A flat-plate voice coil loudspeaker

Abstract

This utility model discloses a planar voice coil loudspeaker. The housing contains a planar voice coil, a diaphragm, a magnetic ring, and a first magnet. The planar voice coil is fixedly mounted on the lower end face of the diaphragm. The first magnet is located within the inner ring of the magnetic ring, with a magnetic field gap between the outer surface of the first magnet and the inner surface of the magnetic ring. The planar voice coil is positioned above this magnetic field gap. An upper sound outlet is located at the center of the upper end face of the housing, and a lower sound outlet is located at the center of the lower end face. A through-hole, running vertically through the first magnet, is located at the center of the first magnet. The through-hole, upper sound outlet, and lower sound outlet are all coaxially arranged. The upper and lower sound outlets connect the cavity of the housing to the atmosphere, creating dual-sided sound emission, expanding the effective bandwidth, eliminating frequency response distortion caused by pressure differences, particularly improving high-frequency loss, and enhancing sound quality. The airflow generated during diaphragm vibration enters and exits vertically, avoiding noise. The first magnet, located within the inner ring of the magnetic ring, works in conjunction with the planar voice coil to reduce the overall volume.

Description

Technical Field

[0001] This utility model relates to the field of loudspeaker technology, and in particular to a flat panel voice coil loudspeaker. Background Technology

[0002] A planar voice coil loudspeaker is a dynamic loudspeaker, consisting of a housing and a diaphragm, voice coil, and magnet installed inside the housing. The voice coil is a coil made of fine copper wire. The voice coil is often wrapped around the magnet and fixed to the diaphragm. Its working principle is that when an electrical signal is given to the voice coil, the voice coil moves under the influence of the magnetic field, thereby causing the diaphragm to vibrate, which in turn pushes the air to produce sound. It is commonly used in electronic devices such as headphones, mobile phones, tablets, and laptops.

[0003] When traditional planar voice coil speakers are used in small electronic devices, it is difficult to obtain a wide frequency range in order to reduce the size. This results in a decrease in sound quality after the size is reduced, and it is impossible to achieve both small size and wide frequency range. In addition, the magnetic field strength is weak and its response sensitivity is low.

[0004] On the other hand, the diaphragm divides the inner cavity of the housing into two chambers, while traditional planar voice coil speakers only have one sound outlet. Therefore, only one chamber is connected to the atmosphere through the sound outlet, while the other chamber is sealed. When the diaphragm vibrates, the pressure in the sealed chamber changes, resulting in insufficient high-frequency sound. Furthermore, with only one sound outlet, the sound direction is singular, and the volume is low. To solve this problem, a balance hole is often set in the housing to connect the sealed cavity to the atmosphere, thereby avoiding pressure difference between the two chambers. However, traditional balance holes are often off-center, while the impact generated by the diaphragm during vibration is towards the center. This results in air not being discharged vertically. The air hitting the inner wall of the housing will generate rebound airflow, producing noise. Therefore, it is necessary to improve this design. Utility Model Content

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a flat-panel voice coil speaker that reduces size while increasing frequency range, improving sound quality, enhancing sensitivity, and avoiding noise.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a planar voice coil speaker, comprising a housing and a PCB board, the PCB board being fixedly mounted on the end face of the housing, a planar voice coil, a diaphragm, a magnetic ring, and a first magnet being disposed inside the housing, the planar voice coil being fixedly mounted on the lower end face of the diaphragm, the first magnet being disposed in the inner ring of the magnetic ring and coaxially disposed with the magnetic ring, a magnetic field gap being formed between the outer surface of the first magnet and the inner surface of the magnetic ring, the planar voice coil being located above the magnetic field gap, an upper sound outlet being provided at the center of the upper end face of the housing, a lower sound outlet being provided at the center of the lower end face of the housing, and a through hole penetrating the first magnet vertically at the center of the first magnet, the through hole, the upper sound outlet, and the lower sound outlet being coaxially disposed.

