CN110278514B9 - Planar voice coil loudspeaker - Google Patents

Abstract

A planar voice coil loudspeaker comprises a central magnet, an inner magnet, an outer ring magnet, a planar voice coil diaphragm and a base. The central magnet, the inner magnet and the outer ring magnet are magnet arrays and are contained in the seat body. The central magnet has a central axis and an axial magnetic direction parallel to the central axis. The inner magnet surrounds the outer periphery of the central magnet, and the inner magnet has a radial magnetic direction perpendicular to the middle axis. The outer ring magnet is arranged around the outer periphery of the inner magnet, and the outer ring magnet is parallel to the middle axis and has opposite axial magnetic directions opposite to the axial magnetic directions. The plane voice coil loudspeaker voice coil vibrating diaphragm is provided with the plane voice coil loudspeaker voice coil, and the plane voice coil loudspeaker voice coil is corresponding to the magnet array. The magnet array can concentrate magnetic force, and the whole face of plane voice coil loudspeaker voice coil is laid on plane voice coil loudspeaker voice coil vibrating diaphragm, makes the vibration of vibrating diaphragm more even, provides the performance of preferred at the high bass frequency.

Description

Planar voice coil loudspeaker

Technical Field

The invention relates to the field of electroacoustic, in particular to a planar voice coil loudspeaker.

Background

A conventional moving-coil speaker generally includes a diaphragm, a voice coil, and a magnet. The voice coil is connected to the inner ring part of the diaphragm and is positioned in the gap of the magnet. When a current signal passes through the voice coil, the voice coil generates a magnetic field, and the voice coil interacts with the magnetic field of the permanent magnet to generate attraction or repulsion so as to push the vibrating diaphragm to vibrate.

Because traditional moving coil speaker, the voice coil loudspeaker voice coil is attached to the part of vibrating diaphragm below, when the current signal passes through the magnetic field that the voice coil loudspeaker voice coil produced and permanent magnet's magnetic field interaction, the vibrating diaphragm produces the vibration to the drive of voice coil loudspeaker voice coil, and the vibration can be diffused by the position that vibrating diaphragm and voice coil loudspeaker voice coil are connected with the mode like the ripple. This phenomenon is called split vibration because of time and position differences in the propagation of vibration. Splitting the vibration may cause the vibration of the diaphragm to be non-average. In addition, when the driving force generated by the interaction is insufficient, the vibration of the diaphragm is reduced, and the sound pressure of specific frequency is reduced, especially the influence of a high-frequency band and a low-frequency band is greatest.

Disclosure of Invention

To solve the above problems of the prior art, a planar voice coil speaker is provided. The planar voice coil loudspeaker comprises a central magnet, an inner magnet, an outer ring magnet, a planar voice coil diaphragm and a base. The central magnet has a central axis and an axial magnetic direction parallel to the central axis. The inner magnet surrounds the outer periphery of the central magnet, and the inner magnet has a radial magnetic direction which is perpendicular to the central axis. The outer ring magnet is arranged around the outer periphery of the inner ring magnet, and the outer ring magnet has opposite axial magnetic directions which are parallel to the middle axis and opposite to the axial magnetic directions. The same one side of central authorities 'magnet, interior magnet and outer loop magnet is located to plane voice coil loudspeaker voice coil vibrating diaphragm neighbour, and plane voice coil loudspeaker voice coil vibrating diaphragm is provided with the plane voice coil loudspeaker voice coil, and the position of plane voice coil loudspeaker voice coil corresponds to central authorities' magnet, interior magnet and outer loop magnet. The base includes a bottom plate and a ring flange. The ring flange is arranged around the ring periphery of the bottom plate to form a containing groove, the central magnet, the inner periphery magnet and the outer ring magnet are contained in the containing groove, and the planar voice coil vibrating diaphragm is fixedly arranged on the ring flange.

In some embodiments, the inner magnet is in the shape of a hollow ring. Furthermore, the inner magnet includes two fan-shaped magnets forming a hollow ring, and the two fan-shaped magnets have a first magnetic direction and a second magnetic direction respectively. The first magnetic direction and the second magnetic direction are both perpendicular to the central axis. Furthermore, the two fan-shaped magnets are arranged in an equiangular distribution mode, or in a symmetrical distribution mode, or in a combination mode.

