KR100872762B1 - Voice coil stucture for bone conduction speaker and bone conduction speaker - Google Patents

Abstract

A voice coil structure for bone conduction and a bone conduction speaker are provided to implement miniaturization and reduce the weight by integrating a vibrator. A bone conduction speaker(1) includes housings(10, 20), a magnet(50), a voice coil structure, and a virator(70). The housing has an inner space. The magnet is positioned in the bottom of the housing. A voice coil structure includes a bobbin(30), a ferrite core(60), and a voice coil(40). A hollow is formed in the center of the bobbin. The voice coil is wound around an outer circumference of the voice coil. The voice coil structure is positioned on the upper side of the magnet. The vibrator includes a first support unit, an upper portion, and a first lower portion. The upper portion faces the inner side of the upper side of the housing.

Description

Voice Coil Stucture For Bone Conduction Speaker And Bone Conduction Speaker}

The present invention relates to a voice coil structure and a bone conduction speaker for a bone conduction speaker, and more particularly, by inserting a ferrite core having a high permeability into the bobbin in which the voice coil is wound, the compact structure, the output of the speaker, and the frequency band The present invention relates to a voice coil structure and a bone conduction speaker for a bone conduction speaker that can improve the noise, reduce the distortion during bass reproduction, and provide an excellent characteristic even at high frequency by minimizing the eddy current loss by constructing the vibrator in one body.

Bone conduction speaker, unlike air conduction speakers, converts electrical signals into vibration signals and converts them into the external or middle ear through the cranial bone or jawbone. Instead of going through the cochlea, it uses the principle of hearing through the auditory nerve. In addition, since it is sent to the cochlea without passing through the three bones formed in the iso bone, the hearing loss with the eardrum or the iso bone can be clearly heard through the bone conduction if the cochlear and auditory nerves are normal. Is also used.

In addition, it is possible to receive hearing protection and ambient sound at the same time by preventing hearing loss and to use it in the environment with severe noise pollution by using without blocking the ears.

Bone conduction speakers are often manufactured in combination with a bone conduction headset. When a bone conduction speaker is worn on the front side of the ear (temporal part) or on the back of the ear and the forehead of the head, The incoming sound is transmitted directly to the auditory nerve, not through the eardrum, so that hearing aids that can't use normal hearing aids and hearing loss (if you have a disability in the external or middle ear), as well as organs of the middle ear that suffer from hearing loss despite having a healthy cochlea It can be used in a wide range of applications for those who are injured, and there is also an advantage that can be applied to a variety of non-deaf people in general when using bone conduction headset. In addition, recently, a mobile phone using a bone conduction speaker has been developed and spread.

Bone conduction headsets are absolutely lacking in the three major elements of sound, such as frequency, amplitude and tone, compared to conventional air conduction headsets. Bone conduction speakers that process signals (MonoSignal) and stereo signals (Stereo Signal) are divided and spread.

Bone conduction speakers widely used for mono signal processing are disclosed in Korean Patent No. 10-586140. The patent is not suitable for stereo signal processing and is used only in limited fields such as communication.

On the other hand, although the bone conduction speaker applied for audio has been developed in various structures, they also can not be satisfied by the three elements of the sound, which is the basis of the speaker in the process of processing stereo signals (StereoSignal) It does not implement the function as a credit.

The conventional bone conduction speaker for audio is largely classified into a housing radial type in which the diaphragm is exposed to the outside of the housing and a housing built-in type in which the diaphragm is installed inside the housing.

A typical example of a housing radial bone conduction speaker is disclosed in Korean Patent Publication No. 10-2007-35376. The housing radial bone conduction speaker has a structure in which a cushion ring connected to a vibration ring, which is a vibration means, protrudes to the outside of the housing so that vibration of the vibration ring is transmitted to the auditory nerve through the cushioning.

The structure of the housing radial bone conduction speaker is the same as the structure and principle of the speaker of the conventional air conduction (Air conduction) except that the cushioning is used in close contact with the bone of the human body.

Such a configuration has been proposed in order to solve the disadvantage that the bone conduction speaker does not improve the disadvantages of volume reduction and sound quality distortion caused by vibration when the input sound signal is reproduced by applying the same principle as the air conduction method. In skin contact due to vibration, it is painful when used for a long time because of friction caused by tickling and vibration.

