Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
  • H04R11/00—Transducers of moving-armature or moving-core type
  • H04R11/02—Loudspeakers
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
  • H04R2400/00—Loudspeakers
  • H04R2400/07—Suspension between moving magnetic core and housing
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
  • H04R2460/00—Details of hearing devices, i.e. of ear- or headphones covered by H04R1/10 or H04R5/033 but not provided for in any of their subgroups, or of hearing aids covered by H04R25/00 but not provided for in any of its subgroups
  • H04R2460/13—Hearing devices using bone conduction transducers

Definitions

• the present invention relates to an electroacoustic transducer and headphones that provide bone conduction.
• a sound output device is known that allows the surface of the outer wall to come into contact with the skull or bones around the entrance of the ear canal, allowing the user to hear air-conducted sound that is generated from the skull or other parts of the ear canal via bone conduction.
• bone conduction vibration source devices for mobile phones and the like that acoustically process audio signals for bone conduction vibration and output the processed signals as drive signals to a bone conduction vibration source (see, for example, Patent Document 1).
• a stereo earphone has been disclosed that has a bone conduction section and a branch section that is connected at one end to the bone conduction section and serves as a vibration source (see, for example, Patent Document 2).
• a sound output device that uses bone conduction has a vibration part that vibrates in response to an audio signal. This vibration part can go wild at the resonance point, vibrating in an unintended direction and generating abnormal noise.
• the present invention aims to provide an electroacoustic transducer and headphones that can maintain stable performance.
• the electroacoustic transducer of the present invention is an electroacoustic transducer that transmits vibrations to bones, and includes a main frame having at least a cylindrical portion, a vibration portion disposed inside the main frame and vibrating along the axial direction of the main frame in response to an input signal, and an elastic member formed of an organic or polymeric material and connected to at least the vibration portion.
• a headphone includes a headband and a pair of electroacoustic transducers held at both ends of the headband, the electroacoustic transducer being the electroacoustic transducer described above.
• the present invention provides an electroacoustic transducer and headphones that can maintain stable performance.
• FIG. 1 is a schematic perspective view showing an embodiment of a headphone according to the present invention.
• 1A is a perspective view of a first embodiment of an electro-acoustic transducer according to the present invention
• FIG. 1B is an exploded perspective view of the electro-acoustic transducer.
• FIG. 2 is a longitudinal sectional view of the electroacoustic transducer.
• 1A is a front perspective view showing a second embodiment of an electro-acoustic transducer according to the present invention
• FIG. 1B is an exploded perspective view of the electro-acoustic transducer.
• FIG. 2 is a longitudinal sectional view of the electroacoustic transducer.
• FIG. 11A is a front perspective view showing a third embodiment of an electro-acoustic transducer according to the present invention
• FIG. 11B is an exploded perspective view of the electro-acoustic transducer.
• FIG. 2 is a longitudinal sectional view of the electroacoustic transducer.
• 13A is a perspective view from the front side showing a fourth embodiment of an electro-acoustic transducer according to the present invention
• FIG. 13B is an exploded perspective view of the electro-acoustic transducer.
• FIG. 2 is a longitudinal sectional view of the electroacoustic transducer.
• 13A is a perspective view from the front side showing a fifth embodiment of an electro-acoustic transducer according to the present invention, and FIG.
• FIG. 13B is an exploded perspective view of the electro-acoustic transducer.
• 2A is a longitudinal sectional view of the electroacoustic transducer
• FIG. 2B is a transverse sectional view of the electroacoustic transducer.
• 13A is a perspective view of a sixth embodiment of an electro-acoustic transducer according to the present invention
• FIG. 13B is an exploded perspective view of the electro-acoustic transducer.
• 2A is a longitudinal sectional view of the electroacoustic transducer
• FIG. 2B is a transverse sectional view of the electroacoustic transducer.
• FIG. 13A is a perspective view from the front side showing a seventh embodiment of an electro-acoustic transducer according to the present invention
• FIG. 13B is an exploded perspective view of the electro-acoustic transducer.
