US4887248A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrostatic transducer and method of making and using same
Assignee: Cleveland Motion Controls Inc
•
Filing: 1989-03-03
•
Granted: 1989-12-12
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Expires: 2009-03-03
Abstract
Abstract An improvement in a capacitance type electrostatic transducer for transmitting and/or receiving pressure energy, wherein the transducer includes a relatively inflexible backplate with at least one major surface thereof formed of electrically conductive material, a relatively flexible membrane including a layer of electrically conductive material stretched across and coextensive with the one major surface of the backplate, electrically insulating means for maintaining a capacitor forming spacing between the major surface and the stretched membrane and wherein the major surface has protrusions extending through the spacing for supporting the membrane. The improvement is providing the protrusions as a multitude of discrete pedestals distributed over the major surface and formed by etching away the major surface except in photographically selected areas defining the pedestals. Each of the pedestals has a top surface covered by an individual thin piece of electrically insulating material remaining after a prior photographic developing process.
Inventors
- 👤 Elmer L. Griebeler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:26
CPC Classifications
B; B06; B06B; B06B1/00; B06B1/02; B06B1/0292; Y; Y10; Y10S; Y10S148/00; Y10S148/135; Y10T; Y10T29/00; Y10T29/43; Y10T29/435
Claims Analysis
Total Claims: 39
Claim 1
Independent Claim
106 words
In a capacitance type, electrostatic air pressure wave transducer, said transducer including: a relatively inflexible backplate with at least one major surface thereof formed of electrically conductive material, a relatively flexible membrane including a layer of electrically conductive material stretched across and coextensive with said one major surface; and means formed in said conductive material for maintaining a capacitor forming spacing between said major surface and said stretched membrane, the improvement comprising: said means for maintaining said spacing is a multitude of discrete metal pedestals distributed on said major surface with a generally flat top surface covered by an individual thinner piece of electrically insulating material.
Claim 2
Dependent Claim
106 words
In a capacitance type, electrostatic air pressure wave transducer, said transducer including: a relatively inflexible backplate with at least one major surface thereof formed of electrically conductive material, a relatively flexible membrane including a layer of electrically conductive material stretched across and coextensive with said one major surface; and means formed in said conductive material for maintaining a capacitor forming spacing between said major surface and said stretched membrane, the improvement comprising: said means for maintaining said spacing is a multitude of discrete metal pedestals distributed on said major surface with a generally flat top surface covered by an individual thinner piece of electrically insulating material.
Claim 3
Dependent Claim
47 words
The improvement as defined in claim 1 wherein said piece of insulating material has a first area and said tops of said pedestals have a second area and said first area being substantially larger than said second area whereby said insulating material extends outwardly from said pedestals.
Claim 4
Dependent Claim
18 words
The improvement as defined in claim 2 wherein each of said pedestals has substantially the same transverse cross-section.
Claim 5
Dependent Claim
13 words
The improvement as defined in claim 3 wherein said cross-section is generally circular.
Claim 6
Dependent Claim
19 words
The improvement as defined in claim 1 wherein a majority of said pedestals have a generally circular transverse cross-section.
Claim 7
Dependent Claim
47 words
The improvement as defined in claim 5 wherein said piece of insulating material has a first area and said tops of said pedestals have a second area and said first area being substantially larger than said second area whereby said insulating material extends outwardly from said pedestals.
Claim 8
Dependent Claim
23 words
The improvement as defined in claim 1 wherein said pedestals are arranged in a preselected array defined by top surfaces of said pedestals.
Claim 9
Dependent Claim
13 words
The improvement as defined in claim 7 wherein said array is created photographically.
Claim 10
Dependent Claim
16 words
The improvement as defined in claim 7 wherein said array includes preselected spacings between adjacent pedestals.
Claim 11
Dependent Claim
23 words
The improvement as defined in claim 9 wherein said spacings are varied to provide different resonant frequencies at different locations on said membrane.
