Speaker and Portable Terminal

Abstract

The present invention discloses a loudspeaker and a portable terminal. The loudspeaker includes a first vibration system, a second vibration system and a magnetic circuit system. The first vibration system includes a first diaphragm and a voice coil disposed inside the first diaphragm. The second vibration system includes a second diaphragm disposed opposite to the first diaphragm. The magnetic circuit system is disposed between the first diaphragm and the second diaphragm. A first sound cavity is formed between the magnetic circuit system and the first diaphragm, and the voice coil is received in the magnetic gap of the magnetic circuit system. A second sound cavity is formed between the magnetic circuit system and the second diaphragm, and a through hole is provided between the first sound cavity and the second sound cavity. The loudspeaker provided by the present invention has two sets of vibration systems, but only one set of voice coil and magnetic circuit system is adopted to realize the structure of bidirectional sound emission, which occupies a small volume and is convenient for wide application in portable terminals.

Description

Technical Field

[0001] The present invention relates to the field of electroacoustic technology, and particularly to a loudspeaker and a portable terminal. Background Art

[0002] At present, as an important component of a terminal with an audio playback function, loudspeakers have been widely used. For some terminals, especially portable terminals such as mobile phones, tablet computers, and earphones, the installation space available for the loudspeaker is very limited. Therefore, existing loudspeakers that can be applied to a narrow installation space usually adopt a structure in which a single diaphragm emits sound from the front. To achieve bidirectional sound emission, the prior art provides a loudspeaker that adopts a combined structure of two sets of voice coils and diaphragms and a magnetic circuit system, in which the magnetic circuit system has two magnetic gaps for accommodating the two voice coils respectively. However, such a loudspeaker is usually large in size and difficult to be widely used. Moreover, in the structure of the prior art, one combined structure of a voice coil and a diaphragm works independently of the other combined structure of a voice coil and a diaphragm. One is used as a high-frequency sound generator, and the other is used as a low-frequency sound generator, and simultaneous bidirectional sound emission cannot be achieved. Summary of the Invention

[0003] The main object of the present invention is to provide a loudspeaker, aiming to solve the technical problem that existing loudspeakers for realizing bidirectional sound emission are difficult to be widely used due to their large size.

[0004] To achieve the above object, the loudspeaker proposed by the present invention includes:

[0005] A first vibration system, including a first diaphragm and a voice coil disposed inside the first diaphragm;

[0006] A second vibration system, including a second diaphragm disposed opposite to the first diaphragm; and

[0007] A magnetic circuit system disposed between the first diaphragm and the second diaphragm. A first sound cavity is formed between the magnetic circuit system and the first diaphragm, and the voice coil is received in the magnetic gap of the magnetic circuit system; a second sound cavity is formed between the magnetic circuit system and the second diaphragm, and a through hole is provided between the first sound cavity and the second sound cavity;

[0008] The voice coil drives the first diaphragm to vibrate and generate sound, and the airflow generated by the vibration of the first diaphragm passes through the first sound cavity, the through hole, and the second sound cavity in sequence and is transmitted to the second diaphragm, thereby driving the second diaphragm to vibrate and generate sound.

[0009] Preferably, the through hole is provided on the magnetic circuit system.

[0010] Preferably, the magnetic circuit system includes a magnetic yoke, a central magnetic circuit portion and a side magnetic circuit portion disposed on the magnetic yoke; a magnetic gap for accommodating the voice coil is formed between the central magnetic circuit portion and the side magnetic circuit portion; at least one of the central magnetic circuit portion and the side magnetic circuit portion is provided with a permanent magnet; the through hole includes a central through hole corresponding to the magnetic yoke and the central magnetic circuit portion.

[0011] Preferably, the central magnetic circuit portion includes a magnetic yoke, a central magnetic steel disposed at the bottom of the magnetic yoke, and a magnetic conductive plate disposed on the top of the central magnetic steel;

[0012] A first inner hole is formed in the magnetic yoke, a second inner hole is formed in the central magnetic steel, and a third inner hole is formed in the magnetic yoke. The first inner hole, the second inner hole and the third inner hole communicate with each other to form the central through hole.

[0013] Preferably, the central magnetic steel includes two sub-magnetic steels spliced together, and the splicing seam of the two sub-magnetic steels is connected to the second inner hole; wherein, the two sub-magnetic steels are symmetric about a vertical plane passing through the center of the second inner hole; or, the two sub-magnetic steels are symmetric about the center of the second inner hole.

[0014] Preferably, a slit is provided on the central magnetic steel to communicate the inner wall surface of the second inner hole and the outer peripheral surface of the central magnetic steel.