• 2A is a longitudinal sectional view of the electroacoustic transducer
• FIG. 2B is a transverse sectional view of the electroacoustic transducer.
• FIG. 13 is a longitudinal sectional view showing an eighth embodiment of an electroacoustic transducer according to the present invention.
• FIG. 13 is a longitudinal sectional view showing a ninth embodiment of an electroacoustic transducer according to the present invention.
• FIG. 4 is a graph showing frequency characteristics of the electroacoustic transducer described above and an electroacoustic transducer of the related art.
• 1 is a vertical cross-sectional view showing a first example of an electro-acoustic transducer according to a related art.
• FIG. 11 is a longitudinal sectional view showing a second example of an electroacoustic transducer according to the related art.
• the headphones 1000 mainly include a pair of electroacoustic transducers 1, a pair of housings 2, and a headband 3.
• Each of the pair of housings 2 is substantially rectangular parallelepiped-shaped, and has the electroacoustic transducer 1 built therein.
• the headband 3 is a substantially U-shaped member. Both ends of the headband 3 are curved in a direction substantially perpendicular to the U-shaped portion, and are designed to be hung on the wearer's ears when worn.
• the housings 2 are connected to both ends of the headband 3. That is, the electroacoustic transducer 1 is held at both ends of the headband 3 via the housings 2.
• the headband 3 When worn, the headband 3 holds the wearer's head, and the housings 2 are pressed against the ears by the elastic force of the headband 3.
• the electro-acoustic transducer mainly transmits vibrations to the ear cartilage, but the technical scope of the present invention is not limited to this and includes headphones and electro-acoustic transducers that transmit vibrations to cartilage other than the ear cartilage and any bone including hard bones such as the skull.
• the main frame 10 is a member having a cylindrical portion that defines the outer wall of the electroacoustic transducer 1.
• the main frame 10 is substantially cylindrical, but any suitable structure, such as an elliptical or rectangular cylindrical shape, can be used.
• the elastic member 20 is a cylindrical member disposed inside the main frame 10. In this embodiment, the elastic member 20 is disposed around the circumferential direction of the vibration section 30.
• the elastic member 20 is a member formed from an organic substance or polymeric material having elasticity.
• the elastic member 20 is, for example, a member that exerts elasticity due to a porous structure, and more specifically, for example, urethane foam.
• the elastic member 20 may also be formed from an appropriate sponge material.
• the elastic member 20 may be composed of an elastic body such as rubber or a gel material.
• the elastic member 20 holds the vibration part 30 to the main frame 10.
• the elastic member 20 is connected to the outer peripheral surface of the vibration part 30 along the vibration direction and to the inner peripheral surface of the main frame 10.
• the elastic member 20 may be adhered to the outer peripheral surface of the vibration part 30 and the inner peripheral surface of the main frame 10 with an appropriate adhesive.
• the elastic member 20 controls the vibration of the vibration part 30.
• the vibration unit 30 is a member disposed inside the through-hole 13 of the main frame 10.
• the vibration unit 30 vibrates inside the through-hole 13 along the axial direction of the through-hole 13 in response to a signal.
• the vibrating part 30 mainly comprises a cap yoke 31, a magnet 32, and a center yoke 33.
• the cap yoke 31 is a cylindrical member with a bottom that constitutes the upper and side surfaces of the vibrating part 30.
• the end of the upper surface (+Y side) of the cap yoke 31 is exposed to the upper surface (+Y side) of the electro-acoustic transducer 1.
• the lower end of the cap yoke 31 on the -Y side faces the unit base 50 with a gap therebetween.
• the inner diameter of the cap yoke 31 is larger than the outer diameter of the coil 40.
• the cap yoke 31 covers part of the outer circumference of the coil 40.
• the elastic member 20 is connected to the outer circumferential surface of the cap yoke 31.
• the magnet 32 is a roughly cylindrical magnet and is disposed inside the cap yoke 31.
