Since the entire inside of the sound insulation box 10 will be cooled, as long as the heating element 50 is thermally conductively connected to the heat dissipation structure of the sound insulation box 10, the cooling process for the heating element 50 can be achieved.

[0074] In this embodiment, the heating element 50 is implemented as a processor chip. The heat generated by the processor chip accumulates on the heat sink and is then taken away by the air flow, finally achieving the heat dissipation effect of the head-mounted device 1 in a manner with less noise.

[0075] Appendix Figure 8 Another embodiment of the head-mounted device 1 of the present application is shown. In this embodiment, the heating element 50 is disposed on one side of the sound insulation box 10, and the heating element 50 is thermally conductively connected to the sound insulation box 10 through a heat conducting member 60. In this embodiment, the heat conducting member 60 can be implemented as a copper tube or the like, so as to facilitate heat conduction. In this embodiment, the heating element 50 is thermally conductively connected to the sound insulation box 10 through the heat conducting member 60, so that the heating element 50 and the sound insulation box 10 can exchange heat. The heat emitted by the heating element 50 can be dissipated through the sound insulation box 10, thus meeting the heat dissipation requirements of the heating element 50.

[0076] The basic principles, main features and advantages of the present invention have been described above. Those skilled in the art of this industry should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification is only the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection required by the present invention is defined by the appended claims and their equivalents.

Claims

1. A head-mounted device, characterized in that, comprising: a head-mounted device main body; a soundproof box, the soundproof box being installed in the head-mounted device main body; a fan, the fan being installed in the soundproof box, the soundproof box having an air outlet structure, the air outlet structure being arranged in the air outlet direction of the fan, the air outlet structure having a first air outlet channel and a second air outlet channel, the length of the second air outlet channel being 4M + 3 times the length of the first air outlet channel, where M is a natural number.

2. The head-mounted device according to claim 1, characterized in that, The length of the first air outlet channel is L 1 , and the length of the second air outlet channel is L 2 , which satisfies the following relational expression: Where V is the speed of sound, H is the rotation frequency of the fan, N is the number of fan blades, and M 1 is a coefficient.

3. The head-mounted device according to claim 2, characterized in that, The air outlet structure further includes a third air outlet channel, and the length of the third air outlet channel is 4M 2 + 3 times the length of the first air outlet channel, where M 2 is a natural number, and the length of the third air outlet channel is L 3 , L 3 satisfies the following relationship: M 3 is a coefficient.

4. The head-mounted device according to claim 3, characterized in that, The width of the first air outlet channel near the fan is W 1 , the width of the second air outlet channel near the fan is W 2 , the width of the third air outlet channel near the fan is W 3 , and the following relational expression is satisfied: 2*W 2 ≤W 1 ≤6*W 2 ; 2*W 3 ≤W 1 ≤6*W 3 ; 0.9*W 3 ≤W 2 ≤1.1*W 3 。 5. The head-mounted device according to claim 4, characterized in that, the air outlet structure includes a first baffle, a second baffle and a third baffle, the first baffle being arranged between the second baffle and the third baffle, the first baffle being two vertical strip-shaped baffles, the first baffle forming the first air outlet channel, the first air outlet channel being a straight-through structure, the second baffle being arranged on one side of the first baffle, the third baffle being arranged on the other side of the first baffle, the second baffle being arranged to have an arc-shaped baffle structure, the second baffle forming the second air outlet channel, the third baffle also being arranged to have an arc-shaped baffle structure, the third baffle forming the third air outlet channel, the third baffle and the second baffle being symmetrical with respect to the first ventilation channel.

6. The head-mounted device according to claim 5, characterized in that, wherein the second baffle sequentially includes a first section, a first arc section, a second section, a second arc section, and a third section along the wind direction, the first section having two parts in the vertical direction and the horizontal direction, one side of the first section being connected to the first arc section, the first arc section having an arc-shaped baffle structure, the first arc section being able to turn the direction of the second air outlet channel to other directions, one side of the first arc section being connected to the second section, the second section extending along a direction, one side of the second section being connected to the second arc section, one side of the second arc section being connected to the third section, the third section including a continuous section from the vertical direction to the horizontal direction and then to the vertical direction.

7. The head-mounted device according to claim 6, characterized in that, the air outlet structure includes a first air outlet, a second air outlet and a third air outlet, the first air outlet being arranged at the end of the first air outlet channel, the second air outlet being arranged at the end of the second air outlet channel, the third air outlet being arranged at the end of the third air outlet channel, the first air outlet, the second air outlet and the third air outlet converging together.

8. The head-mounted device according to claim 7, characterized in that, The head-mounted device further includes a sound silencer, wherein the first air outlet, the second air outlet, and the third air outlet converge in front of the sound silencer, and an opening is hollowed out on the sound silencer as a sound silencing port, and the sound silencing port is an air outlet communicating with the outside.

9. The head-mounted device according to claim 8, wherein, the sound silencer further has a slope surface, wherein the slope surface is set as an arc surface with a curvature towards the outside, and the curvature of the arc surface closer to the outside in the arc surface of the slope surface is greater.

10. The head-mounted device according to claim 9, wherein, the sound silencing box includes an upper heat conducting member and a lower heat conducting member, the upper heat conducting member is arranged above the sound silencing box, and the lower heat conducting member is arranged below the sound silencing box.

11. The head-mounted device according to claim 10, wherein, the head-mounted device includes a heating element, and the heating element is thermally conductively connected to the upper heat conducting member or the lower heat conducting member of the sound silencing box.

12. The head-mounted device according to claim 11, wherein, the sound silencing box includes a fan mounting structure, the fan is mounted in the fan mounting structure, the fan mounting structure includes a first mounting groove, and the center of the fan is offset relative to the center of the first mounting groove.

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