Planar loudspeaker and earphone

Abstract

The invention provides a kind of flat loudspeaker and earphone, including the vibrating diaphragm of periphery being fixed on frame, several permanent magnet group permanent magnet array, the permanent magnet array with the vibrating diaphragm interval arrangement and with the coil of corresponding setting of being applied or embedded on the vibrating diaphragm;The magnetic field intensity of the permanent magnet in the different positions of the permanent magnet array is different, so that at least one acoustic characteristic of the whole loudspeaker is optimized;The difference of vibration direction and amplitude of each part of the vibrating diaphragm is improved, the distortion is reduced, and the sound quality and sound power are improved.

Description

Technical Field

[0001] This invention relates to the field of audio output devices, and more particularly to a planar loudspeaker and headphones. Background Technology

[0002] Planar magnetic speakers embed a flat voice coil within a thin diaphragm, much like a printed circuit board, allowing for an even distribution of driving force. Magnets are concentrated on one or both sides of the diaphragm, causing it to vibrate in the magnetic field they create. Planar magnetic headphones with planar magnetic speakers do not have diaphragms as light as those of electrostatic headphones, but they offer a similarly large vibrating area and comparable sound quality.

[0003] Planar loudspeakers combine the advantages of both dynamic and electrostatic loudspeakers, offering better low-frequency performance than electrostatic loudspeakers and superior high-frequency performance compared to dynamic loudspeakers. Their core transducer typically consists of multiple strip-shaped permanent magnets arranged side-by-side on a yoke. A diaphragm is positioned parallel to the magnetic pole faces of these magnets, and its periphery is fixed to a frame and kept under tension. A coil is positioned on the diaphragm opposite the permanent magnets. The current flowing inside the coil is orthogonal to the magnetic field generated by the permanent magnets. Thus, by flowing an alternating current through the coil, a force obeying Faraday's law is generated, causing the diaphragm to vibrate in the vertical direction. This alternating current signal is converted into a sound signal.

[0004] The maximum amplitude of the existing planar loudspeaker diaphragm is limited by the distance between the diaphragm and the permanent magnet. In order to ensure the magnetic field strength at the diaphragm, the distance between the diaphragm and the permanent magnet is very small. Therefore, the vibration amplitude of the diaphragm is limited, resulting in low power and distortion. Summary of the Invention

[0005] To address the aforementioned shortcomings of existing technologies, this invention proposes a planar loudspeaker, comprising a diaphragm with its periphery fixed to a frame, and a permanent magnet array composed of several permanent magnets. The permanent magnet array is spaced apart from the diaphragm and corresponds to coils applied or embedded on the diaphragm. The permanent magnets at different positions within the permanent magnet array generate different magnetic field strengths, thereby optimizing at least one acoustic characteristic of the entire loudspeaker.

[0006] Preferably, the acoustic features include the following features: the high-frequency response curve of the diaphragm; the mid-frequency response curve of the diaphragm; the low-frequency response curve of the diaphragm; one or more Mel-frequency cepstral coefficients of the diaphragm; the frequency response of the diaphragm at one or more predetermined frequencies; the frequency response of the diaphragm at one or more predetermined locations; the frequency response of the diaphragm across one or more predetermined frequency ranges; and one or more resonant frequency responses that the diaphragm may have in the acoustic path.

[0007] Preferably, the permanent magnets constituting the permanent magnet array are evenly distributed.

[0008] Preferably, the permanent magnet array is composed of several concentric ring-shaped nested permanent magnets; or, the permanent magnet array is composed of several parallel strip-shaped permanent magnets.

[0009] Preferably, the permanent magnet array has two layers, and the diaphragm is located between the two layers of the permanent magnet array.

[0010] Preferably, the magnetic field strength generated by the permanent magnet located in the middle of the permanent magnet array is greater than the magnetic field strength generated by the permanent magnet located on the periphery of the permanent magnet array.

[0011] Preferably, the first end of the permanent magnet facing the diaphragm is a plane parallel to the diaphragm.

[0012] Preferably, the first end of the permanent magnet facing the diaphragm is a plane that is not parallel to the diaphragm.

[0013] Preferably, the distance between the first end of the permanent magnet located in the middle of the permanent magnet array and the diaphragm is greater than the distance between the first end of the permanent magnet located on the periphery of the permanent magnet array and the diaphragm.