• the magnet 32 may be connected to the inner bottom surface of the cap yoke 31.
• the center yoke 33 is a disk-shaped member connected to the lower end of the magnet 32.
• the outer diameter of the magnet 32 is smaller than the inner diameter of the hole 40a of the coil 40. Therefore, the magnet 32 and the center yoke 33 can move axially (y direction) inside the hole 40a.
• a Lorentz force is generated in the magnet 32 and the coil 40. As a result, the vibrating part 30 vibrates in the axial direction.
• the coil 40 is an annular member and is held by the unit base 50.
• the magnet 32 and center yoke 33 are inserted into a hole 40a formed in the center of the coil 40.
• the vibration direction in which the vibration unit 30 vibrates in response to a signal is the Y direction, which is different from the vertical direction when the unit is attached.
• the vibration unit 30 is subjected to gravity in a direction different from the vibration direction.
• the elastic member 20 supports the vibration unit 30 by connecting it to the main frame 10 and the vibration unit 30. In other words, the elastic member 20 can prevent the vibration unit 30 from sagging due to gravity.
• the elastic member 20 has a predetermined hardness and resilience coefficient. As a result, the elastic member 20 damps and eliminates abnormal oscillations at the resonance point of the vibration part 30, and suppresses displacement in a direction different from the vibration direction of the vibration part 30.
• the elastic member 20 is connected along the circumferential direction of the vibration part 30, thereby suppressing displacement in the rotational direction of the vibration part 30. Displacement of the vibration part 30 in a direction other than the vibration direction in which it vibrates according to a signal causes abnormal noise.
• the elastic member 20 suppresses abnormal noise by preventing displacement in directions other than the axial direction, and thus can improve the sound quality of the electro-acoustic transducer 1.
• the characteristics of the elastic member 20, such as the hardness or resilience coefficient, are appropriately adjusted according to the desired sound quality and the mass or shape of the vibration part 30.
• the suspension 20a is in contact with the inside of the flange 15a formed on the inner wall of the main frame 10a.
• the center of the vibrating part 30a is connected to the center of the suspension 20a by a connecting member such as a screw.
• the vibrating part 30a is supported by the flange 15a via the suspension 20a. Therefore, the fulcrum of the vibration of the vibrating part 30a is the connecting member, and the contact part between the suspension 20a and the flange 15a is the point of action.
• an electro-acoustic transducer 1a in which the center of gravity of the vibrating part 30a and the fulcrum of the vibration are separated may vibrate at the resonance point, i.e., vibrate in an unintended direction. Vibration at the resonance point may cause abnormal noise.
• the vertical direction in the mounted state is the downward direction on the page.
• the vibration direction in which the vibrating part 30a vibrates in response to a signal is different from the vertical direction in the mounted state. Therefore, gravity acts on the vibrating part 30a in a direction different from the vibration direction.
• the first end side of the vibrating part 30a is connected to the suspension 20a at approximately the center, while the second end side is not supported and is in a cantilever state. Therefore, the second end of the vibrating part 30a hangs down in the direction of gravity.
• an unnecessary moment or twist is generated in the electro-acoustic transducer 1a during resonance. This moment or twist can cause the transducer to move wildly or break.
• the vibrating part 30a of the electroacoustic transducer 1a may vibrate due to external vibrations.
• the vibration of the vibrating part 30a generates an electromotive force in the coil 140 arranged opposite the vibrating part 30a.
• the vibration may cause abnormal noise that may be mixed into the sound.
• the electroacoustic transducer 2b of the related art shown in Fig. 20 mainly comprises a cylindrical main frame 10b, a vibration part 30b that vibrates inside the main frame 10b, a disk-shaped suspension 20b that holds the vibration part 30b at a first end side of the main frame 10b, and a flat damper 60b that holds the vibration part 30b at a second end side of the main frame 10b.
• the suspension 20b is composed of, for example, a metal leaf spring.
