CN115942201A - Loudspeaker and terminal equipment - Google Patents

Abstract

The disclosure relates to a loudspeaker and a terminal device. The speaker includes: the voice coil surrounds to form a closed space, and generates a first magnetic field after alternating current is introduced; a central magnet located within the enclosed space; and a closed loop disposed around a sidewall of the central magnet, the closed loop inductively generating a second magnetic field based on the first magnetic field; the second magnetic field is directed in a direction opposite to the first magnetic field so as to reduce the impedance of the voice coil. Through set up the closed loop on central magnet, then can make the closed loop respond to out the second magnetic field, the second magnetic field is opposite with the direction in first magnetic field, finally can reduce the impedance of speaker to improve the high frequency performance of speaker, promote whole audio. In addition, an additional loudspeaker unit of the high pitch unit is not needed, so that the cost can be saved, the internal space of the mobile phone is saved, heat generation is less, and more power consumption is avoided.

Description

Loudspeaker and terminal equipment

Technical Field

The present disclosure relates to the field of acoustic devices, and in particular, to a speaker and a terminal device.

Background

In the related art, the audio scheme of the terminal device is mainly side sound, that is, the direction of the diaphragm of the speaker (also called a loudspeaker) of the terminal device is arranged at an angle to the sound channel, and the sound emitted by the speaker needs to be guided out from the side of the terminal device through the longer sound channel. As shown in fig. 1 below, which is a frequency response graph, it can be known that the high frequency drop of the speaker of the side sound output terminal device is significant, and the sound effect is poor, thereby affecting the sound effect of the whole speaker.

Disclosure of Invention

To overcome the problems in the related art, the present disclosure provides a speaker and a terminal device.

According to a first aspect of embodiments of the present disclosure, there is provided a speaker including: the voice coil surrounds to form a closed space, and generates a first magnetic field after alternating current is introduced; a central magnet located within the enclosed space; and a closed loop disposed around a sidewall of the central magnet, the closed loop inductively generating a second magnetic field based on the first magnetic field; the second magnetic field is in a direction opposite to the first magnetic field so as to reduce the impedance of the voice coil.

In some embodiments, the closed loop is made of a metallic material.

In some embodiments, the outer wall of the central magnet is provided with a fixing portion for fixing the closed ring.

In some embodiments, the fixing portion is a stepped step provided around an outer wall of the central magnet, and the closed ring is provided on the stepped step.

In some embodiments, the closed ring is fitted over the outer wall of the central magnet by an interference fit.

In some embodiments, the closed loop is a metal coating formed on an outer wall of the central magnet.

In some embodiments, the closed loop comprises at least one layer of multi-turn coils side-by-side on an outer wall of the central magnet.

In some embodiments, the closed ring is convexly disposed on the outer wall of the central magnet, and/or the closed ring is in the same plane as the outer wall of the central magnet.

In some embodiments, the closed ring covers part or all of the side wall of the central magnet.

In some embodiments, the volume of the closed loop is proportional to the strength of the second magnetic field induced by the closed loop.

According to a second aspect of embodiments of the present disclosure, there is provided a terminal device comprising the speaker according to the first aspect.

The technical scheme provided by the embodiment of the disclosure can have the following beneficial effects: through set up the closed loop on central magnet, then can make the closed loop respond to out the second magnetic field, the second magnetic field is opposite with the direction in first magnetic field, finally can reduce the impedance of speaker to improve the high frequency performance of speaker, promote whole audio. In addition, an additional loudspeaker unit of the high pitch unit is not needed, so that the cost can be saved, the internal space of the mobile phone is saved, the heat production is less, and more power consumption is saved.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and together with the description, serve to explain the principles of the disclosure.

Fig. 1 is a schematic diagram of a frequency response curve of a speaker in the related art.

Fig. 2 is a schematic diagram of a speaker configuration according to an exemplary embodiment.

Fig. 3 is a schematic diagram of a speaker according to another exemplary embodiment.

Fig. 4 is a schematic diagram of a speaker according to another exemplary embodiment.

