JP2023164201A - earphone - Google Patents

Abstract

To improve the characteristics of an electromagnetic sounding body, especially in the high frequency range while aiming to lower the price, and enable wideband audio reproduction as a whole.SOLUTION: A sound emitted from an electromagnetic speaker 30 passes through a gap 44 and is emitted to a sound emitting hole 26 of a rear housing 24 as shown by a thick arrow FSP. In this case, the emitted sound waves (air vibrations) pass through the gap 44, and are also directly radiated to a diaphragm 40. This causes the diaphragm 40 to resonate with the high frequency sound waves output from the electromagnetic speaker 30. Therefore, the high-pitched sound of the diaphragm 40 indicated by an arrow FH is superimposed on the output sound from the electromagnetic speaker 30.SELECTED DRAWING: Figure 1

Description

The present invention relates to improvements in earphones using electromagnetic sounding bodies (electromagnetic speakers).

In recent years, with changes in the residential environment, it has become difficult to enjoy music using large audio devices, etc. due to the need to take into account neighboring noise. On the other hand, as communication speeds have improved, the environment for distributing music sources has improved, and earphones and headphones for music playback using smartphones and portable audio players have become widespread. Furthermore, in line with the speed of music distribution, high-resolution sound sources, which are extremely high-resolution digital sound sources, are becoming more popular, and it has become possible to listen to high-quality music even with portable music playback. At the same time, since high-resolution sound sources reproduce signal sources with higher resolution, earphones and headphones are also required to reproduce high frequency ranges of 40 kHz or higher (see Non-Patent Document 1 below). .

In addition, in the case of an electromagnetic speaker, since it has an inductor component, the impedance in the high frequency range becomes high, making it difficult to reproduce sound in the high frequency range. On the other hand, for example, Patent Document 1 listed below devises a hybrid configuration in which a low frequency range is reproduced by an electromagnetic speaker and a high frequency range is reproduced by a piezoelectric ceramic in a high-quality earphone. This can be thought of as a method that takes advantage of the respective advantages of electromagnetic (inductor component) speakers whose impedance is low in the low frequency range and ceramic (capacitance component) speakers whose impedance is low in the high frequency range.

JP 2016-86404 (Patent No. 5860561)

JAS Journal 2014 Vol.54 No.5 September issue, Japan Audio Association “Hi-Res Definition and Operation” (https://www.jas-audio.or.jp/hi-res/definition)

However, in the background technology described in Patent Document 1, an oscillation phenomenon may occur due to the connection between the inductor component of the electromagnetic speaker and the capacitor component of the ceramic speaker. It was necessary to connect passive elements such as capacitors and capacitors externally. In addition, since high-performance piezoelectric ceramics having linear characteristics up to high frequencies are used, there is a problem in that the price of the product increases when the passive elements mentioned above are added.

The present invention has focused on this point, and its purpose is to improve the characteristics of an electromagnetic sounding body, particularly in the high frequency range, while reducing the cost, thereby making it possible to reproduce wideband audio as a whole. be. Another objective is to improve the performance of earphones while avoiding increases in cost, size, and price.

The present invention provides an earphone in which an electromagnetic sounding body is mounted inside a housing, in which a vibrating body that vibrates due to the sound emitted is provided on the sound emitting side of the electromagnetic sounding body, and the sound emitting body vibrates through the sound emission hole of the housing. It is characterized in that both the sound produced by the electromagnetic sounding body and the sound produced by the vibration of the vibrating body are emitted. According to one of the main aspects, the vibrating body has a gap between its outer periphery and the inner wall of the casing, and is fixed at at least one point other than the outer periphery. According to another aspect, the vibrating body has a structure that resonates due to sound emitted from the electromagnetic sounding body. According to still another embodiment, the resonance of the vibrating body occurs in a high frequency range of the sound produced by the electromagnetic sounding body. These and other objects, features, and advantages of the present invention will become apparent from the following detailed description and accompanying drawings.