[0015] Preferably, the magnetic circuit system includes a magnetic yoke, a central magnetic circuit portion and a side magnetic circuit portion disposed on the magnetic yoke; a magnetic gap for accommodating the voice coil is formed between the central magnetic circuit portion and the side magnetic circuit portion; at least one of the central magnetic circuit portion and the side magnetic circuit portion is provided with a permanent magnet; the through hole further includes side through holes corresponding to the magnetic gap and disposed on the magnetic yoke, and at least one side through hole is provided. When a plurality of side through holes are provided, the plurality of side through holes are arranged at intervals along the circumferential direction of the magnetic gap; or, the through hole further includes side through holes provided at the ends of the magnetic yoke.

[0016] Preferably, the sound generated on the side of the first diaphragm facing away from the second diaphragm is received by the human ear, and the sound generated on the side of the second diaphragm facing away from the first diaphragm is received by the human ear.

[0017] Preferably, the second diaphragm includes a central portion, a surround portion disposed around the central portion, and a fixing portion disposed around the surround portion; the central portion is a planar sheet-like structure, and the surround portion is a structure formed by one protrusion, or the surround portion is a wavy structure formed by at least one protrusion and at least one depression.

[0018] Preferably, the second diaphragm further includes a composite layer bonded to the central portion.

[0019] Preferably, the through hole includes a central through hole disposed corresponding to the center of the first diaphragm, the composite layer is disposed corresponding to the central through hole, the composite layer protrudes outward, and the concave surface of the outwardly protruding composite layer faces the central through hole.

[0020] Preferably, the first diaphragm includes a central portion, a surround portion disposed around the central portion, and a fixing portion disposed around the surround portion, and the central portion of the first diaphragm is a planar sheet structure.

[0021] The present invention also provides a portable terminal, including a housing having an accommodation cavity therein. The portable terminal further includes the loudspeaker, and the loudspeaker includes a first vibration system, a second vibration system, and a magnetic circuit system. The first vibration system includes a first diaphragm and a voice coil disposed inside the first diaphragm; the second vibration system includes a second diaphragm disposed opposite to the first diaphragm; the magnetic circuit system is disposed between the first diaphragm and the second diaphragm, a first sound cavity is formed between the magnetic circuit system and the first diaphragm, the voice coil is received in the magnetic gap of the magnetic circuit system; a second sound cavity is formed between the magnetic circuit system and the second diaphragm, and the magnetic circuit system is provided with a through hole communicating the first sound cavity and the second sound cavity; the loudspeaker is installed in the accommodation cavity, and the housing is provided with a first sound hole corresponding to the first diaphragm and a second sound hole corresponding to the second diaphragm.

[0022] Preferably, the housing has a front surface and a back surface disposed opposite to each other, the first sound hole is disposed on the front surface of the housing, and the second sound hole is disposed on the back surface of the housing; the space of the first diaphragm facing away from the second diaphragm communicates with the first sound hole, and the first sound hole is used for conducting the sound emitted by the first diaphragm; the space of the second diaphragm facing away from the first diaphragm communicates with the second sound hole, and the second sound hole is used for conducting the sound emitted by the second diaphragm.

[0023] The loudspeaker of the present invention has a small occupied volume by adopting a structure of setting two sets of vibration systems but only one set of voice coil and magnetic circuit system to realize two-way sound emission, and is convenient for being widely applied to portable terminals. When the loudspeaker of the present invention works, first, the magnetic circuit system directly drives the diaphragm of the first vibration system, so that the air in the first sound cavity is compressed or expanded. Since there is a through hole communicating between the first sound cavity and the second sound cavity, the air flows through the through hole, and under the push of the air flow, the diaphragm of the second vibration system vibrates and emits sound accordingly, and the second sound cavity is linked to expand or compress. Thus, a two-way sound emission structure of the first diaphragm on the front surface actively radiating and the second diaphragm on the back surface passively radiating is formed, and the first diaphragm and the second diaphragm vibrate simultaneously to realize two-way sound emission at the same time. When applied to a portable terminal, the loudspeaker of the present invention can emit sound in two opposite directions of the portable terminal through the first vibration system and the second vibration system respectively. Description of the Drawings

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0025] Figure 1 Front structural schematic diagram of an embodiment of the loudspeaker of the present invention;

[0026] Figure 2 For Figure 1 Rear structural schematic diagram of the loudspeaker in

[0027] Figure 3 For Figure 1 One cross-sectional structural schematic diagram of the loudspeaker in , in which the first embodiment of the second diaphragm is schematically shown;

[0028] Figure 4 For Figure 3 Right-end enlarged schematic diagram of the structure in ;

[0029] Figure 5 For Figure 3 Right-end enlarged schematic diagram of the structure in , in which the first embodiment of the second diaphragm is replaced by the second embodiment of the second diaphragm;

[0030] Figure 6 For Figure 1 One cross-sectional structural schematic diagram of the loudspeaker in , in which the third embodiment of the second diaphragm is schematically shown;

[0031] Figure 7 For Figure 6 Partial enlarged view at A in .

