Patent Application
20230124537
The present invention relates to the technical field of speakers, and more particularly to a planar diaphragm speaker.
Planar magnetic technology is also known as orthodynamic technology, which is a miniaturized planer loudspeaker, in which magnets are concentrated on one side or two sides of a diaphragm and the diaphragm oscillates in a magnetic field generated thereby. Compared to the moving coil technology, the planar magnetic technology exhibits better performance in high frequencies.
In the known technology, a small-sized planar diaphragm speaker is generally formed of a single-side magnetic circuit together with an odd number, such as three or five, of magnets. This does not provide a 360-degree dead zone free magnetic field. As a result, the small-sized planar diaphragm speaker is poorer than the moving coil technology in respect to speaker sensitivity.
In view of the above, the present invention provides a planar diaphragm speaker, which effectively resolves the problems of the known technology that a small-sized planar diaphragm speaker cannot fulfil a 360-degree dead zone free magnetic field and shows a relatively low magnetic field intensity and low sensitivity.
The present invention provides a planar diaphragm speaker, which comprises an enclosure, a vibration diaphragm assembly, and two magnet assemblies. The two magnet assemblies are both fixed inside the enclosure. The vibration diaphragm assembly is located between the two magnet assemblies and arranged to be spaced from the two magnet assemblies. Each of the magnet assemblies comprises an inner magnet and a ring-shaped outer magnet surrounding the inner magnet with a magnetic gap being formed between an outer side surface of the inner magnet and an inner side surface of the outer magnet. The vibration diaphragm assembly comprises vibration diaphragm and a voice coil, the vibration diaphragm being formed with a trough. An effective-width portion of the voice coil spans over the magnetic gap, a width of the effective-width portion being greater than or equal to a width of the magnetic gap.
In some embodiments, a depth of the trough is ½ of a thickness of the voice coil.
In some embodiments, a magnetic polarity of one end of the inner magnet that is adjacent to the vibration diaphragm assembly is opposite to that of one end that is distant from the vibration diaphragm assembly, and a magnetic polarity of one end of the outer magnet that is adjacent to the vibration diaphragm assembly is opposite to that of one end that is distant from the vibration diaphragm assembly.
In some embodiments, for a same one of the magnet assemblies, magnetic polarities of ends of the inner magnet and the outer magnet that are adjacent to the vibration diaphragm assembly are opposite; and for different ones of the magnet assemblies, magnetic polarities of ends of the outer magnets that are adjacent to the vibration diaphragm assembly are identical, and for different ones of the magnet assemblies, magnetic polarities of ends of the inner magnets that are adjacent to the vibration diaphragm assembly are identical.
In some embodiments, the film is formed, in one end thereof that is close to an adjacent one of the magnet assemblies, in an integrated form, with a bent ring, and the bent ring projects in a direction that is identical a direction in which the trough is recessed.
In some embodiments, the vibration diaphragm divides an internal space of the enclosure into a front compartment space and a rear compartment space; a pad is arranged in the front compartment space; the pad comprises a top face and a bottom face that are opposite to each other and a lateral face connecting between the top face and the bottom face. The top face is positioned against an internal surface of the enclosure, the lateral face being arranged to separate from the internal wall surface of the enclosure, the bottom face being simultaneously in contact engagement with the inner magnet and the outer magnet adjacent thereto.
In some embodiments, the pad does not completely block the magnetic gap, so that the magnetic gap is in communication with a space between the lateral face of the pad and the internal wall surface of the enclosure.
In some embodiments, a length of the pad is less than an inside diameter of the outer magnet, and a width of the pad is greater than the inside diameter of the outer magnet.
In some embodiments, a sidewall of the enclosure is formed with a front-compartment sound outlet opening in communication with the front compartment space, the front-compartment sound outlet opening being arranged at one side of the pad and not blocked by the magnet assemblies.
In some embodiments, the sidewall of the enclosure is formed with a rear-compartment sound outlet opening in communication with the rear compartment space.