Claim 12
Dependent Claim
23 words
The improvement as defined in claim 1 wherein said pedestals are arranged in a preselected array defined by top surfaces of said pedestals.
Claim 13
Dependent Claim
13 words
The improvement as defined in claim 11 wherein said array is created photographically.
Claim 14
Dependent Claim
16 words
The improvement as defined in claim 11 wherein said array includes preselected spacings between adjacent pedestals.
Claim 15
Dependent Claim
23 words
The improvement as defined in claim 13 wherein said spacings are varied to provide different resonant frequencies at different locations on said membrane.
Claim 16
Dependent Claim
124 words
In a capacitance type, electrostatic air pressure wave transducer, said transducer including: a relatively inflexible backplate with at least one major surface thereof formed of electrically conductive material; a relatively flexible membrane including a layer of electrically conductive material stretched across and coextensive with said one major surface; and means formed in said conductive material for maintaining a capacitor forming spacing between said major surface and said stretched membrane, the improvement comprising: said means for maintaining said spacing is a multitude of discrete metal pedestals formed by etching away said major surface except in photographically selected areas defining said pedestals and including a piece of electrically insulating material at each of said selected areas and on the top surface of each of said pedestals.
Claim 17
Dependent Claim
124 words
In a capacitance type, electrostatic air pressure wave transducer, said transducer including: a relatively inflexible backplate with at least one major surface thereof formed of electrically conductive material; a relatively flexible membrane including a layer of electrically conductive material stretched across and coextensive with said one major surface; and means formed in said conductive material for maintaining a capacitor forming spacing between said major surface and said stretched membrane, the improvement comprising: said means for maintaining said spacing is a multitude of discrete metal pedestals formed by etching away said major surface except in photographically selected areas defining said pedestals and including a piece of electrically insulating material at each of said selected areas and on the top surface of each of said pedestals.
Claim 18
Dependent Claim
48 words
The improvement as defined in claim 15 wherein said thin piece of insulating material has a first area and said tops of said pedestals have a second area and said first area being substantially larger than said second area whereby said insulating material extends outwardly from said pedestals.
Claim 19
Dependent Claim
139 words
In a capacitance type, electrostatic air pressure wave transducer, said transducer including: a relatively inflexible backplate with at least one major surface thereof formed of electrically conductive material; a relatively flexible membrane including a layer of electrically conductive material stretched across and coextensive with said one major surface; and means formed in said conductive material for maintaining a capacitor forming spacing between said major surface and said stretched membrane, the improvement comprising: said means for maintaining said spacing is a multitude of discrete metal pedestals with preselected cross-sections and distributed over said surface in a preselected array, said array includes preselected spacings between adjacent pedestals and said spacings are varied to provide different resonant frequencies at different locations on said membrane and including a thin piece of electrically insulating material on the top surface of each of said pedestals.
Claim 20
Dependent Claim
139 words
In a capacitance type, electrostatic air pressure wave transducer, said transducer including: a relatively inflexible backplate with at least one major surface thereof formed of electrically conductive material; a relatively flexible membrane including a layer of electrically conductive material stretched across and coextensive with said one major surface; and means formed in said conductive material for maintaining a capacitor forming spacing between said major surface and said stretched membrane, the improvement comprising: said means for maintaining said spacing is a multitude of discrete metal pedestals with preselected cross-sections and distributed over said surface in a preselected array, said array includes preselected spacings between adjacent pedestals and said spacings are varied to provide different resonant frequencies at different locations on said membrane and including a thin piece of electrically insulating material on the top surface of each of said pedestals.
Claim 21
Dependent Claim
33 words
The improvement as defined in claim 17 wherein said pedestals each have a top flat surface and including a piece of electrically insulating material on the top surface of each of said pedestals.
