Matrix type sound amplification structure and loudspeaker

Abstract

The invention discloses a matrix type sound amplification structure and a loudspeaker, the matrix type sound amplification structure comprises a sound production unit and a plurality of groups of magnetic circuit units, the plurality of groups of magnetic circuit units are arranged in a matrix type, each magnetic circuit unit comprises a central magnetic block and four side magnetic blocks, the four side magnetic blocks are arranged on the four sides of the central magnetic block along the circumferential direction, and the magnetic circuit units are arranged in the central magnetic block along the circumferential direction. The length of the side magnetic blocks is matched with that of the central magnetic block, and a magnetic gap is arranged between the central magnetic block and the side magnetic blocks so as to provide a stable magnetic field for the voice coil; the sound production unit comprises a vibrating diaphragm and a plurality of voice coils matched with the central magnetic block, and the voice coils and the vibrating diaphragm are bonded together; under the limitation of the shape and the space, the voice coil is designed in a matrix mode, the electromagnetic force borne by the voice coil in a magnetic field is increased by increasing the relative length of the voice coil in the magnetic field and the intensity of the magnetic field where the voice coil is located, and therefore the voice coil can have larger amplitude when driving a vibrating diaphragm to vibrate, and the sound of the loudspeaker is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of speakers, and in particular to a matrix sound amplification structure and a speaker. Background Art

[0002] A speaker is an electroacoustic transducer. The speakers used in various electronic products such as mobile phones and tablet computers are thin products. Its basic structure includes a vibration part, a magnetic circuit part and a structural part. The vibration part mainly includes a diaphragm and a voice coil. The diaphragm is connected to the voice coil. After an alternating current is applied, the voice coil moves in the magnetic field and drives the diaphragm to vibrate, thus converting the electrical signal into a mechanical vibration signal. The magnetic circuit part mainly includes a permanent magnet to provide a stable magnetic field for the vibration part. The structural part is used to install the vibration part and the magnetic circuit part, including a chassis for support, a surround located around the diaphragm to provide elastic support to ensure the movement of the diaphragm, and a dust cap to prevent dust from entering the voice coil and the magnetic circuit system, etc. Thus, its principle is that when an audio current passes through the voice coil, the voice coil is affected by the electromagnetic force in the magnetic field and generates an alternating motion. This motion drives the diaphragm to vibrate, and the vibration of the diaphragm pushes the air to generate sound waves, which are finally perceived as sound by the human ear. Limited by the limited space and shape of the thin plate, it is difficult to increase the sound volume of the speaker in electronic products, and the upper limit of its sound improvement is low. Summary of the Invention

[0003] In order to overcome the defects of the prior art, the technical problem to be solved by the present invention is to provide a matrix sound amplification structure and a speaker, which can effectively increase the upper limit of the sound volume of the speaker by increasing the relative length of the voice coil and the magnetic field strength in a limited space.

[0004] To achieve this purpose, the present invention adopts the following technical solutions:

[0005] A matrix sound amplification structure provided by the present invention includes a sound generating unit and a plurality of groups of magnetic circuit units. The plurality of groups of magnetic circuit units are arranged in a matrix. Each magnetic circuit unit includes a central magnetic block and four side magnetic blocks. The central magnetic block is rectangular in shape. The four side magnetic blocks are arranged along the circumference on the four sides of the central magnetic block. The length of the side magnetic blocks is matched with that of the central magnetic block. A magnetic gap is provided between the central magnetic block and the side magnetic blocks to provide a stable magnetic field for the voice coil. The sound generating unit includes a diaphragm and a plurality of voice coils that are matched with the central magnetic blocks. The voice coils are bonded to the diaphragm. The plurality of voice coils are respectively arranged in the magnetic gaps between the central magnetic blocks and the adjacent side magnetic blocks. The voice coils are concentric with the central magnetic blocks. Thus, by dividing the larger voice coil, the relative effective length of the voice coil in the magnetic field is increased, and at the same time, the magnetic fields are superimposed after division, and its intensity and utilization rate can be further improved.

[0006] AsFigure 1 As shown, during the design, to quantify the standard for improving the sound of the speaker, let the sound of the speaker be Q, then the sound Q can be expressed as:

[0007]

[0008] Among them, G is the comprehensive index; h is the width of the side magnet block; r is the width of the magnetic gap; H 2 is the length of the voice coil; H 1 is the width of the voice coil; x is the number of voice coils set, L i refers to the effective length of the i-th voice coil.

