An in-ear headphone

Abstract

The present invention provides an in-ear headphone, which includes a housing. A two-way frequency circuit module, a mid-high frequency speaker and a mid-low frequency speaker are provided inside the housing. A front cavity is provided on the sound output side of each speaker. The outlets of the two groups of front cavities are connected to a sound guide tube. A middle partition is provided inside the sound guide tube. The middle partition divides the headphone into a mid-high frequency sound output channel and a mid-low frequency sound output channel. The diameter of the front cavity of each sound output channel is larger than the diameter of the sound guide tube. A middle frequency sound output channel is further provided at the front section of the middle partition. Sound inlet holes communicating with the middle frequency sound output channel are provided on both sides of the middle partition. The use of dual speakers broadens the frequency response range. When the diaphragm of the speaker vibrates, a strong air pressure is generated inside the headphone, increasing the density of the air medium in the sound guide tube and changing the sound perception. The mid-frequency sound waves mixed on both sides of the middle frequency sound output channel will undergo constructive interference, strengthening the amplitude of the mid-frequency band, while the amplitude of part of the high frequency is weakened after passing through the sound inlet holes, making the mid-frequency human voice segment more prominent, clear and thick.

Description

Technical Field

[0001] The present invention relates to the technical field of in-ear headphones, and specifically refers to an in-ear headphone that can improve sound quality. Background Art

[0002] When the diaphragm of a speaker vibrates, it will cause rhythmic vibrations of the air medium, causing the surrounding air to produce density changes, forming longitudinal waves with alternating density, which generates sound waves; the frequency of the sound waves determines the pitch, and the amplitude of the sound waves determines the volume. And the greater the density of the air medium that propagates the sound waves, that is, the more medium molecules per unit volume, the greater the amount of sound information carried by the air medium in the same time, the more details, and the clearer the sound.

[0003] In-ear headphones are currently the most widely used audio playback products in electronic products. Due to the small internal space of in-ear headphones, it is impossible to set speakers with different frequencies of high, medium, and low frequencies like external speakers. Therefore, the most conventional in-ear headphones all use a single speaker, such as Figure 1 As shown, the sound waves of this kind of headphone are directly conducted from the speaker diaphragm to the eardrum, and the sound output channel has very little influence on the sound quality. The sound quality is completely determined by the quality of the speaker. However, limited by the material characteristics of the speaker, the single-speaker headphone not only has a narrow frequency response range, but also the cost of improving the speaker sound quality is very high.

[0004] If a dual-speaker headphone structure with different frequencies as shown in Figure 2 is adopted, although the frequency response range of the headphone can be expanded, the sound waves emitted by the two speakers have to be reflected multiple times in the front cavity before entering the sound guide tube. Not only is the sound wave attenuation large, but also the sound waves of some of the same frequencies emitted by the two speakers will interfere, and the actual performance is that the sound distortion is large.

[0005] In addition, the Chinese invention patent with the publication number CN204131681 discloses a headphone structure, in which there are main and secondary groups of speakers in the earphone receiver on one side, and each speaker corresponds to a conduit. However, the secondary speaker is only used to play the sound separated from the other channel to simulate the listening effect of a natural environment (non-headphone). This structure is only used to change the sound field environment and cannot change the frequency response range and sound quality of the headphone. Summary of the Invention

[0006] The purpose of the present invention is to provide an in-ear headphone to improve the frequency response range and sound quality of the headphone through the speaker and the sound output channel structure.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0008] An in-ear headphone, comprising a housing, wherein a two-way frequency division circuit module is provided in the housing, and a mid-high frequency speaker and a mid-low frequency speaker respectively connected to the audio output ends of the two-way frequency division circuit module; independent front cavities are provided between the sound-emitting sides of the mid-high frequency speaker and the mid-low frequency speaker and the inner wall of the headphone housing, and the outlets of the two groups of front cavities are commonly connected to a sound guide tube. A middle partition is provided in the sound guide tube, and the middle partition divides the headphone into a mid-high frequency sound-emitting channel corresponding to the mid-high frequency speaker and a mid-low frequency sound-emitting channel corresponding to the mid-low frequency speaker. The diameters of the front cavity sections of the mid-low frequency sound-emitting channel and the mid-high frequency sound-emitting channel are larger than the diameter of a section of the sound guide tube; a mid-frequency sound-emitting channel along the length direction is further provided inside the front section of the middle partition, and sound inlet holes communicating with the mid-frequency sound-emitting channel are provided on both sides of the middle partition.

[0009] In one embodiment, an independent reflux channel is provided in each of the two groups of front cavities. Both ends of the reflux channel communicate with the front cavity and at least one end faces the inlet of the sound guide tube.

