Sound production monomer and sound production module

Abstract

The invention discloses a sound production monomer and a sound production module, and relates to the technical field of electroacoustic energy conversion, the sound production monomer comprises a vibration system and a magnetic circuit system, and the vibration system comprises a vibrating diaphragm and a flat voice coil connected with the vibrating diaphragm; the magnetic circuit system comprises a first magnetic circuit, a second magnetic circuit and a central magnetic conductive plate, the first magnetic circuit comprises two pieces of first magnetic steel which are arranged at an interval along a second direction, and the second magnetic circuit comprises two pieces of second magnetic steel which are arranged at an interval along the second direction; the central magnetic conductive plate comprises a second magnetic conductive part, and the thickness of the second magnetic conductive part in the first direction is gradually reduced from the side close to the magnetic gap to the side away from the magnetic gap. The second magnetic conductive part can fully bend the magnetic induction line before the magnetic induction line enters the magnetic gap, so that more magnetic induction lines enter the magnetic gap, and the magnetic induction intensity of the magnetic gap is further enhanced.

Description

Technical Field

[0001] This invention relates to the field of electroacoustic energy conversion technology, and in particular to a sound-generating unit and a sound-generating module. Background Technology

[0002] Currently, consumer electronics devices are continuously evolving towards thinner, lighter, and higher-performance designs, posing a significant challenge to the design of miniature loudspeakers. The key to technological development lies in overcoming the physical limits of acoustic performance within an ultra-thin space. A core challenge is that, according to the fundamental principles of magnetic circuits, the volume of a magnet is positively correlated with the magnetic flux density it can provide. The strict thickness limitations of ultra-thin units directly compress the usable space of the magnet, resulting in insufficient magnetic energy product and driving force in the drive system, severely restricting the speaker's sensitivity, dynamic range, and especially its low-frequency performance. Therefore, the industry's technological frontiers are dedicated to overcoming this bottleneck through new materials, new structures (such as high-performance magnets and distributed magnetic circuits) or new driving principles (such as piezoelectricity and MEMS). Many novel magnetic circuit technologies have already been applied, providing innovative solutions for loudspeaker design.

[0003] With the existing magnetic circuit structure design, the magnetic flux density is limited by the magnetic gap, making it difficult to improve the acoustic performance of existing loudspeakers under the constraint of volume. Summary of the Invention

[0004] The main objective of this invention is to propose a sound-generating unit and a sound-generating module, aiming to solve the problem of how to improve the magnetic induction intensity of the magnetic gap.

[0005] To achieve the above objectives, the present invention provides a sound-generating unit comprising: A vibration system, the vibration system including a diaphragm and a flat voice coil connected to the diaphragm, the flat voice coil being used to drive the diaphragm to vibrate along a first direction, the axis of the flat voice coil being perpendicular to the first direction; A magnetic circuit system includes a first magnetic circuit, a second magnetic circuit, and a central magnetic guide plate. The first and second magnetic circuits are respectively disposed on both sides of the central magnetic guide plate along a first direction. The first magnetic circuit includes two first magnets spaced apart along a second direction, forming a first gap between the two first magnets. The second magnetic circuit includes two second magnets spaced apart along the second direction, forming a second gap between the two second magnets. The first gap and the second gap are connected to form a magnetic gap. A flat voice coil is disposed corresponding to the magnetic gap. The second direction is perpendicular to the first direction. The central magnetic plate includes a first magnetic part and a second magnetic part connected to each other. The first magnetic part is located at the end of the second magnetic part away from the magnetic gap. The second magnetic part has a first magnetic surface and a second magnetic surface respectively provided on both sides along the first direction. The first magnetic surface is connected to the first magnetic circuit, and the second magnetic surface is connected to the second magnetic circuit. The thickness of the end of the second magnetic part facing the magnetic gap along the first direction is greater than the thickness of the end of the second magnetic part away from the magnetic gap along the first direction. The thickness of the first magnetic part along the first direction gradually increases or is at least partially the same from the end near the second magnetic part to the end away from the second magnetic part.

[0006] In one embodiment, a plane passing through the center of the second magnetically conductive part and perpendicular to the first direction is defined as the center plane, wherein, Both the first magnetically conductive surface and the second magnetically conductive surface are planar or curved surfaces, and the second magnetically conductive surface and the first magnetically conductive surface are symmetrically arranged along the central plane; or, the first magnetically conductive surface is planar, and the second magnetically conductive surface is a curved surface that protrudes toward or away from the side where the diaphragm is located; or, the second magnetically conductive surface is planar, and the first magnetically conductive surface is a curved surface that protrudes toward or away from the side where the diaphragm is located.

[0007] In one embodiment, the first magnet and the second magnet are spaced apart along the first direction, and a gap is formed between the first magnet and the second magnet, exposing the end of the first magnetically conductive portion away from the magnetic gap.

[0008] In one embodiment, the flat voice coil includes two long shaft segments spaced apart along a first direction and two connecting segments located at both ends of the long shaft segments and connected to the two long shaft segments, with the two long shaft segments corresponding to the magnetic gap.

[0009] In one embodiment, a plane passing through the center of the second magnetically conductive portion and perpendicular to the first direction is defined as the center plane; wherein, The thickness of the long axis segment along the first direction is defined as H, the thickness of the first magnet along the second direction is defined as L1, and the angle between the straight line passing through the end of the first magnetic surface near the magnetic gap and the end of the first magnetic surface away from the magnetic gap and the central plane is defined as θ1, where H / 2L1≤tan|θ1|≤1.2H / L1; And / or, define the thickness of the long axis segment along the first direction as H, define the thickness of the second magnet along the second direction as L2, define the angle between the straight line passing through the end of the second magnetic surface near the magnetic gap and the end of the second magnetic surface away from the magnetic gap and the central plane as θ2, H / 2L2≤tan|θ2|≤1.2H / L2.