In some embodiments, the enclosure comprises a top wall and a bottom wall that are opposite to each other and a sidewall connecting between the top portion and the bottom wall. The sidewall comprises two opposite long-side sidewalls and two opposite short-side sidewalls, each of the long-side sidewalls being connected to the two short-side sidewalls adjacent thereto, lengthwise dimensions of the long-side sidewalls being greater than widthwise dimensions of the short-side sidewalls, height-wise dimensions of the long-side sidewalls being equal to height-wise dimensions of the short-side sidewalls.
In some embodiments, the vibration diaphragm assembly is parallel to the top wall and are perpendicular to the four sidewalls; and the front-compartment sound outlet opening and the rear-compartment sound outlet opening are respectively formed in the two opposite short-side sidewalls
In some embodiments, the inner magnet is in the form of a strip, and the magnetic gap is greater than or equal to 0.05 mm and is less than or equal to 0.15 mm.
In some embodiments, the vibration diaphragm comprises a film, a rigid plate, and film ring that are arranged to sequentially stack on each other, and the trough is formed in the rigid plate; and the voice coil and the film ring are located on a same side of the rigid plate.
In some embodiments, a gap between the voice coil and an adjacent one of the magnet assemblies is greater than or equal to 0.1 mm and less than or equal to 0.2 mm.
The present invention provides improvements to the drawbacks of known medium and small sized planar diaphragm for being incapable of providing a 360 ° dead zone free magnetic field and the magnetic field being of a low intensity and having a poor sensitivity, and specifically realizes the following beneficial efficacy:
1 (1) Magnet assemblies comprising an inner magnet and a ring-shaped outer magnet are provided and two of such the magnet assemblies are arranged on two opposite axial sides of a vibration diaphragm assembly to form a closed-loop dual-sized magnetic circuit structure, which forms a 360° all-directional dead zone free magnetic field around the vibration diaphragm assembly so as to enhance the sensitivity of the speaker.
(2) A trough is formed in a vibration diaphragm of the vibration diaphragm assembly and a voice coil is disposed in the trough, so that, without increasing a vibration compartment height, the thickness of the voice coil can be effectively increased to further enhance the speaker sensitivity and also to better position the voice coil, and also to allow an effective-width portion of the voice coil to span over a magnetic gap to ensure that the voice coil is located in the most intense part of the magnetic field to further enhance the sensitivity of the speaker.
(3) Under a condition of ensuring accurate positioning of the outer magnet and the inner magnet, a pad that has a small size is arranged in combination with a front-compartment sound outlet opening of which the location is close to an upper side to enhance low frequency performance
(4) A bent ring is arranged in the film to enhance low frequency performance and the rigid plate and the trough form a dome-like structure to further enhance high frequency performance.
The planar diaphragm speaker according to the present invention has a simple structure and can effectively increase the thickness of the voice coil without increasing a vibration compartment height and a device overall size, and provides, through collaboration with a dual-side magnetic circuit structure, a 360° dead zone free magnetic field to enhance the sensitivity and low frequency performance of the planar diaphragm speaker, exhibiting excellent utilization.
To more clearly illustrate the technical solutions presented in the embodiments of the present invention, the following provides a brief description to the drawings that are essential for the illustration of technical solutions presented in the embodiments or those of the prior art. It is obvious that the drawings of which the description provided below are just for some of the embodiments of the present invention, and for those having ordinary skill in the art, other drawings can be contemplated from theses without paying creative endeavor.
For better understanding of the objectives, the technical solutions, and the advantages of the present invention, the following provides a more detailed description of the present invention with reference to the embodiments of the present invention and the drawings. It is appreciated that the embodiments described herein are provided only for illustration of the present invention and are not intended to impose limitation to the present invention.
It is noted that, in the following description, the terms, such as “length”, “width”, “top”, and “bottom”, which are provided to indicate orientation or positional relationship indicates such orientation or positional relationship as shown in the drawings and are provided for illustration of the present invention and for simplifying the illustration, and are not intended to indicate or suggest that an indicated device or component must involve a specific orientation or position, or must be constructed or operated in a specific orientation or position, and should not be interpreted as limiting to the present invention.