[0007] In a further technical solution, tuning meshes are attached to the upper and lower surfaces of the housing, and the two tuning meshes are respectively placed over the upper sound outlet and the lower sound outlet.

[0008] In a further technical solution, the diameter of the upper sound outlet is larger than the diameter of the lower sound outlet, and a clearance hole is provided in the center of the PCB board. The clearance hole is coaxially arranged with the lower sound outlet, and the diameter of the clearance hole is larger than the diameter of the lower sound outlet. The tuning mesh located on the lower end face of the housing is set in the clearance hole.

[0009] In a further technical solution, the diaphragm includes a flat tympanic membrane, a raised tympanic membrane, and a fixing ring. The raised tympanic membrane is formed on the outer edge of the flat tympanic membrane and arches upward. The fixing ring is formed on the outer edge of the raised tympanic membrane, and the flat voice coil is attached to the lower end face of the flat tympanic membrane.

[0010] In a further technical solution, a second magnet is also provided inside the housing, and the second magnet is positioned above the diaphragm.

[0011] In a further technical solution, the housing includes an upper cover and a lower steel sleeve. The lower steel sleeve has an opening at the top. The upper cover is located at the top of the lower steel sleeve. The outer edge of the upper cover abuts against the inner wall of the lower steel sleeve and abuts against the outer edge of the diaphragm. The upper sound outlet is located at the center of the upper cover, and the lower sound outlet is located at the center of the lower steel sleeve.

[0012] In a further technical solution, a clearance plane is provided on one side of the magnetic ring to form a magnetic ring with an outer contour of "D". The clearance plane and the shell enclose a wiring groove.

[0013] In a further technical solution, a wire-passing hole is provided at the position of the lower steel sleeve corresponding to the wiring groove, which runs through the lower steel sleeve along the vertical line. The wire-passing hole is connected to the wiring groove, and a wiring notch is opened at the position of the PCB board corresponding to the wiring groove.

[0014] In a further technical solution, two solder joints are provided on the lower end face of the PCB board near the wiring notch, and two external solder joints are provided on the lower end face of the PCB board away from the wiring notch. The planar voice coil is provided with two leads. The two leads pass through the wiring groove, the wiring hole and the wiring notch in sequence and are connected to the two solder joints respectively. The wiring groove, the wiring hole and the wiring notch are all filled with waterproof glue.

[0015] In a further technical solution, the upper cover includes a protective plate, a protective ring, and a sealing ring. The upper edge of the protective ring is formed on the outer edge of the protective plate, and the inner ring of the sealing ring is formed on the lower edge of the protective ring and protrudes from the outer side of the protective ring. The outer side of the sealing ring abuts against the inner wall of the lower steel sleeve and abuts against and cooperates with the outer edge of the diaphragm. A sealing gap is formed between the outer wall of the protective ring and the inner wall of the lower steel sleeve, and the sealing gap is filled with sealant.

[0016] The advantages of this invention compared to existing technologies are as follows: The cavity of the housing is connected to the atmosphere via the upper and lower sound outlets, forming double-sided sound emission, expanding the effective bandwidth, and eliminating frequency response distortion caused by pressure difference, especially improving high-frequency loss and enhancing sound quality. The through-hole of the first magnet, along with the upper and lower sound outlets, is located at the center of the housing, allowing the airflow generated during diaphragm vibration to enter and exit vertically, avoiding noise caused by airflow impacting the inner wall of the housing due to eccentric holes. The annular magnetic field gap formed by the magnetic ring and the first magnet, combined with the position of the planar voice coil, enhances the magnetic field strength, improves electroacoustic conversion efficiency, and increases sensitivity. Furthermore, the first magnet is located within the inner ring of the magnetic ring at the same height, which, combined with the planar voice coil, reduces the overall thickness of the planar voice coil speaker, thereby reducing its volume. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Figure 1 This is a schematic diagram of the structure of this utility model;

[0019] Figure 2 This is an exploded view of the present invention;

[0020] Figure 3 This is a cross-sectional view of the present invention;

[0021] Figure 4 This is a schematic diagram of the lower end of the present invention;

[0022] Figure 5 This is a cross-sectional view of the present invention with the addition of a second magnet.