[0032] Figure 8 For Figure 1 Partial structural schematic diagram of the loudspeaker in ;

[0033] Figure 9 For Figure 1 Exploded structural schematic diagram of the loudspeaker in , in which the first embodiment of the magnetic circuit system is schematically shown;

[0034] Figure 10 Structural schematic diagram of the second embodiment of the magnetic circuit system of the loudspeaker of the present invention;

[0035] Figure 11 Structural schematic diagram of the third embodiment of the magnetic circuit system of the loudspeaker of the present invention;

[0036] Figure 12 Structural schematic diagram of the fourth embodiment of the magnetic circuit system of the loudspeaker of the present invention;

[0037] Figure 13 Schematic diagram of the front structure of an embodiment of the portable terminal of the present invention;

[0038] Figure 14 is Figure 13 Schematic diagram of the back structure of the portable terminal in

[0039] Figure 15 is Figure 13 Schematic diagram of the partial cross-sectional structure at position B in

[0040] Explanation of the reference numerals in the drawings:

[0041]

[0042]

[0043] The realization, functional features and advantages of the object of the present invention will be further described in conjunction with the embodiments with reference to the accompanying drawings. Detailed implementation manners

[0044] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than 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 making creative efforts belong to the scope of protection of the present invention.

[0045] It should be noted that all directional indications (such as up, down, left, right, front, back,...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0046] In addition, the descriptions involving "first", "second", etc. in the present invention are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of the technical solutions appears to be contradictory or unable to be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0047] The present invention provides a loudspeaker. Please refer to Figures 1 to 3 and Figure 8 , in an embodiment, the loudspeaker 210 includes:

[0048] The first vibration system 1 includes a first diaphragm 11 and a voice coil 12 disposed inside the first diaphragm 11;

[0049] The second vibration system 2 includes second diaphragms (21a, 21b, 21c) disposed opposite to the first diaphragm 11; and

[0050] A magnetic circuit system (3a, 3b, 3c, 3d) is disposed between the first diaphragm 11 and the second diaphragms (21a, 21b, 21c). A first sound cavity 4 is formed between the magnetic circuit system (3a, 3b, 3c, 3d) and the first diaphragm 11. The voice coil 12 is received in a magnetic gap 31 of the magnetic circuit system (3a, 3b, 3c, 3d). A second sound cavity 5 is formed between the magnetic circuit system (3a, 3b, 3c, 3d) and the second diaphragms (21a, 21b, 21c). A through hole 32 is provided between the first sound cavity 4 and the second sound cavity 5.

[0051] The voice coil 12 drives the first diaphragm 11 to vibrate and generate sound. The airflow generated by the vibration of the first diaphragm 11 passes through the first sound cavity 4, the through hole 32, and the second sound cavity 5 in sequence and is transmitted to the second diaphragms (21a, 21b, 21c), thereby driving the second diaphragms (21a, 21b, 21c) to vibrate and generate sound.

[0052] In this embodiment, for the sake of simplicity of description, the position when the first diaphragm 11 of the speaker 210 is placed upward is used as a reference to define up and down, that is, the side of the first diaphragm 11 facing away from the magnetic circuit system (3a, 3b, 3c, 3d) is up, and the side of the first diaphragm 11 facing the magnetic circuit system (3a, 3b, 3c, 3d) is down.

[0053] The first vibration system 1 may refer to an existing form. Specifically, the voice coil 12 is fixedly connected to the first diaphragm 11 and extends into the magnetic gap 31. When a varying current is applied to the voice coil 12, it is subjected to Ampere forces of different magnitudes and vibrates. The vibration of the voice coil 12 drives the vibration of the first diaphragm 11, and its energy conversion mode is electrical energy - mechanical energy - sound energy. To adjust the frequency characteristics of the vibration, the first vibration system 1 may further include a counterweight.

[0054] The form of the magnetic circuit system (3a, 3b, 3c, 3d) may also refer to an existing structure. For example, the magnetic gap 31 can be formed either between the central magnet (34a, 34b, 34c, 34d) and the edge magnet, or between the central magnet (34a, 34b, 34c, 34d) and the side wall of the magnetic yoke 33. The top view shape of the central magnet (34a, 34b, 34c, 34d) can be either circular or rounded rectangular, etc.