In some embodiments, the outer ring magnet is hollow and ring-shaped.

In some embodiments, the planar voice coil diaphragm includes a first surface and a second surface opposite to the first surface, and the first surface is provided with a planar voice coil. Further, the planar voice coil is a spiral voice coil.

In other embodiments, a back voice coil is further disposed on the second surface of the planar voice coil diaphragm, and the back voice coil is electrically connected to the planar voice coil. Further, the intercommunicating pore has been seted up to plane voice coil vibrating diaphragm, and plane voice coil passes through intercommunicating pore electric connection each other with the back voice coil. Furthermore, the plane voice coil vibrating diaphragm is a circular vibrating diaphragm, and the communicating hole is formed in the circle center of the circular vibrating diaphragm.

In some embodiments, the base further includes a plurality of glue avoiding grooves. The glue avoiding groove is sunken by the bottom plate, and the positions of the glue avoiding groove respectively correspond to the central magnet, the inner magnet and the outer magnet.

In some embodiments, a first gap is provided between the center magnet and the inner magnet, and a second gap is provided between the inner magnet and the outer magnet. The bottom plate is provided with at least one through hole, and the through hole penetrates through the bottom plate and is communicated with the first gap or the second gap.

Further, the base comprises a plurality of first positioning columns and a plurality of second positioning columns. The first positioning column and the second positioning column extend out of the bottom plate, the first positioning column is located in the first gap, the second positioning column is located in the second gap, and the through hole is located between the first positioning column or between the second positioning columns.

Further, the base further comprises at least one vent hole. The vent hole penetrates through the bottom plate and is positioned between the first positioning column and the second positioning column. Furthermore, the inner magnet is further provided with at least one sound adjusting hole, the sound adjusting hole penetrates through the inner magnet, and the position of the sound adjusting hole corresponds to the vent hole.

In some embodiments, the planar voice coil speaker further comprises a baffle fixed to the ring flange between the central magnet, the inner magnet, and the outer ring magnet and the planar voice coil diaphragm. The baffle plate is provided with at least one opening, and the position of the opening corresponds to the through hole.

In some embodiments, the planar voice coil speaker further comprises a cover. The lid is fixed in on the ring flange, and plane voice coil loudspeaker voice coil vibrating diaphragm is located between lid and the baffle.

In some embodiments, the planar voice coil speaker further comprises a plurality of clamping members. The clamping piece comprises two clamping feet and a blocking part, and the two clamping feet extend out of two sides of the blocking part. The two clamping pins are respectively clamped in the first gap, the first gap and the second gap, the second gap and the third gap, or the first gap and the third gap at two sides of the central magnet. Here, the third gap is located between the outer ring magnet and the ring flange.

In the above embodiment, the central magnet, the inner magnet, and the outer magnet of the planar voice coil speaker are arranged in an array in a specific magnetic direction, so that the magnetic force can be concentrated toward the planar voice coil, the magnetic force is enhanced, and the vibration amplitude of the diaphragm of the planar voice coil is increased. In addition, because the plane voice coil is laid on the plane voice coil vibrating diaphragm on the whole surface, when the magnetic field of the magnet array and the current signal generate the magnetic field interaction through the plane voice coil, the plane voice coil can drive the plane voice coil vibrating diaphragm to vibrate on the whole surface. Therefore, the stress and the vibration of the plane voice coil diaphragm are more uniform, and the loudspeaker can have better performance in a high-pitch frequency band and a low-pitch frequency band.

