Acoustic metamaterial notch and waveguide structure suitable for planar magnetic loudspeaker unit

Abstract

The utility model belongs to the technical field of notch and waveguide structures, particularly relates to an acoustic metamaterial notch and waveguide structure suitable for a planar magnetic loudspeaker unit, and aims to reduce unnecessary diffraction reflection and interference. Comprising a plurality of flat blade-shaped structures, a plurality of semicircular structures and a plurality of groups of quarter-wave tube type acoustic metamaterial trapped wave structures, the plurality of groups of quarter-wavelength tubular acoustic metamaterial notch structures are arranged around the plurality of flat blade-shaped structures and the plurality of semicircular structures; the plurality of flat blade-shaped structures are perpendicular to a vibrating diaphragm of the planar magnetic loudspeaker unit, and the plurality of semicircular structures cover a magnet of the planar magnetic loudspeaker unit. The utility model has the advantages that the sound wave reflection path is effectively shortened, the diffraction influence in the sound wave propagation process is reduced, and the accurate frequency response adjustment is realized.

Description

Technical Field

[0001] The utility model belongs to the technical field of notch and waveguide structures, and particularly relates to an acoustic metamaterial notch and waveguide structure applicable to a planar magnetic loudspeaker unit. Background Art

[0002] The quarter-wavelength tube-type acoustic metamaterial notch structure is a design structure that manipulates the propagation of sound waves using the phenomenon of acoustic resonance. By precisely designing the structure and length of the internal pipeline, when the length of the pipeline matches the quarter-wavelength length of the target sound wave, it can effectively manipulate the incidence and reflection of sound waves to generate a phase difference and interfere with and cancel each other, thereby achieving the effect of weakening the sound wave energy. This characteristic enables the material to regulate sound waves within a specific frequency range and achieve fine management of the propagation characteristics of sound waves.

[0003] In the design of a planar magnetic loudspeaker, before the sound waves generated by the diaphragm are transmitted to the outside, the propagation path includes a magnet structure. Especially for high-frequency sound waves, they may be affected by diffraction and reflection when passing through the magnet structure, which may cause secondary sound waves with different phases from the original sound waves, thereby possibly causing phase interference. At the same time, during the operation of the planar magnetic loudspeaker, the reflected noise generated behind the unit will meet the sound waves directly emitted in front of the diaphragm. When these two sound waves meet, they may interfere with each other, causing the enhancement or weakening of sound waves at certain frequencies, which will change the frequency response of the loudspeaker and cause sound distortion.

[0004] To solve these problems, it is necessary to optimize the waveguide structure to reduce unnecessary diffraction, reflection, and interference and ensure the sound quality. Summary of the Utility Model

[0005] In view of the technical problems existing in the background art, the utility model provides an acoustic metamaterial notch and waveguide structure applicable to a planar magnetic loudspeaker unit, which can reduce unnecessary diffraction, reflection, and interference and ensure the sound quality.

[0006] To achieve the above object, the technical solution provided by the utility model is as follows:

[0007] An acoustic metamaterial notch and waveguide structure applicable to a planar magnetic loudspeaker unit includes a plurality of flat blade-like structures, a plurality of semi-circular structures, and multiple groups of quarter-wavelength tube-type acoustic metamaterial notch structures;

[0008] Multiple groups of the quarter-wavelength tube-type acoustic metamaterial notch structures are arranged around the plurality of flat blade-like structures and the plurality of semi-circular structures;

[0009] A plurality of the flat blade-shaped structures are arranged perpendicular to the vibrating diaphragm of the planar magnetic speaker unit, and a plurality of the semi-circular structures cover the magnet of the planar magnetic speaker unit.

[0010] Preferably, the acoustic metamaterial notch and waveguide structure is an annular structure, and multiple groups of the quarter-wavelength tubular acoustic metamaterial notch structures are distributed on the circumference of the annular structure.

[0011] Preferably, a plurality of the flat blade-shaped structures and a plurality of the semi-circular structures are arranged inside the ring of the annular structure.

[0012] Preferably, the semi-circular structure is semi-cylindrical.

[0013] Preferably, the distribution form of the plurality of the semi-circular structures is arranged in multiple rows and multiple columns, and the semi-circular structures are parallel to each other.

[0014] Preferably, each group of the quarter-wavelength tubular acoustic metamaterial notch structures includes multiple connected tubular units.

[0015] Preferably, the lengths of two of the tubular units in each group of the quarter-wavelength tubular acoustic metamaterial notch structures are different or the same.

[0016] Preferably, multiple groups of the quarter-wavelength tubular acoustic metamaterial notch structures are used as the magnetic group support frame of the planar magnetic speaker.