In addition, when the cushioning is in close contact with the face, there is a significant disadvantage that the play space of the vibration ring is reduced and thus the tension is reduced to significantly reduce the volume and sound quality.

In addition, since the vibrating part is exposed to the outside, a gap occurs in the housing, and the structural deformation of the vibrating plate which vibrates finely due to the inflow of foreign substances into the gap and the loading of humidity or the increase of humidity and waterproofing is not constituted. Accelerated thereby reducing the vibration effect has a significant problem in sound quality and volume.

On the other hand, a structure widely used as a housing-integrated bone conduction speaker is disclosed in Korean Patent No. 10-344901.

The patent has a yoke having bent portions formed on both sides, a pair of voice coils fitted to each of the perception formed on the yoke, magnets are arranged while maintaining a constant distance between the pair of voice coils, It comprises a plate facing the bottom surface of the magnet and the vibration plate located on the bottom surface of the plate, forming four magnetic flux tight voids and the vibration plate vibrates due to two magnetic change phenomenon by a pair of voice coil It is characterized by.

Bone conduction speaker with built-in housing is improved compared to radial in that the diaphragm is configured inside the housing, so that distortion does not occur in sound source and sound quality even when physical force is applied from the outside. It is indirectly in close contact with the bones of the skin contact surface and vibrates, so the sound quality is lower than the diaphragm open type in the volume and bass regeneration.

In other words, when the diaphragm vibrates inside the housing and the upper part of the housing comes into contact with the skin contact surface, the three major elements of sound are relatively more technically difficult than the exposed type, and there are many difficulties in realizing this. The situation is devoting the total force, in order to improve this, the vibrator 50 and the diaphragm 60 are manufactured in a complex structure and fine shape.

In addition, the yoke 20 is essentially used as another element for improving sound quality and volume, which has a large size and a large structure.

In addition, another device for improving the volume and sound quality when assembling the above-described devices are additionally applied as shown in the drawings, which will be described in detail through an embodiment of a similar field. do.

However, in this case, not only the manufacturing cost increases due to the increase in the size and weight of the device, but also causes disadvantages in use and the quality of the other side due to the complicated structure, which will be described in detail below. Shall be.

To help understand the problem, a transformer similar in structure to a bone conduction speaker will be described.

Transformers are used in various forms and applications in electronic circuits, and cores, coils, and bobbins are essential.

Transformers typically laminate several sheets of silicon steel sheet symmetrically in an "E" shape, insert a "I" shaped silicon steel sheet into the stacked space, insert a bobbin in the center of the "E" shape, and then bobbin It has a structure in which a coil is wound around the outer circumferential surface thereof.

Here, if the core core is composed of one lump, the eddy currents are short-circuited with each other to increase the occurrence of losses. Thus, a structure in which a plurality of silicon steel sheets are stacked is used to prevent the Eddy Currents loss. Eddy current is the current generated in the silicon steel sheet when the magnetic field is formed.

However, as the frequency increases, the loss of eddy current gradually increases, resulting in narrow spaces stacked on the E and I cores. Therefore, when the frequency rises above a certain level, the core core becomes difficult to use due to the eddy current loss. You lose.

Because of this, iron core is mainly used only in low frequency band.

The problem of the core core composed of such a silicon steel sheet is applied very similarly to the conventional housing-integrated bone conduction speaker.

That is, in the coil, magnet, vibrator and the housing surrounding the core components of the conventional housing-integrated bone conduction speaker, the diaphragm for delivering the final vibration sound has a structure in which many parts other than the yoke, the frame, the vibrator are stacked. More specifically, there are many components for adjusting the tension by using a material such as a screw for supporting and binding these elements, a configuration of a diaphragm having a tension function in a vibrator for a vibration role, and a diaphragm for a spring. The structure of is very similar to that of the E, I iron core of the transformer.

Therefore, the increase of the current increases with the increase of the required device, and thus signal processing in the high frequency band is limited.

For this reason, in the frequency band processing the high frequency band, the distortion of the sound quality is increased by applying an indirect effect to the high frequency band due to unnecessary high frequency noise oscillation.