[0014] Preferably, the second end of the permanent magnet that is away from the diaphragm is a plane parallel to the diaphragm.

[0015] Preferably, the thickness of the permanent magnet located in the middle of the permanent magnet array is less than the thickness of the permanent magnet located on the periphery of the permanent magnet array.

[0016] Preferably, the device further includes multiple magnetic conductors, and the second ends of two adjacent permanent magnets with opposite magnetic poles that are away from the diaphragm can be connected to the two ends of the magnetic conductors respectively.

[0017] Preferably, it further includes multiple magnetic actuators, each of which drives one or a group of magnetic conductors to move toward or away from the second end of the permanent magnet, so that the magnetic conductors connect to or disconnect from the second end of the permanent magnet; by controlling different magnetic actuators to move different magnetic conductors, the magnetic field strength generated by the permanent magnets at different positions in the permanent magnet array is different.

[0018] Preferably, the permanent magnet is a neodymium iron boron magnet.

[0019] The present invention also proposes an earphone having any of the planar speakers described above.

[0020] The present invention proposes a planar loudspeaker and headphones, comprising a diaphragm whose periphery is fixed on a frame, and a permanent magnet array composed of several permanent magnets. The permanent magnet array is spaced apart from the diaphragm and corresponds to coils applied or embedded on the diaphragm. The permanent magnets at different positions within the permanent magnet array generate different magnetic field strengths, thereby optimizing at least one acoustic characteristic of the entire loudspeaker. This improves the difference in vibration direction and amplitude at various points on the diaphragm, reduces distortion, and enhances sound quality and sound power. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a first planar loudspeaker according to an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of a second planar loudspeaker according to an embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of a third type of planar loudspeaker according to an embodiment of the present invention;

[0024] Figure 4 For the present invention Figure 3 The diagram shows the state changes of a planar loudspeaker.

[0025] Figure 5 For the present invention Figure 1-3 A schematic diagram illustrating the change in diaphragm vibration characteristic curves achievable by the planar loudspeaker in this embodiment.

[0026] Among them, the planar loudspeaker-100, permanent magnet-110, permanent magnet-110A in the outer position, permanent magnet-110B in the middle position, diaphragm-120, coil-130, and magnetic conductor-140 are included. Detailed Implementation

[0027] To address the limitations of the overall amplitude of existing planar speaker diaphragms and the resulting distortion, the planar speaker and headphones provided by this invention are achieved through the following technical solutions:

[0028] Example 1:

[0029] This embodiment provides a planar loudspeaker 100. Please refer to [link / reference]. Figures 1 to 5 The speaker includes a diaphragm 120 with its periphery fixed to a frame, and a permanent magnet array composed of several permanent magnets 110. The permanent magnet array is spaced apart from the diaphragm 120 and corresponds to coils 130 applied to or embedded in the diaphragm 120. The permanent magnets 110 at different positions within the permanent magnet array generate different magnetic field strengths. This optimizes at least one acoustic characteristic of the entire speaker, improving sound reproduction.

[0030] Specifically, the acoustic characteristics include the following features: the high-frequency response curve of the diaphragm 120; the mid-frequency response curve of the diaphragm 120; the low-frequency response curve of the diaphragm 120; one or more Mel-frequency cepstral coefficients of the diaphragm 120; the frequency response of the diaphragm 120 at one or more predetermined frequencies; the frequency response of the diaphragm 120 at one or more predetermined locations; the frequency response of the diaphragm 120 across one or more predetermined frequency ranges; and one or more resonant frequency responses that may exist in the acoustic path of the diaphragm 120. For example, Figure 5 As shown, the magnetic field strength generated by the permanent magnets 110 at different positions within the permanent magnet array is different, which can change the amplitude characteristics of the diaphragm 120 between the solid line and the dashed line; wherein, the amplitude characteristics shown by the dashed line are more suitable for representing mid-to-high frequency audio.

[0031] Specifically, the permanent magnets 110 that make up the permanent magnet array are evenly distributed.

[0032] Specifically, the permanent magnet array is composed of several concentric nested permanent magnets; or, the permanent magnet array is composed of several parallel strip-shaped permanent magnets. When the permanent magnet array is composed of several parallel strip-shaped permanent magnets, the magnetic field strength generated at different length positions of a single strip-shaped permanent magnet 110 is different.