[0010] In one embodiment, the center point of the end of the central magnetic plate away from the magnetic gap in the first direction is defined as a1, the center point of the long axis segment away from the diaphragm in the first direction is defined as a2, and the distance between a1 and a2 in the first direction is defined as d, where 0mm≤|d|≤2H / 3; And / or, the thickness of the end of the central magnetic plate near the magnetic gap along the first direction is not greater than the thickness of the long axis segment along the first direction; And / or, if we define the thickness of the end of the second magnetically conductive part away from the magnetic gap along the first direction as d1, and define the thickness of the end of the second magnetically conductive part near the magnetic gap along the first direction as d2, then we have 0 < d1 / d2 ≤ 0.72.

[0011] In one embodiment, the thickness of the first magnetically conductive portion along the first direction is the same from the side closest to the second magnetically conductive portion to the side furthest from the second magnetically conductive portion, and the thickness of the end of the first magnetically conductive portion facing the second magnetically conductive portion along the first direction is not greater than the thickness of the end of the second magnetically conductive portion facing the first magnetically conductive portion along the first direction. And / or, the center of the first magnetically conductive part and the center of the second magnetically conductive part are arranged collinearly; And / or, the central magnetic plate further includes a third magnetic part, which is disposed on the side of the second magnetic part away from the first magnetic part. The thickness of the third magnetic part along the first direction is not less than the thickness of the end of the second magnetic part facing the magnetic gap along the first direction. The two sides of the third magnetic part disposed opposite to each other along the first direction are respectively connected to the first magnetic circuit and the second magnetic circuit.

[0012] In one embodiment, the central magnetic plate is an annular magnetic plate, and the central magnetic plate is a one-piece molded part; Alternatively, the central magnetic conductive plate may include two plates spaced apart along the second direction, with the two central magnetic conductive plates connected to the first magnetic circuit and the second magnetic circuit respectively on both sides along the first direction.

[0013] In one embodiment, both the first magnet and the second magnet are magnetized along the first direction, and the magnetization directions of the first magnet and the second magnet located on the same side of the magnetic gap are opposite, and the magnetization directions of the two first magnets are opposite. And / or, the magnetic circuit system further includes a magnetic guide plate, which is disposed on the side of the first magnetic circuit away from the second magnetic circuit; And / or, the magnetic circuit system further includes a magnetically conductive yoke, which is disposed on the side of the second magnetic circuit away from the first magnetic circuit.

[0014] In one embodiment, the sound-generating unit further includes a housing, the outer edge of the diaphragm is connected to the housing, the housing has a receiving space for accommodating the flat voice coil and the magnetic circuit system, and the housing has through holes on two side walls that are arranged opposite to each other along the second direction, the first magnetic circuit and the second magnetic circuit extending into the through holes; And / or, the diaphragm includes a diaphragm body and a reinforcing portion connected to the diaphragm body, and the flat voice coil is connected to the reinforcing portion.

[0015] The present invention also proposes a sound-generating module, the sound-generating module comprising a housing and the aforementioned sound-generating unit, the sound-generating unit being disposed within the housing.

[0016] The technical solution of the present invention provides a second magnetically conductive part, and the thickness of the second magnetically conductive part at the end facing the magnetic gap along the first direction is greater than the thickness of the second magnetically conductive part at the end away from the magnetic gap along the first direction. This makes at least one of the first and second magnetically conductive surfaces an irregularly shaped structure surface compared to a conventional rectangular central washer. The second magnetically conductive part with this irregularly shaped structure surface can fully bend the magnetic field lines before they enter the magnetic gap, allowing more magnetic field lines to enter the magnetic gap and further enhancing the magnetic induction intensity of the magnetic gap. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 A schematic diagram of the structure of an embodiment of the sound-generating unit provided by the present invention; Figure 2 An exploded structural diagram of an embodiment of the sound-generating monomer provided by the present invention; Figure 3 A cross-sectional structural schematic diagram of an embodiment of the sound-generating unit provided by the present invention; Figure 4 A cross-sectional view of another embodiment of the sound-generating unit provided by the present invention; Figure 5 Cross-sectional structural schematic diagrams of several embodiments of the central magnetic guide plate provided by the present invention; Figure 6 A partial structural schematic diagram of an embodiment of the sound-generating unit provided by the present invention; Figure 7 A partial structural schematic diagram of an embodiment of the magnetic circuit system and vibration system provided by the present invention; Figure 8 A schematic diagram of magnetic field lines simulation for an embodiment of the sound-generating unit provided by the present invention.

[0019] Explanation of icon numbers: 100. Sound-generating unit; 1. Vibration system; 11. Diaphragm; 111. Diaphragm body; 112. Reinforcing part; 12. Flat voice coil; 121. Long axis section; 122. Connecting section; 2. Magnetic circuit system; 21. First magnetic circuit; 211. First magnet; 22. Second magnetic circuit; 221. Second magnet; 23. Central magnetic guide plate; 231. First magnetic guide part; 232. Second magnetic guide part; 2321. First magnetic guide surface; 2322. Second magnetic guide surface; 2323. Central plane; 233. Third magnetic guide part; 24. Magnetic gap; 241. First gap; 242. Second gap; 25. Void; 26. Magnetic guide plate; 27. Magnetic yoke; 271. Through hole; 28. Acoustic resistance; 3. Outer shell; 31. Through hole.