[0023] In the picture:

[0024] 1. Upper cover, 11. Protective plate, 111. Upper sound outlet, 12. Protective ring, 13. Sealing ring, 14. Sealing gap;

[0025] 2 lower steel sleeve, 21 lower sound outlet hole, 22 wire hole;

[0026] 3. PCB board, 31. Clearance hole, 32. Wiring notch, 33. Wiring solder joint, 34. External solder joint;

[0027] 4. Planar voice coil;

[0028] 5. Diaphragm; 51. Planar tympanic membrane; 52. Raised tympanic membrane; 53. Fixing ring;

[0029] 61 First magnet, 611 Through hole, 62 Second magnet, 63 Magnetic ring, 631 Clearance plane, 632 Wiring groove, 64 Magnetic field gap;

[0030] 7 Tuning Network. Detailed Implementation

[0031] The following are merely preferred embodiments of the present invention and do not limit the scope of protection of the present invention.

[0032] A type of flat-panel voice coil speaker, such as Figures 1 to 4 As shown, the device includes a housing and a PCB board 3. The PCB board 3 is fixedly mounted on the end face of the housing. The housing contains a planar voice coil 4, a diaphragm 5, a magnetic ring 63, and a first magnet 61. The planar voice coil 4 is fixedly mounted on the lower end face of the diaphragm 5. The first magnet 61 is located in the inner ring of the magnetic ring 63 and is coaxial with the magnetic ring 63. There is a magnetic field gap 64 between the outer side of the first magnet 61 and the inner side of the magnetic ring 63. The planar voice coil 4 is located above the magnetic field gap 64. The upper end face of the housing has an upper sound outlet hole 111 at its center, and the lower end face of the housing has a lower sound outlet hole 21 at its center. The first magnet 61 has a through hole 611 that penetrates the first magnet 61 vertically at its center. The through hole 611, the upper sound outlet hole 111, and the lower sound outlet hole 21 are all coaxially arranged.

[0033] Traditional planar voice coil loudspeakers have only one upper sound outlet 111. When the diaphragm 5 vibrates, a pressure difference is generated inside the housing, leading to frequency response distortion. Some planar voice coil loudspeakers solve this problem by adding a balance hole at the bottom of the housing to eliminate the pressure difference. However, the balance hole has a small diameter and does not have a sound output function. Moreover, it is often off-center, so the airflow generated by the diaphragm cannot be discharged vertically. Instead, it first hits the inner wall of the housing and then exits through the balance hole. The airflow rebounds after hitting the housing, resulting in noise. Therefore, traditional planar voice coil loudspeakers have poor sound quality and narrow frequency response. This invention connects the cavity of the housing to the atmosphere through the upper sound outlet 111 and the lower sound outlet 21, forming a dual-channel system. The surface-emitting sound expands the effective bandwidth and eliminates frequency response distortion caused by pressure difference, especially improving high-frequency loss and enhancing sound quality. The through hole 611 of the first magnet 61, the upper sound outlet hole 111, and the lower sound outlet hole 21 are all located in the center of the housing, allowing the airflow generated when the diaphragm vibrates to enter and exit vertically, avoiding noise caused by airflow impacting the inner wall of the housing due to eccentric holes. The annular magnetic field gap 64 formed by the magnetic ring 63 and the first magnet 61, in conjunction with the position of the planar voice coil 4, enhances the magnetic field strength, improves electroacoustic conversion efficiency, and enhances sensitivity. Furthermore, the first magnet 61 is located in the inner ring of the magnetic ring 63 at the same height, in conjunction with the planar voice coil 4, thereby reducing the overall thickness of the planar voice coil speaker and reducing its volume.