Drawings

The above and other exemplary embodiments, advantages and features of the present invention will become more apparent by describing in further detail exemplary embodiments thereof with reference to the attached drawings, in which:

FIG. 1 is an exploded view of a first embodiment of a planar voice coil speaker;

FIG. 2A is a schematic sectional view of a portion of a planar voice coil speaker according to a first embodiment;

FIG. 2B is a schematic sectional view of a portion of a planar voice coil speaker according to a second embodiment;

fig. 3 to 7 are schematic top views of magnet arrays according to third to seventh embodiments, respectively;

FIG. 8 is a schematic view of a first embodiment of a flat diaphragm voice coil;

FIG. 9 is a schematic view of a second embodiment of a flat diaphragm voice coil;

FIG. 10 is a perspective view of the base;

FIG. 11 is a schematic partial top view of a planar voice coil speaker;

FIG. 12 is a schematic top view of a magnet array of an eighth embodiment; and

fig. 13 is a graph comparing frequency spectra of a flat voice coil speaker and a moving coil voice coil.

Wherein the reference numerals are:

1 planar voice coil loudspeaker 10 magnet array

11 center magnet 111 middle shaft

13 inner magnet 131 first fan magnet

132 second sector magnet 133 sector magnet

134 trapezoidal magnet 135 magnet

136 magnet 137 magnet

138 magnets 140 magnet spacing

145 tuning hole 15 outer ring magnet

151L-shaped magnet 152 magnet

153 magnet 161 first gap

163 second gap 165 third gap

20 plane voice coil vibrating diaphragm

21 first surface 23 second surface

25 plane voice coil with 30 through holes

35 back voice coil 40 circuit board

50 seat body 51 bottom plate

511 glue avoiding groove 513 through hole

515 vent hole 53 collar

55 receiving groove 551 first receiving area

553 the second receiving area 555 the third receiving area

57 first positioning post 59 second positioning post

60 baffle 61 opening

70 cover 80 clamp

81 clip leg 811 projection

83 stop part A1 axial magnetic direction

A2 radial magnetic direction A21 first magnetic direction

A23 second magnetic direction A3 opposite axial magnetic direction

Detailed Description

Fig. 1 is an exploded view of a planar voice coil speaker according to a first embodiment. As shown in fig. 1, the planar voice coil speaker 1 includes a center magnet 11, an inner magnet 13, an outer ring magnet 15, a planar voice coil diaphragm 20, and a base 50. The central magnet 11, the inner magnet 13, and the outer magnet 15 are arranged on the same plane, and may constitute a magnet array 10. The central magnet 11 has a central axis 111. The inner magnet 13 surrounds the outer periphery of the central magnet 11. The outer ring magnet 15 is arranged around the outer periphery of the inner ring magnet 13, the planar voice coil diaphragm 20 is arranged adjacent to the same side of the magnet array 10, the planar voice coil diaphragm 20 is provided with a planar voice coil 30, and the position of the planar voice coil 30 corresponds to the range of the magnet array 10. The base 50 includes a bottom plate 51 and a ring flange 53. The ring flange 53 is disposed around the ring periphery of the bottom plate 51 to form a receiving groove 55, the central magnet 11, the inner magnet 13 and the outer magnet 15 are received in the receiving groove 55, and the planar voice coil diaphragm 20 is fixed on the ring flange 53. The flat voice coil diaphragm 20 may be bonded at its periphery to the ring flange 53, or the periphery of the flat voice coil diaphragm 20 may be locked to the ring flange 53 by a fixing member, such as a screw.

As shown in fig. 1, the inner ring magnet 13 and the outer ring magnet 15 may be hollow rings, and the term "ring" as used herein refers to a surrounding, may be a closed surrounding, or may cover a plurality of arranged surrounding. And "ring" represents a closed loop. Here, although represented by a circle, it is not limited thereto, and may refer to any closed geometric pattern, for example, a rectangle, a hexagon, etc.

Fig. 2A is a schematic partial cross-sectional view of a planar voice coil speaker according to the first embodiment, and fig. 2B is a schematic partial cross-sectional view of a planar voice coil speaker according to the second embodiment. As shown in fig. 1, 2A, and 2B, the center magnet 11 has an axial magnetic direction a1, and an axial magnetic direction a1 parallel to the central axis 111. The inner magnet 13 has a radial magnetic direction a2, the radial magnetic direction a2 being perpendicular to the central axis 111. The outer ring magnet 15 has an opposite axial magnetic direction A3, the opposite axial magnetic direction A3 being parallel to the central axis 111 and opposite to the axial magnetic direction a 1. Here, the magnetic direction refers to a magnetic line direction from S-level to N-level inside the magnet.