[0010] In one embodiment, the side wall of the front cavity is straight, and the front wall of the front cavity is a smooth hourglass-shaped curved surface.

[0011] In one embodiment, the reflux channel is partitioned by an arc-shaped partition parallel to the side wall of the front cavity.

[0012] In one embodiment, sound inlet grooves along the length direction are further provided on the rear sections of the side walls of the middle partition. The sound inlet grooves penetrate through the rear end of the middle partition, and the sound inlet holes are provided at the front ends of the sound inlet grooves.

[0013] In one embodiment, the two-way frequency division circuit module includes a first audio signal connected in parallel with each other and having its audio output end connected to the mid-low frequency speaker, and a second audio signal connected to the mid-high frequency speaker. A resistor is connected in series on the first audio signal, and a capacitor is connected in series on the second audio signal.

[0014] In one embodiment, the headphone further includes an audio input interface, and the audio input interface includes a Bluetooth receiving module and an audio plug-in terminal.

[0015] Its beneficial effects are as follows: The two-way frequency division circuit module divides the audio signal of one-sided earphones into medium-high frequency signals and medium-low frequency signals, and plays them through the medium-high frequency speaker and the medium-low frequency speaker, broadening the frequency response range of the earphones at the speaker level; the medium-high frequency sound outlet channel and the medium-low frequency sound outlet channel are both independent sound outlet channels, and the sound waves between the two will not be distorted due to interference. And because the diameter of one section of the front cavity of each sound outlet channel is larger than the diameter of one section of the sound guide tube, when the diaphragm of the speaker vibrates, a strong air pressure is generated inside the earphone, increasing the air medium density in the sound guide tube, which can change the sound perception and provide conditions for sound quality adjustment; and part of the sound waves in the medium-high frequency sound outlet channel and the medium-low frequency sound outlet channel respectively enter the medium-frequency sound outlet channel from the sound inlet holes, and the medium-frequency sound waves of the same frequency mixed on both sides will have an interference phenomenon. Among them, constructive interference will strengthen the amplitude of the medium frequency band. After tuning, the medium-frequency sound waves with enhanced amplitude pass through the medium-frequency sound outlet channel, which is manifested in the listening perception as a clearer and thicker vocal frequency band; in addition, after part of the high-frequency sound waves pass through the sound inlet holes, due to the diffraction phenomenon, the amplitude of part of the high-frequency sound waves will be reduced, and in the listening perception, the overly sharp high tones are weakened, making the middle tone part relatively more prominent and clear. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0017] Figure 1 is a schematic diagram of the internal structure of a pair of earphones in the background art;

[0018] Figure 2 is a schematic diagram of the internal structure of another pair of earphones in the background art;

[0019] Figure 3 is a schematic diagram of the overall structure of the earphones in the embodiment;

[0020] Figure 4 is Figure 3 a schematic diagram of the A-A sectional structure of the earphones in

[0021] Figure 5 is a schematic diagram of a partial structure inside the earphones in the embodiment;

[0022] Figure 6 is a schematic diagram of the sound wave propagation path of the earphones in the embodiment;

[0023] Figure 7 is a schematic diagram of the sound insulation board structure;

[0024] Figure 8 Another perspective schematic diagram of the sound insulation board structure in the embodiment;

[0025] Figure 9 is a frequency response curve graph of the earphones.

[0026] Figure 10 Schematic diagram of the principle of the frequency division circuit in the embodiment;

[0027] Wherein, 1. housing; 2. circuit board; 31. mid-high frequency speaker; 32. mid-low frequency speaker; 300. front cavity; 301. cover body; 4. sound guide tube; 41. middle partition; 411. sound inlet hole; 412. sound inlet groove; 51. mid-high frequency sound outlet channel; 52. mid-low frequency sound outlet channel; 53. intermediate frequency sound outlet channel; 54. return channel. 6. arc-shaped partition. Specific implementation manners

[0028] The present invention will be further described below with reference to the accompanying drawings:

[0029] It should be noted that: in this application document, the "rear end" refers to the end of each sound outlet channel close to the speaker, and the "front end" refers to the outlet end of each sound outlet channel. And "mid-low frequency", "mid-high frequency" and "intermediate frequency" are only relative concepts. In acoustics, there is no strict boundary between the three, and there are overlapping frequency bands. In addition, the final sound quality effect of the earphone is jointly determined by many factors, and there is a very complex correlation between the factors. Therefore, this implementation scheme only provides a headphone structure that can improve the sound quality. Under this structure, better sound quality can be achieved through tuning, but it does not mean that as long as this structure is adopted, better sound quality can be achieved with any other conditions changed.

