Acoustic device
To make it possible to improve a low-tone reproducing ability with a simple structure in an acoustic device including speakers in a headrest. The acoustic device includes a core material of a closed structure functioning as a core of a headrest main body, acoustic speakers 50, 50 disposed in the core material, and hollow headrest stays 15, 15 that pierce through the core material. The headrest stays 15, 15 circulate the air on the inside of the core material to the outer side via hollow sections.
1. An acoustic device comprising:
a core material of a closed structure functioning as a core of a headrest main body, the core material having an inner space;
acoustic speakers communicating with the inner space of the core material and attached to the core material; and
hollow headrest stays that pierce through the core material, wherein
the hollow headrest stays are configured to be inserted into a backrest section of a seat to connect the headrest main body to the backrest section,
the inner space of the core material forms a sound chamber, air therein vibrating and reinforcing sound from the acoustic speakers,
at least one of the hollow headrest stays includes a hollow section including a first communication hole, which is opened to the sound chamber formed by the inner space, and a second communication hole, which is opened to an inside of the backrest section, so as to flow air from the sound chamber formed by the inner space of the core material to the inside of the backrest section via the hollow section, and
the first communication hole is located behind a vibration face of the acoustic speakers, and opens to an upper side of the hollow headrest stays.
2. The acoustic device according to claim 1 , wherein the hollow headrest stays are a pipe shape and include the first and second communication holes for the air at ends or on side surfaces of the hollow headrest stays.
3. The acoustic device according to claim 2 , wherein when the second communication hole is provided at the side surface of the hollow headrest stay, the end of the hollow headrest stay is closed, the air flows through the second communication hole at the side surface,
when the second communication hole is non-provided at the side surface of the hollow headrest stay, the end of the hollow headrest stay is non-closed, the air flows through the non-closed end.
4. The acoustic device according to claim 1 , further comprising: an extended enclosure having a box shape and forming an inner space provided inside the backrest section, wherein
the inner space of the extended enclosure forms a sound chamber and air therein vibrates and reinforces sound from the acoustic speakers,
the second communication hole is opened to an inside of the sound chamber which is formed by the inner space of the extended enclosure, and the sound chamber formed by the inner space of the core material and the sound chamber formed by the inner space of the extended enclosure are connected through the hollow section of at least one of the hollow headrest stays.
5. The acoustic device according to claim 4 , wherein the extended enclosure includes a port for discharging the air to a front surface side of the backrest section.
6. The acoustic device according to claim 1 , wherein
the acoustic speakers are provided as a pair on left and right, and
the hollow headrest stays are provided as a pair on the left and the right in positions close to the acoustic speakers.
7. The acoustic device according to claim 1 , further comprising: a frame member made of metal provided on an inner side of the headrest main body, wherein
the frame member integrally includes the hollow headrest stays, and
a heat generating body is fixed to the frame member.
8. The acoustic device according to claim 7 , wherein portions near the heat generating body in the hollow headrest stays are formed small in a sectional area.
9. The acoustic device according to claim 7 , wherein
the frame member is provided on an inner side of the core material and supports the core material, and
the hollow headrest stays include a space on the inner side of the core material to communicate with the outer side.
10. The acoustic device according to claim 7 , wherein the heat generating body is an acoustic signal processing circuit for the acoustic speakers.
11. The acoustic device according to claim 1 , wherein the acoustic speakers include a vibration plate in which a front face is directed toward a user side, and a rear face is directed toward an opposite side of the front face, and
the first communication hole is positioned adjacent to the rear face of the vibration plate and is disposed in a position overlapping the acoustic speakers when viewed from the front face of the vibration plate.