Fig. 5 is a schematic diagram of a speaker according to another exemplary embodiment.

Fig. 6 is a schematic diagram illustrating a structure of a speaker according to another exemplary embodiment.

Fig. 7 is a top view of a loudspeaker shown in accordance with another exemplary embodiment.

Fig. 8 is a graph comparing impedance curves shown in accordance with an exemplary embodiment.

FIG. 9 is a graph illustrating a frequency response curve comparison in accordance with an exemplary embodiment.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the exemplary embodiments below are not intended to represent all implementations consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

The high frequency of the side sound output loudspeaker of the terminal equipment falls obviously, so that the sound effect of the sound emitted by the terminal equipment loudspeaker is poor, and the sound effect of the whole loudspeaker is influenced. In order to compensate for the disadvantage of high frequency drop, in the related art, the high frequency performance of the terminal device is improved by adding a tweeter unit. Specifically, a bass unit loudspeaker and a treble unit loudspeaker are simultaneously arranged in the terminal equipment, a preset audio threshold value of audio frequency is set, and when the audio frequency is larger than the preset audio threshold value, the treble unit loudspeaker is used for playing audio; and when the frequency is smaller than the preset audio threshold value, playing the audio by using the bass unit loudspeaker. Better sound effects are achieved through the combination of the bass unit horn and the treble unit horn.

The scheme of combining the bass unit loudspeaker and the treble unit loudspeaker occupies larger space, so that the foldable mobile phone loudspeaker can be applied to a foldable mobile phone. However, most of the existing terminal devices are non-folding terminal devices, and two loudspeakers are arranged in the non-folding terminal devices at the same time, so that on one hand, the added components increase the cost of the terminal devices, and the added components also occupy the stacking space in the terminal devices. On the other hand, the added high-frequency unit loudspeaker and the low-frequency unit loudspeaker are used simultaneously, the debugging difficulty is increased, and the cost of the technology and the process is increased.

To solve the above technical problem, the present disclosure provides a speaker. As shown in fig. 2, the speaker includes a magnetic circuit system and a vibration system. Wherein the magnetic circuit system comprises a center magnet 10, a side magnet (not shown in the figure), etc. The vibration system comprises a voice coil 20, a diaphragm 30 and the like, wherein the voice coil 20 is fixedly connected with the diaphragm 30.

The working principle of the loudspeaker is as follows: a magnetic gap is formed between the center magnet 10 and the side magnets of the magnetic circuit system, and the voice coil 20 of the vibration system is positioned in the magnetic gap of the magnetic circuit system. When an alternating electric signal is transmitted to the voice coil 20 from an external circuit through a lead of the voice coil 20, the voice coil 20 introduced with the alternating electric signal forms an alternating magnetic field in a magnetic gap, the voice coil 20 magnetized alternately generates vibration under the action of a uniform magnetic field of a magnetic circuit system, the voice coil 20 drives the diaphragm 30 to vibrate up and down in the magnetic gap, and the diaphragm 30 applies work to air to cause the change of density and density of the air, so that sound which can be heard by human ears is formed and is emitted from a sound outlet of the loudspeaker.

Specifically, the voice coil 20 is formed by winding a coil of plural turns. The coil can be a self-melting enameled wire, such as an enameled oxygen-free copper wire, a copper-clad aluminum wire, a pure aluminum wire and the like. The voice coil 20 forms a closed space around the coil, and generates a first magnetic field after alternating current is supplied, wherein the first magnetic field is a changing magnetic field. The lines of magnetic induction generated by the first magnetic field form a first magnetic flux in the spatial area enclosed by the voice coil 20.

The central magnet 10 is located in the closed space surrounded by the voice coil 20. The voice coil 20 is spaced apart from the center magnet 10 by a predetermined distance. A closed ring 40 is disposed around the side wall of the central magnet 10. The side wall of the center magnet 10 is a side corresponding to the inner wall of the voice coil 20. Since the center magnet 10 is disposed in the closed space in the middle of the voice coil 20 and the closed ring 40 is disposed on the center magnet 10, the closed ring 40 is also located in the closed space enclosed by the voice coil 20, and the closed ring 40 is not abutted against the voice coil 20 and is spaced apart from the voice coil 20 by a certain distance, thereby avoiding the influence on the vibration of the voice coil 20.