Further, the terms “first”, “second”, and the likes are provided for illustration only and should not be construed as indicating or suggesting relative importance or implying the quantity of the specific technical feature so indicated. Thus, a technical feature that is identified as being “first” or “second” may involve an explicit indication or an implication of including a single one or a plurality of such features. In the description of the present invention, “plurality” indicates two or more than two, unless a clear description is provided to the contrary.
To expound the technical solutions of the present invention, a description is provided below with reference to the attached drawings and embodiments.
As a first embodiment, the instant embodiment provides a planar diaphragm speaker, in which, guaranteeing the speaker being miniature without an increase of the size thereof, an arrangement of a magnetic field is so made as to realize a 360° omnidirectional dead zone-free magnetic field so as to enhance the sensitivity of the speaker.
Referring to
The magnet assembly 3 comprises an outer magnet 31 and an inner magnet 32. The outer magnet 31 is a ring-shaped magnet. The inner magnet 32 is disposed inside the outer magnet 31. A gap is arranged between an outside surface of the inner magnet 32 and an inside surface of the outer magnet 31 The gap will be referred to as a magnetic gap 33. Specifically, since the outer magnet 31 is a ring-shaped magnet, a through hole 311 is formed in an interior thereof, and the inner magnet 32 is disposed in the through hole 311. A space between the outside surface of the inner magnet 32 and the inside surface of the outer magnet 31 forms the magnetic gap 33. The inner magnet 32 is so disposed in the through hole 311 as to collaborate with the outer magnet 31 to form a 360° closed-loop internal/external magnetic field structure without dead zone, which helps increase an electromagnetic force so as to ensure a wider range of vibration frequency for the vibration diaphragm assembly 2, and providing the planar diaphragm speaker with higher sensitivity.
An external surface of the outer magnet 31 and an internal surface of the enclosure 1 are set in tight engagement with each other. A shape of the outer magnet 31 is conformed with a shape of the enclosure 1. The outer magnet 31 can be a magnet in the form of a rectangular loop or a magnet in the form of a circular loop
It is noted that the outer magnet 31 is a ring-shaped magnet, and the term “ring-shaped magnet” used herein indicates a central portion of the outer magnet 31 is formed with an internal hole penetrating therethrough. The internal hole functions to receive the inner magnet 32 to dispose therein, and the magnetic gap 33 is formed between the outer side surface of the inner magnet 32 and the inner side surface of the outer magnet 31. The application imposes no specific limitation to the shape of the internal hole, and the hole can be a circle, a rectangle, a square, or a corner-rounded rectangle. The term “ring-shape magnet” used herein should not be construed as constraining the shape of the outer magnet 31 to be a circular ring, and in fact, the application imposes no specific limitation to the shape of the outer magnet 31. A projection of an outer contour of the outer magnet 31 can be a circle, a rectangle, a square, or a comer-rounded rectangle. Further, in the instant embodiment, no specific limitation is applied to the shape of the inner magnet 32.
The vibration diaphragm assembly 2 is disposed between the two magnet assemblies 3, and magnetic poles of surfaces facing each other of the two magnet assemblies 3 mutually repel each other. The magnet assemblies 3 are arranged on top and bottom sides of the vibration diaphragm assembly 2 to form double-side closed-loop magnetic circuit to further enhance the electromagnetic force and further improve the sensitivity of the planar diaphragm speaker.
Referring to
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The vibration diaphragm 21 comprises a film 211 and a rigid plate 212 stacked together. The rigid plate 212 is formed with a trough 2121, and the voice coil 22 is fixed in the trough 2121, such that a portion of the voice coil 22 is located in the trough 2121, while another portion is located outside the trough 2121, meaning in a thickness direction, a portion of the voice coil 22 is located in the trough 2121 and another portion is outside of the trough 2121. Compared to a rigid plate that is in the form of a flat board without trough, under the condition that a vibration compartment height remains identical, the thickness of the voice coil 22 fixed in the trough 2121 of the rigid plate 212 can be significantly increased, where the increased thickness is the depth of the trough 2121. A thickened voice coil 22 can firstly generate a stronger magnetic force between the voice coil 22 and the magnetic field, and secondly, the thickened voice coil 22 is hard to deform during machining, so as to reduce the difficulty of machining.
