Unidirectional dynamic microphone unit
AssigneeKabushiki Kaisha Audio-Technica
InventorsTatsuya IKEDA, Hiroshi AKINO
Life of this patent
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Abstract
In a unidirectional dynamic microphone unit, a cylindrical tube is provided to cover the microphone unit, a cylindrical wall of a first cylindrical portion that is included in the cylindrical tube and extends to at least the rearward is provided with a rear sound wave introducing portion weighted such that an acoustic resistance value is gradually made smaller toward the rearward side from positions of sound holes for taking in a sound wave transmitting around from the rearward side, preferably formed of a trumpet-shaped opening, and it is possible to enhance the sensibility to sound pressures without degradation of the frequency response and the directionality.
Claims6
A unidirectional dynamic microphone unit comprising;
- a diaphragm having a voice coil on the backside;
- a magnetic circuit portion having a magnetic gap;
- and
- a cylindrical housing, wherein the magnetic circuit portion is supported within the housing, a peripheral edge portion of the diaphragm is supported by the housing such that the voice coil can vibrate within the magnetic gap, and the housing is provided with a sound hole introducing a sound wave transmitting around the housing from the rearward side to the backside of the diaphragm, the unidirectional dynamic microphone unit further comprising:
- a cylindrical tube for accommodating therein the housing coaxially, the cylindrical tube including a first cylindrical portion extending closer to the rearward side than the sound hole and a second cylindrical portion extending closer to the forward side than a front surface of the diaphragm;
- and
- a rear sound wave introducing portion provided on a cylindrical wall of the first cylindrical portion, the rear sound wave introducing portion being weighted such that an acoustic resistance value is gradually made smaller toward the rearward side from a position of the sound hole.
Dependencies are inferred from the claim text.