[0034] Specifically, tuning mesh 7 is attached to the upper and lower surfaces of the housing, respectively, and the two tuning meshes 7 cover the upper sound outlet 111 and the lower sound outlet 21. By covering the upper sound outlet 111 and the lower sound outlet 21 with the two tuning meshes 7, the sound waves in specific frequency bands can be micro-damped, the frequency response curve can be smoothed, the harsh sound can be reduced, the high-frequency resonance peak can be suppressed, the sound quality can be improved, and the entry of external particles into the housing can be prevented from causing the diaphragm 5 to jam, thereby improving reliability and stability.

[0035] Specifically, the diameter of the upper sound outlet 111 is larger than the diameter of the lower sound outlet 21. A clearance hole 31 is provided in the center of the PCB board 3. The clearance hole 31 is coaxially arranged with the lower sound outlet 21, and the diameter of the clearance hole 31 is larger than the diameter of the lower sound outlet 21. The tuning mesh 7 located on the lower end face of the housing is disposed in the clearance hole 31. The relatively large diameter of the upper sound outlet 111 can enhance the positive sound pressure, i.e., the user direction, while the relatively small diameter of the lower sound outlet 21 can suppress the reverse sound wave interference, thereby comprehensively improving clarity and optimizing acoustic directivity. The clearance hole 31 allows the tuning mesh 7 below the lower sound outlet 21 to be embedded in the PCB board 3, thereby avoiding stacking and reducing the overall thickness.

[0036] Specifically, the diaphragm 5 includes a planar diaphragm 51, a raised diaphragm 52, and a fixing ring 53. The raised diaphragm 52 is formed on the outer edge of the planar diaphragm 51 and arches upward. The fixing ring 53 is formed on the outer edge of the raised diaphragm 52, and the planar voice coil 4 is attached to the lower end face of the planar diaphragm 51. The fixing ring 53 is a rigid metal ring. The fixing ring 53 supports and fixes the diaphragm 5, which can constrain the boundary of the diaphragm 5, reduce harmonic distortion caused by asymmetric deformation, provide a rigid foundation for the planar diaphragm 51, and improve the mid-to-high frequency response. The raised diaphragm 52 increases the edge flexibility and broadens the frequency response.

[0037] Specifically, the housing includes an upper cover 1 and a lower steel sleeve 2. The lower steel sleeve 2 has an opening at the top, and the upper cover 1 is located on the upper part of the lower steel sleeve 2. The outer edge of the upper cover 1 abuts against the inner wall of the lower steel sleeve 2 and engages with the outer edge of the diaphragm 5. The upper sound outlet 111 is located at the center of the upper cover 1, and the lower sound outlet 21 is located at the center of the lower steel sleeve 2. The housing is composed of the upper cover 1 and the lower steel sleeve 2, which facilitates assembly. The diaphragm 5 is clamped and installed between the upper cover 1 and the lower steel sleeve 2 to prevent air leakage that could cause acoustic short circuits and improve low-frequency performance.

[0038] Specifically, a clearance plane 631 is provided on one side of the outer edge of the magnetic ring 63, forming a magnetic ring 63 with an outer contour of "D". The clearance plane 631 and the housing enclose a wiring groove 632. The wiring groove 632 isolates and accommodates the lead wire of the planar voice coil 4, preventing the lead wire from being clamped between the magnetic ring 63 and the diaphragm 5, avoiding contact with the diaphragm 5, preventing friction between the diaphragm 5 and the lead wire during vibration and generating noise, and protecting the lead wire with a small diameter from breakage. The magnetic ring 63 opens up a wiring channel in a compact space through D-shaped cutting, without adding extra volume and reducing the overall volume.

[0039] Specifically, the lower steel sleeve 2 has a through hole 22 at the position corresponding to the wiring groove 632, which runs vertically through the lower steel sleeve 2. The through hole 22 is connected to the wiring groove 632. The PCB board 3 has a wiring notch 32 at the position corresponding to the wiring groove 632. The lead wire passes through the wiring groove 632 out of the lower steel sleeve 2 and passes through the wiring notch 32 to connect with the PCB board 3. This avoids the lead wire throughout the entire process, opens up a wiring channel, prevents the lead wire from protruding, protects the lead wire, and further prevents the lead wire from breaking.