[0020] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0023] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0024] Currently, consumer electronics devices are continuously evolving towards thinner, lighter, and higher-performance designs, posing a significant challenge to the design of miniature loudspeakers. The key to technological development lies in overcoming the physical limits of acoustic performance within an ultra-thin space. A core challenge is that, according to the fundamental principles of magnetic circuits, the volume of a magnet is positively correlated with the magnetic flux density it can provide. The strict thickness limitations of ultra-thin units directly compress the usable space of the magnet, resulting in insufficient magnetic energy product and driving force in the drive system, severely restricting the speaker's sensitivity, dynamic range, and especially its low-frequency performance. Therefore, the industry's technological frontiers are dedicated to overcoming this bottleneck through new materials, new structures (such as high-performance magnets and distributed magnetic circuits) or new driving principles (such as piezoelectricity and MEMS). Many novel magnetic circuit technologies have already been applied, providing innovative solutions for loudspeaker design.

[0025] With the existing magnetic circuit structure design, the magnetic flux density is limited by the magnetic gap, making it difficult to improve the acoustic performance of existing loudspeakers under the constraint of volume.

[0026] The inventors discovered that, taking a conventional magnetic structure as an example, an upper washer, an upper magnet, a central washer, and a lower magnet are stacked on both sides of the magnetic gap. A voice coil is placed inside the magnetic gap. The side of the lower magnet furthest from the central washer is placed on the magnetic yoke. The upper washer is connected to the upper magnet by adhesive or other means. The magnetization direction of the upper magnet on one side of the magnetic gap is upward, while the magnetization direction of the upper magnet on the other side of the magnetic gap is downward. The magnetization directions of the upper and lower magnets on the same side of the magnetic gap are opposite. The central washer is glued between the upper and lower magnets, and the lower magnet is glued to the magnetic yoke. In this magnetic circuit system, the magnetic field lines need to rotate 90° after entering the central washer before entering the magnetic gap. However, the existing rectangular central washer, due to its shape, does not bend the magnetic field lines sufficiently, resulting in the cancellation of some magnetic field lines with opposite directions. This reduces the number of magnetic field lines entering the magnetic gap and affects the magnetic induction intensity of the magnetic gap.

[0027] In view of this, the present invention proposes a sound-generating unit, which aims to solve the problem of how to improve the magnetic induction intensity of the magnetic gap.

[0028] Please see Figures 1 to 3 In one embodiment of the present invention, the sound-generating unit 100 includes a vibration system 1 and a magnetic circuit system 2. The vibration system 1 includes a diaphragm 11 and a flat voice coil 12 connected to the diaphragm 11. The flat voice coil 12 is used to drive the diaphragm 11 to vibrate along a first direction, and the axis of the flat voice coil 12 is perpendicular to the first direction. The magnetic circuit system 2 includes a first magnetic circuit 21 and a second magnetic circuit 22 and a central magnetic guide plate 23. The first magnetic circuit 21 and the second magnetic circuit 22 are respectively disposed on both sides of the central magnetic guide plate 23 along the first direction. The first magnetic circuit 21 includes two first magnets 2 spaced apart along a second direction. 11. A first gap 241 is formed between two first magnets 211. The second magnetic circuit 22 includes two second magnets 221 spaced apart along a second direction. A second gap 242 is formed between the two second magnets 221. The first gap 241 and the second gap 242 are connected to form a magnetic gap 24. A flat voice coil 12 is disposed corresponding to the magnetic gap 24. The second direction is perpendicular to the first direction. The central magnetic guide plate 23 includes a second magnetic guide portion 232. The thickness of the second magnetic guide portion 232 in the first direction gradually decreases from the side closer to the magnetic gap 24 to the side farther away from the magnetic gap 24.

[0029] The sound-emitting unit 100 of this invention can be a miniature loudspeaker unit. The sound-emitting unit 100 can be applied in the sound-emitting module of electronic devices, such as computers, mobile phones, smart wearable devices, laptops, virtual reality devices, augmented reality devices, mixed reality devices, or extended reality devices. This embodiment uses a loudspeaker unit as an example for illustration.

[0030] The technical solution of the present invention provides a second magnetically conductive part 232, and the thickness of the second magnetically conductive part 232 at the end facing the magnetic gap 24 along the first direction is greater than the thickness of the end of the second magnetically conductive part 232 away from the magnetic gap 24 along the first direction. This results in at least one of the first magnetically conductive surfaces 2321 and 2322 being an irregularly shaped surface compared to a traditional rectangular center washer. An irregularly shaped surface refers to a surface that differs from the horizontal magnetically conductive surface of a traditional rectangular center washer. While the two ends of a horizontal magnetically conductive surface along the second direction are on the same horizontal line, the two ends of an irregularly shaped surface along the second direction are not on the same horizontal line. The irregularly shaped surface can be a plane, a curved surface convex towards the diaphragm 11, or a curved surface convex away from the diaphragm 11. Please refer to [link to relevant documentation]. Figure 8 The presence of the irregularly shaped surface allows the second magnetically conductive part 232, which has this irregularly shaped surface, to fully bend the magnetic field lines before they enter the magnetic gap 24, allowing more magnetic field lines to enter the magnetic gap 24 and further enhancing the magnetic induction intensity of the magnetic gap 24. For example, if only the first magnetically conductive surface 2321 is an irregularly shaped surface, and this irregularly shaped surface is a plane, the first magnetically conductive surface 2321 is inclined relative to the central plane 2323 compared to the magnetically conductive plane of a conventional central washer, while the magnetically conductive surface of a conventional central washer is parallel to the central plane 2323. This difference causes the magnetic field lines of the first magnetic circuit 21 to be fully bent by the second magnetically conductive part 232, which has the first magnetically conductive surface 2321, before entering the magnetic gap 24, allowing more magnetic field lines to enter the magnetic gap 24 and further enhancing the magnetic induction intensity of the magnetic gap 24.

[0031] Furthermore, the inventors' research also revealed that the existing traditional rectangular center washer, due to the inadequate bending of the magnetic field lines, causes the magnetic field lines overflowing through the magnetic gap 24 of the center washer to be non-horizontal, which in turn reduces the component of the magnetic field lines cut by the voice coil in the horizontal direction (left and right direction).