Based on the varying first magnetic field, the closed loop 40 inductively generates a second magnetic field; wherein the direction of the second magnetic field is opposite to the direction of the first magnetic field, so that the impedance of the voice coil 20 is reduced. In a circuit having a resistance and an inductance, the resistance acting on the current in the circuit is called impedance. In the present embodiment, the impedance of the speaker is reduced to the reduction of the impedance of the voice coil 20. The impedance of the voice coil 20 affects the amplitude of the vibration of the voice coil 20, and the large amplitude is reduced, so that the sound level of the sound in the frequency band is affected when the impedance of the voice coil 20 is reduced.

Specifically, in some embodiments, the closure ring 40 is a closed ring-like structure, and the closure ring 40 is made of a metallic material. The closed loop 40 of metal material generates a first magnetic field that varies when the voice coil 20 is subjected to a varying current. The changing first magnetic field then generates a changing magnetic flux. According to the electromagnetic induction principle, when the changing magnetic flux passes through the closed ring 40 with the annular structure, an induced electromotive force is generated in the closed ring 40, the induced electromotive force forms an induced current, and the induced current generates an induced magnetic field, i.e., a second magnetic field. According to lenz's law, the second magnetic field generated by the induced current always counteracts the change of the first magnetic flux causing the induced current.

Therefore, when the voice coil 20 moves up and down, the first magnetic field passes through the first magnetic flux of the closed loop 40 inside the voice coil 20, and since the second magnetic field induced by the closed loop 40 is opposite to the first magnetic field generated by the voice coil 20, the change of the first magnetic flux is suppressed, i.e., equivalent to the reduction of the first magnetic flux, which is proportional to the induced current of the voice coil 20 itself, the first magnetic flux is reduced, the induced current of the voice coil 20 is reduced, and therefore the self-inductance of the voice coil 20 itself is reduced.

Inductance is a property of a closed loop and is a physical quantity. When current passes through the coil, an induced magnetic field is formed in the coil, which in turn generates an induced current to oppose the current passing through the coil. The inductance includes self-inductance and mutual inductance. As can be seen from the above, the self-inductance decreases, and the overall inductance decreases, that is, the equivalent inductance of the voice coil 20 decreases.

In a circuit having a resistance and an inductance, the resistance acting on the current in the circuit is called impedance. As can be seen from the above, the inductance of the voice coil 20 itself decreases, and the corresponding impedance also decreases. The amplitude of the vibration of the voice coil 20 is affected by the impedance of the voice coil 20, and thus the sound level of the sound in this frequency band is affected. When the impedance decreases, the influence of the amplitude of the voice coil 20 at high frequencies decreases, and therefore, when the amplitude at high frequencies does not change or changes little, the sound at high frequencies does not change, and therefore, the sound of the speaker at high frequencies does not change.

Fig. 8 is a graph illustrating a variation of an impedance curve according to an exemplary embodiment. In fig. 8, the abscissa is frequency (in Hz) and the ordinate is impedance (in Ω).

The solid line curve is an impedance curve when the closed loop 40 is not provided, and the dotted line curve is an impedance curve when the closed loop 40 is provided. As can be seen from fig. 8, the impedance curve after the closed loop 40 is provided is overlapped with the impedance curve without the closed loop 40 in the low frequency range of 2KHz to 7 KHz. While in the range of 7 KHz-20 KHz in the high frequency band, the impedance is obviously reduced, and is kept stable as the impedance in the range of 2 KHz-7 KHz in the low frequency band. In other words, the closed loop 40 has a greater influence on lowering the impedance generated in the high frequency band.