[0033] Specifically, the permanent magnet array has two layers, and the diaphragm 120 is located between the two layers of the permanent magnet array.

[0034] Specifically, the magnetic field strength generated by the permanent magnet 110B located in the center of the permanent magnet array is greater than that generated by the permanent magnet 110A located on the periphery of the permanent magnet array. Based on this, the diaphragm 120 at its center can vibrate more fully, effectively reducing mid-to-high frequency distortion in the planar loudspeaker. When the magnetic field strength generated by the permanent magnet 110B located in the center of the permanent magnet array is 3.5-5.0 times that generated by the permanent magnet 110A located on the periphery of the permanent magnet array, the mid-to-high frequency distortion of the diaphragm 120 can be reduced to the greatest extent. For example, the maximum magnetic energy product of the permanent magnet 110B located in the center of the permanent magnet array is greater than that of the permanent magnet 110A located on the periphery of the permanent magnet array.

[0035] Specifically, please refer to Figure 1 The first end of the permanent magnet 110 facing the diaphragm 120 is a plane parallel to the diaphragm 120.

[0036] Specifically, please refer to Figure 2The first end of the permanent magnet 110 facing the diaphragm 120 is a plane that is not parallel to the diaphragm 120.

[0037] Specifically, the distance between the first end of the permanent magnet 110B located in the middle of the permanent magnet array and the diaphragm 120 is greater than the distance between the first end of the permanent magnet 110A located on the periphery of the permanent magnet array and the diaphragm 120. Based on this, the vibration space at the middle position of the diaphragm 120 can be larger, effectively reducing mid-to-high frequency distortion in the planar loudspeaker.

[0038] Specifically, the second end of the permanent magnet 110 that is away from the diaphragm 120 is a plane parallel to the diaphragm 120.

[0039] Specifically, the thickness of the permanent magnet 110B located in the middle of the permanent magnet array is less than the thickness of the permanent magnet 110A located on the periphery of the permanent magnet array.

[0040] Specifically, please refer to Figure 3 , Figure 4 It also includes multiple magnetic conductors 140, and the second ends of two adjacent permanent magnets 110 with opposite magnetic poles can be connected to the two ends of the magnetic conductors 140 respectively. The magnetic conductors 140 can effectively reduce the magnetic field interference generated by the opposite poles of the permanent magnets 110 located between the two permanent magnets 110, thereby reducing field strength loss.

[0041] Specifically, it also includes multiple magnetic conductors 140. The second ends of two adjacent permanent magnets 110 located at magnetic field enhancement positions in the permanent magnet array, away from the diaphragm 120, can be connected to the two ends of the magnetic conductors 140 respectively. For example, only the permanent magnet 110B located in the middle of the permanent magnet array strengthens its magnetic field through the magnetic conductors 140, while the permanent magnet 110A located on the periphery of the permanent magnet array is not equipped with the magnetic conductors 140, so that the magnetic field strength generated by the permanent magnet 110B located in the middle of the permanent magnet array is greater than the magnetic field strength generated by the permanent magnet 110A located on the periphery of the permanent magnet array.

[0042] Specifically, it also includes multiple magnetic actuators (not shown), each of which drives one or a group of magnetic conductors 140 to move toward or away from the second end of the permanent magnet 110, so that the magnetic conductor 140 connects to or disconnects from the second end of the permanent magnet 110; by controlling different magnetic actuators to move different magnetic conductors 140, the magnetic field strength generated by the permanent magnets 110 at different positions within the permanent magnet array is made different. For example, please refer to... Figure 4By controlling different magnetic actuators, the second end of the permanent magnet 110B located in the middle of the permanent magnet array is connected through the magnetic conductor 140, while the second end of the permanent magnet 110A located on the periphery of the permanent magnet array is not connected through the magnetic conductor 140. This results in the magnetic field strength generated by the permanent magnet 110B located in the middle of the permanent magnet array being greater than the magnetic field strength generated by the permanent magnet 110A located on the periphery of the permanent magnet array.

[0043] Specifically, the permanent magnet 110 is a neodymium iron boron magnet.