[0055] To facilitate the installation of the first vibration system 1, the second vibration system 2, and the magnetic circuit system (3a, 3b, 3c, 3d) located therebetween, the loudspeaker 210 further includes a housing 6, a front cover 7, and a rear cover 8. The housing 6 is used to accommodate the first vibration system 1, the second vibration system 2, and the magnetic circuit system (3a, 3b, 3c, 3d). The front cover 7 and the rear cover 8 cooperate with the housing 6 to form a protection frame. Specifically, the edge portion of the first diaphragm 11 for fixation is clamped by the front cover 7 and the housing 6, and the edge portion of the second diaphragm (21a, 21b, 21c) for fixation is clamped by the rear cover 8 and the housing 6. The front cover 7 is disposed corresponding to the first vibration system 1 and is provided with a front sound outlet hole 71 for sound to exit, and the rear cover 8 is disposed corresponding to the second vibration system 2 and is provided with a rear sound outlet hole 81 for sound to exit.

[0056] The opening form of the through hole 32 can be to only open the magnetic circuit system (3a, 3b, 3c, 3d), or it can be opened on the housing 6, as long as it can communicate the first sound cavity 4 and the second sound cavity 5, and the flow area of the through hole 32 is large enough so that the airflow flowing through the through hole 32 can drive the second diaphragm (21a, 21b, 21c) to generate sound.

[0057] The loudspeaker 210 of the present invention has a small occupied volume by adopting a structure of setting two sets of vibration systems but only using one set of voice coils 12 and magnetic circuit systems (3a, 3b, 3c, 3d) to achieve two-way sound emission, and is convenient for being widely applied to the portable terminal 100. When the loudspeaker 210 of the present invention works, first, the magnetic circuit system (3a, 3b, 3c, 3d) directly drives the diaphragm of the first vibration system 1, so that the air in the first sound cavity 4 is compressed or expanded. Since there is a through hole 32 communicating between the first sound cavity 4 and the second sound cavity 5, the air flows through the through hole 32. Driven by the airflow, the diaphragm of the second vibration system 2 vibrates to generate sound, and the second sound cavity 5 is linked to expand or contract. Thus, a two-way sound emission structure of active radiation of the first diaphragm 11 on the front side and passive radiation of the second diaphragm (21a, 21b, 21c) on the back side is formed, and the first diaphragm 11 and the second diaphragm (21a, 21b, 21c) vibrate simultaneously to achieve two-way sound emission at the same time. When applied to the portable terminal 100, the loudspeaker 210 of the present invention can emit sound in two opposite directions of the portable terminal 100 through the first vibration system 1 and the second vibration system 2 respectively.

[0058] Furthermore, the through hole 32 is provided on the magnetic circuit system (3a, 3b, 3c, 3d).

[0059] In this embodiment, the through hole 32 can be opened on the bottom wall of the magnetic yoke 33, corresponding to communicating the magnetic gap 31 and the second sound cavity 5, or can be opened on the side surface of the central magnet (34a, 34b, 34c, 34d) and bent downward in the central magnet (34a, 34b, 34c, 34d) and then penetrate the bottom wall of the magnetic yoke 33. As an example, the airflow in the through hole 32 is asFigure 3 as shown by AF in the figure.

[0060] Further, the magnetic circuit system includes a magnetic yoke 33, and a central magnetic circuit part and side magnetic circuit parts (both not marked) provided on the magnetic yoke 33;

[0061] A magnetic gap 31 for accommodating the voice coil 12 is formed between the central magnetic circuit part and the side magnetic circuit parts;

[0062] At least one of the central magnetic circuit part and the side magnetic circuit parts is provided with a permanent magnet;

[0063] The through hole 32 includes a central through hole 321 corresponding to the magnetic yoke 33 and the central magnetic circuit part.

[0064] In this embodiment, since the amplitude of the central part of the first diaphragm 11 is usually the largest, by arranging the central through hole 321 corresponding to the central part of the first diaphragm 11, a relatively large amount of air flow can be transmitted, and then the air flow can be better utilized to push the second diaphragms (21a, 21b, 21c).

[0065] Further, please refer to Figures 9 to 12 , the central magnetic circuit part of the magnetic circuit system (3a, 3b, 3c, 3d) includes central magnetic steels (34a, 34b, 34c, 34d) provided at the bottom of the magnetic yoke 33, and a magnetic conductive plate 35 provided on the top of the central magnetic steels (34a, 34b, 34c, 34d);

[0066] A first inner hole 331 is formed on the magnetic yoke 33, second inner holes (341a, 341b, 341c, 341d) are formed on the central magnetic steels (34a, 34b, 34c, 34d), a third inner hole 351 is formed on the magnetic yoke 33, and the first inner hole 331, the second inner holes (341a, 341b, 341c, 341d) and the third inner hole 351 communicate to form the central through hole 321.

[0067] In this embodiment, the central through hole 321 directly penetrates the magnetic yoke 33, the central magnetic steels (34a, 34b, 34c, 34d) and the magnetic conductive plate 35, with a simple form, which is beneficial to promoting the gas flow between the first sound cavity 4 and the second sound cavity 5.