More specifically, the radial direction a2 of the inner magnet 13 is from the outside to the inside toward the central axis 111 of the central magnet 11, or is radiated outward from the central axis 111 of the central magnet 11. As shown in fig. 2A, the radial magnetic direction a2 is from outside to inside toward the central axis 111 of the central magnet 11, and the radial magnetic direction a2 includes a first magnetic direction a21 and a second magnetic direction a23, and the first magnetic direction a21 and the second magnetic direction a23 are perpendicular to the central axis 111 and both face from outside to inside toward the central axis 111, but the first magnetic direction a21 and the second magnetic direction a23 are opposite directions, as viewed in cross section. The second embodiment shown in fig. 2B may have the same magnet shape and arrangement as fig. 1, but the axial magnetic direction a1, the first magnetic direction a21 and the second magnetic direction a23, and the opposite axial magnetic direction A3 of fig. 2B are all opposite to the embodiment shown in fig. 2A, being the direction radiating from the central axis 111. However, in the magnet arrangement of fig. 2A and 2B, the magnetic force generated by the magnet array 10 can be concentrated toward the planar voice coil 30 without dissipation, so that the magnetic field of the magnet array 10 and the current signal can generate a larger driving force when interacting with each other through the magnetic field generated by the planar voice coil 30, thereby enhancing the amplitude of the planar voice coil diaphragm 20.

Although the inner magnet 13 is a single ring in fig. 1, 2A, and 2B, two magnets, for example, the first magnet segment 131 and the second magnet segment 132, may be welded or bonded. In addition, one magnet can be divided into two magnetic pole regions by magnetizing. Further, the first and second segment magnets 131 and 132 may be disposed in an equiangular distribution, a symmetrical distribution, or a combination thereof. Further, the geometric centers of the center magnet 11, the inner magnet 13, and the outer ring magnet 15 may be the same, e.g., concentric with each other.

Fig. 3 to 7 are schematic top views of magnet arrays according to third to seventh embodiments, respectively. As shown in fig. 3, the central magnet 11 of the third embodiment is circular, the inner peripheral magnet 13 is a hollow ring formed by four fan-shaped magnets 133, the outer ring magnet 15 is a single magnet, and the four fan-shaped magnets 133 are equiangularly distributed. The two segment magnets 133 have a magnet spacing 140 therebetween. As shown in fig. 4, the center magnet 11 of the fourth embodiment is rectangular, the inner peripheral magnet 13 is a hollow rectangle composed of four trapezoidal magnets 134, and the outer ring magnet 15 is a hollow rectangle composed of two L-shaped magnets 151. As shown in fig. 5, the center magnet 11 of the fifth embodiment is circular, the inner magnet 13 is a hollow hexagonal shape composed of two magnets 135, and the outer magnet 15 is a hollow ring shape formed of a single magnet. As shown in fig. 6, the center magnet 11 of the sixth embodiment is hexagonal, the inner magnet 13 is hollow hexagonal composed of two magnets 136, and the outer ring magnet 15 is hexagonal ring formed of two magnets 152. As shown in fig. 7, the center magnet 11 of the seventh embodiment is octagonal, the inner periphery magnet 13 is a hollow octagonal shape composed of four magnets 137 in common, and the outer ring magnet 15 is an octagonal ring shape formed by two magnets 153.

However, the above embodiments are merely illustrative and not restrictive. The shapes of the center magnet 11, the inner circumference magnet 13, and the outer ring magnet 15 are not limited to these, and the number of the inner circumference magnet 13 and the outer ring magnet 15 is not limited to these. Only, the magnetic directions of the central magnet 11, the inner magnet 13 and the outer ring magnet 15 should be the same as those shown in fig. 2A or fig. 2B in any cross section crossing the central axis 111. The magnetic orientation of the magnet array 10 may be aligned by magnetization, adhesion, welding, or other various means. Further, the magnet Array 10 may be a Halbach Array (Halbach Array) in practice, so that the magnetic force can be concentrated toward the planar voice coil 30.