Further, a top/bottom surface area of the outer magnet 31 is identical to a top/bottom surface area of the vibration diaphragm assembly 2, in order to ensure that the closed-loop internal/external magnetic field structure so formed can completely cover and shield the vibration diaphragm assembly 2, thereby ensuring the entirety of the vibration diaphragm assembly 2 is located within the effective magnetic field.
Further, four lateral surfaces of the outer magnet 31 and four lateral surfaces of the vibration diaphragm assembly 2 are all set in contact engagement with the internal wall surface of the enclosure 1, in order to realize high utilization of the magnetic field and space.
In the above-described structure, the film 211 can be made of a material that is similar to that used to make a film of a known moving-coil speaker, and can be for example paper, ceramic, polypropylene, and wood, or can be other film materials commonly used in moving-coil speakers. The rigid plate 212 can be made of a material of metal, or plastics or fibers, and a metallic material is preferred. The metallic material is relatively thin and light in weight, while showing a relatively high strength, allowing for increase of high frequency and also for easy mounting of the voice coil 22 in the trough 2121. The trough 2121 is formed by means of stamping and, meanwhile, the voice coil 22 may be modified according to the size and shape of the magnetic circuit. The size of the trough 2121 corresponds to the voice coil 22.
In the above-described structure, under the condition that the height of the vibration compartment between the two magnet assemblies 3 remains the same, arranging the trough 2121 in the vibration diaphragm 21 helps increase the receiving space for the voice coil 22, allowing the thickness of the voice coil 22 to be increased to thereby enhance the speaker sensitivity.
In the instant embodiment, the ring-shaped outer magnet 31 and the inner magnet 32 are arranged collaboratively to form the closed-loop internal/external magnetic field structure, forming a 360° dead zone free closed-loop internal/external magnetic field. The arrangement of the closed-loop internal/external magnetic field structure on both top and bottom sides of the vibration diaphragm assembly 2 forms a double-sized closed-loop magnetic circuit that significantly increases the electromagnetic force, increases the vibration frequency of the vibration diaphragm assembly 2, and thus enhances the sensitivity of the planar diaphragm speaker.
Referring to
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The following two arrangements may be present in the instant embodiment:
In the first one, the inner magnet 32 and the outer magnet 31 are polarized axially, ends of the inner magnet 32 and the outer magnet 31 of one of the magnet assemblies 3 that face the vibration diaphragm assembly 2 are set as an N pole and an S pole, respectively, while ends of the inner magnet 32 and the outer magnet 31 of the other one of the magnet assemblies 3 that face the vibration diaphragm assembly 2 are similarly set as an N pole and an S pole, respectively
In the second one, which is exactly opposite to the first one, ends of the inner magnet 32 and the outer magnet 31 of one of the magnet assemblies 3 that face the vibration diaphragm assembly 2 are set as an S pole and an N pole, respectively, while ends of the inner magnet 32 and the outer magnet 31 of the other one of the magnet assemblies 3 that face the vibration diaphragm assembly 2 are similarly set as an S pole and an N pole, respectively.
Referring to
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The front compartment space 111 is a space between the vibration diaphragm 21 and the internal surface of the enclosure 1, which specifically comprises a space between an end face of the vibration diaphragm 21 and an end face of one of the magnet assemblies 3 adjacent thereto, a corresponding one of the magnetic gaps 33, and a space between the lateral face of the pad 4 and the internal side surface of the enclosure 1. Two ends of the magnetic gap 33 are respectively in communication with the space between the one end of the vibration diaphragm 21 and the one end of the adjacent magnet assembly 3 and the space between the lateral face of the pad 4 and the internal side surface of the enclosure 1, so that the front compartment space 111 is formed as one continuous and integrated space.