As such, the conventional bone conduction speaker has a complicated structure in which many elements are stacked to improve the volume, sound quality, and frequency characteristics, and even in this structure, even though each element is precisely mechanically assembled, In accordance with the increase in the size and the dimensional distribution of the required parts, the variation in the amount of vibration occurs, resulting in the failure of vibration characteristics.

This problem is similarly generated in the housing radial bone conduction speaker.

In other words, although the conventional bone conduction speaker is configured to complexly and finely stack many elements to improve the sound quality of the bone conduction speaker, as described in the above-mentioned problems, it is difficult to implement some core functions of the bone conduction speaker. There is a problem, and moreover, such a structural configuration causes a lot of inconvenience even in a feeling of wearing irrelevant to performance and sound quality.

On the other hand, Korean Patent No. 10-799428 discloses a structure for improving the output of the vibrator and the diaphragm by forming a magnet on the upper portion of the diaphragm as a means for improving the output of the bone conduction speaker.

However, the registered patent is not only harmful to the human body since the magnetic force of the magnet is directly transmitted to the human body, there is still a problem that the degree of output improvement of the speaker is not sufficient.

According to these various problems, all existing sound equipments are being spread by air conduction method, and bone conduction speakers are limited in their use.

Therefore, in the bone conduction speaker which processes the acoustic signal as vibration and receives it as an acoustic signal, the improvement of sound quality, the increase in output, and the reduction of external leakage sound generated during vibration are urgently required through the development of new devices and structures for vibration. It is necessary.

An object of the present invention for solving the above problems is to insert a ferrite core having a high permeability inside the bobbin wound around the voice coil, compact structure, speaker output enhancement, frequency band improvement, noise blocking, distortion during bass reproduction To reduce the

Another object of the present invention is to reduce the weight significantly by configuring the vibrator in one-piece thin structure, and to reduce the weight and miniaturization, and the vibrator is composed of a single shape to block the noise caused by the vibration generated from the vibrator during vibration To make it possible.

Still another object of the present invention is to reduce the distortion of the vibration sound and attenuate the external leakage sound by interposing a buffer member between the upper housing and the lower housing.

According to a preferred embodiment of the present invention for achieving the above object, characterized in that it comprises a bobbin formed in the center of the hollow, the ferrite core is inserted into the hollow of the bobbin and a voice coil wound around the outer peripheral surface of the bobbin A voice coil structure for a bone conduction speaker is provided.

Here, the bobbin is preferably formed on the upper and lower ends of the support extending outward, jig coupling projections are coupled to the winding machine jig on the upper surface of the support of the upper end.

According to another embodiment of the present invention for achieving the above object, a housing having an inner space, a magnet located at the bottom of the housing, a bobbin formed in the center, a ferrite core inserted into the hollow of the bobbin And a voice coil wound around an outer circumferential surface of the bobbin, and extending from a voice coil structure and a first support portion positioned above the magnet, an upper surface portion extending from an upper end of the first support portion, and a lower end of the first support portion. And a first lower surface portion formed between the first lower surface portion and the magnet and the voice coil structure, wherein the upper surface portion includes a vibrator that is in contact with an upper inner surface of the housing. .

Here, the housing preferably has a structure in which a buffer member is interposed between the upper housing and the lower housing.

In addition, the seating surface of the vibrator is bent in two stages to form a second support portion and the second lower surface portion, it is more preferable that the magnet is inserted into the space between the first lower surface portion and the second lower surface portion.

In addition, it is more preferable that a plurality of coupling protrusions are formed on a lower surface of the lower housing, and a coupling hole is formed at a position corresponding to the coupling protrusion.

In addition, it is possible to form a headset engaging projection for coupling to the headset on the bottom of the lower housing.

In addition, the bobbin is preferably formed on the upper and lower ends of the support extending outward, jig coupling projections are coupled to the winding machine jig on the upper surface of the support of the upper end.

In addition, it is more preferable that an air gap is formed between the upper surface of the voice coil structure and the upper surface of the vibrator so as to be spaced a predetermined distance apart.

In addition, the cross section of the bobbin is formed in a circular shape, it is more preferable that the voice coil is wound in the form of a solenoid on the outer peripheral surface of the bobbin.