Fig. 8 is a schematic diagram of a first embodiment of a planar diaphragm 20, in which the planar diaphragm 20 includes a first surface 21 and a second surface 23 opposite to the first surface 21, and a planar voice coil 30 is disposed on the first surface 21. Here, the planar voice coil 30 may be adhered to the first surface 21 of the planar voice coil diaphragm 20 by an adhering method, or may be directly printed on the first surface 21 by a printing or photolithography and etching method. Further, the planar voice coil 30 may be a helical coil, for example, an archimedean spiral voice coil, an equiangular spiral voice coil, a claw spiral voice coil, an interlocking spiral voice coil, or the like. Or may be a plurality of concentric circles.

Fig. 9 is a schematic view of a second embodiment of a flat diaphragm voice coil. As shown in fig. 9, a back voice coil 35 is further disposed on the second surface 23, and the back voice coil 35 is electrically connected to the planar voice coil 30. A back voice coil 35 may be attached to the planar voice coil 30 at the periphery of the planar voice coil diaphragm 20. Or may be connected to each other through the communication hole 25 of the planar voice coil diaphragm 20. The communication hole 25 penetrates through the first surface 21 and the second surface 23, and conductive adhesive may be disposed in the communication hole 25, so that the back voice coil 35 is electrically connected to the planar voice coil 30. As shown in fig. 9, the planar voice coil diaphragm 20 is a circular diaphragm, the communication hole 25 is formed in the center of the circular diaphragm, and the conductive adhesive electrically connects the back voice coil 35 and the planar voice coil 30. In addition, the back voice coil 35 and the flat voice coil 30 in fig. 8 and 9 are all archimedean spiral coils, so that when a current signal is inputted from the flat voice coil 30, the current signal can be outputted from the back voice coil 35, or vice versa. However, this is merely an example and is not meant to be limiting. Further, referring to fig. 1, 8 and 9, the planar voice coil speaker 1 further includes a circuit board 40, as shown in fig. 9, the circuit board 40 may be disposed on the periphery of the planar voice coil diaphragm 20 and electrically connected to the back voice coil 35 and the planar voice coil 30, respectively.

In either fig. 8 or fig. 9, the positions of the flat voice coil 30 and the back voice coil 35 correspond to the same side of the magnet array 10, and the flat voice coil 30 and the back voice coil 35 are attached to the flat voice coil diaphragm 20 in a full-face flat-attached manner, when the current signal interacts with the magnetic field of the magnet array 10 through the magnetic field generated by the flat voice coil 30, the back voice coil 35, or the combination thereof, the flat voice coil 30 or the back voice coil 35 drives the flat voice coil diaphragm 20 to vibrate in a full-face manner, which can reduce the problem of split vibration, and the vibration is more uniform and sensitive, compared with the conventional moving coil speaker, and has more detailed performance in the high-pitch frequency band and the low-frequency band for the listener.

Fig. 10 is a perspective view of the base. Fig. 11 is a partial top view of a planar voice coil speaker. Referring to fig. 2A, 2B, 3, 10 and 11, fig. 10 illustrates the inner magnet 13 of the four fan-shaped magnets 133 of fig. 3, but the cross-section of the magnet array 10 and the base 50 should be as shown in fig. 2A or 2B, but it should be understood that this is only an example and not a limitation. As shown in fig. 2A, 2B and 10, the bottom plate 51 further includes a plurality of glue avoiding grooves 511. The glue avoiding groove 511 is recessed from the bottom plate 51. The positions of the glue avoiding grooves 511 correspond to the center magnet 11, the inner magnet 13, and the outer magnet 15, respectively. The central magnet 11, the inner magnet 13, and the outer magnet 15 can be adhered to the bottom plate 51 by gluing, and the glue avoiding groove 511 can prevent excessive residual glue from overflowing.