The audible frequency of human ears is 20-20 KHz. As can be seen from fig. 8, when the frequency of the audio frequency is between 2KHz and 7KHz, the impedance remains stable and unchanged, so that when the speaker generates a sound with a frequency between 2KHz and 7KHz, the impedance of the speaker does not affect the sound within the frequency range. And when the frequency of the audio is in the range of 7KHz to 20KHz, the impedance increases as the frequency increases (as shown by the solid line). As can be seen from the above, the blocking affects the amplitude of the vibration of the voice coil 20, which is related to the sound loudness, so that the impedance affects the sound loudness in the frequency band of 7 KHz-20 KHz, and thus the high frequency performance of the speaker in the frequency band of 7 KHz-20 KHz.

In some embodiments, as further shown in FIG. 8, the impedance of the speaker drops by 0-20% in the high frequency band of frequencies between 7KHz and 20KHz. The impedance of the loudspeaker with the closed loop 40 is reduced by 0-20% compared with the original impedance without the closed loop 40. The higher the frequency of the audio, the more the impedance value drops. Therefore, the impedance value can be kept stable in the high-frequency range with the frequency of 7 KHz-20 KHz, and the impedance value is the same as the impedance value with the frequency of 2 KHz-7 KHz, so that the amplitude of the vibration of the voice coil 20 is not influenced if the impedance value is not changed, and the sound of the loudspeaker cannot be reduced.

Fig. 9 is a graph illustrating a frequency response curve according to an exemplary embodiment. Frequency Response (Frequency Response), is the Response of a system to an input signal of a different Frequency. "frequency" means "frequency", the higher the frequency vibration, the higher the tone; the "sound" may then be the response of the speaker to the conversion of the "frequency" in the input electrical signal into acoustic energy.

A stable signal of 0-20KHz is output through a signal transmitter in the electroacoustic tester, a signal sent by an earphone is captured through a receiving microphone and is presented in a dB SPL logarithm value form, and when a plurality of frequency response values are connected together, a frequency response curve with peaks and valleys is formed. Where Frequency is the abscissa (in Hz) and Relative Response is the ordinate (in dB), it can also be called the output level.

The fluctuation of the frequency response curve is the expressive ability to identify the area of the headphone or audio set (e.g., speaker) in this protrusion or depression. The curve is too prominent, which shows that the expressive force of the frequency band is very strong, and when music is played, the sound which is originally very weak to be expressed can be enhanced; if the band is too concave, the band is weak, the sound pressure of the input signal is reduced, the band is weak, the band is strong, and the band is distorted. Therefore, the frequency response curve reflects the degree of reduction of the volume of each frequency band in the input signal by the audio system or the audio equipment.

As can be seen from fig. 9, when the frequency of the sound emitted by the speaker is 5KHz to 20KHz, the frequency response curve begins to sag, which indicates that the sound expression of the speaker in the frequency band of 5KHz to 20KHz is weak, and the boost of the input high-frequency signal is reduced, so that the speaker cannot restore the loudness of the real sound in the frequency band of 5KHz to 20KHz.

In some embodiments, the output level value of the speaker is increased by 0 to 30% in a high frequency band having a frequency of 5KHz to 20KHz.

The output level of the speaker having the closed loop 40 is increased by 0 to 30% from the output level of the speaker having no closed loop 40. Therefore, the frequency response curve becomes more straight, in other words, the loudspeaker can keep stable in the high-frequency range with the frequency of 5 KHz-20 KHz, the frequency response curve is the same as the frequency response curve with the frequency of 1 KHz-5 KHz, and the more stable and straight frequency response curve shows that the expressive force of the frequency band is enhanced, the sound at the high-frequency section is increased when the music is played, and the restoring degree of the loudspeaker is high when the music of the high-frequency band is played.

In some embodiments, the outer wall of the central magnet 10 is provided with a fixing portion for fixing the closure ring 40. The closure ring 40 is fitted over the outer wall of the central magnet 10 and is opposed to the inner wall of the voice coil 20. The closure ring 40 may also be secured to the outside of the central magnet 10 by an interference fit or adhesive.