[0044] This embodiment proposes a planar loudspeaker, including a diaphragm 120 whose periphery is fixed on a frame, and a permanent magnet array composed of a plurality of permanent magnets 110. The permanent magnet array is spaced apart from the diaphragm 120 and corresponds to the coils 130 applied or embedded on the diaphragm 120. The magnetic field strength generated by the permanent magnets 110 at different positions within the permanent magnet array is different, thereby optimizing at least one acoustic feature of the entire loudspeaker. This improves the difference in vibration direction and amplitude at various points of the diaphragm 120, reduces distortion, and improves sound quality and sound power.

[0045] Example 2:

[0046] This embodiment proposes an earphone that has the planar speaker 100 described in any of the embodiments in Example 1 and has the same performance, which will not be described again.

[0047] It should be noted that the above content is a further detailed description of the present invention in conjunction with specific embodiments, and it should not be considered that the specific embodiments of the present invention are limited to this. Under the guidance of the above embodiments, those skilled in the art can make various improvements and modifications based on the above embodiments, and these improvements or modifications fall within the protection scope of the present invention.

Claims

1. A planar loudspeaker, characterized in that, The speaker includes a diaphragm with its periphery fixed to a frame, and a permanent magnet array consisting of several permanent magnets. The permanent magnet array is spaced apart from the diaphragm and corresponds to coils applied or embedded on the diaphragm. The permanent magnets at different positions within the permanent magnet array generate different magnetic field strengths, thereby optimizing at least one acoustic characteristic of the entire loudspeaker. Each permanent magnet has a first end facing the diaphragm and a second end facing away from the diaphragm. The magnetic field strength generated by the permanent magnet located in the middle of the permanent magnet array is greater than that generated by the permanent magnet located on the periphery of the permanent magnet array; The distance between the first end of the permanent magnet located in the middle of the permanent magnet array and the diaphragm is greater than the distance between the first end of the permanent magnet located on the periphery of the permanent magnet array and the diaphragm. It also includes multiple magnetic conductors, and the second ends of two adjacent permanent magnets with opposite magnetic poles can be connected to the two ends of the magnetic conductors respectively; It also includes multiple magnetic actuators, each of which drives one or a group of magnetic conductors to move toward or away from the second end of the permanent magnet, so that the magnetic conductors connect to or disconnect from the second end of the permanent magnet; by controlling different magnetic actuators to move different magnetic conductors, the magnetic field strength generated by the permanent magnets at different positions in the permanent magnet array is different.

2. The planar loudspeaker according to claim 1, characterized in that, The acoustic features include the following features: the high-frequency response curve of the diaphragm; the mid-frequency response curve of the diaphragm; the low-frequency response curve of the diaphragm; one or more Mel-frequency cepstral coefficients of the diaphragm; the frequency response of the diaphragm at one or more predetermined frequencies; the frequency response of the diaphragm at one or more predetermined locations; the frequency response of the diaphragm across one or more predetermined frequency ranges; and one or more resonant frequency responses of the diaphragm in the acoustic path.

3. The planar loudspeaker according to claim 2, characterized in that, The permanent magnets that make up the permanent magnet array are uniformly distributed.

4. The planar loudspeaker according to claim 3, characterized in that, The permanent magnet array is composed of several concentric ring-shaped nested permanent magnets; or, the permanent magnet array is composed of several parallel strip-shaped permanent magnets.

5. The planar loudspeaker according to claim 2, characterized in that, The permanent magnet array consists of two layers, and the diaphragm is located between the two layers of the permanent magnet array.

6. The planar loudspeaker according to claim 2, characterized in that, The first end of the permanent magnet facing the diaphragm is a plane parallel to the diaphragm.

7. The planar loudspeaker according to claim 2, characterized in that, The first end of the permanent magnet facing the diaphragm is a plane that is not parallel to the diaphragm.

8. The planar loudspeaker according to claim 7, characterized in that, The second end of the permanent magnet that is away from the diaphragm is a plane parallel to the diaphragm.

9. The planar loudspeaker according to claim 8, characterized in that, The thickness of the permanent magnet located in the middle of the permanent magnet array is less than the thickness of the permanent magnet located on the periphery of the permanent magnet array.

10. The planar loudspeaker according to claim 1 or 2, characterized in that, The permanent magnet is a neodymium iron boron magnet.

11. An earphone having a planar loudspeaker as described in any one of claims 1-10.

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