Claim 22
Independent Claim
158 words
A method of producing a generally flat membrane supporting surface as an electrically conductive portion of a backplate of an electrostatic shock wave transducer for transmitting and/or receiving pressure energy waves, said method comprising the steps of: (a) applying an electrically insulating, photoresist costing on said supporting surface; (b) masking a multitude of preselected small discrete pedestal areas in a preselected array distributed over said supporting surface to define non-pedestal areas, said pedestal areas being separated by said non-pedestal areas; (c) directing a sensitizing wave against said supporting surface to expose one of said areas of said support surface; (d) photographically removing said photoresist coating from said non-pedestal areas whereby small pieces of said photoresist coating remain on said pedestal areas; (e) spray etching said supporting surface with a solution reactive with only said supporting surface in said non-pedestal areas; and, (f) continuing said spray etching until said small pieces each define a pedestal on said supporting surface.
Claim 23
Independent Claim
158 words
A method of producing a generally flat membrane supporting surface as an electrically conductive portion of a backplate of an electrostatic shock wave transducer for transmitting and/or receiving pressure energy waves, said method comprising the steps of: (a) applying an electrically insulating, photoresist costing on said supporting surface; (b) masking a multitude of preselected small discrete pedestal areas in a preselected array distributed over said supporting surface to define non-pedestal areas, said pedestal areas being separated by said non-pedestal areas; (c) directing a sensitizing wave against said supporting surface to expose one of said areas of said support surface; (d) photographically removing said photoresist coating from said non-pedestal areas whereby small pieces of said photoresist coating remain on said pedestal areas; (e) spray etching said supporting surface with a solution reactive with only said supporting surface in said non-pedestal areas; and, (f) continuing said spray etching until said small pieces each define a pedestal on said supporting surface.
Claim 24
Independent Claim
149 words
A method of producing a generally flat membrane supporting surface as an electrically conductive portion of a backplate of an electrostatic pressure wave transducer, said method comprising the steps of: (a) applying an electrically insulating, photoresist coating on said supporting surface; (b) masking a multitude of preselected discrete pedestal areas in a preselected array distributed over said supporting surface to define non-pedestal areas, said pedestal areas being separated by said non-pedestal areas; (c) directing a sensitizing wave against said supporting surface to expose one of said areas of said support surface; (d) photographically removing said photoresist coating from said non-pedestal areas whereby pieces of said photoresist coating remain on said pedestal areas; (e) spray etching said supporting surface with a solution reactive with only said supporting surface in said non-pedestal areas; and, (f) continuing said spray etching until said small pieces each define a pedestal on said supporting surface.
Claim 25
Independent Claim
149 words
A method of producing a generally flat membrane supporting surface as an electrically conductive portion of a backplate of an electrostatic pressure wave transducer, said method comprising the steps of: (a) applying an electrically insulating, photoresist coating on said supporting surface; (b) masking a multitude of preselected discrete pedestal areas in a preselected array distributed over said supporting surface to define non-pedestal areas, said pedestal areas being separated by said non-pedestal areas; (c) directing a sensitizing wave against said supporting surface to expose one of said areas of said support surface; (d) photographically removing said photoresist coating from said non-pedestal areas whereby pieces of said photoresist coating remain on said pedestal areas; (e) spray etching said supporting surface with a solution reactive with only said supporting surface in said non-pedestal areas; and, (f) continuing said spray etching until said small pieces each define a pedestal on said supporting surface.
Claim 26
Independent Claim
155 words
A method of transmitting a pressure wave from a capacitance type, electrostatic transducer used for determining distance of an object and for receiving an echo of said pressure wave, said transducer including a relatively inflexible backplate with at least one major surface thereof formed of electrically conductive material, a relatively flexible membrane formed of an electrically insulating layer and an outer electrically conductive layer stretched over and coextensive with said major surface and cavities in said surface to define capacitance spacing between said conductive layer and conductive material, said method comprising the steps of: (a) applying a known high voltage greater than 150 volts D.C. across said conductive layer and conductive material to create a sudden pressure wave; (b) holding said known voltage across said layer and conductive material until said echo is received; and, (c) gradually removing said known voltage from across said layer and conductive material whereby a sudden pressure is not created.
