Earphone

1. An earphone comprising:

an electrodynamic speaker unit configured to electroacoustically convert an audio signal into a high-frequency sound wave containing a band component having a higher frequency than that of an audible band of a human being, thereby emitting the high-frequency sound wave;

an electromagnetic speaker unit configured to electroacoustically convert the audio signal into a low-frequency sound wave containing more band components having a lower frequency than that of the high-frequency sound wave, thereby emitting the low-frequency sound wave; and

a housing to an inside of which the electrodynamic speaker unit and the electromagnetic speaker unit are attached, wherein

in the housing, the electrodynamic speaker unit is attached such that a first acoustic space and a second acoustic space are defined on one side and the other side of a diaphragm of the electrodynamic speaker unit, and the electromagnetic speaker unit is attached and housed in the second acoustic space,

the housing includes a nozzle portion communicating with the first acoustic space to guide the low-frequency sound wave and the high-frequency sound wave to an ear canal of a user, and

the nozzle portion of the housing is formed in such a pipe shape that the one side of the diaphragm of the electrodynamic speaker unit is able to be directly viewed at least from an end portion of the nozzle portion through an acoustic path formed inside the nozzle portion and the first acoustic space.

2. The earphone according to claim 1 , wherein

the electrodynamic speaker unit

includes a magnetic circuit having a magnetic gap in which a voice coil is arranged, and the diaphragm coupled to the voice coil and exposed to an outside, and

emits the high-frequency sound wave, and

the electromagnetic speaker unit

includes a magnetic driver having an armature portion configured to vibrate a drive rod portion, a diaphragm connected to the drive rod portion, and a case configured to house the magnetic driver and the diaphragm inside and forming an output hole for outputting a sound wave emitted from the diaphragm, and

emits the low-frequency sound wave.

3. The earphone according to claim 1 , wherein

the housing further includes a port portion configured to guide the low-frequency sound wave emitted by the electromagnetic speaker unit to the first acoustic space such that the low-frequency sound wave is not emitted to the second acoustic space.

4. The earphone according to claim 3 , wherein

the housing further includes an inner leak port portion forming an acoustic path for communication between the first acoustic space and the second acoustic space.

5. The earphone according to claim 4 , wherein

the inner leak port portion includes a housing member forming an outer shell of the housing, and an attachment member interposed and attached among the housing member, the electrodynamic speaker unit, and the electromagnetic speaker unit, and

a groove provided at the housing member or the attachment member forms the acoustic path for communication between the first acoustic space and the second acoustic space.

6. The earphone according to claim 3 , wherein

the housing further includes an outer leak port portion forming an acoustic path for communication between the first acoustic space and an external space or forming an acoustic path for communication between the second acoustic space and the external space.

7. The earphone according to claim 1 , further comprising:

a network circuit including a circuit element configured to limit a band of the audio signal to a frequency band of equal to or higher than a predetermined frequency to supply the audio signal to the electrodynamic speaker unit, and/or a circuit element configured to limit the band of the audio signal to a frequency band of equal to or lower than the predetermined frequency to supply the audio signal to the electromagnetic speaker unit.

8. The earphone according to claim 7 , wherein

the predetermined frequency is a frequency of equal to or higher than 1 kHz and equal to or lower than 20 kHz.

9. The earphone according to claim 1 , further comprising:

an ear piece to be inserted into the ear canal of the user; and

an ear piece attachment portion for attachment of the ear piece to the nozzle portion.

10. An earphone comprising:

an electrodynamic speaker unit configured to electroacoustically convert an audio signal into a high-frequency sound wave containing a band component having a higher frequency than that of an audible band of a human being, thereby emitting the high-frequency sound wave;

an electromagnetic speaker unit configured to electroacoustically convert the audio signal into a low-frequency sound wave containing more band components having a lower frequency than that of the high-frequency sound wave, thereby emitting the low-frequency sound wave; and

a housing to an inside of which the electrodynamic speaker unit and the electromagnetic speaker unit are attached, wherein

in the housing, the electrodynamic speaker unit is attached such that a first acoustic space and a second acoustic space are defined on one side and the other side of a diaphragm of the electrodynamic speaker unit, and the electromagnetic speaker unit is attached and housed in the second acoustic space,

the housing includes an inner leak port portion forming an acoustic path for communication between the first acoustic space and the second acoustic space,

the inner leak port portion includes a housing member forming an outer shell of the housing, and an attachment member interposed and attached among the housing member, the electrodynamic speaker unit, and the electromagnetic speaker unit, and

a groove provided at the housing member or the attachment member forms the acoustic path for communication between the first acoustic space and the second acoustic space.

11. The earphone according to claim 10 , wherein

the housing further includes a port portion configured to guide the low-frequency sound wave emitted by the electromagnetic speaker unit to the first acoustic space such that the low-frequency sound wave is not emitted to the second acoustic space, and a nozzle portion communicating with the first acoustic space to guide the low-frequency sound wave and the high-frequency sound wave emitted by the electrodynamic speaker unit to an ear canal of a user.