JP2012244350A - Canal-type earphone - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an earphone which is hardly dropped down from an ear even when used during a movement, allows a user to hear circumferential sound in a wearing state, obtains excellent reproduction sound quality with less inward sound and a sufficient amount of bass.SOLUTION: An ear piece 16 of a canal-type earphone to be excellently worn in an ear includes through-holes 22 so as to enable the hearing of circumferential sound. An open type driver is used as a driver 11 in order to obtain a sufficient amount of bass even in a state where the ear piece 16 includes the through-holes 22.

Description

  The present invention relates to an earphone, and more particularly to a canal-type earphone having excellent adhesion to an ear.

  The canal type earphone is provided with an earpiece having good adhesion to the external auditory canal, and is suitable for a user to use while moving, such as listening to music while jogging. Further, in the canal type earphone, since the earpiece almost completely blocks the ear canal and transmits acoustic vibrations to the eardrum through a sealed space, high reproduction sound quality can be realized.

JP 2010-68299 A

  However, the above-described conventional canal type earphone has the following problems. First, since the earpiece almost completely blocks the ear canal when worn on the ear, there is a problem in that when the earpiece is pushed into the ear canal, the pressure in the ear canal increases, compressing the eardrum and causing discomfort to the user. Second, since the earpiece completely blocks the ear canal, there is a problem that it is difficult for the user wearing the earphone to listen to surrounding sounds. Thirdly, in the canal type earphone, the earpiece almost completely blocks the ear canal to form a sealed acoustic space, and this acoustic space changes the sound pressure frequency characteristic of the sound output by the driver of the earphone. As a result, there has been a problem that a particularly loud sound is generated by greatly increasing the sound pressure in the low range.

  As an earphone for solving these problems, there is a canal-type earphone in which a through hole that connects the space inside the ear canal and the outside space is formed in the earpiece. Here, the canal type earphone enhances the reproduction sound quality by forming a sealed acoustic space and emitting sound. However, when a through hole is opened in the earpiece in order to solve the above problem, a driver ( Since the resonance frequency of the vibrating body of the speaker is high, the sound volume in the low range is greatly reduced. Therefore, there arises a problem that sufficient reproduction sound quality suitable for music appreciation cannot be obtained. In view of this, an earphone in which a through hole is provided in the earpiece and the opening / closing operation of the through hole is enabled has also been proposed (for example, Patent Document 1). However, an earphone having such a through-hole opening / closing mechanism has a problem that it is difficult to manufacture because of its complicated structure.

  The present invention has been made in view of the circumstances described above, and even when used while moving, it is difficult to drop off from the ear, it is possible to listen to the surrounding sound in the mounted state, there is little muffled sound, An object of the present invention is to provide a canal type earphone capable of obtaining a good reproduction sound quality with a sufficiently low volume.

  The present invention has a vibrating body having a resonance frequency near the lower limit of the audible frequency band, and by vibrating the vibrating body with an electric signal, an electric signal belonging to a band higher than the resonance frequency can be obtained with a high gain. An open-type driver for converting to acoustic vibration, and an earpiece having a sound path that is inserted into the ear canal with an outer peripheral portion in close contact with the inner wall of the ear canal and that guides and outputs the acoustic vibration obtained from the open-type driver from the opening at the tip There is provided a canal-type earphone having a through hole that communicates a space in the ear canal closed by the earpiece with a space outside the ear.

  According to such a canal type earphone, since it has the earpiece having good adhesion to the ear canal, it is difficult to drop off from the ear even when used while moving. In addition, since the through-hole that allows the space in the ear canal closed by the earpiece to communicate with the space outside the ear is opened, it is possible to listen to surrounding sounds in a worn state. Moreover, since there is this through-hole, the muffled noise is reduced. In addition, since an open-type driver with a low resonance frequency is used as the driver, even if the low-frequency gain is reduced by opening the through-hole, the low-frequency gain is still sufficient and can withstand listening to music. High reproduction sound quality can be obtained.

It is a figure which shows the 1st structural example of the canal type earphone by one Embodiment of this invention. It is a figure showing the 2nd example of composition of a canal type earphone by the embodiment. It is a figure which shows the frequency characteristic of the gain of the transmission system from the electric signal input terminal of the earphone in the state which mounted | wore the ear with the conventional canal-type earphone using a sealed type driver to the eardrum inside the ear canal. It is a figure which shows the effect of the same embodiment. It is a figure which shows the structural example of the canal type | mold earphone by other embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
1 (a) and 1 (b) are diagrams schematically showing a first configuration example of a canal type earphone according to an embodiment of the present invention. FIGS. 2 (a) and 2 (b) show the same canal. It is a figure which shows typically the 2nd structural example of a type | mold earphone. Here, FIG. 1A and FIG. 2A are longitudinal sectional views of the canal-type earphone cut along a plane along the sound output direction Z, and FIG. 1B and FIG. ) Shows a view of the canal type earphone inserted into the ear canal 1 as seen from the eardrum side.