[0009] At the same time, to avoid sound distortion and ensure structural stability, the following constraint conditions need to be met:

[0010] S10: Distortion constraint, satisfying:

[0011]

[0012] C is the distortion critical parameter;

[0013] S20: Space limitation, when the area of the diaphragm is A, satisfying:

[0014]

[0015] Among them, T 1 is the width of the central magnet block; T 2 is the length of the central magnet block;

[0016] S30: Feasibility constraint, satisfying:

[0017] S31: The width h of the side magnet block does not exceed the length H and width H of the voice coil 2 of the voice coil, that is: 1 h < H

[0018] h<H 1 ,H 2

[0019] S32: To prevent mechanical interference between the voice coil and the side magnet block and the central magnet block, let r min be the minimum value of the magnetic gap during normal operation, then:

[0020] r min ≤r

[0021] S33: To ensure structural stability, the minimum values of the length and width of the voice coil are H min :

[0022] H min ≤H 1 ,H 2

[0023] A loudspeaker includes a diaphragm, and the above-mentioned matrix sound amplification structure is arranged in the diaphragm; to efficiently improve the upper limit of the sound improvement of the loudspeaker.

[0024] The beneficial effects of the present invention are as follows:

[0025] In the present invention, the voice coil is designed in a matrix under the limitations of shape and space. By increasing the relative length of the voice coil in the magnetic field and the intensity of the magnetic field where the voice coil is located, the electromagnetic force received by the voice coil in the magnetic field is increased, so that the voice coil can have a larger amplitude when driving the diaphragm to vibrate, thereby improving the sound of the loudspeaker. At the same time, by establishing a design calculation model based on the above structure, the optimal sound improvement design under different requirements can be optimized and assisted to avoid sound quality distortion of the loudspeaker. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic diagram of the principle of a matrix sound amplification structure provided in the specific embodiment of the present invention;

[0027] Figure 2 represents a comparison frequency response curve graph of a loudspeaker using the design of this case and a loudspeaker with a conventional structure.

[0028] In the figure:

[0029] 1, sound generating unit; 2, magnetic circuit unit;

[0030] 21, central magnetic block; 22, edge magnetic block; 23, magnetic gap;

[0031] 11, diaphragm; 12, voice coil. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] The technical solutions of the present invention will be further described below with reference to the drawings and through specific embodiments.

[0033] The sound volume of the loudspeaker depends on the electromagnetic force received by the voice coil 12 in the magnetic field, that is, when the received electromagnetic force is large, the amplitude of the voice coil 12 driving the diaphragm 11 will be larger, so that the loudspeaker can emit a louder sound. When the received electromagnetic force is small, the amplitude of the voice coil 12 driving the diaphragm 11 will be smaller, and at this time the sound emitted by the loudspeaker will be smaller; the electromagnetic force received by the voice coil 12 in the magnetic field can be expressed by the following formula:

[0034] F = B·I·L

[0035] Among them, F represents the electromagnetic force received by the voice coil 12 in the magnetic field; B represents the intensity of the magnetic field; I represents the current passing through the voice coil 12; L represents the length of the voice coil 12;

[0036] As can be seen from the above formula, the magnitude of the force is proportional to the current, the magnetic field strength, and the length of the voice coil 12. When the current is used as the signal input, the electromagnetic force on the voice coil 12 in the magnetic field can be increased by increasing the magnetic field strength and the length of the voice coil 12, so as to achieve the purpose of increasing the sound of the speaker; that is, assuming the sound of the speaker is Q, then:

[0037] Q ∝ F

[0038] Based on the above principle, as Figure 1 shown, a matrix sound amplification structure is proposed,

[0039] including a sound generating unit 1 and several groups of magnetic circuit units 2. The several groups of magnetic circuit units 2 are arranged in a matrix, and the number of magnetic circuit units 2 is even. When several magnetic circuit units 2 are arranged in a matrix, they are in a symmetrical structure to ensure the stability of the structure;