[0068] Further, please refer to Figure 10 and Figure 11For the magnetic circuit systems of the second and third embodiments shown, the central magnet (34b, 34c) includes two sub-magnets (342b, 342c) joined together, and the seam between the two sub-magnets (342b, 342c) is connected to the second inner hole (341b, 341c). In this embodiment, the second inner hole (341b, 341c) is formed by splicing the two sub-magnets (342b, 342c), and the inner wall surface of the second inner hole (341b, 341c) is actually transformed into the outer peripheral surface of each sub-magnet (342b, 342c), that is, the open groove wall surface on the outer peripheral surface of the sub-magnets (342b, 342c). In this way, it is convenient for the central magnet (34b, 34c) to form the second inner hole (341b, 341c) in terms of processing.

[0069] Preferably, in order to facilitate assembly and improve the interchangeability of the raw materials of the two sub-magnets (342b, 342c), the two sub-magnets (342b, 342c) are symmetric about a vertical plane passing through the center of the second inner hole (341b, 341c) or the two sub-magnets (342b, 342c) are symmetric about the center of the second inner hole (341b, 341c). Specifically, when assembling the central magnet (34b, 34c), the blanks of the two sub-magnets (342b, 342c) before magnetization can be joined first, and then magnetized. The blanks of the two sub-magnets (342b, 342c) can be interchanged, so only one kind of blank with a certain shape and size needs to be provided.

[0070] Further, please refer to Figure 12 For the fourth embodiment of the magnetic circuit system shown, a slit 342d communicating the inner wall surface of the second inner hole 341d and the outer peripheral surface of the central magnet 34d is provided on the central magnet 34d. In this embodiment, it is suitable to adopt the wire cutting process to machine the second inner hole 341d. Specifically, the slit 342d can be machined first, and then the second inner hole 341d is machined. Compared with drilling the second inner hole 341d, it is more practical.

[0071] Preferably, please refer to Figures 8 to 12 again. The first diaphragm 11, the second diaphragms (21a, 21b, 21c) and the central magnets (34a, 34b, 34c, 34d) are all strip-shaped, the long axes of the first diaphragm 11, the second diaphragms (21a, 21b, 21c) and the central magnets (34a, 34b, 34c, 34d) are located in the same vertical plane, and the central through hole 321 extends along the length direction of the central magnet (34a, 34b, 34c, 34d).

[0072] In this embodiment, it can be understood that the vertical plane is a plane parallel to the up-down direction. Since the first diaphragm 11, the second diaphragms (21a, 21b, 21c) and the central magnetic steel (34a, 34b, 34c, 34d) are all strip-shaped, correspondingly, the shape of the loudspeaker 210 is also strip-shaped. Compared with a circular shape, this structure has a higher space utilization rate when applied to the portable terminal 100. At the same time, on the premise of the same area, the strip-shaped first diaphragm 11 and the second diaphragms (21a, 21b, 21c) are more likely to obtain a larger amplitude. For the first diaphragm 11, it can actively fan a larger amount of air towards the central through-hole 321, and the second diaphragms (21a, 21b, 21c) are more easily pushed by the air flow passing through the central through-hole 321.

[0073] Further, the magnetic circuit system includes a magnetic yoke 33 and a central magnetic circuit part and a side magnetic circuit part (both not labeled) provided on the magnetic yoke 33;

[0074] A magnetic gap 31 for accommodating the voice coil 12 is formed between the central magnetic circuit part and the side magnetic circuit part;

[0075] At least one of the central magnetic circuit part and the side magnetic circuit part is provided with a permanent magnet;

[0076] The through-hole 32 further includes side through-holes 322 provided on the magnetic yoke 33 corresponding to the magnetic gap 31. There is at least one side through-hole 322. When there are multiple side through-holes 322, the multiple side through-holes 322 are arranged at intervals along the circumferential direction of the magnetic gap 31; alternatively, the through-hole 322 further includes side through-holes 322 provided at the ends of the magnetic yoke 33.

[0077] In this embodiment, the side through-holes 322 can be separately provided at the ends of the magnetic yoke 33, or provided on the magnetic yoke 33 and corresponding to the magnetic gap 31. In a preferred embodiment, the side through-holes 322 can also be provided in combination with the central through-hole 321, which further increases the connectivity between the first sound cavity 4 and the second sound cavity 5. Furthermore, when the first diaphragm 11 vibrates, more air can flow between the first sound cavity 4 and the second sound cavity 5 per unit time, and the second diaphragms (21a, 21b, 21c) can also be driven to a greater extent.