• the suspension 20b of the electroacoustic transducer 2b in the related art is a metal leaf spring, and so there is a risk of plastic deformation.
• the effect of resonance may be large, and the cost may be high.
• the electroacoustic transducer 1 according to the present invention is provided with an elastic member 20 formed of an organic or polymeric material having a predetermined or higher elasticity, instead of an elastic member that exerts elasticity due to its metal or resin structure. Therefore, the electroacoustic transducer 1 according to the present invention reduces the risk of plastic deformation of the elastic member 20. It also reduces the effects of resonance and can be constructed at low cost.
• Fig. 18 shows the frequency characteristics of a headphone unit. That is, the horizontal axis shows frequency, and the vertical axis shows output level (dBV).
• the dashed line shows the frequency characteristics of an electroacoustic transducer 1a according to the related art
• the dashed line shows the frequency characteristics of an electroacoustic transducer 1b according to the related art
• the solid line shows the frequency characteristics of the electroacoustic transducer 1 according to the present invention.
• the frequency characteristics of the electroacoustic transducer 1b of the related art are smoother than those of the electroacoustic transducer 1a because low-frequency resonance is damped by the damper 60b. In other words, the electroacoustic transducer 1b can suppress unintended resonance and reduce discomfort to the head.
• the frequency characteristics of the electroacoustic transducer 1 according to the present invention are low and smooth, similar to the electroacoustic transducer 1b of the related art.
• the peak frequency is higher than the resonance point F0 of the electroacoustic transducer 1a. Therefore, it can be said that the damping provided by the elastic member 20 is functioning adequately.
• the frequency characteristics of the electroacoustic transducer 1 according to the present invention also have a sufficiently high sensitivity, and it can be seen that a sound pressure equal to or greater than that of the electroacoustic transducer 1a can be achieved over a wide frequency band.
• Electroacoustic transducer (2) ⁇ the electroacoustic transducer of this embodiment will be described with a focus on the differences from the embodiment described above. Note that the same components as those in the first embodiment are denoted by the same reference numerals. Furthermore, the electroacoustic transducer described below has the same configuration as the electroacoustic transducer 1 unless otherwise specified.
• the electroacoustic transducer 101 of the second embodiment shown in FIG. 4 and FIG. 5 is different from the first embodiment in that the main frame 110 and the elastic member 120 are bottomed cylindrical bodies formed by connecting the bottoms 112, 122 to the cylindrical parts 111, 121, respectively.
• the surface of the vibration part 30 facing the vibration direction i.e., the outer wall surface 31a of the cap yoke 31, faces the bottom 112 of the main frame 110 via the elastic member 120.
• the cylindrical part 121 of the elastic member 120 is connected to the cylindrical part 111 of the main frame 10, and the bottom 122 of the elastic member 120 is connected to the bottom 112 of the main frame 10.
• the electroacoustic transducer 201 of the third embodiment shown in FIG. 6 and FIG. 7 includes a suspension 260 in addition to the electroacoustic transducer 101 of the second embodiment.
• the suspension 260 is a member having a protruding portion 262 at the center of a substantially circular disk portion 261.
• a plurality of holes are formed in the disk portion 261, and the disk portion 261 functions as a spring that exerts elastic force in the Y direction.
• a radial end of the disk portion 261 is engaged with one end of the main frame 10.
• a hole 233a is formed along the axial direction of the main frame 10 at the substantially center of the center yoke 233.
• the suspension 260 is connected to the vibration portion 230 by inserting the protruding portion 262 into the hole 233a.
• the suspension 260 regulates the position of the vibration portion 230 and limits the vibration of the vibration portion 230 in the Y direction. According to this configuration, the position of the vibration portion 230 is determined by the suspension 260, making assembly easy.
• the electroacoustic transducer 301 of the fourth embodiment shown in FIG. 8 and FIG. 9 is different from the previously described embodiment in that it includes a plurality of elastic members 320.
• the elastic member 320 includes a small member 320a disposed on the bottom surface of the cap yoke 31, and small members 320b, 320c, 320d, and 320e disposed at intervals along the circumferential direction of the cap yoke 31.