[0030] Refer to Figures 3 to 8 , an in-ear earphone, including a housing 1, a circuit board 2 is provided in the housing 1, the circuit board 2 includes a power supply module, an audio power amplifier module and a frequency division circuit module, and further includes a mid-high frequency speaker 31 and a mid-low frequency speaker 32 respectively connected to the audio output ends of the frequency division circuit module; independent front cavities 300 are provided between the sound output sides of the mid-high frequency speaker 31 and the mid-low frequency speaker 32 and the inner wall of the earphone housing 1, and the outlets of the two groups of front cavities 300 are commonly connected to a sound guide tube 4. In this embodiment, the sound guide tube 4 is straight and is inserted at the outlets of the two groups of front cavities 300 of the housing 1. A middle partition 41 is provided in the sound guide tube 4, and the middle partition 41 divides the earphone into a mid-high frequency sound outlet channel 51 corresponding to the mid-high frequency speaker 31 and a mid-low frequency sound outlet channel 52 corresponding to the mid-low frequency speaker 32. The diameter of the section of the front cavity 300 of the mid-low frequency sound outlet channel 52 and the mid-high frequency sound outlet channel 51 is larger than the diameter of the section of the sound guide tube 4; an intermediate frequency sound outlet channel 53 along the length direction is further provided inside the front section of the middle partition 41, and sound inlet holes 411 communicating with the intermediate frequency sound outlet channel 53 are provided on both sides of the middle partition 41. The sizes of the intermediate frequency sound outlet channel 53 and the sound inlet holes 411 need to be adjusted according to the actual effect during the tuning process.

[0031] The two - frequency circuit module divides the audio signal of one - side earphone into medium - high - frequency signal and medium - low - frequency signal, and plays them through the medium - high - frequency speaker 31 and the medium - low - frequency speaker 32. From the speaker level, it broadens the frequency response range of the earphone, can reduce the requirements for the sound quality of the speaker itself, and has more cost advantages. The medium - high - frequency sound outlet channel 51 and the medium - low - frequency sound outlet channel 52 are both independent sound outlet channels, and the sound waves between them will not be distorted due to interference. And because the diameter of one section of the front cavity 300 of each sound outlet channel is larger than the diameter of one section of the sound guide tube 4, when the diaphragm of the speaker vibrates, a strong air pressure is generated inside the earphone, making the density of the air medium in the sound guide tube 4 increase, which provides conditions for sound quality adjustment. The increase in the density of the air medium is physically manifested as an increase in sound pressure and is perceptually manifested as clearer and more elastic sound. And some of the sound waves in the medium - high - frequency sound outlet channel 51 and the medium - low - frequency sound outlet channel 52 respectively enter the medium - frequency sound outlet channel 53 from the sound inlet hole 411. The medium - frequency sound waves with the same frequency mixed on both sides will have an interference phenomenon. Among them, constructive interference will strengthen the amplitude of the medium - frequency band. After tuning, the medium - frequency sound waves with enhanced amplitude are transmitted from the medium - frequency sound outlet channel 53, which is perceptually manifested as a clearer and thicker vocal frequency band. In addition, after some high - frequency sound waves pass through the sound inlet hole, due to the diffraction phenomenon, the amplitude of some high - frequency sound waves will be reduced. Perceptually, the overly sharp high - pitched sounds are weakened, making the middle - frequency part relatively more prominent and clear.

[0032] Figure 9 It is a comparison diagram of the frequency response curves measured after simple tuning for the earphone with a conventional single - speaker structure (B - line) and the earphone with the structure of this embodiment (A - line). From this frequency response curve diagram, it can be seen that for the earphone structure in this embodiment, the frequency response curve in the 2K - 4.5K frequency band is significantly flatter.

[0033] Reference Figure 6 , in one embodiment, an independent return channel 54 is provided in each of the two groups of the front cavities 300. Both ends of the return channel 54 communicate with the front cavity 300 and at least one end faces the inlet of the sound guide tube 4. Because the air flow pressure in the front cavity 300 is relatively large, some of the air flow will bypass the return channel 54 and then enter the sound guide tube 4, making some of the sound waves have a certain delay, which provides conditions for phase adjustment of the sound waves.

[0034] An embodiment, the side wall of the front cavity 300 is in a straight cylindrical shape, and the front wall of the front cavity 300 is a smooth hourglass-shaped curved surface. Further, the reflux channel 54 is partitioned by an arc-shaped partition 6 parallel to the side wall of the front cavity 300. In this embodiment, the top edge of the arc-shaped partition 6 abuts against the cover 301 at the front end of each speaker. Of course, a number of sound holes are provided on the cover 301; and the bottom edge of the arc-shaped partition 6 abuts against the inner wall of the housing 1 to form a sealed tubular structure all around. The inner wall of the arc-shaped partition 6 is still in a straight cylindrical shape, which not only causes less interference to the propagation of sound waves, but is also easy to be integrally formed in structure and the structure is more stable.