According to the present invention, a diaphragm is provided on the sound emitting side of the electromagnetic sounding body, and this vibrates as the electromagnetic sounding body emits sound, so that the sound emission characteristics of the electromagnetic sounding body in the high frequency range can be improved. It is possible to perform wideband audio reproduction as a whole.

1 is a main cross-sectional view showing the basic structure of an earphone according to Example 1 of the present invention. 3 is a graph showing the output sound emission characteristics of the entire earphone, electromagnetic speaker, and diaphragm in Example 1. FIG. 2 is a main cross-sectional view of an earphone according to a second embodiment of the present invention. (A) is an exploded view of the second embodiment, and (B) is a diagram showing how the diaphragm vibrates. 7 is a graph showing output sound emission characteristics in the second embodiment. (A) shows the entire earphone, (B) shows the electromagnetic speaker, and (C) shows the sound emission characteristics of the diaphragm. FIG. 3 is a main cross-sectional view of an earphone according to a third embodiment of the present invention. (A) is an exploded view of the third embodiment, and (B) is a view showing the support of the diaphragm. FIG. 7 is a perspective view showing how the diaphragm is attached in the third embodiment. 12 is a graph showing output sound emission characteristics in the third embodiment. (A) shows the entire earphone, (B) shows the electromagnetic speaker, and (C) shows the sound emission characteristics of the diaphragm.

Hereinafter, the best mode for carrying out the present invention will be described in detail based on examples.

First, the basic form of the present invention will be explained with reference to FIGS. 1 and 2. FIG. 1 shows the basic structure of the earphone of the present invention. In the figure, a housing (or case) 20 of the earphone 10 includes a front housing 22 into which electrical signals are input, and a rear housing 24 through which reproduced sound is emitted. The front housing 22 is provided with an electromagnetic sounding body or an electromagnetic speaker 30 and a diaphragm 40. The diaphragm 40 is arranged on the sound emitting side of the electromagnetic speaker 30, and its center 42 is fixed. A gap 44 is formed between the diaphragm 40 and the front housing 22. A sound emitting hole 26 is formed in the rear housing 24. Each part is fixed to the housing 20 using adhesive, for example.

Next, to explain the basic operation, the sound emitted from the electromagnetic speaker 30 passes through the gap 44 and is emitted to the sound emission hole 26 of the rear housing 24, as shown by the thick arrow FSP. be done. In this case, the emitted sound waves (air vibrations) pass through the gap 44 and are also directly radiated to the diaphragm 40 at the same time. This causes the diaphragm 40 to vibrate due to the radiated sound waves. Here, for example, if a metal plate is used as the diaphragm 40 and its resonant frequency is set in a high frequency range, the diaphragm 40 will resonate with the sound waves in the high frequency range output from the electromagnetic speaker 30. Therefore, the high-pitched sound of the diaphragm 40 shown by the arrow FH is superimposed on the output sound of the electromagnetic speaker 30, and the diaphragm 40 acts as a tweeter to compensate for the high-frequency sound of the earphone as a whole. It will now function as a two-way system.

FIG. 2 shows an example of the output sound pressure characteristics of the earphone 10. FIG. 2A is a diagram showing the sound pressure characteristics of the electromagnetic speaker 30 (see dotted line graph G2A) and the sound pressure characteristics of the diaphragm 40 that vibrates due to resonance of the speaker 30 (see solid line graph G2B). Since the impedance Z of the electromagnetic speaker 30 is Z=2πfL (f is the frequency and L is the inductance of the coil), in the high frequency range, the impedance Z increases and the current flowing into the coil is suppressed. As a result, the sound pressure in the high frequency range gradually decreases. On the other hand, the sound pressure of the diaphragm 40 is based on its resonance frequency, and since a highly rigid material such as a metal plate is used, sound in a high frequency range is generated by a resonance phenomenon. From the earphone 10, the sounds of these graphs G2A and G2B are superimposed and output, and as shown in the graph G2C of FIG. Compensatory sound pressure characteristics can be obtained by the resonance sound pressure of the plate 40.