[0032] For ease of description, we will also use the example of a plane with only the first magnetic conductive surface 2321 as an irregularly shaped structure. Since the first magnetic conductive surface 2321 is inclined relative to the central plane 2323, the magnetic field lines of the first magnetic circuit 21 can be fully bent by the second magnetic conductive part 232 with the first magnetic conductive surface 2321 before entering the magnetic gap 24. This makes the magnetic field lines overflowing from the central magnetic plate 23 into the magnetic gap 24 tend to be horizontal, increasing the magnetic field component cut by the voice coil in the second direction. In other words, more magnetic field lines can be cut by the voice coil, enhancing the acoustic performance of the sound-generating unit 100.

[0033] It should be noted that the first direction is Figure 4 The vertical direction is shown, and the second direction is... Figure 4In the left-right direction shown, the axis of the flat voice coil 12 is parallel to the second direction. The thickness of the second magnetically conductive portion 232 in the first direction gradually decreases from the end near the magnetic gap 24 to the end away from the magnetic gap 24. The thickness of the first magnetically conductive portion 231 along the first direction can gradually increase from the end near the second magnetically conductive portion 232 to the end away from the second magnetically conductive portion 232, or it can be at least partially the same. That is, there are at least several locations on the first magnetically conductive portion 231 where their thickness is the same. Alternatively, the first magnetically conductive portion 231 can be a rectangular magnetically conductive portion, with its thickness remaining consistent from the end near the second magnetically conductive portion 232 to the end away from the second magnetically conductive portion 232; this is not a limitation. By providing the first magnetically conductive portion 231, it is easier to position the central magnetically conductive plate 23 and process the second magnetically conductive portion 232. The first magnetically conductive portion 231 and the second magnetically conductive portion 232 can be integrally molded parts or bonded together with adhesive; this is not a limitation. In addition, the first magnetic conductive part 231 can be rectangular or trapezoidal, and there is no limitation here; the second magnetic conductive part 232 can be an isosceles trapezoid or a right trapezoid, and there is also no limitation here.

[0034] Please see Figure 5 In one embodiment, a plane passing through the center of the second magnetically conductive part 232 and perpendicular to the first direction is defined as the central plane 2323. The first magnetically conductive surface 2321 and the second magnetically conductive surface 2322 are both planes or curved surfaces, and the second magnetically conductive surface 2322 and the first magnetically conductive surface 2321 are symmetrically arranged along the central plane 2323. Alternatively, the first magnetically conductive surface 2321 is a plane, and the second magnetically conductive surface 2322 is a curved surface that protrudes toward or away from the side where the diaphragm 11 is located. Alternatively, the second magnetically conductive surface 2322 is a plane, and the first magnetically conductive surface 2321 is a curved surface that protrudes toward or away from the side where the diaphragm 11 is located. In this embodiment, the first magnetically conductive surface 2321 can be a plane, a curved surface convex towards the diaphragm 11, or a curved surface convex away from the diaphragm 11; no limitation is imposed here. The second magnetically conductive surface 2322 can also be a plane, a curved surface convex towards the diaphragm 11, or a curved surface convex away from the diaphragm 11; no limitation is imposed here. The first magnetically conductive surface 2321 and the second magnetically conductive surface 2322 can be symmetrically arranged with respect to the central plane 2323, or they can be asymmetrically arranged; no limitation is imposed here either. For details, please refer to [link to relevant documentation]. Figure 3 , Figure 5 (a) and Figure 5 (b) If the first magnetically conductive surface 2321 and the second magnetically conductive surface 2322 are symmetrically arranged, then both the first magnetically conductive surface 2321 and the second magnetically conductive surface 2322 are planar or curved surfaces. If the first magnetically conductive surface 2321 and the second magnetically conductive surface 2322 are asymmetrically arranged, then when the first magnetically conductive surface 2321 is planar, please refer to [the relevant documentation]. Figure 5 (i) and Figure 5(j) The second magnetically conductive surface 2322 may be a plane that is asymmetrically arranged with respect to the first magnetically conductive surface 2321. Please refer to [link / reference]. Figure 5 (d) could also be a curved surface convex toward the diaphragm 11, see [link to relevant documentation]. Figure 5 (c) It can also be a curved surface away from the protrusion of the diaphragm 11; when the first magnetic surface 2321 is a curved surface convex towards the diaphragm 11, the second magnetic surface 2322 can be a curved surface asymmetrically arranged with respect to the first magnetic surface 2321 and away from the protrusion of the diaphragm 11. Please refer to [link to relevant documentation]. Figure 5 (h) The second magnetically conductive surface 2322 can also be a curved surface near the protrusion of the diaphragm 11. Please refer to [link / reference]. Figure 5 (e) The second magnetically conductive surface 2322 can also be a plane; when the first magnetically conductive surface 2321 is a curved surface away from the protrusion of the diaphragm 11, the second magnetically conductive surface 2322 can be a curved surface asymmetrically arranged with respect to the protrusion of the diaphragm 11. Please refer to [link to relevant documentation]. Figure 5 (g) The second magnetically conductive surface 2322 can also be a curved surface away from the protrusion of the diaphragm 11. Please refer to [link / reference]. Figure 5 (f) The second magnetic surface 2322 can also be a plane.

[0035] Please see Figure 8 In one embodiment, both the first magnet 211 and the second magnet 221 are magnetized along a first direction. The magnetization directions of the first magnet 211 and the second magnet 221 located on the same side of the magnetic gap 24 are opposite, and the magnetization directions of the two first magnets 211 are opposite. For example, if the first magnet 211 located on the left side of the magnetic gap 24 is magnetized upward, the first magnet 211 located on the right side of the magnetic gap 24 is magnetized downward. The second magnet 221 located on the left side of the magnetic gap 24 is magnetized downward, and the second magnet 221 located on the right side of the magnetic gap 24 is magnetized upward, so as to form a magnetic circuit.

