Sound pickup device
View Patent ↗A sound pickup device includes a diaphragm that vibrates according to an acoustic pressure of input sound, an acoustic member having a sound channel formed to guide sound to the diaphragm, and a Helmholtz resonator having an opening formed in a wall surface surrounding the sound channel, in which the diaphragm is disposed inside a microphone in which a sound hole is formed, the acoustic member includes: a first substrate that has a through hole formed at the same position as the sound hole, and is attached to the microphone; and a second substrate that has the sound channel formed at a position corresponding to the through hole, and is attached to the first substrate.
1. A sound pickup device, comprising:
a diaphragm that vibrates according to an acoustic pressure of input sound;
an acoustic member having a sound channel formed to guide sound to the diaphragm; and
a resonator having an opening formed in a wall surface surrounding the sound channel, wherein
the diaphragm is disposed inside a microphone in which a sound hole is formed,
the acoustic member includes:
a first acoustic member that has a through hole formed at a same position as the sound hole, and is attached to the microphone; and
a second acoustic member that has the sound channel formed at a position corresponding to the through hole, and is attached to the first acoustic member,
the resonator is formed in a direction perpendicular to the wall surface surrounding the sound channel, and
the sound channel of the second acoustic member is formed to be tapered from an input port of the sound toward an inside of the sound channel.
2. The sound pickup device according to claim 1 , wherein the resonator is a Helmholtz resonator.
3. The sound pickup device according to claim 1 , wherein
the resonator includes:
a neck portion formed in a periphery of the sound channel and having a space of a first volume; and
a cavity portion formed in a periphery of the neck portion and having a space of a second volume larger than the first volume.
4. The sound pickup device according to claim 3 , wherein
the neck portion is an annular space surrounding the periphery of the sound channel, and
the cavity portion is an annular space surrounding the periphery of the neck portion.
5. The sound pickup device according to claim 3 , wherein
the neck portion is a tubular space radially extending from the wall surface of the sound channel, and
the cavity portion is an annular space surrounding the periphery of the neck portion.
6. The sound pickup device according to claim 3 , wherein
the neck portion is a tubular space radially extending from the wall surface of the sound channel, and
the cavity portion is provided individually for the neck portion.
7. The sound pickup device according to claim 3 , further comprising a sound absorbing material disposed inside at least one of the neck portion and the cavity portion.
8. The sound pickup device according to claim 1 , wherein
the resonator includes:
a first resonator formed in a direction perpendicular to the wall surface surrounding the sound channel; and
a second resonator formed outside the first resonator and having an opening connected to the first resonator.
9. The sound pickup device according to claim 1 , wherein the microphone is a micro electro mechanical systems (MEMS) microphone.
10. A sound pickup device, comprising:
a diaphragm that vibrates according to an acoustic pressure of input sound;
an acoustic member having a sound channel formed to guide sound to the diaphragm; and
a resonator having an opening formed in a wall surface surrounding the sound channel, wherein
the diaphragm is disposed inside a microphone in which a sound hole is formed,
the sound pickup device further comprises:
a substrate mounted with the microphone such that a surface of the microphone opposed to a surface on which the sound hole is formed is in contact with the substrate,
the acoustic member includes:
a first acoustic member that has a through hole formed at a same position as the sound hole, and is attached to the microphone; and
a second acoustic member that has the sound channel formed at a position corresponding to the through hole, and is attached to the first acoustic member, and
the resonator is formed in a direction perpendicular to the wall surface surrounding the sound channel.
11. A sound pickup device, comprising:
a diaphragm that vibrates according to an acoustic pressure of input sound;
an acoustic member having a sound channel formed to guide sound to the diaphragm; and
a resonator having an opening formed in a wall surface surrounding the sound channel, wherein
the resonator includes:
a neck portion formed in a periphery of the sound channel and having a first space of a first volume; and
a cavity portion formed in a periphery of the neck portion and having a second space of a second volume larger than the first volume,
the neck portion is an annular space surrounding the periphery of the sound channel, and
the cavity portion is an annular space surrounding the periphery of the neck portion.
12. A sound pickup device, comprising:
a diaphragm that vibrates according to an acoustic pressure of input sound;
an acoustic member having a sound channel formed to guide sound to the diaphragm; and
a resonator having an opening formed in a wall surface surrounding the sound channel, wherein
the resonator includes:
a neck portion formed in a periphery of the sound channel and having a first space of a first volume; and
a cavity portion formed in a periphery of the neck portion and having a second space of a second volume larger than the first volume,
the neck portion is a tubular space radially extending from the wall surface of the sound channel, and
the cavity portion is an annular space surrounding the periphery of the neck portion.