[0040] The magnetic circuit unit 2 includes a central magnetic block 21 and four side magnetic blocks 22. The shape of the central magnetic block 21 is rectangular, and the four corners of the central magnetic block 21 are rounded; the four side magnetic blocks 22 are arranged along the circumference on the four sides of the central magnetic block 21, that is, the central magnetic block 21 and the four circumferential side magnetic blocks 22 form an internal magnetic structure. The central magnetic block 21 and the side magnetic blocks 22 are permanent magnets; the length of the side magnetic blocks 22 matches the central magnetic block 21, and a magnetic gap 23 is provided between the central magnetic block 21 and the side magnetic blocks 22 to provide a stable magnetic field for the voice coil 12;

[0041] The sound generating unit 1 includes a diaphragm 11 and several voice coils 12 that cooperate with the central magnetic block 21. The voice coils 12 and the diaphragm 11 are bonded together, that is, the diaphragm 11 covers and bonds to several voice coils 12. When sounding, several voice coils 12 jointly drive the diaphragm 11 to vibrate. The diaphragm 11 is made of a polymer composite film material TPEE middle film or metal film with a foam sandwich structure; by decomposing the large voice coil 12 into more voice coils 12, the relative length of the voice coil 12 in the magnetic field is increased, and then the diaphragm 11 is driven to vibrate; several voice coils 12 are respectively arranged in the magnetic gaps 23 between several central magnetic blocks 21 and adjacent side magnetic blocks 22, and the voice coils 12 are concentric with the central magnetic blocks 21; preferably, several voice coils 12 are connected to each other through a circuit, and the voice coils 12 are connected to the external circuit through FPC to ensure the lossless transmission of the audio signal; at this time, assuming the total electromagnetic force received by several voice coils 12 is F t , then:

[0042] Q ∝ F t

[0043] The electromagnetic force F i received by the i-th voice coil 12 is: F i = B·L i ·I

[0044] where Li It refers to the effective length of the i-th voice coil 12. Let the width of the magnetic gap 23 be r and the width of the side magnetic block 22 be h. The length of the side magnetic block 22 corresponds to that of the central magnetic block 21, then k is a proportionality coefficient;

[0045] Furthermore, let the length of the voice coil 12 be H 2 and the width be H 1 ; The resistance of the voice coil 12 is:

[0046] Then

[0047] where U is the signal voltage input to the voice coil 12; S is the cross-sectional area of the voice coil 12; ρ is the resistivity of the voice coil 12;

[0048] When the number of voice coils 12 set is x:

[0049] where F t is the resultant electromagnetic force on x voice coils 12;

[0050] In summary: The sound of the speaker is Q as:

[0051]

[0052] Let Get:

[0053]

[0054] Thus, according to the above function model, based on the above sound amplification structure, the adjustment strategy to maximize the sound Q is:

[0055] (1) Increase the number of voice coils 12 set to x within the allowable space to improve the total effective length of the voice coils 12 in the magnetic field as much as possible

[0056] (2) Enhance the magnetic field strength where the voice coil 12 is located, that is, increase the width of the side magnetic block 22 and decrease the width r of the magnetic gap 23;

[0057] (3) Decrease the length and width of the voice coil 12 to make it more convenient for a single voice coil 12 to vibrate.

[0058] Preferably, when improving the sound through the above strategy, the following constraint conditions need to be met:

[0059] To avoid sound quality distortion, it is necessary to limit F t within the linear range, that is:

[0060]

[0061] Among them, C is the distortion critical parameter;

[0062] At the same time, the influence in the physical space also needs to be considered, which mainly includes the following three aspects:

[0063] (1) The width h of the side magnet block 22 does not exceed the length H of the voice coil 12 2 and the width H 1 , that is:

[0064] h < H 1 and h < H 2

[0065] (2) To prevent mechanical interference between the voice coil 12 and the side magnet block 22 and the center magnet block 21; let r min be the minimum value of the magnetic gap 23 during normal operation, then:

[0066] r min ≤ r

[0067] (3) To ensure structural stability, the minimum values of the length and width of the voice coil 12 are H min :

[0068] H min ≤ H 1 , H 2

[0069] Due to space limitations, when the area of the speaker cone is A, it satisfies:

[0070]

[0071] Among them, T 1 is the width of the center magnet block 21; T 2 is the length of the center magnet block 21.