  In the first and second configuration examples, the driver 11 is a speaker that has a vibrating body and converts the electric signal into acoustic vibration by vibrating the vibrating body with an electric signal, and the vibration surface of the vibrating body. The front cavity 12 is provided in the front of the housing, and the back cavity 13 is provided in the rear. In the first example, the driver 11 is housed in the housing 14 in a posture in which the vibration surface is parallel to the sound output direction Z, whereas in the second example, the driver 11 It is accommodated in the housing 14 in a posture in which the surface is orthogonal to the sound output direction Z.

  In the first and second configuration examples, a cylindrical portion 15 protrudes from the housing 14, and an earpiece 16 is fixed to the tip of the cylindrical portion 15. The earpiece 16 is formed by forming a soft elastic body such as rubber in the shape of an umbrella. When the earphone is attached to the ear, the earpiece 16 is inserted into the ear canal 1 with its outer peripheral portion in close contact with the inner wall of the ear canal 1 as shown in FIGS. 1 (a) and 2 (a). Prevent falling off.

  As shown in FIGS. 1 (a) and 2 (a), a sound path 21, which is a through hole that allows the front cavity 12 to communicate with the space in the ear canal 1, is formed in the tube portion 15. Moreover, the earpiece 16 has four through holes 22 at equal intervals along the circumference centered on the opening of the sound path 21 as shown in FIGS. 1B and 2B. ing.

  The through-hole 22 provided in the earpiece 16 has a role of reducing the pressure applied to the eardrum by escaping the air pressure in the ear canal 1 blocked by the earpiece 16 to the outside when the earphone is attached to the ear, and the ambient sound. Is guided into the external auditory canal 1 to make the user listen. Here, the through hole 22 is preferably provided at a position as close as possible to the opening of the sound path 21 in the earpiece 16. This is because the position and shape of the opening of the sound path 21 at the tip of the earpiece 16 is designed so that the acoustic vibration generated by the driver 11 can be faithfully transmitted to the eardrum without damaging the waveform as much as possible. In addition, it is possible to hear the ambient sound more naturally if the through hole 22 for introducing the ambient sound is also provided at a position as close as possible.

  Here, the driver 11 used in the present embodiment will be described. Generally, the earphone driver includes a contact type driver and an open type driver. The close contact type driver is a driver designed to emit sound into a sealed space like a canal type earphone. This close contact type driver is a driver having a configuration in which the resonance frequency of the vibration body is high and the vibration body is vibrated in a lower band of the resonance frequency to generate sound. On the other hand, the open-type driver is used in a state where there are many gaps between the inner wall of the ear canal and designed to be applied to an intra concha-type earphone that emits sound into an open space. Driver. In this open type driver, the resonance frequency of the vibrating body is near the lower limit of the audible band, and an electric signal belonging to a band higher than the resonance frequency is converted into acoustic vibration with a high gain. In the present embodiment, the latter open type driver is used as the driver 11.

A feature of the present embodiment is that a canal type earphone provided with an earpiece 16 having good adhesion to the ear canal has a through hole in the vicinity of the sound path opening of the earpiece 16 and an open type driver is adopted as the driver 11. It is in. According to the present embodiment having such characteristics, the following effects can be obtained.
a. Since the earpiece 16 having excellent adhesion to the ear canal is provided, even when using the earphone while moving the body, such as listening to music while jogging, it is difficult for the earphone to fall off the ear.
b. Since the earpiece 16 has a through hole, there is no pressure on the eardrum when the earphone is worn on the ear. Also, the humming sound that can be heard when the earphone is worn is reduced. In addition, in the state where the earphone is worn on the ear, the surrounding sound reaches the eardrum of the earphone wearer through the through hole of the earpiece, so that the wearer of the earphone can listen to the surrounding sound.
c. Since an open-type driver is used as the driver 11, even if a through hole is formed in the earpiece 16, a sufficient gain can be obtained in a low frequency range, and a sufficient reproduction sound quality that can withstand listening to music can be realized.

  Hereinafter, the effect c will be described in comparison with the prior art. FIG. 3 shows the frequency characteristics of the gain of the transmission system from the electric signal input terminal of the earphone to the eardrum when the conventional canal-type earphone using a sealed driver is worn on the ear, and N0 is the same earphone. Frequency characteristic when no through hole is made in the earpiece, N1 is frequency characteristic when one through hole with a diameter of 1 mm is made in the earpiece of the earphone, and N2 is a through hole with 1 mm diameter in the earpiece of the earphone. Frequency characteristics when a single piece is opened, N3 is a frequency characteristic when three through-holes with a diameter of 1 mm are made in the earpiece of the same earphone, N4 is a frequency characteristic when four through-holes with a diameter of 1 mm are made in the earpiece of the same earphone Each characteristic is shown. As shown in FIG. 3, in a conventional canal type earphone, when a through hole is made in an earpiece, a low frequency gain of 1000 Hz or less, particularly 100 Hz to 500 Hz, is greatly reduced, and low reproduction sound quality unsuitable for music appreciation. Become.