The closed ring 40 may be a metal ring sleeved on the outer wall of the central magnet 10, or a plurality of closed rings 40 are laminated on the outer wall of the central magnet 10. At this time, each of the closed rings 40 has a circular ring plate-shaped structure. The plurality of closed rings 40 are stacked, that is, the inner diameter value of each closed ring 40 is gradually increased, the smallest closed ring 40 is sleeved on the outer wall of the central magnet 10, the second largest closed ring 40 is sleeved on the outer wall of the smallest closed ring 40, and the plurality of closed rings 40 with different inner diameters are sequentially sleeved.

In one embodiment, the closure ring 40 is a metal coating formed on the outer wall of the central magnet 10. The metal coating is as follows: the coating is prepared by a thermal spraying method by using metal as a spraying material. The metal coating may be applied to the outer wall of the central magnet 10 by spraying, plating or oxidation (treatment), bluing, phosphating (i.e., chemical treatment), and other methods.

Alternatively, the closed loop 40 may be formed of a multi-turn coil and wound around the outer wall of the central magnet 10. The inner diameters of the multi-turn coils are the same, and the multi-turn coils are arranged in parallel. Assuming that the multi-turn coil attached to the central magnet 10 is an inner closed ring, a layer of multi-turn coil, i.e. an outer closed ring, may be further disposed outside the inner closed ring, and the inner diameter of the outer closed ring is equal to the outer diameter of the inner closed ring.

It should be noted that the structure of the closed loop 40 is only exemplary and is not intended to limit the structure of the closed loop 40 of the present disclosure. In some embodiments, the closure ring 40 may consist of one or a combination of several of the embodiments listed above.

In some embodiments, the closed ring 40 covers part or all of the side wall of the central magnet 10. Specifically, it is assumed that the direction along which the voice coil 20 vibrates is a first direction a, and the direction perpendicular to the direction in which the voice coil 20 vibrates is a second direction B. The partial covering is such that the dimension of the closed loop 40 in the first direction a may be smaller than the dimension of the central magnet 10 in the first direction a. In this case, when the closing ring 40 is fitted around the outer wall of the central magnet 10, the closing ring 40 does not cover the outer wall of the central magnet 10 entirely.

In this embodiment, the volume of the closed loop 40 is proportional to the strength of the second magnetic field generated by the closed loop 40. The larger the volume, the larger the resistance of the first magnetic flux by the second magnetic field, the smaller the induced current generated by the self-inductance of the voice coil 20, and thus the lower the impedance of the voice coil 20, so that the loudspeaker has better sound effect in the high frequency band.

In addition, the closed ring 40 may be covered completely in the first direction a, and the size of the closed ring may be equal to the size of the central magnet 10 in the first direction a. In this case, when the closing ring 40 is fitted around the outer wall of the center magnet 10, the closing ring 40 may cover the entire outer wall of the center magnet 10.

In some embodiments, the closed loop 40 is raised above, and/or flush with, the outer wall of the central magnet 10. The closed ring 40 may protrude from the outer wall of the central magnet 10, may be flush with the outer wall of the central magnet 10, and may protrude from the outer wall of the central magnet 10 and be flush with the outer wall of the central magnet 10. The configuration is not particularly limited, and may be set according to design requirements and requirements of the internal space of the terminal device.

The relationship of the closed ring 40 to the outer wall of the central magnet 10 will be described in detail below from several exemplary embodiments.

As can be seen from the above description, the first direction a may be a direction in which the voice coil 20 vibrates, where the first direction a may include positive and negative directions, that is, a direction in which the voice coil 20 vibrates to push the diaphragm 30 outwards is a positive direction of the first direction a, and a direction in which the voice coil 20 vibrates to pull the diaphragm 30 inwards is a negative direction of the first direction a. Likewise, the second direction B may be a direction perpendicular to the first direction a. The second direction B includes positive and negative directions, and the direction toward the voice coil 20 is a positive direction of the second direction B, and the direction toward the center magnet 10 is a negative direction of the second direction B.