[0036] Please see Figure 2 , Figure 4 and Figure 8 In one embodiment, the magnetic circuit system 2 further includes a magnetic guide plate 26, which is disposed on the side of the first magnetic circuit 21 away from the second magnetic circuit 22. By setting the magnetic guide plate 26, the magnetic field lines are corrected, thereby allowing more magnetic field lines to pass through the voice coil and improving the acoustic performance of the sound-generating unit 100. According to one embodiment of the present invention, the magnetic guide plate 26 can be a one-piece molded part, that is, the magnetic guide plate 26 is an annular magnetic guide plate, which facilitates the assembly of the sound-generating unit 100. According to another embodiment of the present invention, the number of magnetic guide plates 26 includes two, and the two magnetic guide plates 26 are arranged one-to-one with the two first magnets 211. The two magnetic guide plates 26 are smaller in volume and occupy less space than the annular magnetic guide plate, which can reduce the overall size of the sound-generating unit 100.

[0037] Please see Figure 2 , Figure 4 and Figure 8 In one embodiment, the magnetic circuit system 2 further includes a magnetic yoke 27, which is disposed on the side of the second magnetic circuit 22 away from the first magnetic circuit 21. By providing the magnetic yoke 27, the magnetic field lines are guided, thereby allowing more magnetic field lines to pass through the voice coil and improving the acoustic performance of the sound-generating unit 100.

[0038] Please see Figure 2 According to an embodiment of the present invention, a through hole 271 is provided on the magnetic yoke 27. The quality factor of the sound-generating unit 100 can be adjusted by providing the through hole 271, that is, the quality factor can be adjusted by adjusting the size or number of the through holes 271. The sound-generating unit 100 also includes an acoustic resistor 28, which is used to cover the through hole 271. The acoustic resistor 28 is essentially an energy-consuming component that converts sound energy into heat energy.

[0039] Please see Figure 3 In one embodiment, a first magnet 211 and a second magnet 221 are spaced apart along a first direction, forming a gap 25 between them that exposes the end of the first magnetically conductive portion 231 away from the magnetic gap 24. The side of the first magnet 211 facing the second magnet 221 can be completely fitted with the first magnetically conductive surface 2321, allowing the second magnetically conductive portion 232 with the first magnetically conductive surface 2321 to better bend the magnetic field lines of the first magnet 211, resulting in more magnetic field lines entering the magnetic gap 24 and enhancing the magnetic induction intensity of the magnetic gap 24. Similarly, the side of the second magnet 221 facing the first magnet 211 can be completely fitted with the second surface, allowing the second magnetically conductive portion 232 with the second surface to better bend the magnetic field lines of the second magnet 221, resulting in more magnetic field lines entering the magnetic gap 24 and enhancing the magnetic induction intensity of the magnetic gap 24.

[0040] Please see Figure 2 In one embodiment, the flat voice coil 12 includes two long axis segments 121 spaced apart along a first direction and two connecting segments 122 located at both ends of the long axis segments 121 and connected to the two long axis segments 121. The two long axis segments 121 are configured to correspond to the magnetic gap 24. The flat voice coil 12 has long axis segments 121 spaced apart along a vertical direction and two short axis segments located at both ends of the long axis segments 121. One end of each long axis segment 121 is connected to both ends of one of the short axis segments, and the other end of each long axis segment 121 is connected to both ends of the other short axis segment, thereby forming the flat voice coil 12. The two long axis segments 121 are configured to correspond to the magnetic gap 24 to ensure that sufficient magnetic field lines can pass through the flat voice coil 12.

[0041] Please see Figure 6In one embodiment, a plane passing through the center of the second magnetically conductive portion 232 and perpendicular to the first direction is defined as the center plane 2323; wherein, the thickness of the major axis segment 121 along the first direction is defined as H, the thickness of the first magnet 211 along the second direction is defined as L1, and the angle between the straight line passing through the end of the first magnetically conductive surface 2321 near the magnetic gap 24 and the end of the first magnetically conductive surface 2321 away from the magnetic gap 24 and the center plane 2323 is defined as θ1, where H / 2L1≤tan|θ1|≤1.2H / L1; wherein, a second magnetically conductive portion 2322 is provided. After the center washer of 2, the magnetic flux density of the magnetic gap 24 changes with the size of θ1, showing a trend of first increasing and then decreasing. To ensure that the magnetic gap 24 has a good magnetic flux density, the range of θ1 needs to be controlled within H / 2L1≤tan|θ1|≤1.2H / L1. Within this range, the magnetic flux density of the magnetic gap 24 corresponding to θ1 is significantly improved compared to the traditional rectangular center washer, which also effectively improves BL and makes the BL(x) curve smoother than that of the traditional washer. Here, BL represents the product of the loudspeaker's magnetic field strength and the voice coil length, i.e., the combination of B (magnetic flux density) and L (voice coil length). B represents the magnetic flux density produced by the magnet, usually measured in Tesla (T); L is the effective length of the voice coil, usually measured in meters (m). The BL value is one of the key indicators for measuring the driving capability of a loudspeaker. The BL value determines the loudspeaker's ability to convert electrical signals into sound.

[0042] It should be noted that, taking the first magnetically conductive surface 2321 as a plane as a reference, bending the first magnetically conductive surface 2321 upwards to form a curved surface convex towards the diaphragm 11, and bending the first magnetically conductive surface 2321 downwards to form a curved surface convex away from the diaphragm 11, the inventors have discovered that the bending direction and curvature of the curved surface, combined with the size of θ1 and the ratio of d1 to d2, provide new degrees of freedom for adjusting the BL(x) curve, thereby enabling a flatter BL(x) curve to be obtained by combining and adjusting the above features; for example, when θ1 and the ratio of d1 to d2 remain unchanged, the curved surface formed by bending the first magnetically conductive surface 2321 downwards further enhances the magnetic induction intensity of the magnetic gap 24 compared to when the first magnetically conductive surface 2321 is a plane.