The rear compartment space 121 is a space between the vibration diaphragm 21 and the internal surface of the enclosure 1, which specifically comprises a space between an opposite end face of the vibration diaphragm 21 and an end face of one of the magnet assemblies 3 adjacent thereto, and a corresponding one of the magnetic gaps 33. The magnetic gap 33 is in communication with the space between the opposite end of the vibration diaphragm 21 and the end face of the adjacent magnet assembly 3, and makes the rear compartment space 121 one continuous and integrated space.
Referring to
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The inner magnet 32 is a magnet having a form of a strip. In view of the outer magnet 31 being a ring-shaped magnet and being made to correspond to the inner magnet 32 and further in view of a uniform width of the magnetic gap 33, the central internal through hole of the outer magnet 31 is similarly a rectangular hole.
The width of the pad 4 is greater than the width of the central internal hole of the outer magnet 31, and the length of the pad 4 is less than the length of the inner magnet 32.
Specifically, referring to
The above-described arrangement provides a primary purpose of making a length-to-width ratio of the pad 4 relatively small so that the shape of the pad 4 is a rectangle that is closer to a square, but not close to an elongate strip. Such an arrangement is for easiness of machining and also for easiness for the pad 4 to fix the adjacent one of the magnet assemblies 3, and also for expanding the volume of the front compartment space 111 to ensure low frequency performance.
Referring to
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The front-compartment sound outlet opening 1111 and the rear-compartment sound outlet opening 1211 are respectively defined in the two short-side sidewalls. Since the sound outlet channel in the earphone sound nozzle is an elongate passage, when the speaker is disposed in the sound outlet channel, such an arrangement makes the lengthwise direction of the enclosure 1 be parallel to an extension direction of the sound outlet channel, so as to ensure that the enclosure 1 and the sound outlet channel correspond to each other in respect of shape. Such an arrangement ensures the short-side sidewall in which the front-compartment sound outlet opening 1111 is arranged faces toward a sound outlet direction of the sound outlet channel of the earphone, making the front-compartment sound outlet opening 1111 in direct communication with the sound outlet channel of the earphone and the sound generated by the speaker being allowed to directly transmit to the sound outlet opening of the sound nozzle by way of the front-compartment sound outlet opening 1111 to ensure the sound quality.
Referring to
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The front-compartment sound outlet opening 1111 is arranged in the sidewall of the enclosure 1 and distant from the vibration diaphragm 21, and the front-compartment sound outlet opening 1111 is correspondingly in communication with a space around the pad 4, so as to ensure complete transmission of low frequency sound effect by the front-compartment sound outlet opening 1111 can be fulfilled in a better way. The front-compartment sound outlet opening 1111 being arranged in the short sidewall of the enclosure 1 facilitates the front-compartment sound outlet opening 1111 to align with the extension direction of the sound outlet tube of the earphone for direct transmission of sound effect. If the front-compartment sound outlet opening 1111 is formed in the top surface of the enclosure, it is not possible to make the front-compartment sound outlet opening 1111 directly orientate toward the extension direction of the sound outlet tube of the earphone, making it not possible to completely and directly transmit the sound effect so as to affect the sound quality.
Referring to
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In one embodiment, the enclosure 1 comprises a top cover 11 and a bottom shell 12 The bottom shell 12 receives all the components/parts described above. The top cover 11 is set on and covers the bottom shell 12. Such an arrangement eases dismantling and replacing the components/parts. A space between an internal surface of the top cover 11 and the pad 4 forms a part of the front compartment, and the front-compartment sound outlet opening 1111 is formed in a side wall/surface of the top cover 11 to prevent the front-compartment sound outlet opening 1111 from being blocked by the magnet assembly 3 to thereby ensure better low frequency performance of the device.
The above embodiments are provided only to explain the technical solution of the present invention and are not for constraining. Although a detailed description has been made with reference to the above embodiments, those having ordinary skill in the art may appreciate that it is possible to make modifications to the technical solution disclosed in each of the above embodiments, or to make equivalent substitute for some of the technical features thereof. Such modifications or substitutes do not make the essences of the corresponding technical solutions depart from the spirit and scope of the technical solutions provided in each of the embodiments of the present invention and are included in the scope of protection covered by the claims of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202111209409.0 | Oct 2021 | CN | national |