[0072] In summary, compared with the conventional structure speaker of the same caliber, the speaker adopting the above matrix - type sound amplification design structure has a 5 - 7 dB increase in the sound pressure level in the low - frequency band and a 4 - 5 dB increase in the sound pressure level in the mid - high - frequency band under the same test conditions. The comparison frequency response curve is as follows Figure 2 shown. The ordinate represents the sound pressure level (dB), the abscissa represents the frequency (Hz), the dashed line represents the speaker adopting the design of this case, and the solid line represents the conventional structure speaker.

[0073] The present invention is described through preferred embodiments. Those skilled in the art know that without departing from the spirit and scope of the present invention, various changes or equivalent replacements can be made to these features and embodiments. The present invention is not limited by the specific embodiments disclosed herein, and other embodiments falling within the scope of the claims of this application belong to the scope of protection of the present invention.

Claims

1. A matrix sound amplification structure, characterized in that: It comprises a sound-generating unit (1) and a plurality of groups of magnetic circuit units (2), wherein the plurality of groups of magnetic circuit units (2) are arranged in a matrix. The magnetic circuit unit (2) comprises a central magnetic block (21) and four side magnetic blocks (22); the central magnetic block (21) is rectangular in shape; the four side magnetic blocks (22) are circumferentially arranged on four sides of the central magnetic block (21); the length of the side magnetic blocks (22) matches that of the central magnetic block (21); a magnetic gap (23) is arranged between the central magnetic block (21) and the side magnetic blocks (22) to provide a stable magnetic field for the voice coil (12); The sound-emitting unit (1) comprises a diaphragm (11) and a plurality of voice coils (12) matched with the central magnetic block (21); the voice coils (12) and the diaphragm (11) are bonded together; the plurality of voice coils (12) are respectively arranged in magnetic gaps (23) between a plurality of the central magnetic blocks (21) and adjacent side magnetic blocks (22); and the voice coils (12) and the central magnetic block (21) are concentrically arranged.

2. The matrix sound amplification structure according to claim 1, characterized in that: The number of the magnetic circuit units (2) is an even number, and a plurality of the magnetic circuit units (2) are arranged in a matrix to form a symmetrical structure.

3. The matrix sound amplification structure according to claim 2, characterized in that: A plurality of the voice coils (12) are interconnected via a circuit, and the voice coil (12) is connected to an external circuit via an FPC to ensure lossless transmission of audio signals.

4. The matrix sound amplification structure according to claim 3, characterized in that: The four corners of the central magnetic block (21) are rounded.

5. The matrix sound amplification structure according to claim 3, characterized in that: The central magnetic block (21) and the four circumferential side magnetic blocks (22) form an internal magnetic structure, and the central magnetic block (21) and the side magnetic blocks (22) are permanent magnets.

6. The matrix sound amplification structure according to claim 5, characterized in that: The diaphragm (11) is made of a polymer composite film material TPEE with a foamed sandwich structure or a metal film.

7. The matrix sound amplification structure according to claim 6, characterized in that: Assume the sound of the speaker is Q, then the sound Q can be expressed as: Wherein, G is a comprehensive index; h is the width of the side magnet block (22); r is the width of the magnetic gap (23); H2 is the length of the voice coil (12); H1 is the width of the voice coil (12); x is the number of voice coils (12) set, L i Refers to the effective length of the ith voice coil (12).

8. The matrix sound amplification structure according to claim 7, characterized in that: To avoid sound distortion and structural stability, the following constraints need to be met: S10: Distortion constraint, satisfying: C is the distortion critical parameter; S20: Space limitation, assuming the area of ​​the cone is A, it satisfies: Wherein, T1 is the width of the central magnetic block (21); T2 is the length of the central magnetic block (21); S30: Feasibility constraints, satisfying: S31: The width h of the side magnet block (22) does not exceed the length H2 and the width H1 of the voice coil (12), that is: h<H1,H2 S32: In order to prevent mechanical interference between the voice coil (12) and the side magnetic blocks (22) and the center magnetic block (21), it is assumed that r min The minimum value of the magnetic gap (23) during normal operation is: r min ≤r S33: To ensure structural stability, the length and width of the voice coil (12) are at least H min : H min ≤H1,H2。 9. A loudspeaker, characterized in that: It comprises a sound basin, in which a matrix sound amplification structure as claimed in any one of claims 1 to 8 is arranged.

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