[0035] An embodiment, on the rear sections of the two side walls of the middle partition 41, there are also sound inlet grooves 412 along the length direction. The sound inlet grooves 412 penetrate through the rear end of the middle partition 41, and the sound inlet holes 411 are arranged at the front ends of the sound inlet grooves 412. Specifically, the cross-section of the rear section of the middle partition 41 is in an "I" shape. This structure of the middle partition 41, on the one hand, when the air flow in the middle-high frequency sound outlet channel 51 and the middle-low frequency sound outlet channel 52 flows through the sound guide tube 4, since the inner diameter of the front section of the sound guide tube 4 will become smaller again, the air flow will be squeezed again, and the front end of the sound inlet groove 412 will force more air flow into the middle-frequency sound outlet channel 53. All these factors will provide favorable conditions for sound quality adjustment. Part of the high-frequency sound waves in the middle-high frequency sound outlet channel 51 are blocked by the front end of the sound inlet groove 412 and will undergo a winding phenomenon, resulting in a reduction in the amplitude of part of the high-frequency sound waves. In the sense of hearing, the overly sharp high tones are weakened, making the middle tone part relatively more prominent and clear.

[0036] Reference Figure 10 , an embodiment, the two-way frequency division circuit module includes a first audio signal and a second audio signal that are connected in parallel and the audio output ends of which are connected to the middle-low frequency speaker 32 and the middle-high frequency speaker 31 respectively. A resistor is connected in series on the first audio signal, and a capacitor is connected in series on the second audio signal. The two-way frequency division circuit is a mature prior art, and the solution adopted in this embodiment is very simple in circuit structure.

[0037] An embodiment, the earphone further includes an audio input interface, and the audio input interface includes a Bluetooth receiving module and an audio plug-in terminal. Setting two audio input interfaces can facilitate the application of the earphone in different situations.

[0038] The above does not impose any limitation on the technical scope of the present invention. Any modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. An in-ear headphone, characterized in that: it includes a housing, a two-way frequency division circuit module is provided in the housing, and a mid-high frequency speaker and a mid-low frequency speaker respectively connected to the audio output ends of the two-way frequency division circuit module; independent front cavities are provided between the sound output sides of the mid-high frequency speaker and the mid-low frequency speaker and the inner wall of the headphone housing, and the outlets of the two groups of front cavities are commonly connected to a sound guide tube. A middle partition is provided in the sound guide tube. The middle partition divides the headphone into a mid-high frequency sound output channel corresponding to the mid-high frequency speaker and a mid-low frequency sound output channel corresponding to the mid-low frequency speaker. The diameters of the front cavity sections of the mid-low frequency sound output channel and the mid-high frequency sound output channel are larger than the diameter of a section of the sound guide tube; an intermediate frequency sound output channel along the length direction is further provided inside the front section of the middle partition, and sound inlet holes communicating with the intermediate frequency sound output channel are provided on both sides of the middle partition; an independent return channel is provided in each of the two groups of front cavities, and both ends of the return channel communicate with the front cavity and at least one end faces the inlet of the sound guide tube; the side wall of the front cavity is straight, and the front wall of the front cavity is a smooth hourglass-shaped curved surface; the return channel is partitioned by an arc-shaped partition parallel to the side wall of the front cavity; covers are provided at the front ends of the mid-high frequency speaker and the mid-low frequency speaker, and a plurality of sound holes are provided on the covers. The top edge of the arc-shaped partition abuts against the cover; and the bottom edge of the arc-shaped partition abuts against the inner wall of the housing to form a tubular structure sealed all around.

2. The in-ear headphone according to claim 1, characterized in that: sound inlet grooves along the length direction are further provided at the rear sections of the two side walls of the middle partition, the sound inlet grooves penetrate through the rear end of the middle partition, and the sound inlet holes are provided at the front ends of the sound inlet grooves.

3. The in-ear headphone according to claim 1, characterized in that: the two-way frequency division circuit module includes a first audio signal connected in parallel with each other and having an audio output end connected to the mid-low frequency speaker and a second audio signal connected to the mid-high frequency speaker. A resistor is connected in series on the first audio signal, and a capacitor is connected in series on the second audio signal.

4. The in-ear headphone according to claim 1, characterized in that: the headphone further includes an audio input interface, and the audio input interface includes a Bluetooth receiving module and an audio plug-in terminal.

Images