Earphone with an acoustic rear chamber vent
An earphone comprising a rear chamber and a vent structure. The vent structure comprises a longitudinal recess in the housing wall, which recess is defined by a bottom wall and recess walls connecting the bottom wall and the housing wall, a recess opening in the recess, which recess opening connects the recess and the rear chamber, a mesh device arranged parallel with the bottom wall, whereby a longitudinal recess cavity is provided between the bottom wall and the mesh structure. The invention also relates to the manufacturing such an earphone.
1. An earphone configured to provide an acoustic output to an ear of a wearer and further configured to be arranged on the wearer's head in an operating position such that a front chamber between the head and the earphone is separated from ambient space, the earphone comprising:
a housing having a housing wall separating a rear chamber from ambient space, the housing wall including a dividing wall separating the rear chamber from the front chamber,
a diaphragm suspended across an opening in the dividing wall and configured to be actively driven to provide the acoustic output,
a vent structure fluidly connecting the rear chamber and ambient space through the housing wall,
wherein the vent structure comprising
a longitudinal recess in the housing wall, which recess is defined by a bottom wall and recess walls connecting the bottom wall and the housing wall,
a recess opening in the recess, which recess opening connects the recess and the rear chamber,
a mesh device arranged parallel with the bottom wall, whereby a longitudinal recess cavity is provided between the bottom wall and the mesh structure,
wherein the earphone comprises a unitary earphone element comprising an end wall and a side wall, and wherein the recess is provided in the end wall, and wherein the earphone element is shaped, such it can be manufactured in an injection mould without overhangs.
2. An earphone according to claim 1 , wherein the recess cavity has a length (L r ) of 5-30 mm.
3. An earphone according to claim 1 , wherein the recess cavity has a width (W r ) of 1-10 mm.
4. An earphone according to claim 1 , wherein the recess cavity has a depth (D r ) of 1-10 mm.
5. An earphone according to claim 1 , wherein the recess cavity has a cross-section of 2-20 mm 2 .
6. An earphone device according to claim 1 , wherein the recess is curved.
7. A earphone according to claim 1 , wherein the recess cavity is tuned to provide a resonance frequency in one of the ranges: 50-1000 Hz, 100-500 Hz, 150-400 HZ, 200-300 Hz.
8. An earphone according to claim 1 , wherein the side wall is circumferential.
9. A method of manufacturing an earphone according to claim 1 , wherein the earphone element is manufactured in an injection molding process, where after the mesh device is attached to the earphone element.
10. A method of manufacturing an earphone according to claim 1 , wherein the dividing wall is attached to the circumferential side wall after the injection molding of the earphone element.