[0078] It can be understood that there is at least one side through-hole 322. In order to increase the flow area as much as possible, there are multiple side through-holes 322, and the multiple side through-holes 322 are arranged at intervals along the circumferential direction of the magnetic gap 31. In this way, both the balance of connectivity and the balanced connection of the magnetic circuit can be ensured.

[0079] Preferably, the magnetic circuit system (3a, 3b, 3c, 3d) includes a magnetic yoke 33, a central magnet (34a, 34b, 34c, 34d) disposed at the bottom of the magnetic yoke 33, and a magnetic plate 35 disposed on top of the central magnet (34a, 34b, 34c, 34d);

[0080] The magnetic yoke 33 is provided with a first inner hole 331, the central magnet (34a, 34b, 34c, 34d) is provided with a second inner hole (341a, 341b, 341c, 341d), the magnetic yoke 33 is provided with a third inner hole 351, and the first inner hole 331, the second inner hole (341a, 341b, 341c, 341d) and the third inner hole 351 communicate to form a central through hole 321. The side through hole 322 is opened at the bottom of the magnetic yoke 33. Since the bottom of the magnetic yoke 33 is closest to the second sound cavity 5 compared to the central magnet (34a, 34b, 34c, 34d) and the magnetic plate 35, it is most convenient to process the side through hole 322 at the bottom of the magnetic yoke 33.

[0081] Furthermore, the first diaphragm 11, the second diaphragms (21a, 21b, 21c) and the central magnet (34a, 34b, 34c, 34d) are all strip-shaped. The long axes of the first diaphragm 11, the second diaphragms (21a, 21b, 21c) and the central magnet (34a, 34b, 34c, 34d) are located in the same vertical plane, and the central through hole 321 extends along the length direction of the central magnet (34a, 34b, 34c, 34d).

[0082] In this embodiment, it can be understood that the vertical plane is a plane parallel to the up and down direction. Since the first diaphragm 11, the second diaphragms (21a, 21b, 21c) and the central magnet (34a, 34b, 34c, 34d) are all strip-shaped, correspondingly, the shape of the loudspeaker 210 is also strip-shaped. Compared with a circular shape, this structure has a higher space utilization rate when applied to the portable terminal 100. At the same time, on the premise of the same area, the strip-shaped first diaphragm 11 and the second diaphragms (21a, 21b, 21c) are more likely to obtain a larger diaphragm. For the first diaphragm 11, it can actively fan a larger amount of air, and the second diaphragms (21a, 21b, 21c) are more easily pushed by the air flow passing through the central through hole 321 and the side through hole 322.

[0083] Further, the sound generated on the side of the first diaphragm 11 facing away from the second diaphragms (21a, 21b, 21c) is received by the human ear, and the sound generated on the side of the second diaphragms (21a, 21b, 21c) facing away from the first diaphragm 11 is received by the human ear. In this embodiment, both the first diaphragm 11 and the second diaphragms (21a, 21b, 21c) can generate sounds within the audible range of the human ear. For example, the frequency range is 20 - 20000 HZ. In this way, the user can directly receive sound information from both the front and back directions of the speaker. It can be understood that in other embodiments, the first diaphragm 11 and the second diaphragms (21a, 21b, 21c) can also be used to generate sounds in other frequency ranges, such as the "sound password" within the corresponding audible range of the human ear. This kind of sound can be decoded by a machine to achieve corresponding signal transmission.

[0084] Further, please refer to Figure 4 and Figure 5 , the second diaphragms (21a, 21b) include a central portion 211, a surround portion (212a, 212b) provided around the central portion 211, and a fixing portion 213 provided around the surround portion (212a, 212b); the central portion 211 is a planar sheet-like structure, and the surround portion (212a, 212b) is a structure formed by one protrusion, or the surround portion is a wavy structure formed by at least one protrusion and at least one depression.

[0085] In this embodiment, the central portion 211 is used to sense the density change of the air in the second sound cavity 5 and vibrate accordingly to generate sound, that is, passive radiation sound generation. By setting the central portion 211 as a planar sheet-like structure, the second diaphragms (21a, 21b) occupy less space in the up and down directions and can generate a sufficiently large amplitude. The surround portion (212a, 212b) provides a certain compliance for the movement of the central portion 211, that is, provides a certain flexibility, making the central portion 211 more easily pushed by the air flow passing through the central through hole 321 and the side through hole 322.

[0086] Further, please refer to Figure 6 , the second diaphragm 21c further includes a composite layer 214 bonded to the central portion 211. The setting of the composite layer 214 can reduce the mass of the second diaphragm 21c and ensure that the second diaphragm 21c is more easily pushed by the air flow. Preferably, in order to ensure better sound generation performance of the second diaphragm 21c for passive radiation, the composite layer 214 is made of a material with a high specific modulus, such as aluminum composite material, aluminum, aluminum magnesium alloy, magnesium lithium alloy material, carbon fiber, PEN (polyethylene naphthalate), LCP (Liquid Crystal Polymer), foam, etc.