[0040] Specifically, two solder joints 33 are provided on the lower end face of PCB board 3 near the wiring notch 32, and two external solder joints 34 are provided on the lower end face of PCB board 3 away from the wiring notch 32. The planar voice coil 4 is provided with two leads. The two leads pass through the wiring groove 632, the wire hole 22 and the wiring notch 32 in sequence and are connected to the two solder joints 33 respectively. The wiring groove 632, the wire hole 22 and the wiring notch 32 are all filled with waterproof glue. The leads of the planar voice coil 4 are connected via two solder joints 33, while two external solder joints 34 facilitate soldering and fixing with the leads of an external signal source for receiving electrical signals. This facilitates soldering and fixing, and the leads of the planar voice coil 4 and the leads of the external signal source can be physically isolated over a long distance through the solder joints 33 and external solder joints 34, reducing electromagnetic crosstalk and thus lowering the background noise. The wiring trough 632, the wire hole 22, and the wiring notch 32 are sealed with waterproof glue to prevent external water or impurities from entering the housing. The leads are also wrapped with waterproof glue to protect them. At the same time, the waterproof glue is applied to the two solder joints 33 to prevent short circuits caused by conductive materials connecting the two solder joints 33, thus improving protection.

[0041] Specifically, the upper cover 1 includes a protective plate 11, a protective ring 12, and a sealing ring 13. The upper edge of the protective ring 12 is formed on the outer edge of the protective plate 11, and the inner ring of the sealing ring 13 is formed on the lower edge of the protective ring 12 and protrudes from the outer side of the protective ring 12. The outer side of the sealing ring 13 abuts against the inner wall of the lower steel sleeve 2 and abuts against the outer edge of the diaphragm 5. A sealing gap 14 is formed between the outer wall of the protective ring 12 and the inner wall of the lower steel sleeve 2, and the sealing gap 14 is filled with sealant. The upper cover 1 and the sealant form a double blocking structure, thereby improving the ability to prevent sound source leakage, ensuring that the diaphragm energy is 100% converted into sound energy, improving the sound energy conversion efficiency, and the sealant facilitates the bonding and fixing between the upper cover 1 and the lower steel sleeve 2, making assembly easier and preventing foreign objects from entering the housing.

[0042] Specifically, such as Figure 5As shown, a second magnet 62 is also provided inside the housing, and the second magnet 62 is positioned above the diaphragm 5. By increasing the second magnet 62 to form a symmetrical magnetic field with the first magnet 61, the uniformity of the force on the planar voice coil 4 is improved, the acceleration of the diaphragm 5 is increased, thereby accelerating the transient response; the additional magnetic field strength increases the amplitude of the diaphragm 5 under the same current, thereby increasing the sound pressure.

[0043] The above description is only a preferred embodiment of this utility model. For those skilled in the art, there will be changes in the specific implementation method and application scope based on the idea of ​​this utility model. The content of this specification should not be construed as a limitation of this utility model.

Claims

1. A flat-panel voice coil loudspeaker, comprising a housing and a PCB board (3), wherein the PCB board (3) is fixedly mounted on the end face of the housing, characterized in that: The housing contains a planar voice coil (4), a diaphragm (5), a magnetic ring (63), and a first magnet (61). The planar voice coil (4) is fixedly installed on the lower end face of the diaphragm (5). The first magnet (61) is located in the inner ring of the magnetic ring (63) and is coaxial with the magnetic ring (63). There is a magnetic field gap (64) between the outer side of the first magnet (61) and the inner side of the magnetic ring (63). The planar voice coil (4) is located above the magnetic field gap (64). The upper end face of the housing has an upper sound outlet hole (111) at its center. The lower end face of the housing has a lower sound outlet hole (21) at its center. The center of the first magnet (61) has a through hole (611) that passes through the first magnet (61) in a vertical direction. The through hole (611), the upper sound outlet hole (111), and the lower sound outlet hole (21) are all coaxial.

