EP0194958A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Electret transducer and method of fabrication
Assignee: Bosch Security Systems Inc
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Filing: 1986-03-06
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Granted: —
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Expires: 2006-03-06
Abstract
Abstract An electret transducer is comprised of a motor and signal processing apparatus, that may include an amplifier and/or impedance matching means, disposed within a sealed conductive housing. The motor is fabricated in place within a housing and the signal processing means is mounted on the underside of the cover for the housing so that each may be independently tested prior to combining into a unitary structure. The motor is comprised of easily fabricated and assembled components that include means for spacing a backplate from the walls of the conductive housing and a spacer intermediate the backplate and the center of a diaphragm. The backplate and the diaphragm are provided with registering apertures. The amplifier is mounted to the cover to conductively connect to the housing and to provide rigid outwardly extending terminals for ready connection to further electrical circuits, as in a hearing aid. The component parts of the transducer are fabricated by half etching through the use of etching resist patterns that are placed in registering cooperative disposition on the surfaces of a flat sheet of material of which the components are comprised, to provide variations in thickness of predetermined portions of the finished components.
Inventors
- 👤 Dean W. Flygstad
- 👤 Craig E. Tromborg
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 09:03
CPC Classifications
H; H04; H04R; H04R19/00; H04R19/01; H04R25/00; H04R25/60; H04R25/604; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49226
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
48 words
In an electret transducer having a flexible conductive diaphragm and a rigid electret coated conductive backplate; spacer means disposed intermediate a diaphragm and a backplate, said spacer means being operable to maintain a predetermined spacing between said diaphragm and said backplate at the center and peripheral portions thereof.
Claim 2
Dependent Claim
48 words
In an electret transducer having a flexible conductive diaphragm and a rigid electret coated conductive backplate; spacer means disposed intermediate a diaphragm and a backplate, said spacer means being operable to maintain a predetermined spacing between said diaphragm and said backplate at the center and peripheral portions thereof.
Claim 3
Dependent Claim
20 words
The subject matter of claim 1 in which the center and peripheral portions of the spacer are of uniform thickness.
Claim 4
Dependent Claim
17 words
The subject matter of claim 1 in which the spacer means engages the center of said diaphragm.
Claim 5
Dependent Claim
68 words
An electret transducer comprising; a) a sealed hollow housing including an aperture adjacent the bottom; b) motor means disposed adjacent the bottom of said housing said motor means including a diaphragm disposed above the aperture in said housing c) electrical signal processing means disposed inside the top of said housing; and d) conductive means inside of said housing connecting said motor means to said electrical signal processing means.
Claim 6
Dependent Claim
68 words
An electret transducer comprising; a) a sealed hollow housing including an aperture adjacent the bottom; b) motor means disposed adjacent the bottom of said housing said motor means including a diaphragm disposed above the aperture in said housing c) electrical signal processing means disposed inside the top of said housing; and d) conductive means inside of said housing connecting said motor means to said electrical signal processing means.
Claim 7
Dependent Claim
24 words
The subject matter of claim 4 in which the signal processing means is mounted on the underside of a cover of said housing means.
Claim 8
Dependent Claim
20 words
The subject matter of claim 5 in which terminals on the signal processing means extend outwardly of the hollow housing.
Claim 9
Dependent Claim
240 words
An electret transducer comprising; a) a conductive hollow housing having an open top end and an aperture opening into the bottom end in compressional wave transmitting relationship therewith; b) a conductive diaphragm support member having a lower portion adapted to engage the bottom and sidewalls of said housing and including a peripherally disposed upper portion adapted to receive and support the edges of a diaphragm above the aperture in said housing; c) a flexible dielectric diaphragm having a conductive coating on the lower side thereof and edge portions conductively mounted on the peripherally disposed upper portion of said support member; d) spacer means including a centrally disposed portion, disposed on top of said diaphragm; e) an electret backplate disposed on top of said spacer means, said backplate including a conductive upper surface and a lower a dielectric surface adjacent the top of said spacer means; f) a conductive cover mounted on the open top end of said housing; g) signal processing circuit means mounted on the underside of said cover and including an input terminal disposed inwardly of the inside periphery of said housing and further terminals extending outwardly through said housing; h) resilient conductive means disposed intermediate the input terminal on said circuit means and the conductive top of said backplate; and i) compressional wave sealing means extending between the periphery of said backplate and the inside periphery of said housing and said outwardly extending terminals and said housing.
Claim 10
Dependent Claim
240 words
An electret transducer comprising; a) a conductive hollow housing having an open top end and an aperture opening into the bottom end in compressional wave transmitting relationship therewith; b) a conductive diaphragm support member having a lower portion adapted to engage the bottom and sidewalls of said housing and including a peripherally disposed upper portion adapted to receive and support the edges of a diaphragm above the aperture in said housing; c) a flexible dielectric diaphragm having a conductive coating on the lower side thereof and edge portions conductively mounted on the peripherally disposed upper portion of said support member; d) spacer means including a centrally disposed portion, disposed on top of said diaphragm; e) an electret backplate disposed on top of said spacer means, said backplate including a conductive upper surface and a lower a dielectric surface adjacent the top of said spacer means; f) a conductive cover mounted on the open top end of said housing; g) signal processing circuit means mounted on the underside of said cover and including an input terminal disposed inwardly of the inside periphery of said housing and further terminals extending outwardly through said housing; h) resilient conductive means disposed intermediate the input terminal on said circuit means and the conductive top of said backplate; and i) compressional wave sealing means extending between the periphery of said backplate and the inside periphery of said housing and said outwardly extending terminals and said housing.
Claim 11
Independent Claim
114 words
A method of fabricating components of miniature electret transducers comprising the steps of; a) providing a flat sheet of material for a component; b) covering predetermined areas of said sheet by disposing an etchant resist in cooperative registration on opposed surfaces of said flat sheet of material so that volumes to be removed from surface to surface remain uncovered, volumes to remain from surface to surface and volumes to remain adjacent one or the other surface are covered with said resist on only one of said surfaces; and c) exposing said resist coated sheet of material to an etchant less than the time required for said etchant to remove material from surface to surface.
Claim 12
Independent Claim
114 words
A method of fabricating components of miniature electret transducers comprising the steps of; a) providing a flat sheet of material for a component; b) covering predetermined areas of said sheet by disposing an etchant resist in cooperative registration on opposed surfaces of said flat sheet of material so that volumes to be removed from surface to surface remain uncovered, volumes to remain from surface to surface and volumes to remain adjacent one or the other surface are covered with said resist on only one of said surfaces; and c) exposing said resist coated sheet of material to an etchant less than the time required for said etchant to remove material from surface to surface.
Claim 13
Dependent Claim
125 words
9 . The electret transducer of claim 4 in which the backplate, spacer and diaphragm support means are fabricated according to the method of; a) providing a flat sheet of material for a component; b) covering predetermined areas of said sheet by disposing an etchant resist in cooperative registration on opposed surfaces of said flat sheet of material so that volumes to be removed from surface to surface remain uncovered, volumes to remain from surface to surface and volumes to remain adjacent one or the other surface are covered with said resist on only one of said surfaces; and c) exposing said resist coated sheet of material to an etchant less than the time required for said etchant to remove material from surface to surface.
References Cited (Backward Citations)
No citation records indexed.
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