[0043] Please see Figure 6In one embodiment, the thickness of the long axis segment 121 along the first direction is defined as H, the thickness of the second magnet 221 along the second direction is defined as L2, and the angle between the straight line passing through the end of the second magnetically conductive surface 2322 near the magnetic gap 24 and the end of the second magnetically conductive surface 2322 away from the magnetic gap 24 and the central plane 2323 is defined as θ2, where H / 2L2≤tan|θ2|≤1.2H / L2. With a central washer equipped with the second magnetically conductive part 232, the magnetic induction intensity of the magnetic gap 24 changes with the magnitude of θ2, showing a trend of first increasing and then decreasing. To ensure that the magnetic gap 24 has a good magnetic induction intensity, it is necessary to control the range of θ2 within H / 2L2≤tan|θ2|≤1.2H / L2. The magnetic induction intensity of the magnetic gap 24 corresponding to θ2 within this range is significantly improved compared to a traditional rectangular central washer, effectively increasing the magnetic induction intensity of the magnetic gap 24 and also effectively improving BL, and making the BL(x) curve smoother compared to a traditional washer. L1 and L2 can be equal or slightly different; no restrictions are imposed here.

[0044] Please see Figure 7 In one embodiment, the center point of the end of the central magnetic plate 23 furthest from the magnetic gap 24 in the first direction is defined as a1, and the center point of the long axis segment 121 furthest from the diaphragm 11 in the first direction is defined as a2. The distance between a1 and a2 in the first direction is defined as d, where 0 mm ≤ |d| ≤ 2H / 3. By controlling the distance between the center point of the second magnetic part 232 and the center point of the long axis segment 121 located below, a better effect can be obtained, that is, the absolute value of d is controlled within the range of 0 mm ≤ |d| ≤ 2H / 3, resulting in a stronger magnetic induction intensity of the magnetic gap 24 and a larger BL. Here, the distance between a1 and a2 in the first direction refers to the relative positional relationship between the second magnetic part 232 and the long axis segment 121 when the sound-generating unit 100 is in the assembled state, not in the working state.

[0045] In one embodiment, the thickness of the end of the central magnetic plate 23 near the magnetic gap 24 along the first direction is not greater than the thickness of the long axis segment 121 along the first direction. If the thickness of the end of the central magnetic plate 23 near the magnetic gap 24 along the first direction is too large, it will inevitably encroach on the space of the magnet when the size of the sound-generating unit 100 is fixed, thereby reducing the size of the magnet and potentially causing a decrease in the acoustic performance of the sound-generating unit 100. Therefore, it is necessary to control the thickness of the second magnetic guide portion 232 in the first direction to be less than or equal to the thickness of the long axis segment 121 in the first direction, thereby ensuring that the magnetic gap 24 has a good magnetic induction intensity.

[0046] Please see Figure 7In one embodiment, the thickness of the end of the second magnetically conductive part 232 away from the magnetic gap 24 along the first direction is defined as d1, and the thickness of the end of the second magnetically conductive part 232 near the magnetic gap 24 along the first direction is defined as d2. Then, 0 < d1 / d2 ≤ 0.72.

[0047] The inventors discovered that existing central washers are generally rectangular, with a consistent thickness in the first direction. For central washers of this shape, there is a magnetic short circuit phenomenon at the outer edge. Specifically, part of the magnetic field generated by the magnet overflows along the outer edge of the central washer away from the magnetic gap 24. The overflowing magnetic field forms a loop with the upper washer and the magnetic yoke 27, thereby affecting the magnetic induction intensity of the magnetic gap 24.

[0048] In this embodiment, the ratio of the thickness dimension of the second magnetically conductive part 232 at the end away from the magnetic gap 24 along the first direction to the thickness dimension of the second magnetically conductive part 232 at the end near the magnetic gap 24 along the first direction is between 0 and 0.72. This effectively controls the thickness of the second magnetically conductive part 232 at the end away from the magnetic gap 24, reduces the intensity of the magnetic field overflowing from the end of the central washer away from the magnetic gap 24, significantly reduces the leakage magnetic field on the outside of the magnetic circuit system 2, reduces the overflow of magnetic field lines at the end of the central washer away from the magnetic gap 24, effectively suppresses magnetic short circuits, and drives the restricted overflowing magnetic field lines to the side of the magnetic gap 24. More magnetic field lines pass through the magnetic gap 24, thereby significantly increasing the magnetic induction intensity of the magnetic gap 24, that is, significantly increasing the magnetic field intensity of the magnetic gap 24, and effectively improving the acoustic performance of the sound-generating unit 100.

[0049] Please see Figure 3 and Figure 4 In one embodiment, the thickness of the first magnetically conductive portion 231 along the first direction is the same from the side closest to the second magnetically conductive portion 232 to the side furthest from the second magnetically conductive portion 232. The thickness of the end of the first magnetically conductive portion 231 facing the second magnetically conductive portion 232 along the first direction is not greater than the thickness of the end of the second magnetically conductive portion 232 facing the first magnetically conductive portion 231 along the first direction. By controlling the thickness of the first magnetically conductive portion 231, magnetic short circuits can be effectively suppressed, allowing more magnetic field lines to pass through the magnetic gap 24, thereby significantly increasing the magnetic induction intensity of the magnetic gap 24, that is, significantly increasing the magnetic field strength of the magnetic gap 24. This effectively improves the acoustic performance of the sound-generating unit 100. On the other hand, since the thickness of the second magnetic conductive part 232 gradually decreases from the end near the magnetic gap 24 to the end away from the magnetic gap 24 in the first direction, and the thickness of the first magnetic conductive part 231 is the same from the side near the second magnetic conductive part 232 to the side away from the second magnetic conductive part 232 in the first direction, the central magnetic conductive plate 23 of this embodiment is smaller in volume than a conventional central washer with no change in thickness. The volume of the first magnet 211 and the second magnet 221 is further increased, thereby further improving the magnetic field strength.