2. A planar voice coil loudspeaker according to claim 1, characterized in that: Tuning meshes (7) are attached to the upper and lower surfaces of the housing, respectively, and the two tuning meshes (7) cover the upper sound outlet (111) and the lower sound outlet (21) respectively.

3. A planar voice coil loudspeaker according to claim 2, characterized in that: The diameter of the upper sound outlet (111) is larger than the diameter of the lower sound outlet (21). A clearance hole (31) is provided in the center of the PCB board (3). The clearance hole (31) is coaxially arranged with the lower sound outlet (21). The diameter of the clearance hole (31) is larger than the diameter of the lower sound outlet (21). The tuning mesh (7) located on the lower end face of the housing is disposed in the clearance hole (31).

4. A planar voice coil loudspeaker according to claim 1, characterized in that: The diaphragm (5) includes a flat tympanic membrane (51), a raised tympanic membrane (52), and a fixing ring (53). The raised tympanic membrane (52) is formed on the outer edge of the flat tympanic membrane (51) and arches upward. The fixing ring (53) is formed on the outer edge of the raised tympanic membrane (52). The flat voice coil (4) is attached to the lower end face of the flat tympanic membrane (51).

5. A planar voice coil loudspeaker according to claim 1, characterized in that: The housing is also provided with a second magnet (62), which is located above the diaphragm (5).

6. A planar voice coil loudspeaker according to any one of claims 1 to 5, characterized in that: The housing includes an upper cover (1) and a lower steel sleeve (2). The lower steel sleeve (2) has an opening at the top. The upper cover (1) is located at the top of the lower steel sleeve (2). The outer edge of the upper cover (1) abuts against the inner wall of the lower steel sleeve (2) and abuts against the outer edge of the diaphragm (5). The upper sound outlet (111) is located at the center of the upper cover (1), and the lower sound outlet (21) is located at the center of the lower steel sleeve (2).

7. A flat-panel voice coil loudspeaker according to claim 6, characterized in that: The outer edge of one side of the magnetic ring (63) is provided with a clearance plane (631) to form a magnetic ring (63) with an outer contour of "D". The clearance plane (631) and the shell form a wiring groove (632).

8. A flat-panel voice coil loudspeaker according to claim 7, characterized in that: The lower steel sleeve (2) is provided with a wire hole (22) that runs through the lower steel sleeve (2) along the vertical line at the position corresponding to the wiring groove (632). The wire hole (22) is connected to the wiring groove (632). The PCB board (3) is provided with a wiring notch (32) at the position corresponding to the wiring groove (632).

9. A flat-panel voice coil loudspeaker according to claim 8, characterized in that: Two solder joints (33) are provided on the lower end face of the PCB board (3) near the wiring notch (32), and two external solder joints (34) are provided on the lower end face of the PCB board (3) away from the wiring notch (32). The planar voice coil (4) is provided with two leads. The two leads pass through the wiring groove (632), the wire hole (22) and the wiring notch (32) in sequence and are respectively connected to the two solder joints (33). The wiring groove (632), the wire hole (22) and the wiring notch (32) are all filled with waterproof glue.

10. A planar voice coil loudspeaker according to claim 6, characterized in that: The upper cover (1) includes a protective plate (11), a protective ring (12) and a sealing ring (13). The upper edge of the protective ring (12) is formed on the outer edge of the protective plate (11). The inner ring of the sealing ring (13) is formed on the lower edge of the protective ring (12) and protrudes from the outer side of the protective ring (12). The outer side of the sealing ring (13) abuts against the inner wall of the lower steel sleeve (2) and abuts against the outer edge of the diaphragm (5). A sealing gap (14) is formed between the outer wall of the protective ring (12) and the inner wall of the lower steel sleeve (2). The sealing gap (14) is filled with sealant.

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