Electret transducer array and fabrication technique
First Claim
1. A foil for use in a transducer array comprising one or more transducers, the foil comprising:
- a layer of insulating material; and
a layer of metal in contact with the layer of insulating material, wherein the layer of metal comprises a plurality of physically discrete areas of metal, one or more of the discrete areas defining areas which convert between acoustic and electric energy by variation of capacitance of one or more transducers of the array when the foil is used in said transducer array.
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Accused Products
Abstract
An electret transducer array and fabrication technique are disclosed. The array comprises a foil having a layer of insulating material and a layer of metal in contact therewith. The layer of metal comprises one or more discrete areas of metal which define the active areas of one or more transducers in the array. Electrical leads are coupled to the discrete areas of metal. By means of these leads, electrical signals produced by each transducer in response to incident acoustic signals may be accessed. The areas of metal may be formed by selectively removing metal from the foil, or by selective metal deposition. The layer of insulating material is electrostatically charged. The electret transducer array further comprises a porous backplate of sintered metal. The backplate further comprises a rough surface in contact with the layer of insulating material. The backplate serves as a common electrode for transducers of the array. A second backplate is provided positioned adjacent to the metal layer of the foil forming an air gap therewith. The second backplate provides, among other things, shielding from stray electromagnetic fields.
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Citations
35 Claims
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1. A foil for use in a transducer array comprising one or more transducers, the foil comprising:
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a layer of insulating material; and a layer of metal in contact with the layer of insulating material, wherein the layer of metal comprises a plurality of physically discrete areas of metal, one or more of the discrete areas defining areas which convert between acoustic and electric energy by variation of capacitance of one or more transducers of the array when the foil is used in said transducer array. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A transducer array comprising:
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a. a first backplate, the first backplate comprising a rough metal surface; and b. a foil disposed at a predetermined position with respect to the first backplate, the foil comprising i. a layer of insulating material, and ii. a layer of metal, wherein the layer of metal comprises a plurality of physically. discrete areas of metal, one or more of the discrete areas of metal defining areas which convert between acoustic and electric energy in one or more transducers of the array. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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27. An electret transducer array comprising:
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a. a backplate, the backplate comprising a rough metal surface; and b. an electret foil disposed at a predetermined position with respect to the backplate, the electret foil comprising; a layer of insulating material, the layer of insulating material selectively charged with a first polarity at a plurality of physically discrete areas, and ii. a layer of metal. - View Dependent Claims (28)
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29. An electret transducer array comprising:
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a. a first backplate, the first backplate comprising a rough metal surface; and b. a foil, the foil comprising; i. a layer of electrostatically charged insulating material, and ii. a layer of metal, wherein the layer of metal comprises a plurality of physically discrete areas of metal which define areas which convert between acoustic and electric energy in one or more transducers of the array; the foil positioned such that the layer of insulating material is in contact with the metal surface of the first backplate and held in position by electrostatic force between itself and the first backplate. - View Dependent Claims (30, 31, 32, 33)
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34. A transducer array comprising:
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a. a first backplate, the first backplate comprising a rough metal surface; and b. a foil disposed at a predetermined position with respect to the first backplate, the foil comprising; i. a layer of insulating material, and ii. a layer of metal, wherein the layer of metal comprises a plurality of physically discrete areas of metal, one or more of the discrete areas of metal defining areas which convert between acoustic and electric energy by variation of capacitance of one or more transducers of the array.
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35. An electret transducer array comprising:
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a. a first backplate, the first backplate comprising a rough metal surface; and b. a foil, the foil comprising; i. a layer of electrostatically charged insulating material, and ii. a layer of metal, wherein the layer of metal comprises a plurality of physically discrete areas of metal, one or more of the discrete areas of metal defining areas which convert between acoustic and electric energy by variation of capacitance of one or more transducers of the array; the foil positioned such that the layer of insulating material is in contact with the metal surface of the first backplate and held in position by electrostatic force between itself and the first backplate.
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Specification