According to this embodiment, an electromagnetic speaker is used to reproduce low sounds of the earphone, and a diaphragm that resonates with the sound waves generated by the electromagnetic speaker is used to reproduce high sounds. By using a resonating diaphragm, its material, diameter, thickness, etc. can be used to adjust the sound pressure in the high frequency range of the electromagnetic speaker. Since it is not necessary to use a plurality of active sounding bodies at the same time, it is possible to suppress power consumption during sound emission and provide earphones capable of wideband reproduction. Furthermore, since a diaphragm is simply added, it is possible not only to reduce costs but also to save space, and it is possible to improve the performance of the earphone while avoiding an increase in size and price.

Next, Example 2, which is a specific example of the present invention, will be described with reference to FIGS. 3 to 5. 3 and 4 show the configuration of an earphone according to a second embodiment. FIG. 3 shows a main cross section, and FIG. 4(A) shows an exploded state. In these figures, a housing 110 of the earphone 100 includes a front housing 112 and a rear housing 114. The front housing 112 is provided with a sound emitting hole 116 having a reduced diameter. Further, a sound emitting unit 150, which will be described later, is provided in the space between the front housing 112 and the rear housing 114.

An audio signal is supplied to the electromagnetic speaker 120 of the sound emitting unit 150 via a lead wire 122 and a conducting wire 124 on the rear housing 114 side. A protector 130 is provided on the sound emitting side of the electromagnetic speaker 120, and a plurality of sound emitting holes (four in the illustrated example) 132 are provided at equal intervals. Further, a mounting hole 134 is provided in the center of the protector 130, and a bush 136 is mounted therein. A diaphragm 140 is attached to the tip of this bush 136. These electromagnetic speaker 120, protector 130, bush 136, and diaphragm 140 constitute a sound emitting unit 150, which is placed in a cylindrical space formed by the front housing 112 and the rear housing 114. It is set in.

Among the above-mentioned parts, the electromagnetic speaker 120 has a diameter of 10 mm, for example, and its end is fixed to the rear housing 114 with adhesive. A lead wire 122 for transmitting an audio signal is inserted into the rear housing 114, and positive and negative conducting wires 124 branching from the lead wire 122 are electrically connected to input terminals of the electromagnetic speaker 120 with solder.

The protector 130 provided on the sound emitting surface of the electromagnetic speaker 120 is made of stainless steel and has a thickness of 0.3 mm for the purpose of protection. The protector 130 is provided with four holes each having a diameter of 2 mm as the sound emitting holes 132. Further, a fixing bush 136 made of ABS resin was fixed to a mounting hole 134 having a diameter of 2.5 mm in the center of the protector 130 with adhesive. Furthermore, the tip of the bush 136 was inserted into the center hole 142 of the diaphragm 140 and fixed with the same adhesive. Thereafter, a sound emitting unit 150 including the electromagnetic speaker 120, protector 130, bush 136, and diaphragm 140 is mounted in the cylindrical internal space of the front housing 112 and the rear housing 114. Finally, the cylindrical openings of the front housing 112 and the rear housing 114 are fixed by inserting the convex portion of one into the concave portion of the other and fitting them with an adhesive. In this way, the earphone 100 is completed.

To explain the overall operation of the earphone 100, when an audio signal is supplied to the electromagnetic speaker 120 from the lead wire 122 through the conducting wire 124, the electromagnetic speaker 120 emits sound. This sound is emitted from the sound emitting hole 132 of the protector 130 on the front of the electromagnetic speaker 120, passes through the gap 144 between the diaphragm 140 and the front housing 112 (see FIG. It is released forward (see arrow FSP in Figure 3). At this time, the sound waves also hit the diaphragm 140. Therefore, the diaphragm 140 resonates due to air vibrations of the sound waves and generates sound (see arrow FH in FIG. 3). That is, it is possible to obtain a sound in which the resonance sound of the diaphragm 140 is superimposed on the sound of the electromagnetic speaker 120, and this is output from the sound emitting hole 116.