[0017] The utility model has the following advantages and beneficial effects:

[0018] In the utility model, through the perpendicular arrangement of the flat blade-shaped structure and the vibrating diaphragm, the sound wave reflection path is effectively shortened, the wavelength is reduced, thereby improving the performance of the sound wave in the high-frequency band;

[0019] In the utility model, through the circular structure, the bending and diffusion of the sound wave at the edge of the magnet are reduced, further reducing the influence of diffraction during the propagation of the sound wave;

[0020] In the utility model, through multiple groups of the quarter-wavelength tubular acoustic metamaterial notch structures arranged around, the phase inversion of the sound wave at a specific frequency is realized, so that the incident wave and the reflected wave cancel each other out, effectively weakening or eliminating the sound wave at these frequencies, and thus realizing precise frequency response adjustment;

[0021] In the utility model, the waveguide structure is cleverly combined with the magnetic group support frame of the planar magnetic speaker to form an integrated design. Description of the Drawings

[0022] Figure 1 is a schematic structural diagram of the acoustic metamaterial notch and waveguide structure applicable to the planar magnetic speaker unit provided by the utility model;

[0023] Figure 2 is Figure 1 a sectional view of along the A-A direction;

[0024] Figure 3 is a schematic diagram of sound waves when a semi-circular structure is provided and when it is not provided;

[0025] Figure 4 is Figure 1 a sectional view of along the B-B direction;

[0026] Figure 5 is a schematic diagram for comparing sound wave transmission by finite element simulation with and without a flat blade-like structure;

[0027] Figure 6 is a schematic diagram of the structure of a set of quarter-wavelength tube-type acoustic metamaterial notch structures;

[0028] Icon: 101 - Quarter-wavelength tube-type acoustic metamaterial notch structure, 102 - Flat blade-like structure, 103 - Semi-circular structure, 1011 - Tubular unit. Detailed implementation manners

[0029] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model.

[0030] Therefore, the following detailed description of the embodiments of the present utility model provided in the drawings is not intended to limit the scope of the present utility model claimed, but is merely representative of the selected embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts fall within the scope of protection of the present utility model.

[0031] Embodiment 1

[0032] This embodiment provides an acoustic metamaterial notch and waveguide structure applicable to a planar magnetic speaker unit. Referring to Figure 1 , it includes a plurality of flat blade-like structures 102, a plurality of semi-circular structures 103, and a plurality of groups of quarter-wavelength tube-type acoustic metamaterial notch structures 101;

[0033] The plurality of groups of quarter-wavelength tube-type acoustic metamaterial notch structures 101 are arranged around the plurality of flat blade-like structures 102 and the plurality of semi-circular structures 103;

[0034] A plurality of the flat blade-like structures 102 are arranged perpendicular to the diaphragm of the planar magnetic speaker unit, and a plurality of the semi-circular structures 103 cover the magnet of the planar magnetic speaker unit.

[0035] In this embodiment, through delicate design, the dual effects of optimizing acoustic performance and enhancing product practicality are achieved. First, the flat blade-like structures 102 are arranged perpendicular to the diaphragm, effectively shortening the acoustic wave reflection path, reducing the wavelength, thereby enhancing the performance of acoustic waves in the high-frequency band and reducing the adverse effects on the frequency bands within the human ear's audible frequency range. Second, the application of the semi-circular structures covering the magnet helps reduce the bending and diffusion of acoustic waves at the edge of the magnet, further reducing the influence of diffraction during the propagation of acoustic waves. Moreover, multiple groups of quarter-wavelength tubular acoustic metamaterial notch structures 101 arranged around achieve the inversion of the phase of acoustic waves at specific frequencies, enabling the incident wave and the reflected wave to cancel each other out, effectively weakening or eliminating the acoustic waves at these frequencies and achieving precise frequency response adjustment. In addition, in this embodiment, the waveguide structure is also cleverly combined with the magnetic group support frame of the planar magnetic speaker to form an integrated design, which not only reduces the volume of the speaker unit but also lowers the production cost and improves the market competitiveness of the product.

[0036] Embodiment 2

[0037] Based on the technical solution of Embodiment 1, this embodiment further describes the structures of each component.

[0038] In this embodiment, the acoustic metamaterial notch and waveguide structure is an annular structure, and multiple groups of quarter-wavelength tubular acoustic metamaterial notch structures 101 are distributed on the circumference of the annular structure.

[0039] As a preferred solution of this embodiment, a plurality of the flat blade-like structures 102 and a plurality of the semi-circular structures 103 are arranged inside the ring of the annular structure.

[0040] In addition, referring to Figure 2 , the semi-circular structure 103 is preferably semi-cylindrical.

[0041] Furthermore, the distribution form of the plurality of semi-circular structures 103 is arranged in multiple rows and columns, and the semi-circular structures 103 are parallel to each other.

[0042] The semi-circular structure helps reduce the diffraction phenomenon of acoustic waves when passing through the edge of the magnet, thereby reducing the bending and diffusion caused by passing through the edge of the magnet during the propagation of acoustic waves, effectively reducing the influence of diffraction on the propagation of acoustic waves. For the schematic diagram of acoustic waves with and without the semi-circular structure, refer to Figure 3, where the upper figure is a schematic diagram of sound waves when the semi-circular structure is not set. It can be seen that when the semi-circular structure covering the magnet is not added, the sound waves bend and spread when passing through the edge of the magnet.