• the number of small members 320b to 320e is four, but the number is not limited to this.
• An appropriate connecting member for connecting the small members 320a to 320e may be included.
• This elastic member 320 is suitable for using a gel material, which is a relatively hard member. With this configuration, the contact area of the elastic member 320 is smaller than that of the elastic member 120 of the bottomed cylinder, and the vibration unit 30 can be vibrated more greatly.
• ⁇ Electroacoustic transducer (6) ⁇ 12 and 13 includes a housing 570 that houses the vibration unit 30.
• the housing 570 houses the elastic member 20, the vibration unit 30, the coil 40, and the unit base 50 by, for example, an upper housing 570a and a lower housing 570b being fitted together.
• the shape of the housing 570 is a substantially rectangular parallelepiped in the figures, but is not limited thereto, and any appropriate shape that matches the outer shape of the headphones 1000 can be adopted.
• a protruding rib 571 is formed on the inside of the upper housing 570a.
• the rib 571 is, for example, cylindrical and corresponds to the elastic member 20, but is not limited to this and may be, for example, composed of a plurality of protrusions.
• the elastic member 20 is connected to the inside of the rib 571.
• the elastic member 20 may be glued to the rib 571, for example.
• the rib 571 of the upper housing 570a corresponds to the cylindrical portion of the main frame, and a separate member is not required, simplifying the configuration.
• the vibration of the vibration section 30 in the Y direction can also be restricted.
• the electroacoustic transducer 601 can be configured with a small number of parts.
• the inside of the housing 770 mainly contains the coil 40, the vibrating part 730 inserted into the coil, and the elastic member 720.
• the coil 40 is fixed to the inside of the housing 770.
• the vibrating part 730 is composed of, for example, a magnet 733 and a center yoke 760.
• the vibrating part 730 is configured such that, for example, two magnets 733 sandwich the center yoke 760. In this case, the two magnets 733 sandwich the center yoke 760 with the same poles, i.e., the south poles or the north poles, facing each other. With this configuration, it is possible to improve sensitivity compared to a configuration with one magnet and one center yoke.
• the elastic members 720 are disposed at the front and rear of the vibration direction of the vibration part 730.
• the elastic members 720 may be disposed only at either the front or rear of the vibration direction.
• the first end of the elastic member 720 is connected to the inside of the housing 770, and the second end is connected to the vibration part 730.
• the vibration part 730 vibrates mainly in the up and down direction in the figure while deforming the elastic member 720.
• the acoustic characteristics can be adjusted by selecting the material of the elastic member 720. For example, by selecting a material with a small restitution coefficient, it is possible to suppress steep resonance.
• An electro-acoustic transducer 801 of the ninth embodiment shown in Fig. 17 differs from the previously described embodiments in that it has a vibration part 830 formed by connecting one magnet 833 and one center yoke 860, instead of the vibration part 730 shown in Fig. 16.
• the coil 40 may be disposed near the end of the vibration direction of the vibration part 830 in accordance with the position of the center yoke 860. Even with such a configuration, an electro-acoustic transducer 801 with high sound quality can be realized while suppressing unintended vibrations.

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• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Engineering & Computer Science (AREA)
• Acoustics & Sound (AREA)
• Signal Processing (AREA)
• Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)
• Headphones And Earphones (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

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Citations (10)

• 2024
  • 2024-04-04 WO PCT/JP2024/013968 patent/WO2024210179A1/ja not_active Ceased
  • 2024-04-04 CN CN202480016085.4A patent/CN120814248A/zh active Pending
  • 2024-04-04 EP EP24784961.5A patent/EP4694183A1/en active Pending
  • 2024-04-04 JP JP2025513176A patent/JPWO2024210179A1/ja active Pending
  • 2024-04-08 TW TW113112963A patent/TW202448186A/zh unknown

Patent Citations (10)

Non-Patent Citations (1)

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