[0087] Further, the through-hole 32 includes a central through-hole 321 disposed corresponding to the center of the first diaphragm 11. The composite layer 214 is disposed corresponding to the central through-hole 321. The composite layer 214 protrudes outward, and the concave surface of the outwardly protruding composite layer 214 faces the central through-hole 321.

[0088] In this embodiment, the concave surface of the composite layer 214 faces the central through-hole 321. Thus, when the airflow flowing from the central through-hole 321 to the second sound cavity 5 acts on the composite layer 214, it can be "held" by the composite layer 214, and the thrust acting on the second diaphragm 21c can act more concentratedly on the central portion 211 of the second diaphragm 21c, and thus a larger amplitude of vibration can be generated.

[0089] Further, since the second diaphragm (21a, 21b, 21c) uses passive radiation to generate sound, in order to ensure that the second diaphragm (21a, 21b, 21c) is more easily pushed by the airflow, the second diaphragm (21a, 21b, 21c) is made of a material with a relatively low elastic modulus. For example, if the first diaphragm 11 and the second diaphragm (21a, 21b, 21c) both include a central portion, a surround portion disposed around the central portion, and a fixing portion disposed around the surround portion, that is, the two diaphragms adopt the same structure, then the elastic modulus of the central portion of the second diaphragm (21a, 21b, 21c) is lower than that of the central portion of the first diaphragm, and the elastic modulus of the surround portion of the second diaphragm (21a, 21b, 21c) is lower than that of the surround portion of the first diaphragm 11.

[0090] Further, the first diaphragm 11 includes a central portion, a surround portion disposed around the central portion, and a fixing portion disposed around the surround portion. The central portion of the first diaphragm 11 is a flat sheet-like structure. Similarly, by setting the central portion of the first diaphragm 11 as a flat sheet-like structure, the first diaphragm 11 occupies less space in the up and down directions and can generate a sufficiently large amplitude. After combining with the embodiment in which the central portion of the second diaphragm (21a, 21b, 21c) is also set as a sheet-like structure, the loudspeaker body provided by the present invention forms a relatively thin structure in the up and down directions as a whole. Thus, it is more easily applied to a flat installation space.

[0091] The present invention also proposes a portable terminal 100. Please refer to Figures 13 to 15 , the portable terminal 100 includes a housing 110. The housing 110 has an accommodation cavity 120 inside. The portable terminal 100 further includes a loudspeaker 210. The specific structure of the loudspeaker 210 refers to the above embodiments. Since the present portable terminal 100 adopts all the technical solutions of the above all embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be elaborated herein one by one.

[0092] The speaker 210 is installed in the accommodation cavity 120. The housing 110 is provided with a first sound hole 130 corresponding to the first diaphragm 11 and a second sound hole 140 corresponding to the second diaphragms (21a, 21b, 21c). Preferably, in order to shorten the sound propagation path inside the housing 110 and reduce the acoustic resistance, the first sound hole 130 is opened at a position of the housing 110 facing the first diaphragm 11, and the second sound hole 140 is opened at a position of the housing 110 facing the second diaphragms (21a, 21b, 21c).

[0093] Furthermore, the housing 110 has a front surface and a back surface which are oppositely arranged. The first sound hole 130 is provided on the front surface of the housing 110, and the second sound hole 140 is provided on the back surface of the housing 110;

[0094] The space where the first diaphragm 11 faces away from the second diaphragms (21a, 21b, 21c) communicates with the first sound hole 130, and the first sound hole 130 is used for conducting the sound emitted by the first diaphragm 11;

[0095] The space where the second diaphragms (21a, 21b, 21c) face away from the first diaphragm 11 communicates with the second sound hole 140, and the second sound hole 140 is used for conducting the sound emitted by the second diaphragms (21a, 21b, 21c). In this way, the speaker 210 can emit sound in two opposite directions, i.e., the front and the back of the portable terminal 100, through the first vibration system 1 and the second vibration system 2 respectively.

[0096] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. All equivalent structural transformations made under the inventive concept of the present invention by using the content of the specification and drawings of the present invention, or direct / indirect applications in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A loudspeaker, characterized in that, Comprising: A first vibration system, including a first diaphragm and a voice coil disposed inside the first diaphragm; A second vibration system, including a second diaphragm disposed opposite to the first diaphragm; and A magnetic circuit system, disposed between the first diaphragm and the second diaphragm, a first sound cavity is formed between the magnetic circuit system and the first diaphragm, the voice coil is received in the magnetic gap of the magnetic circuit system; a second sound cavity is formed between the magnetic circuit system and the second diaphragm, and a through hole is provided between the first sound cavity and the second sound cavity; The voice coil drives the first diaphragm to vibrate and generate sound, and the air flow generated by the vibration of the first diaphragm passes through the first sound cavity, the through hole, and the second sound cavity in sequence and is transmitted to the second diaphragm, thereby driving the second diaphragm to vibrate and generate sound; The through hole is provided on the magnetic circuit system.