Next, an example of the sound pressure characteristics in the above embodiment will be described with reference to the graph of FIG. 5 as well. This figure shows the sound pressure characteristics when a stainless steel plate with a diameter of 9 mm, a thickness of 0.17 mm, and an inner diameter of the center hole 142 attached to the bushing 136 is 1.7 mm is used as the diaphragm 140. A preliminary numerical analysis of the resonance frequency of the diaphragm 140 revealed that a bending mode resonance displacement as shown in FIG. 4(B) occurs at about 12.1 kHz. In the figure, thin lines indicate the state before bending, and thick lines indicate the state when bent. Therefore, when the diaphragm 140 causes resonance vibration due to the sound waves radiated from the electromagnetic speaker 120, the sound around 12.1 kHz will be amplified.

As a result of measuring the output sound pressure characteristics of the earphone 100 as described above using an IEC:711 coupler and sweeping the frequency with an output of 10 mW, the results shown in FIG. 5(A) were obtained. The sound pressure characteristics in the figure are the characteristics of the entire earphone 100, and are the result of superimposing the characteristics of the electromagnetic speaker 120 and the diaphragm 140. Therefore, when a comparative earphone was made in which the bush 136 and the diaphragm 140 were removed and the characteristics were measured in the same manner, the results shown in FIG. 5(B) were obtained. This graph can be considered to be the characteristics of the electromagnetic speaker 120 alone. Therefore, when we calculated the difference (A) - (B) between (A) and (B) in Figure 5, we obtained a graph as shown in Figure 5 (C). This graph shows the sound pressure characteristics obtained by resonance of the diaphragm 140. As shown in Figure 5(C), there is a sound pressure peak at 12.3kHz, which is almost the same as "12.1kHz" obtained as a result of the numerical analysis mentioned above, which indicates the usefulness of the present invention. Is recognized.

Next, a third embodiment of the present invention will be described with reference to FIGS. 6 to 9. Note that the same reference numerals are used for the same or corresponding components as in the above-described embodiment. In the second embodiment, the diaphragm was provided on the electromagnetic speaker side, but in this embodiment, the diaphragm was provided on the front housing side. FIG. 6 shows a main cross section of the earphone 200 of this embodiment, FIG. 7(A) shows an exploded state, and FIG. 7(B) shows the mounting support 250 of the diaphragm 240 viewed from the electromagnetic speaker side. show. Moreover, FIG. 8 shows how the diaphragm is attached. As shown in these figures, a support body 250 is provided on the front housing 112 instead of the bush 136 for fixing the diaphragm, and a diaphragm 240 is attached to the support body 250, which is different from the embodiment described above. Although this embodiment is different from Embodiment 2, other parts have the same structure as Embodiment 2.

More specifically, a support 250 as shown in FIG. 7(B) is provided inside the front housing 112 toward the electromagnetic speaker 120 of the rear housing 114. In the support body 250, three wing-shaped arms 252 provided at equal angles are joined to the inner side surface of the front housing 112, and a support portion 254 is provided at the center of these wings. Further, each arm 252 has an acute angle on the sound input side so as not to obstruct passage of sound as indicated by arrows in FIGS. 6 to 8(B). Then, the support portion 254 is inserted into the center hole 242 of the diaphragm 240, and the diaphragm 240 is fixed and supported using an adhesive or the like (see FIG. 8). At this time, as shown in FIGS. 6 to 8(B), a gap 144 is formed between the inside of the front housing 112 and the outer periphery of the diaphragm 240.

To explain the overall operation of such an earphone 200, the sound emitted from the electromagnetic speaker 120 is emitted from the sound emitting hole 132 of the protector 130 on the front of the electromagnetic speaker 120, and is emitted from the diaphragm 240 and the front housing. It passes through the gap 144 in the body 112 and further passes through the gap between the arms 252 of the support body 250, and is ejected to the front of the front housing 112. At this time, the sound waves also hit the diaphragm 240, so the diaphragm 240 resonates due to the air vibration of the sound waves and generates sound. That is, it is possible to obtain a sound in which the resonance sound of the diaphragm 240 is superimposed on the sound of the electromagnetic speaker 120, and this is output from the sound emission hole 116.

