Acoustic transducer with improved low frequency response
AssigneeThe Charles Stark Draper Laboratory, Inc.
InventorJonathan J. Bernstein
Life of this patent
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Abstract
An acoustic transducer includes a perforated member; a movable diaphragm spaced from the perforated member; spring means interconnecting the diaphragm and the perforated member for movably supporting the diaphragm relative to the perforated member; a pressure equalization slot for controlling the flow of fluid through the diaphragm, the slot equalizing the pressure on opposite sides of the diaphragm for defining the low frequency response; and means for applying an electric field across the perforated member and the diaphragm for producing an output signal representative of the variation in capacitance induced by the variation of the space between the perforated member and the diaphragm in response to an incident acoustic signal.
Claims20
An acoustic transducer comprising:
- a perforated member;
- a movable diaphragm spaced from said perforated member;
- spring means interconnecting said diaphragm and said perforated member for movably supporting said diaphragm relative to said perforated member;
- a pressure equalization slot for controlling the flow of fluid through said diaphragm;
- said slot equalizing the pressure on opposite sides of the diaphragm and having a width between 0.1 and 10.mu. for defining the low frequency response;
- and
- means for applying an electric field across said perforated member and said diaphragm for producing an output signal representative of the variation in capacitance induced by the variation of the space between said perforated member and said diaphragm in response to an incident acoustic signal.
An acoustic transducer comprising:
- a perforated member;
- a movable diaphragm spaced from said perforated member;
- spring means interconnecting said diaphragm and said perforated member for movably supporting said diaphragm relative to said perforated member;
- a pressure equalization slot for controlling the flow of fluid through said diaphragm;
- said slot equalizing the pressure on opposite sides of the diaphragm for defining the low frequency response;
- a substantial portion of said slot being covered by said perforated member and said slot and perforations being unaligned to deflect and lengthen the path of the fluid flow from said slot through said perforations;
- and
- means for applying an electric field across said perforated member and said diaphragm for producing an output signal representative of the variation in capacitance induced by the variation of the space between said perforated member and said diaphragm in response to an incident acoustic signal.
Dependencies are inferred from the claim text.