Example one

In some embodiments, as shown in fig. 2, the closure ring 40 is fitted over the outer wall of the central magnet 10 (as shown in fig. 7), and the closure ring 40 may be fixed to the outer wall of the central magnet 10 by interference fit or adhesive. And the dimension of the closed ring 40 in the first direction a is smaller than the dimension of the central magnet 10 in the first direction a.

In some embodiments, as shown in fig. 3, the closure ring 40 is fitted over the outer wall of the central magnet 10, and the closure ring 40 may be fixed to the outer wall of the central magnet 10 by interference fit or adhesive. And the dimension of the closed ring 40 in the first direction a is equal to the dimension of the central magnet 10 in the first direction a.

In this embodiment, the closed loop 40 may correspond to a multi-turn metal coil and is disposed on the outer wall of the central magnet 10 side by side, and the larger the size of the closed loop 40 in the first direction a, the more turns of the closed loop 40 disposed on the outer wall of the central magnet 10 can be represented. Each turn of the closed loop 40 induces a second magnetic field under the influence of the varying first magnetic field, which suppresses the variation of the first magnetic flux because the second magnetic field induced by the closed loop 40 is in the opposite direction to the first magnetic field generated by the energized voice coil 20.

When the multiple turns of the closed ring 40 are sleeved on the outer wall of the central magnet 10 side by side and the number of turns is larger, the magnetic flux equivalent to the second magnetic field generated by each turn of the closed ring 40 is superimposed, so that the second magnetic field of the whole closed ring 40 is strengthened, that is, the first magnetic flux is reduced more, and the first magnetic flux is proportional to the induced current of the voice coil 20 itself, and the more the first magnetic flux is reduced, the induced current of the voice coil 20 is reduced, and therefore the self-inductance of the voice coil 20 itself is reduced.

The more the corresponding impedance of the voice coil 20 is reduced. When the impedance decreases, the influence of the amplitude of the voice coil 20 at high frequencies decreases, and therefore, when the amplitude at high frequencies does not change or changes little, the sound at high frequencies does not change, and therefore, the sound change rate of the speaker at high frequencies decreases.

It should be noted that, in practical applications, the size of the closed loop 40 in the first direction a may be set according to the range of values of the output level that fig. 9 needs to be increased. The closed loop 40 may be selected to have a suitable dimension in the first direction to meet the acoustic requirements of the high frequency band. Not only can the weight of the loudspeaker be reduced, but also the production cost of the loudspeaker can be reduced.

Example two

In some embodiments, as shown in fig. 4, the fixing portion is a stepped step disposed around the outer wall of the central magnet 10, and the closure ring 40 is disposed on the stepped step. In this embodiment, the closing ring 40 is disposed on the outer wall of the central magnet 10, and the closing ring 40 may be fixed on the outer wall of the central magnet 10 by interference fit or adhesive.

Furthermore, the thickness of the closure ring 40 in the second direction B is the same as the dimension of the step in the second direction B. The outer wall of the closure ring 40 is flush with the outer wall of the central magnet 10.

In some embodiments, as shown in fig. 5, the fixing portion is a stepped step disposed around the outer wall of the central magnet 10, and the closure ring 40 is disposed on the stepped step. In this embodiment, the closing ring 40 is disposed on the outer wall of the central magnet 10, and the closing ring 40 may be fixed on the outer wall of the central magnet 10 by interference fit or adhesive.

Furthermore, the thickness of the closure ring 40 in the second direction B is greater than the dimension of the step in the second direction B. The outer wall of the closed ring 40 thus protrudes beyond the outer wall of the central magnet 10.

In this embodiment, the closure ring 40 is secured by a stepped step. It can be known from the working principle of the speaker that the voice coil 20 moves up and down under the action of the central magnet 10 and drives the diaphragm 30 to vibrate up and down, and the vibration of the voice coil 20 inevitably causes the vibration of the whole speaker.