2. The loudspeaker according to claim 1, wherein The magnetic circuit system includes a magnetic yoke and a central magnetic circuit portion and a peripheral magnetic circuit portion disposed on the magnetic yoke; A magnetic gap for accommodating the voice coil is formed between the central magnetic circuit portion and the peripheral magnetic circuit portion; At least one of the central magnetic circuit portion and the peripheral magnetic circuit portion is provided with a permanent magnet; The through hole includes a central through hole corresponding to the magnetic yoke and the central magnetic circuit portion.

3. The loudspeaker according to claim 2, wherein The central magnetic circuit portion includes a central magnet disposed at the bottom of the magnetic yoke and a magnetic conductive plate disposed on the top of the central magnet; a first inner hole is formed in the magnetic yoke, a second inner hole is formed in the central magnet, and a third inner hole is formed in the magnetic conductive plate, and the first inner hole, the second inner hole, and the third inner hole communicate to form the central through hole.

4. The loudspeaker according to claim 3, wherein The central magnet includes two sub-magnets spliced together, and the splicing seam of the two sub-magnets is connected to the second inner hole, wherein The two sub-magnets are symmetric about a vertical plane passing through the center of the second inner hole; or, The two sub-magnets are symmetric about the center of the second inner hole.

5. The loudspeaker according to claim 3, characterized in that, A slit is provided on the central magnet to communicate the inner wall surface of the second inner hole and the outer peripheral surface of the central magnet.

6. The loudspeaker according to any one of claims 2-5, characterized in that, The magnetic circuit system includes a magnetic yoke and a central magnetic circuit portion and a peripheral magnetic circuit portion disposed on the magnetic yoke; A magnetic gap for accommodating the voice coil is formed between the central magnetic circuit portion and the peripheral magnetic circuit portion; At least one of the central magnetic circuit portion and the peripheral magnetic circuit portion is provided with a permanent magnet; The through hole further includes a peripheral through hole corresponding to the magnetic gap and provided on the magnetic yoke, and at least one peripheral through hole is provided. When a plurality of peripheral through holes are provided, the plurality of peripheral through holes are arranged at intervals along the circumference of the magnetic gap; or, The through hole further includes a peripheral through hole provided at the end of the magnetic yoke.

7. The loudspeaker according to any one of claims 1-5, characterized in that, The sound generated on the side of the first diaphragm facing away from the second diaphragm is received by the human ear, and the sound generated on the side of the second diaphragm facing away from the first diaphragm is received by the human ear.

8. The loudspeaker according to claim 1, wherein The second diaphragm includes a central portion, a surround portion disposed around the central portion, and a fixing portion disposed around the surround portion; the central portion is a planar sheet-like structure, the surround portion is a structure formed by a single protrusion, or the surround portion is a wavy structure formed by at least one protrusion and at least one recess.

9. The loudspeaker according to claim 8, wherein, The second diaphragm further includes a composite layer bonded to the central portion.

10. The loudspeaker according to claim 9, characterized in that, The through hole includes a central through hole disposed corresponding to the center of the first diaphragm, the composite layer is disposed corresponding to the central through hole, the composite layer protrudes outward, and the concave surface of the outwardly protruding composite layer faces the central through hole.

11. The loudspeaker according to any one of claims 1-5, 8-10, characterized in that, The first diaphragm includes a central portion, a surround portion disposed around the central portion, and a fixing portion disposed around the surround portion, and the central portion of the first diaphragm is a planar sheet-like structure.

12. A portable terminal, comprising a housing, wherein an accommodation cavity is provided inside the housing, and characterized in that, It further includes the loudspeaker according to any one of claims 1-11, the loudspeaker is installed in the accommodating cavity, and the housing is provided with a first sound hole corresponding to the first diaphragm and a second sound hole corresponding to the second diaphragm.

13. The portable terminal according to claim 12, characterized in that, The housing has a front surface and a back surface disposed opposite to each other, the first sound hole is disposed on the front surface of the housing, and the second sound hole is disposed on the back surface of the housing; The space of the first diaphragm facing away from the second diaphragm communicates with the first sound hole, and the first sound hole is used for conducting the sound emitted by the first diaphragm; The space of the second diaphragm facing away from the first diaphragm communicates with the second sound hole, and the second sound hole is used for conducting the sound emitted by the second diaphragm.

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