Referring to fig. 1, 2A, 2B, 10 and 11 again, a first gap 161 is formed between the central magnet 11 and the inner magnet 13, a second gap 163 is formed between the inner magnet 13 and the outer magnet 15, and a third gap 165 is formed between the outer magnet 15 and the ring flange 53 of the base 50. The bottom plate 51 is provided with at least one through hole 513, the through hole 513 penetrates through the bottom plate 51, and the through hole 513 can be communicated with the first gap 161, the second gap 163 or the third gap 165. So, the back chamber of the planar voice coil loudspeaker 1, that is, between the planar voice coil diaphragm 20 and the seat body 50, the air in the back chamber can be conducted with the outside, so as to maintain a certain air pressure, thereby avoiding the increase of the air pressure caused by the air flow generated by the vibration of the planar voice coil diaphragm 20 and hindering the vibration of the planar voice coil diaphragm 20.

Referring to fig. 1, 10, and 11 again, the base 50 further includes a plurality of first positioning posts 57 and a plurality of second positioning posts 59. The first positioning post 57 and the second positioning post 59 extend from the bottom plate 51. The first positioning post 57 and the second positioning post 59 can divide the accommodating groove 55 into a first accommodating area 551, a second accommodating area 553, and a third accommodating area 555. The first receiving area 551 is an area surrounded by the first positioning post 57 for receiving the central magnet 11. The second receiving area 553 is a region between the first positioning pillar 57 and the second positioning pillar 59 for receiving the inner magnet 13. The third receiving area 555 is an area between the second positioning pillar 59 and the ring flange 53 for receiving the outer ring magnet 15. In addition, the first positioning post 57 is located in the first gap 161, the second positioning post is located in the second gap 163, and the through hole 513 is located between the two first positioning posts 57 or between the two second positioning posts 59. Furthermore, a vent hole 515 penetrating through the bottom plate 51 may be formed between the first positioning column 57 and the second positioning column 59 to adjust the ventilation amount. Referring to fig. 3 and 11, the vent 515 may be in communication with the magnet gap 140 between the two segment magnets 133.

Fig. 12 is a schematic top view of a magnet array according to an eighth embodiment. As shown in fig. 12, the center magnet 11 of the eighth embodiment is circular, the inner peripheral magnet 13 is composed of two fan-shaped magnets 138, and at least one of the two fan-shaped magnets 138 may have a tuning hole 145. The tuning hole 145 penetrates the inner magnet 13. Referring also to fig. 11, the position of the tuning hole 145 corresponds to the vent 515. Further, the outer ring magnet 15 may be provided with the tuning hole 145, and the tuning hole 145 may be provided with a through hole 513 (not shown) at a position corresponding to the bottom plate 51.

Referring again to fig. 1, the planar vcm speaker 1 further includes a baffle 60, the baffle 60 is fixed to the ring flange 53, and the baffle 60 is located between the magnet array 10 and the planar vcm diaphragm 20. The baffle 60 is provided with at least one opening 61, and the position of the opening 61 corresponds to the through hole 513. Further, referring to fig. 10 and 11 simultaneously, the opening 61 may also correspond to the vent 515, the tuning hole 145, or a combination thereof. The baffle 60 is made of a non-magnetically permeable material, such as copper, aluminum, tin, and the like. The baffle 60 mainly maintains the position of the magnet array 10, so as to prevent the central magnet 11, the inner magnet 13, or the outer magnet 15 from falling off and popping up when being hit or vibrated, thereby causing damage to the planar voice coil speaker 1.

Referring to fig. 1 again, the planar voice coil speaker 1 further includes a cover 70. The cover 70 is fixed on the ring flange 53 and assembled with the base 50, and the planar voice coil diaphragm 20 is located between the cover 70 and the baffle 60. The cover 70 can prevent the planar voice coil diaphragm 20 and the magnet array 10 from falling off due to external force. The cover 70 may further include an in-ear sound guide tube (not shown). In other embodiments, the inner edge of the cover 70 may be pre-assembled with the periphery of the planar voice coil diaphragm 20, and the cover 70 is then assembled with the collar 53, such that the cover 70 pre-adjusts the tension of the planar voice coil diaphragm 20 to achieve the default sound field frequency response.