According to the present invention as described above, by inserting a ferrite core having a high permeability inside the bobbin wound voice coil, compact structure, speaker output can be improved, frequency band improvement, noise blocking, can reduce distortion during bass reproduction It works.

In addition, by constructing a vibrator in one-piece thin structure, the weight is drastically reduced, so that the weight and size can be reduced, and the vibrator is composed of a single shape, and also the effect of blocking the noise caused by the vibration generated from the vibrator during vibration. have.

In addition, by interposing the buffer member between the upper housing and the lower housing, there is an effect that can reduce the distortion of the vibration sound and attenuate the external leakage sound.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

1 is a front view of a bone conduction speaker according to the invention, Figure 2 is an exploded front view of a bone conduction speaker according to the invention, Figure 3 is an exploded perspective view of the vibration unit of Figure 2, Figure 4 is a bone conduction speaker according to the present invention Is a cross-sectional view of.

Referring to the drawings, the bone conduction speaker 1 according to the present invention is located between the upper housing 10 and the lower housing 20, the vibrator 70, the voice coil structure is located in the upper space of the vibrator 70 The magnet 50 is inserted into the lower space of the vibrator 70 has a structure.

The inner surface of the upper housing 10 is coupled to the coupling groove (10a) for coupling to the engaging projection 26 of the lower housing 20 protrudes downward to be fixed to the upper housing 10 and the lower housing 20 fixedly have.

In addition, the outer periphery of the upper housing 10 and the lower housing 20 is configured to be spaced apart by a predetermined distance when mutually coupled, the buffer member 80 is inserted into the spaced space.

Therefore, when the upper housing 10 and the lower housing 20 are coupled, the lower end surface of the upper housing 10 has a predetermined space other than the engaging protrusion 26 of the coupling groove 10a and the lower housing 20 to be cushioned. The portion 80 is to be inserted.

The inner surface of the upper housing 10 is in close contact with the upper surface portion 72 of the vibrator 70 to be described later serves to deliver the vibration sound generated from the upper surface portion 72 in close contact with the skin of the human body.

A coupling protrusion 21 for fixing the vibrator is formed on the inner surface of the lower housing 20 so as to be coupled to the coupling hole 75a formed in the second lower surface portion 75 of the vibrator 70. have.

In addition, the bottom surface of the lower housing 20 has a headset coupling protrusion 25 for coupling the bone conduction speaker 1 with the housing portion of the headset (not shown). The headset coupling protrusion 25 facilitates assembly with a coupling groove (not shown) configured in the headset when coupled with the headset, thereby compensating for a problem that the contact surface is spaced along the head of the human body when using the headset. It is configured to be rotatable so as to be firmly in contact with the skin in order to.

As described above, the upper surface of the upper housing 10 is in close contact with the skin of the human body to transfer the vibration sound of the vibrator 70 to the bone and at the same time to implement a role of an external cover to embed the vibrator 2 inside the housing. do.

Therefore, even if a physical force is applied to the upper surface of the upper housing 10, there is an advantage that the change in the sound quality and volume generated in the vibration unit 2 does not occur.

When the vibrator 2 is configured inside the housing, sound quality and volume decrease may occur as in the prior art, but this may be significantly improved through a ferrite core 60, an integrated vibrator 70, and the like, which will be described later.

In addition, since the vibrator 2 is configured inside the housing, the foreign substance such as temperature, humidity and dust caused by the external environment is blocked at the source, thereby improving the function of the product and providing economical life. .

Although the example in which the bone conduction speaker 1 is configured separately from the headset in the present embodiment has been described as an example, it is obvious that the bone conduction speaker 1 may be installed in the headset.

The shock absorbing member 80 is interposed between the upper housing 10 and the lower housing 20 when the upper and lower housings 10 and 20 made of the same material are directly coupled when the vibrator 70 vibrates in the inner space of the housing. It is used to attenuate the distortion and external leakage that may occur, and to improve the volume and sound quality transmitted to the outside together with a buffering role during vibration, and a cushioning member such as silicone and rubber may be used. The effect was found to be great.