Next, an example of the sound pressure characteristics in the above embodiment will be described with reference to the graph in FIG. 9 as well. The figure is a graph when an aluminum plate with an outer diameter of 9 mm, a thickness of 0.13 mm, and an inner diameter (the diameter of the center hole 242) of 1.7 mm is used as the diaphragm 240, and the resonant frequency is 14.0 kHz. It has been calculated. Then, when the sound pressure characteristics were measured in the same manner as in the above embodiment, the sound pressure characteristics of the earphone 200 were as shown in FIG. 9(A). The sound pressure characteristics in the figure are the characteristics of the entire earphone 200, and are the result of superimposing the characteristics of the electromagnetic speaker 120 and the diaphragm 240. Therefore, when a comparative earphone was prepared in which the diaphragm 240 was removed from the support 250 and the characteristics were measured in the same manner, the results shown in FIG. 9(B) were obtained. This graph can be considered to be the characteristics of the electromagnetic speaker 120 alone. Therefore, when we calculated the difference (A) - (B) between (A) and (B) in Figure 9, we obtained a graph as shown in Figure 9 (C). This graph shows the sound pressure characteristics obtained by resonance of the diaphragm 240. As shown in Fig. 9(C), there is a sound pressure peak at 13.9kHz, which almost coincides with "14.0kHz" obtained as a result of the numerical analysis mentioned above, which indicates the usefulness of the present invention. Is recognized.

<Other Examples> Note that the present invention is not limited to the above-described embodiments, and various changes can be made without departing from the gist of the present invention. Examples include:
(1) The shapes and dimensions shown in the above embodiments are merely examples, and may be modified as necessary to provide the same functions. For example, the appearance and shape of the earphone housing may be changed as appropriate depending on the shape of the ear.
(2) In the above embodiment, the center of the diaphragm is fixed, but if resonance occurs in a high frequency range, it may be fixed at multiple locations. Note that if the outer circumference of the diaphragm is fixed, uneven vibrations will occur and the sound will be distorted. It is preferable to fix it except for the outer periphery.

According to the present invention, a diaphragm is provided on the sound emitting side of the electromagnetic sounding body, and this vibrates as the electromagnetic sounding body emits sound, so that the sound emission characteristics of the electromagnetic sounding body in the high frequency range can be improved. As a result, it is possible to reproduce wideband audio as a whole, and is particularly suitable for earphones that reproduce audio including high frequency ranges.

10: Earphone 20: Housing 22: Front housing 24: Rear housing 26: Sound emission hole 30: Electromagnetic speaker 40: Vibration plate 42: Center 44: Gap 100: Earphone 110: Housing 112: Front housing Body 114: Rear housing 116: Sound emitting hole 120: Electromagnetic speaker 122: Lead wire 124: Conducting wire 130: Protector 132: Sound emitting hole 134: Mounting hole 136: Bush 140: Vibration plate 142: Center hole 144: Gap 150 : Sound emitting unit 200: Earphone 240: Vibration plate 242: Center hole 250: Support body 252: Arm 254: Support part

Claims (4)

In earphones with an electromagnetic sounding body mounted inside the housing,
A vibrating body that vibrates due to the sound emitted is provided on the sound emitting side of the electromagnetic sounding body,
An earphone characterized in that both the sound produced by the electromagnetic sounding body and the sound produced by the vibration of the vibrating body are emitted from the sound emission hole of the housing. 2. The earphone according to claim 1, wherein the vibrating body has a gap between its outer periphery and the inner wall of the housing, and is fixed at at least one point other than the outer periphery. 2. The earphone according to claim 1, wherein the vibrating body has a structure that resonates due to sound emitted from the electromagnetic sounding body. 4. The earphone according to claim 3, wherein resonance of the vibrating body occurs in a high frequency range of sound produced by the electromagnetic sounding body.

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