Referring again to fig. 1, 2A and 2B, the planar vcm speaker 1 further includes a clamping member 80, and the clamping member 80 may be located between the baffle 60 and the magnet array 10. The clamping member 80 includes two clamping legs 81 and a stopper 83. The two clamping legs 81 extend downward from two sides of the stopping portion 83. The two clamping legs 81 of the clamping member 80 can be respectively clamped in the first gap 161, the first gap 161 and the second gap 163, the second gap 163 and the third gap 165, or the first gap 161 and the third gap 165 on both sides of the central magnet 11. Thus, the stopper 83 can be located on the center magnet 11, the inner magnet 13, the outer ring magnet 15, the inner magnet 13 and the outer ring magnet 15, or the center magnet 11, the inner magnet 13, and the outer ring magnet 15. The clamp legs 81 have elasticity, and can clamp the central magnet 11, the inner magnet 13, the outer ring magnet 15, or a combination thereof on both sides, so as to further fasten the magnet array 10. The stopper 83 is located above the magnet array 10 to prevent the center magnet 11, the inner magnet 13, or the outer ring magnet 15 from being ejected. The above are merely examples and are not limiting. The length of the stop portion 83 and the insertion position of the two clamping legs 81 can be adjusted according to the product specification.

Further, in other embodiments, the clamping leg 81 may further have a protrusion 811, and the protrusion 811 is located at one end of the clamping leg 81 and extends toward the other clamping leg 81 in a direction parallel to the stop portion 83. The bump 811 may be located above the glue avoiding groove 511 and abut against the bottom surface of the central magnet 11, the inner magnet 13, or the outer magnet 15, so as to fasten the magnet array 10 in a manner of being sandwiched by the top surface, the side surface, and the bottom surface. The clamping member 80 can fasten the central magnet 11, the inner magnet 13, or the outer ring magnet 15, so as to prevent the central magnet 11, the inner magnet 13, or the outer ring magnet 15 from falling off and popping up when the planar voice coil speaker 1 is impacted or vibrated, thereby preventing the planar voice coil speaker 1 from being damaged.

Fig. 13 is a graph comparing frequency spectra of a flat voice coil speaker and a moving coil voice coil. As shown in fig. 13, the amplitude versus spectrum curves for the same 40 Φ flat voice coil speaker are compared to the moving coil voice coil. Curve a is the amplitude-spectrum curve for a flat voice coil speaker and curve B is the amplitude-spectrum curve for a moving coil voice coil. It is clearly understood that the amplitude of curve a is significantly higher than curve B in the treble and bass frequency bands, i.e., the flat voice coil speaker has a better amplitude response in the treble and bass frequency bands.

In the above embodiment, the center magnet 11, the inner circumference magnet 13, and the outer ring magnet 15 of the planar voice coil speaker 1 are arranged in a specific magnetic direction and in an array, and can concentrate the magnetic force toward the planar voice coil 30, so that the magnetic force can be enhanced to increase the vibration amplitude of the planar voice coil diaphragm 20. In addition, the planar voice coil 30 is flatly attached to the planar voice coil diaphragm 20, and when the current interacts with the magnetic field generated by the magnet array 10 through the magnetic field generated by the planar voice coil 30, the planar voice coil 30 drives the planar voice coil diaphragm 20 to vibrate across. Therefore, the stress and vibration of the planar voice coil diaphragm 20 are more uniform, and the vibration of the planar voice coil diaphragm 20 corresponding to the current signal is more sensitive, so that the loudspeaker can have better performance on sound pressure or vibration in a high-frequency region and a low-frequency region.

While the invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims (16)

1. A planar voice coil speaker, comprising:

the central magnet is provided with a middle shaft and an axial magnetic direction, and the axial magnetic direction is parallel to the middle shaft;

an inner magnet surrounding the outer periphery of the central magnet, the inner magnet having a radial magnetic direction perpendicular to the central axis, wherein a first gap is formed between the central magnet and the inner magnet;

the outer ring magnet is arranged around the outer periphery of the inner ring magnet and provided with an opposite axial magnetic direction, the opposite axial magnetic direction is parallel to the middle shaft and is opposite to the axial magnetic direction, and a second gap is formed between the inner ring magnet and the outer ring magnet;