This is because when the object of the same material or the material of the hard material is assembled and fixed to each other, when the vibration is applied to one object from the outside, noise is generated along with the vibration to other assembled objects, and a part of the vibration sound leaks to the outside. And, as the shape change of the part facing due to the external impact increases, the life is shortened.

However, when the shock absorbing member 80, such as elastic silicone and rubber, is inserted between the upper and lower housings 10 and 20 of the same material as the present invention, the vibrator sound may be generated when the vibrator 70 vibrates in the inner space of the housing. It can attenuate the distortion and external leakage and improve the volume and sound quality transmitted to the outside along with the buffering role in vibration.

The voice coil structure includes a bobbin 30, a voice coil 40, and a ferrite core 60.

The bobbin 30 is hollow so that the ferrite core 60 can be inserted into the central inner circumferential surface, and upper and lower coils are provided with upper coil support 30b and lower coil support 30c.

 The upper support 30b and the lower support 30c are configured in a shape having an appropriate height and thickness in order to constantly fix the shape of the stacked structure when winding the voice coil 40 in multiple layers.

On the upper surface of the upper support (30b) jig engaging projection (30a) for coupling to the winding machine jig protruding in a circular shape so that the jig coupling projection (30a) is fixed to the jig of the winding machine in close contact with the rotation of the winding machine at the time of coil winding It is possible to prevent the departure of the bobbin 30 due to the workability, and to implement cost reduction by reducing the defective rate and productivity.

The voice coil 40 is wound by the solenoid type on the outer peripheral surface of the bobbin 30 comprised circularly.

If the strength (H) of the magnetic field near the center in the voice coil (40) is the radius (r), length (L) of the coil, number of turns per unit length (n), and current (I), the following formula is established. do.

H = nIL / 2r2 + (L / 2) 2

The solenoid type voice coil 40 is in the form of a circular conductor, and the magnetic fields produced by the respective circular conductors are synthesized with each other. The strength of the magnetic field is the strongest at the center of the coil, and the upper and lower centers of the coil are approximately increased. There is a tendency to lose. In this embodiment, the magnetic field strength is improved by using the ferrite core 60 having a high susceptibility.

Since the strength of the magnetic field is proportional to the number of turns of the voice coil 40, when a current is applied to the voice coil 40, a magnetic field is generated inside the voice coil 40, and an AC signal generated by the voice coil 40 is ferrite. The predetermined frequency is formed by the magnetism of the core 60 and the magnet 50 and the change of current and voltage of the voice coil 40.

In addition, the voice coil 40 has a property of stabilizing a change in current. That is, when the current is about to flow, the voice coil 40 does not disturb the current and tries to flow the current, and when the current decreases, there is a property to continue to flow. Therefore, the induced current generated in the circuit by the electromagnetic induction is always induced. It flows in a direction that prevents the change of the magnetic flux that causes the action.

The ferrite core 60 is a bar type of a circular shape, is inserted into the hollow of the bobbin 30 is installed.

The ferrite core 60 has a disadvantage that can be broken in the strong external impact despite the many advantages. Therefore, in the present embodiment, the upper and lower portions of all the elements constituting the bone conduction speaker 1 with respect to the central axis of the ferrite core 60 are arranged around the central axis, that is, the structure surrounding the ferrite core 60. It is characterized in that it provides an excellent bone conduction speaker (1) that can be configured to withstand a shock from the outside.

As the material of the ferrite core 60, it is preferable to apply a generally used high-frequency ferrite material.

The ferrite core 60 collectively refers to a ceramic magnetic material mainly composed of iron oxide (Fe ₂ O ₃ ), and the nickel-zinc group has a permeability of 20 to 800, which is high in electrical resistance and excellent in stability against temperature changes. In particular, there is an advantage in that the high frequency noise can be filtered using a unique magnetic damping effect.

In addition, the ferrite core 60 has a property of low loss of eddy current or eddy current loss in the high frequency band and low hysteretic hand, and thus is widely used for high frequency.

In addition, the ferrite core 60 reduces leakage inductance with stability and improvement of inductance of the voice coil 40, and has an advantage of improving magnetic force applied to the voice coil 40.