FIG. 4 is a diagram showing the effect of this embodiment. In FIG. 4, B1 to B4 are canal type earphones according to the present embodiment, that is, from an electric signal input terminal of the earphone when an open type driver is used as the driver of the canal type earphone and a through hole is opened in the earpiece. This is a frequency characteristic of the gain of the transmission system to the eardrum, and B1 is a through hole with a diameter of 1 mm when one through hole with a diameter of 1 mm is opened (the area of the through hole is 7.85 × 10 ⁻⁷ m ² ). 2 holes (through hole area 1.57 × 10 ⁻⁶ m ² ), B4 has 4 through holes 1 mm in diameter (through hole area 3.14 × 10 ⁻⁶ m 2). ² ). In FIG. 4, in order to facilitate understanding of the effect of the present embodiment, the frequency characteristic B0 in the case where an open type driver is used as the driver of the canal type earphone and no through hole is made in the earpiece, The frequency characteristics A of the intra concha type earphone and the frequency characteristics S of the conventional canal type earphone using the sealed driver are shown together with the frequency characteristics B1 to B4 in this embodiment.

  As shown in FIG. 4, when an open-type driver is used as a driver for a canal-type earphone and a through-hole is not formed in the earpiece, a large gain can be obtained in a low range (frequency characteristic B0). However, this increases the pressure in the ear canal when the earphone is worn on the ear, and makes it difficult to hear ambient sounds. Therefore, using an open-type driver as the driver for the canal-type earphone and making a through-hole in the earpiece, although the low-frequency gain is slightly lower than the conventional canal-type earphone (frequency characteristic S), A sufficient gain is obtained in an important band of 1000 Hz or less (frequency characteristics B1 to B4). As described above, the open type driver employed in the present embodiment has a resonance frequency in the low frequency range, and generates acoustic vibration with a sufficient sound pressure in the low frequency range. A sufficient gain can be obtained in the region. Here, as the number of through holes is increased, the gain in the band of 100 Hz or less of the canal type earphone according to the present embodiment gradually decreases, but it is still sufficiently higher than the gain A of the normal intra concha type earphone. High gain.

  As described above, according to the present embodiment, even when used while exercising, it is difficult to drop off from the ear, it is possible to listen to surrounding sounds in a worn state, and the low-frequency volume is sufficiently good An earphone that can achieve a good reproduction sound quality is realized.

In this embodiment, the effect of reducing discomfort at the time of wearing on the ear, the effect of reducing the booming sound, and the effect of increasing the ease of listening to ambient sounds are in a trade-off relationship with the reproduction sound quality. Increasing the number of through-holes opened in the earpiece or increasing the total area of the through-holes increases the three effects of the former, but increases the decrease in gain at low frequencies, thereby reducing the reproduced sound quality. If the number or total area of the through holes is excessive, the reproduced sound quality of the canal type earphone according to the present embodiment approaches the reproduced sound quality of the intra concha type earphone. According to the study conducted by the present inventor (see FIG. 4), the total area of the through holes provided in the earpiece is set to 0.785 mm ² or more in order to obtain the three effects of the former, and 3. in order to obtain the necessary reproduction sound quality. It was confirmed that the thickness was preferably 14 mm ² or less.

  Although one embodiment of the present invention has been described above, other embodiments can be considered in addition to this. For example:

(1) In the above embodiment, the earpiece 16 has the through-hole 22 that communicates the space inside the ear canal 1 that is blocked by the earpiece 16 with the space outside the ear. However, as illustrated in FIG. 15 may be provided. According to this aspect, since the through hole 22 can be brought closer to the opening of the sound path 21, it becomes possible to hear ambient sound more clearly. In addition, the through hole 22 in FIG. 5 is less likely to contact or approach the external auditory canal when worn, and the opening surface is directed to the inner depth of the external auditory canal than the through hole 22 in FIGS. 1 and 2 described above. So you can hear the surrounding sound more naturally.
(2) The earpiece 16 may be configured to be detachable from the cylindrical portion 15. In this case, various types of earpieces 16 having different sizes and numbers of through holes 22 may be provided, and the user may select his / her favorite earpiece 16 and attach it to the cylindrical portion 15 for use.

DESCRIPTION OF SYMBOLS 11 ... Driver, 12 ... Front cavity, 13 ... Back cavity, 14 ... Housing | casing, 15 ... Tube part, 16 ... Earpiece, 21 ... Sound path, 22 ... Through-hole.

Claims (3)

Having a vibrating body whose resonance frequency is near the lower limit of the audible frequency band, and vibrating this vibrating body with an electric signal, converts an electric signal belonging to a band higher than the resonance frequency into acoustic vibration with high gain. An open-type driver that
An earpiece having a sound path that is inserted into the external auditory canal in close contact with the inner wall of the external auditory canal and guides the acoustic vibration obtained from the open-type driver to output from the opening at the tip,
A canal type earphone having a through hole for communicating a space in the ear canal closed by the earpiece with a space outside the ear.   2. The canal type earphone according to claim 1, wherein the through hole is in a position in the vicinity of the opening of the sound path in the earpiece.   2. The canal according to claim 1, wherein the earpiece is provided at a distal end of a cylindrical portion that protrudes from a housing that houses the open-type driver, and the through hole is provided in the cylindrical portion. Type earphone.

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