As can be seen from the above, the closure ring 40 can be fixed to the outer wall of the central magnet 10 by interference fit or adhesive, but the closure ring 40 fitted over the central magnet 10 is likely to fall off or fall off after a long period of use. Therefore, the center magnet 10 is provided with a stepped portion, and the lower surface of the closed ring 40 abuts against the stepped portion of the stepped portion, so that the closed ring 40 is prevented from falling off the center magnet 10 in the negative direction of the first direction a, and the influence of the closed ring 40 that has fallen off on the center magnet 10 is further prevented.

With the above structure, when the closing ring 40 protrudes from the outer wall of the central magnet 10 in the second direction B, it is explained that the thicker the thickness of the closing ring 40 is, the smaller the distance between the closing ring 40 and the inner wall of the voice coil 20 is. The thicker the closed ring 40 is, the more the first magnetic flux passing through the closed ring 40 when the first magnetic field induced by the voice coil 20 passes through the closed ring 40, the more the induced current generated on the closed ring 40, the more the induced current is, the more the second magnetic field is generated, since the direction of the second magnetic field is opposite to the direction of the first magnetic field, the more the first magnetic flux is reduced, and the first magnetic flux is proportional to the induced current of the voice coil 20 itself, the more the first magnetic flux is reduced, the less the induced current of the voice coil 20 is, and therefore the self-inductance of the voice coil 20 itself is reduced.

The more the corresponding impedance of the voice coil 20 is reduced. When the impedance decreases, the influence of the amplitude of the voice coil 20 at high frequencies decreases, and therefore, when the amplitude at high frequencies does not change or changes little, the sound at high frequencies does not change, and therefore, the sound change rate of the speaker at high frequencies decreases.

EXAMPLE III

In some embodiments, as shown in fig. 6, the fixing portion is a stepped step disposed around the outer wall of the central magnet 10, and the closure ring 40 is disposed on the stepped step. In this embodiment, the closing ring 40 includes a first closing ring 41 and a second closing ring 42, the first closing ring 41 and the second closing ring 42 are both sleeved on the outer wall of the central magnet 10, and the first closing ring 41 and the second closing ring 42 are both fixed on the outer wall of the central magnet 10 by interference fit or adhesive.

In the present embodiment, the first closure ring 41 is provided on a stepped step. And the thickness dimension of the first closure ring 41 in the second direction B is equal to the dimension of the step in the second direction B. The second closed ring 42 is fitted around the outer wall of the central magnet 10 by interference fit or adhesive, and the outer wall of the second closed ring 40 protrudes from the outer wall of the central magnet 10.

In another embodiment, the first closing ring 41 and the second closing ring 42 of the closing ring 40 are integrally formed. A first closing ring 41 of the closing ring 40 is arranged on the step, and a second closing ring 42 is fitted over the outer wall of the central magnet 10. Externally, the first closed ring 41 and the second closed ring 42 are the same size in the positive direction of the second direction B, but the thickness of the first closed ring 41 is greater than the thickness of the second closed ring 42.

As can be seen from the first embodiment, the larger the dimension of the closed loop 40 in the first direction a is, the smaller the impedance generated by the voice coil 20 is (the detailed principle is not repeated, and is the same as the first embodiment). On this basis, the thickness of the first closed ring 41 is increased in the present embodiment, and it can be known from the second embodiment that the impedance of the voice coil 20 is further reduced (the specific principle is not described again, which is the same as the second embodiment), and meanwhile, due to the stepped step matching between the closed ring 40 and the central magnet 10, the closed ring 40 is not easy to fall off under the long-term use of the speaker, and the service life of the speaker is prolonged.

It should be noted that the above embodiments are exemplary, and those skilled in the art can freely change the positional relationship between the closed ring 40 and the central magnet 10 and the installation method. It is sufficient to provide a ring of closed rings 40 at the outer wall of the central magnet 10 and can be implemented within the scope of the present disclosure.