[0050] It should be noted that the center of the first magnetic conductive part 231 and the center of the second magnetic conductive part 232 are arranged collinearly; that is, the center position of the first magnetic conductive part 231 and the center position of the second magnetic conductive part 232 are on the same horizontal line.

[0051] Please see Figure 4 In one embodiment, the central magnetic plate 23 further includes a third magnetic part 233. The third magnetic part 233 is disposed on the side of the second magnetic part 232 away from the first magnetic part 231. The thickness of the third magnetic part 233 along the first direction is not less than the thickness of the end of the second magnetic part 232 facing the magnetic gap 24 along the first direction. The two sides of the third magnetic part 233, which are disposed opposite each other along the first direction, are respectively connected to the first magnetic circuit 21 and the second magnetic circuit 22. By providing the third magnetic part 233 on the side of the second magnetic part 232 facing the magnetic gap 24, it is convenient to position and process the central magnetic plate 23. That is, by positioning and clamping the third magnetic part 233, the shapes of the second magnetic part 232 and the first magnetic part 231 can be processed. The thickness of the third magnetically conductive part 233 on the side away from the magnetic gap 24 in the first direction can be greater than the thickness of the second magnetically conductive part 232 on the side near the magnetic gap 24 in the first direction, and the thickness of the third magnetically conductive part 233 on the side away from the magnetic gap 24 in the first direction can also be equal to the thickness of the second magnetically conductive part 232 on the side near the magnetic gap 24 in the first direction; no limitation is imposed here. It should be noted that the third magnetically conductive part 233 is in contact with the first magnet 211 and the second magnet 221 on both sides along the first direction, respectively.

[0052] In one embodiment, the central magnetic plate 23 is an annular magnetic plate, and the central magnetic plate 23 is an integrally formed part; wherein, the central magnetic plate 23 is an integral annular magnetic plate. Compared with two independent central magnetic plates 23, which need to be assembled twice, the annular magnetic plate in this embodiment only needs to be assembled once. Therefore, the use of an annular magnetic plate makes it easier to assemble the sound-generating unit 100.

[0053] Please see Figures 2 to 4 In one embodiment, the central magnetic guide plate 23 includes two plates spaced apart along a second direction. The two central magnetic guide plates 23 are connected to the first magnetic circuit 21 and the second magnetic circuit 22 on their respective sides along a first direction. The two central magnetic guide plates 23 are located on the left and right sides of the magnetic gap 24. Each central magnetic guide plate 23 is sandwiched between the first magnet 211 and the second magnet 221 located on the same side. Compared to an annular magnetic guide plate, the two central magnetic guide plates 23 occupy less space, which is beneficial for reducing the size of the sound-generating unit 100.

[0054] Please see Figure 1 and Figure 2In one embodiment, the sound-generating unit 100 further includes a housing 3, the outer edge of the diaphragm 11 is connected to the housing 3, and a receiving space is formed inside the housing 3 to accommodate the flat voice coil 12 and the magnetic circuit system 2. Two side walls of the housing 3 arranged opposite each other along the second direction are provided with through holes 31, and the first magnetic circuit 21 and the second magnetic circuit 22 extend into the through holes 31. By opening through holes 31 on the housing 3 to allow the left and right sides of the first magnetic circuit 21 and the second magnetic circuit 22 to extend in, the volume of the first magnet 211 and the second magnet 221 is increased without increasing the overall size of the sound-generating unit 100, thereby effectively improving the acoustic performance of the sound-generating unit 100.

[0055] Please see Figure 2 and Figure 3 In one embodiment, the diaphragm 11 includes a diaphragm body 111 and a reinforcing portion 112 connected to the diaphragm body 111, and a flat voice coil 12 is connected to the reinforcing portion 112. By providing the reinforcing portion 112, it is helpful to adjust the acoustic performance of the sound-generating unit 100 through the reinforcing portion 112.

[0056] The present invention also proposes a sound-generating module, which includes a housing and the aforementioned sound-generating unit 100, wherein the sound-generating unit 100 is disposed within the housing. Since the sound-generating module employs all the technical solutions of the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated upon here.

[0057] The above description is merely an exemplary embodiment of the present invention and does not limit the scope of protection of the present invention. Any equivalent structural transformations made based on the technical concept of the present invention and the contents of the specification and drawings of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of protection of the present invention.

Claims

1. A sound-emitting monomer, characterized in that, include: A vibration system, the vibration system including a diaphragm and a flat voice coil connected to the diaphragm, the flat voice coil being used to drive the diaphragm to vibrate along a first direction, the axis of the flat voice coil being perpendicular to the first direction; A magnetic circuit system includes a first magnetic circuit, a second magnetic circuit, and a central magnetic guide plate. The first and second magnetic circuits are respectively disposed on both sides of the central magnetic guide plate along a first direction. The first magnetic circuit includes two first magnets spaced apart along a second direction, forming a first gap between the two first magnets. The second magnetic circuit includes two second magnets spaced apart along the second direction, forming a second gap between the two second magnets. The first gap and the second gap are connected to form a magnetic gap. A flat voice coil is disposed corresponding to the magnetic gap. The second direction is perpendicular to the first direction. The central magnetic plate includes a first magnetic part and a second magnetic part connected to each other. The first magnetic part is located at the end of the second magnetic part away from the magnetic gap. The second magnetic part has a first magnetic surface and a second magnetic surface respectively provided on both sides along the first direction. The first magnetic surface is connected to the first magnetic circuit, and the second magnetic surface is connected to the second magnetic circuit. The thickness of the end of the second magnetic part facing the magnetic gap along the first direction is greater than the thickness of the end of the second magnetic part away from the magnetic gap along the first direction. The thickness of the first magnetic part along the first direction gradually increases or is at least partially the same from the end near the second magnetic part to the end away from the second magnetic part.