[0043] On the other hand, referring to Figure 4 , the multiple flat blade-like structures 102 help to guide the sound waves to propagate along a shorter path during the reflection process. This can not only effectively reduce the propagation path length of the sound waves and correspondingly reduce their wavelength, thereby reducing the interference with the frequency bands within the audible frequency range of the human ear. For the comparison of the finite element simulation of sound wave transmission with and without the flat blade-like structure 102, refer to Figure 5 .

[0044] Finally, referring to 6, each group of the quarter-wavelength tubular acoustic metamaterial notch structures 101 preferably includes multiple connected tubular units 1011.

[0045] Furthermore, the lengths of two of the tubular units 1011 in each group of the quarter-wavelength tubular acoustic metamaterial notch structures 101 are different or the same.

[0046] In this embodiment, multiple groups of quarter-wavelength tubular acoustic metamaterial notch structures 101 are adopted. This structure is a flattened sound-absorbing structure, which can achieve a broadband sound-absorbing effect through different permutations and combinations, effectively reducing the reflection noise behind the unit. In this embodiment, each group of this structure is formed by connecting two tubular units 1011 with different lengths. When sound waves with a frequency corresponding to the pipe length enter and are reflected at the closed end of the pipe, the phase of the reflected wave will be opposite to that of the incident wave. Through this phase inversion, the incident wave and the reflected wave cancel each other out, thereby weakening or eliminating sound waves of a specific frequency and achieving the purpose of adjusting the frequency response. It should be particularly noted that the length and size of the pipe can be adjusted according to specific usage requirements to specifically reduce or eliminate sound waves in a specific frequency band, so as to enhance the ability to adjust the frequency response of the speaker unit. In addition, the multiple groups of quarter-wavelength tubular acoustic metamaterial notch structures 101 in this embodiment not only act as the waveguide structure of the diaphragm, but also undertake the supporting frame function of the magnetic assembly of the planar magnetic speaker. That is to say, the multiple groups of quarter-wavelength tubular acoustic metamaterial notch structures 101 are integrated through the frame. The entire frame not only supports the various structures of the notch and waveguide materials but also is responsible for supporting the planar magnetic speaker unit. This integrated design effectively reduces the volume of the planar magnetic speaker unit, enhances its portability and ease of use, and reduces the production cost while reducing the material usage.

[0047] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. For those skilled in the art, the present utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. Acoustic metamaterial notch and waveguide structures applicable to planar magnetic speaker units, characterized in that : It includes multiple flat blade-like structures (102), multiple semi-circular structures (103), and multiple groups of quarter-wavelength tubular acoustic metamaterial notch structures (101); Multiple groups of the quarter-wavelength tubular acoustic metamaterial notch structures (101) are arranged around multiple flat blade-like structures (102) and multiple semi-circular structures (103); Multiple flat blade-like structures (102) are arranged perpendicular to the vibrating diaphragm of the planar magnetic speaker unit, and multiple semi-circular structures (103) cover the magnet of the planar magnetic speaker unit.

2. The acoustic metamaterial notch and waveguide structure applicable to the planar magnetic speaker unit according to claim 1, characterized in that: The acoustic metamaterial notch and waveguide structure is an annular structure, and multiple groups of quarter-wavelength tubular acoustic metamaterial notch structures (101) are distributed on the circumference of the annular structure.

3. The acoustic metamaterial notch and waveguide structure applicable to the planar magnetic speaker unit according to claim 2, characterized in that: Multiple flat blade-like structures (102) and multiple semi-circular structures (103) are arranged inside the ring of the annular structure.

4. The acoustic metamaterial notch and waveguide structure applicable to the planar magnetic speaker unit according to claim 1, characterized in that: The semi-circular structure (103) is semi-cylindrical.

5. The acoustic metamaterial notch and waveguide structure applicable to the planar magnetic speaker unit according to claim 4, wherein: The distribution form of multiple semi-circular structures (103) is arranged in multiple rows and columns, and the semi-circular structures (103) are parallel to each other.

6. The acoustic metamaterial notch and waveguide structure applicable to a planar magnetic speaker unit according to claim 1, wherein: Each group of the quarter-wavelength tubular acoustic metamaterial notch structures (101) includes multiple connected tubular units (1011).

7. The acoustic metamaterial notch and waveguide structure applicable to the planar magnetic speaker unit according to claim 6, characterized in that: The lengths of two tubular units (1011) in each group of the quarter-wavelength tubular acoustic metamaterial notch structures (101) are different or the same.

8. The acoustic metamaterial notch and waveguide structure applicable to the planar magnetic speaker unit according to claim 7, characterized in that: Multiple groups of the quarter-wavelength tubular acoustic metamaterial notch structures (101) are used as the magnetic group support frame of the planar magnetic speaker.

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