a planar voice coil diaphragm, which is adjacent to the same side of the central magnet, the inner magnet and the outer magnet, and is provided with a planar voice coil, and the position of the planar voice coil corresponds to the central magnet, the inner magnet and the outer magnet;

a baffle plate located between the central magnet, the inner magnet, the outer ring magnet and the planar voice coil diaphragm;

the circuit board is arranged on the periphery of the planar voice coil vibrating diaphragm and is electrically connected with the planar voice coil;

a base body, including a bottom plate and a ring flange, the ring flange surrounding the ring periphery of the bottom plate to form a containing groove, the containing groove containing the central magnet, the inner magnet and the outer magnet, the planar voice coil diaphragm fixed on the ring flange, the ring flange fixed with the baffle, wherein a third gap can be provided between the outer magnet and the ring flange of the base body;

a plurality of clamping members, each clamping member comprising two clamping pins and a blocking part, the two clamping pins extending from two sides of the blocking part, the two clamping pins being respectively clamped in the first gap, the first gap and the second gap, or the second gap and the third gap, or the first gap and the third gap at two sides of the central magnet, the blocking part being located on at least one part of the central magnet, the inner magnet, or the outer magnet; and

and the cover body is fixed on the ring flange, and the planar voice coil vibrating diaphragm is positioned between the cover body and the baffle plate.

2. The planar voice coil speaker as claimed in claim 1, wherein the inner magnet has a hollow ring shape.

3. The planar voice coil speaker as claimed in claim 2, wherein the inner magnet comprises two fan-shaped magnets forming the hollow ring, and the two fan-shaped magnets have a first magnetic direction and a second magnetic direction respectively, and the first magnetic direction and the second magnetic direction are perpendicular to the central axis.

4. The planar voice coil speaker as claimed in claim 3, wherein the two fan-shaped magnets are disposed equiangularly or symmetrically with respect to each other or a combination thereof.

5. The planar voice coil speaker as claimed in claim 1, wherein the outer ring magnet has a hollow ring shape.

6. The planar voice coil speaker as claimed in claim 1, wherein the planar voice coil diaphragm comprises a first surface and a second surface opposite to the first surface, the first surface having the planar voice coil disposed thereon.

7. The planar voice coil speaker as claimed in claim 6, wherein the planar voice coil is a spiral voice coil.

8. The planar voice coil speaker as claimed in claim 6, wherein a back voice coil is further disposed on the second surface and electrically connected to the planar voice coil.

9. The planar voice coil speaker as claimed in claim 8, wherein the planar voice coil diaphragm has a through hole, and the planar voice coil and the back voice coil are electrically connected to each other through the through hole.

10. The planar voice coil speaker as claimed in claim 9, wherein the planar voice coil diaphragm is a circular diaphragm, and the communication hole is opened at a center of the circular diaphragm.

11. The planar voice coil speaker as claimed in claim 1, wherein the base further comprises a plurality of glue avoiding grooves recessed from the bottom plate, and the positions of the glue avoiding grooves correspond to the central magnet, the inner magnet, and the outer magnet, respectively.

12. The planar voice coil speaker as claimed in claim 1, wherein the bottom plate has at least one through hole formed therein, the through hole penetrating the bottom plate and communicating with the first gap or the second gap.

13. The planar voice coil speaker as claimed in claim 12, wherein the base further comprises a plurality of first positioning posts and a plurality of second positioning posts, the plurality of first positioning posts and the plurality of second positioning posts extend from the bottom plate, the plurality of first positioning posts are located in the first gap, the plurality of second positioning posts are located in the second gap, and the through hole is located between the plurality of first positioning posts or between the plurality of second positioning posts.

14. The planar voice coil speaker as claimed in claim 13, wherein the base further comprises at least one vent hole penetrating through the bottom plate and located between the first positioning posts and the second positioning posts.

15. The planar voice coil speaker as claimed in claim 14, wherein the inner magnet further defines at least one tuning hole, the tuning hole extends through the inner magnet, and the tuning hole is located corresponding to the vent hole.

16. The planar voice coil speaker as claimed in claim 12, wherein the baffle has at least one opening formed therein, the opening corresponding to the through hole.

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