2. The sound-generating unit as described in claim 1, characterized in that, A plane passing through the center of the second magnetically conductive part and perpendicular to the first direction is defined as the center plane, wherein, Both the first magnetically conductive surface and the second magnetically conductive surface are planar or curved surfaces, and the second magnetically conductive surface and the first magnetically conductive surface are symmetrically arranged along the central plane; or, the first magnetically conductive surface is planar, and the second magnetically conductive surface is a curved surface that protrudes toward or away from the side where the diaphragm is located; or, the second magnetically conductive surface is planar, and the first magnetically conductive surface is a curved surface that protrudes toward or away from the side where the diaphragm is located.

3. The sound-generating unit as described in claim 1, characterized in that, The first magnet and the second magnet are spaced apart along the first direction, and a gap is formed between the first magnet and the second magnet, exposing the end of the first magnetically conductive part away from the magnetic gap.

4. The sound-generating unit as described in claim 1, characterized in that, The flat voice coil includes two long shaft segments spaced apart along a first direction and two connecting segments located at both ends of the long shaft segments and connected to the two long shaft segments, with the two long shaft segments corresponding to the magnetic gap.

5. The sound-generating unit as described in claim 4, characterized in that, A plane passing through the center of the second magnetically conductive part and perpendicular to the first direction is defined as the center plane; wherein, The thickness of the long axis segment along the first direction is defined as H, the thickness of the first magnet along the second direction is defined as L1, and the angle between the straight line passing through the end of the first magnetic surface near the magnetic gap and the end of the first magnetic surface away from the magnetic gap and the central plane is defined as θ1, where H / 2L1≤tan|θ1|≤1.2H / L1; And / or, define the thickness of the long axis segment along the first direction as H, define the thickness of the second magnet along the second direction as L2, define the angle between the straight line passing through the end of the second magnetic surface near the magnetic gap and the end of the second magnetic surface away from the magnetic gap and the central plane as θ2, H / 2L2≤tan|θ2|≤1.2H / L2.

6. The sound-generating unit as described in claim 4, characterized in that, Define the center point of the end of the central magnetic plate away from the magnetic gap in the first direction as a1, define the center point of the long axis segment away from the diaphragm in the first direction as a2, define the distance between a1 and a2 in the first direction as d, 0mm≤|d|≤2H / 3; And / or, the thickness of the end of the central magnetic plate near the magnetic gap along the first direction is not greater than the thickness of the long axis segment along the first direction; And / or, if we define the thickness of the end of the second magnetically conductive part away from the magnetic gap along the first direction as d1, and define the thickness of the end of the second magnetically conductive part near the magnetic gap along the first direction as d2, then we have 0 < d1 / d2 ≤ 0.

72.

7. The sound-generating unit as described in claim 1, characterized in that, The thickness of the first magnetically conductive portion along the first direction is the same from the side closest to the second magnetically conductive portion to the side furthest from the second magnetically conductive portion, and the thickness of the first magnetically conductive portion at the end facing the second magnetically conductive portion along the first direction is not greater than the thickness of the second magnetically conductive portion at the end facing the first magnetically conductive portion along the first direction. And / or, the center of the first magnetically conductive part and the center of the second magnetically conductive part are arranged collinearly; And / or, the central magnetic plate further includes a third magnetic part, which is disposed on the side of the second magnetic part away from the first magnetic part. The thickness of the third magnetic part along the first direction is not less than the thickness of the end of the second magnetic part facing the magnetic gap along the first direction. The two sides of the third magnetic part disposed opposite to each other along the first direction are respectively connected to the first magnetic circuit and the second magnetic circuit.

8. The sound-generating unit as described in any one of claims 1 to 7, characterized in that, The central magnetic plate is an annular magnetic plate, and the central magnetic plate is a one-piece molded part; Alternatively, the central magnetic conductive plate may include two plates spaced apart along the second direction, with the two central magnetic conductive plates connected to the first magnetic circuit and the second magnetic circuit respectively on both sides along the first direction.

9. The sound-generating unit as described in any one of claims 1 to 7, characterized in that, Both the first magnet and the second magnet are magnetized along the first direction. The first magnet and the second magnet located on the same side of the magnetic gap are magnetized in opposite directions. The magnetization directions of the two first magnets are opposite. And / or, the magnetic circuit system further includes a magnetic guide plate, which is disposed on the side of the first magnetic circuit away from the second magnetic circuit; And / or, the magnetic circuit system further includes a magnetically conductive yoke, which is disposed on the side of the second magnetic circuit away from the first magnetic circuit.

10. The sound-generating unit as described in any one of claims 1 to 7, characterized in that, The sound-generating unit also includes a housing, the outer edge of the diaphragm is connected to the housing, the housing has a receiving space for accommodating the flat voice coil and the magnetic circuit system, and the two side walls of the housing arranged opposite to each other along the second direction are provided with through holes, the first magnetic circuit and the second magnetic circuit extend into the through holes; And / or, the diaphragm includes a diaphragm body and a reinforcing portion connected to the diaphragm body, and the flat voice coil is connected to the reinforcing portion.

11. A sound-generating module, characterized in that, The sound-generating module includes a housing and a sound-generating unit as described in any one of claims 1 to 10, wherein the sound-generating unit is disposed within the housing.

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