As can be seen from the above structure, the present disclosure provides the following advantages: by arranging the closed ring 40 on the central magnet 10, a second magnetic field can be induced by the closed ring 40, the direction of the second magnetic field is opposite to that of the first magnetic field, and finally, the impedance of the loudspeaker can be reduced, so that the high-frequency performance of the loudspeaker is improved, and the integral sound effect is improved. In addition, an additional loudspeaker unit of the high pitch unit is not needed, so that the cost can be saved, the internal space of the mobile phone is saved, the heat production is less, and more power consumption is saved.

Based on the same concept, the embodiment of the disclosure also provides a terminal device, which includes the loudspeaker. The terminal device may be a mobile phone, a computer, a digital broadcast terminal, a messaging device, a game console, a tablet device, a medical device, a fitness device, a personal digital assistant, a translator, a watch, a bracelet and other wearable devices.

It is understood that the terminal device provided by the embodiments of the present disclosure includes a hardware structure and/or a software module for performing the above functions. The disclosed embodiments can be implemented in hardware or a combination of hardware and computer software, in combination with the exemplary elements and algorithm steps disclosed in the disclosed embodiments. Whether a function is performed as hardware or computer software drives hardware depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

With regard to the apparatus in the above-described embodiments, the specific manner in which the respective modules perform operations has been described in detail in the embodiments related to the speaker, and will not be described in detail here.

It is understood that "a plurality" in this disclosure means two or more, and other words are analogous. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship. The singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It will be further understood that the terms "first," "second," and the like are used to describe various information and that such information should not be limited by these terms. These terms are only used to distinguish one type of information from another, and do not indicate a particular order or degree of importance. Indeed, the terms "first," "second," and the like are fully interchangeable. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope of the present disclosure.

It will be further understood that the terms "central," "longitudinal," "lateral," "front," "rear," "upper," "lower," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in an orientation or positional relationship indicated in the drawings for convenience in describing the present embodiment and to simplify the description, but do not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation.

It is further understood that, unless otherwise specified, "connected" includes direct connections between the two without other elements and indirect connections between the two with other elements.

It is further to be understood that while operations are depicted in the drawings in a particular order, this is not to be understood as requiring that such operations be performed in the particular order shown or in serial order, or that all illustrated operations be performed, to achieve desirable results. In certain environments, multitasking and parallel processing may be advantageous.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

It will be understood that the present disclosure is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is to be limited only by the scope of the appended claims.

Claims (11)

1. A loudspeaker, comprising:

the voice coil surrounds to form a closed space, and generates a first magnetic field after alternating current is introduced;

a central magnet located within the enclosed space; and

a closed loop disposed around a sidewall of the central magnet, the closed loop inductively generating a second magnetic field based on the first magnetic field; the second magnetic field is directed in a direction opposite to the first magnetic field so as to reduce the impedance of the voice coil.

2. A loudspeaker according to claim 1, wherein the closed loop is made of a metallic material.

3. A loudspeaker according to claim 1, wherein the outer wall of the central magnet is provided with a fixing portion for fixing the closed loop.

4. The loudspeaker of claim 3, wherein the fixed portion is a stepped step disposed around the outer wall of the central magnet, the closed loop being disposed on the stepped step.

5. The loudspeaker of claim 1, wherein the closed ring is disposed about the outer wall of the central magnet by an interference fit.

6. The loudspeaker of claim 1, wherein the closed loop is a metal coating formed on an outer wall of the central magnet.

7. The loudspeaker of claim 1 wherein said closed loop comprises at least one layer of multi-turn coils disposed side-by-side about an outer wall of said central magnet.

8. The loudspeaker of claim 1,

the closed ring is convexly arranged on the outer wall of the central magnet, and/or

The outer wall of the closed ring is in the same plane as the outer wall of the central magnet.

9. The loudspeaker of claim 1, wherein the closed ring covers part or all of the side wall of the central magnet.

10. The loudspeaker of claim 1,

the volume of the closed loop is proportional to the strength of the second magnetic field induced by the closed loop.

11. A terminal device, characterized in that it comprises a loudspeaker according to any one of claims 1-10.

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