On the other hand, since the ferrite core 60 acts as a kind of magnetic material, it has the effect of maximizing the electromagnetic force by increasing the magnetic flux density together with the magnet 50, thereby increasing the sound pressure and sound efficiency of the vibrator 70 to generate a strong vibration force. Let's do it.

For reference, in the material of the ferrite core 60, the manganese-zinc group has a permeability of 800 or more. It is applied as a permanent magnet having a terminal structure and increased coercivity, and the Br-, Sr- and Nd-based mainstreams, and the loss of hystresis is large, are limitedly applied in the low frequency band. Therefore, detailed description thereof will be omitted.

On the other hand, the permeability of the ferrite core 60 is a constant representing the pass rate of the magnetic field lines, which means the magnetic flux density by the magnetic field, the higher the permeability, the larger the magnetic force can be obtained even with a small ferrite core (60) .

On the other hand, another method for improving the output of the bone conduction speaker 100 is to increase the number of turns of the voice coil 40 and to apply a ferrite core 60 and a magnet 50 having a high permeability and a large specification. In this case, the ferrite core 60 is saturated, so that the strength of the electromagnet is lowered, and thus the resistance component due to the increased number of turns in the voice coil 40 is increased to decrease the current flowing in the voice coil 40. It should be noted that.

Therefore, in the present invention, in determining the material and the structural change of the ferrite core 60, which optimized the maximum value of the associated function between the voice coil 40 and the magnet 50, it was established and applied through numerous experiments and analysis. .

Numerous experiments have shown that when the ferrite core 60 is inserted into the bobbin 30, it is possible to use a small magnet 50 by providing a strong magnetic force, and to reduce the thickness of the vibrator. As a result, the speaker can be miniaturized and the current consumption is reduced accordingly.

The vibrator 70 is composed of an integrated type in which a plate material of elastic stainless material having a thin shape is processed and plated by processing a structure and a shape through a press die.

The vibrator 70 may be formed by bending the upper and lower ends of the stainless steel plate to form a "c" shape, and as shown in the drawing, it may be formed into a shape in which the "r" letter is inverted by multiple bending. .

When the vibrator 70 is formed in a “c” shape, a magnet 50 is installed between the vibrator lower portion and the lower housing 20, and the voice coil structure is seated in the “c” shape.

However, in order to simplify the manufacture and assembly, as shown in the figure, it is more preferable to manufacture the shape in which the vibrator 70 is bent in a multi-stage "d" shape.

Referring to the latter case, the vibrator 70 is bent in four stages, the first support portion 71, the second support portion 74, which serves to support the structure, the upper surface portion 72 serving as the diaphragm, the voice coil A first lower surface portion 73 providing a surface on which the structure is seated and a second lower surface portion 75 fixedly installed in the lower housing 20 and providing a space in which the magnet 50 is installed.

Since the voice coil assembly seated on the first lower surface portion 73 does not have a separate fixing structure, the ferrite core 60 is magnetic, so that the voice coil assembly is stably fixed by the magnet 50 and the magnetic force. It is also possible to have a separate fixing structure for a more secure fixing.

The gap between the upper surface portion 72 and the first lower surface portion 73 of the vibrator 70 is slightly larger than the height of the voice coil structure such that the air gap 77 which is a vibration region between the upper surface and the upper surface portion 72 of the voice coil structure. It is desirable to secure).

The upper surface portion 71 of the vibrator 70 has a shape similar to the inner surface of the upper housing 10 so as to be in light contact with the inner surface of the upper housing 10 when the upper and lower housings 10 and 20 are assembled. .

The bent shape and structure of the vibrator 70 is to minimize the flow due to vibration by fixing the magnet 50 and the voice coil structure integrally, to improve workability during assembly.

In addition, since the structure of the vibrator is integrated as a conventional structure rather than a structure in which a plurality of elements are stacked, the vortex loss is reduced, the high frequency characteristic is improved, and the vibration characteristic is remarkably improved compared to the conventional structure.

Referring to the operation of the bone conduction speaker according to the present invention.

When an electrical signal is applied to the voice coil 40, the magnetic force generated in the voice coil 40 and the magnetic field generated in the magnet 50 and the ferrite core 60 interact with each other by attraction and repulsive force, and suction and repulsion accordingly. Furnace vibration occurs so that the upper surface portion 72 of the vibrator 70 vibrates.

In the configuration in which current is applied to the voice coil 40, the magnet 50 is formed under the vibrator 70, the voice coil structure is formed at the center of the vibrator 70, and the upper surface portion 72 of the vibrator is a vibration region. Due to the structure configured together with the air gap 77, the vibration is generated in each part of the vibrator 70, but due to the structure of the vibrator 70 described above, the maximum generated from the upper surface portion 72 side serving as the diaphragm The vibration sound of is applied.

When the voice coil structure is inserted into the center portion of the vibrator 70, that is, the first lower surface portion 73, the air gap 77, which is a vibration region in which the upper surface portion 72 of the vibrator 70 can vibrate freely, naturally occurs. It is formed, which prevents the saturation of the ferrite core 60 during vibration.

In addition, the air gap 77, which is a vibration region, needs an appropriate space. Therefore, when the upper and lower spaces are narrow, a decrease in volume and sound quality occurs. On the contrary, the same phenomenon occurs even when the upper and lower spaces are increased.

Therefore, the upper and lower spaces should be properly designed on the basis of the minimum and maximum center points to improve the vibration sound output from the speaker even at the same current consumption, which is the upper surface portion 72 and the vibration portion 2 of the vibrator 70. There is a close interrelationship with which.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it is possible to make various modifications or variations without departing from the spirit and scope of the invention. Accordingly, the appended claims will cover such modifications and variations as fall within the spirit of the invention.

1 is a front view of a bone conduction speaker according to the present invention.

2 is an exploded front view of a bone conduction speaker according to the present invention.

3 is an exploded perspective view of the vibrator of FIG. 2.

4 is a front sectional view of a bone conduction speaker according to the present invention.

<Description of the major reference numerals>

1: bone conduction speaker 2: vibrating unit

10: upper housing 10a: coupling groove

20: lower housing 21: engaging projection

25: headset coupling protrusion 26: coupling protrusion

30: bobbin 30a: jig coupling projection

30b: upper support 30c: lower support

40: voice coil 50: magnet

60: ferrite core 70: vibrator

71: first support part 72: upper surface part

73: first lower surface portion 74: second support portion

75: second lower surface portion 77: air gap

80: buffer member

Claims (10)

delete delete In the bone conduction speaker, A housing in which an inner space is formed; A magnet located at the bottom of the housing; A voice coil structure including a bobbin having a hollow formed in the center thereof, a ferrite core inserted into the hollow of the bobbin and a voice coil wound around an outer circumferential surface of the bobbin, and positioned on an upper portion of the magnet; And A first support portion, an upper surface portion extending from an upper end of the first support portion, and a first lower surface portion extending from a lower end of the first support portion, wherein the first lower surface portion is interposed between the magnet and the voice coil structure, And the upper surface portion includes a vibrator that faces the upper inner surface of the housing. The method of claim 3, wherein The housing has a bone conduction speaker, characterized in that having a structure in which a buffer member is interposed between the upper housing and the lower housing. The method of claim 4, wherein The seating surface of the vibrator is bent in two stages downward to form a second support portion and a second lower surface portion, The bone conduction speaker, characterized in that the magnet is inserted into the space between the first lower surface and the second lower surface. The method of claim 5, wherein A plurality of coupling protrusions are formed on a lower surface of the lower housing, and the second lower surface portion has a coupling hole formed at a position corresponding to the coupling protrusion. The method of claim 4, wherein The lower surface of the lower housing is a bone conduction speaker, characterized in that the headset engaging projection for coupling to the headset is formed. The method of claim 3, wherein The bobbin is a bone conduction speaker, characterized in that the support is formed on the top and bottom extending outward, the jig engaging projection is coupled to the winding machine jig on the upper surface of the support of the upper end. The method of claim 3, wherein And an air gap formed between the upper surface of the voice coil structure and the upper surface of the vibrator to be spaced a predetermined distance apart. The method of claim 3, wherein The cross section of the bobbin is formed in a circular, bone conduction speaker, characterized in that the voice coil is wound in the form of a solenoid on the outer peripheral surface of the bobbin.

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