Claim 27
Independent Claim
155 words
A method of transmitting a pressure wave from a capacitance type, electrostatic transducer used for determining distance of an object and for receiving an echo of said pressure wave, said transducer including a relatively inflexible backplate with at least one major surface thereof formed of electrically conductive material, a relatively flexible membrane formed of an electrically insulating layer and an outer electrically conductive layer stretched over and coextensive with said major surface and cavities in said surface to define capacitance spacing between said conductive layer and conductive material, said method comprising the steps of: (a) applying a known high voltage greater than 150 volts D.C. across said conductive layer and conductive material to create a sudden pressure wave; (b) holding said known voltage across said layer and conductive material until said echo is received; and, (c) gradually removing said known voltage from across said layer and conductive material whereby a sudden pressure is not created.
Claim 28
Dependent Claim
20 words
A method as defined in claim 21 wherein said steps (a), (b) and (c) are repeated at a given rate.
Claim 29
Dependent Claim
16 words
A method as defined in claim 21 wherein said sudden pressure wave is a shock wave.
Claim 30
Independent Claim
143 words
A method of producing a generally flat membrane supporting surface as an electrically conductive portion of a backplate of an electrostatic shock wave transducer, said method comprising the steps of: (a) applying an electrically insulating, photoresist coating on said supporting surface; (b) masking a multitude of preselected small discrete pedestal areas in a preselected array distributed over said supporting surface to define non-pedestal areas, said pedestal areas being separated by said non-pedestal areas; (c) directing a sensitizing wave against said supporting surface to expose one of said areas of said supporting surface; (d) photographically removing said photoresist coating from said non-pedestal areas whereby small pieces of said photoresist coating remain on said pedestal areas; (e) spray etching said supporting surface with a solution reactive with only said supporting surface in said non-pedestal areas; and, (f) leaving said photoresist coating on said pedestal areas.
Claim 31
Independent Claim
143 words
A method of producing a generally flat membrane supporting surface as an electrically conductive portion of a backplate of an electrostatic shock wave transducer, said method comprising the steps of: (a) applying an electrically insulating, photoresist coating on said supporting surface; (b) masking a multitude of preselected small discrete pedestal areas in a preselected array distributed over said supporting surface to define non-pedestal areas, said pedestal areas being separated by said non-pedestal areas; (c) directing a sensitizing wave against said supporting surface to expose one of said areas of said supporting surface; (d) photographically removing said photoresist coating from said non-pedestal areas whereby small pieces of said photoresist coating remain on said pedestal areas; (e) spray etching said supporting surface with a solution reactive with only said supporting surface in said non-pedestal areas; and, (f) leaving said photoresist coating on said pedestal areas.
Claim 32
Independent Claim
137 words
A method of producing a generally flat membrane supporting surface as an electrically conductive portion of a backplate of an electrostatic pressure wave transducer, said method comprising the steps of: (a) applying an electrically insulating, photoresist coating on said supporting surface; (b) masking a multitude of preselected discrete pedestal areas in a preselected array distributed over said supporting surface to define non-pedestal areas, said pedestal areas being separated by said non-pedestal areas; (c) directing a sensitizing wave against said supporting surface to expose one of said areas of said supporting surface; (d) photographically removing said photoresist coating from said non-pedestal areas whereby pieces of said photoresist coating remain on said pedestal areas; (e) spray etching said supporting surface with a solution reactive with only said supporting surface; and, (f) leaving said photoresist coating on said pedestal areas.
Claim 33
Independent Claim
137 words
A method of producing a generally flat membrane supporting surface as an electrically conductive portion of a backplate of an electrostatic pressure wave transducer, said method comprising the steps of: (a) applying an electrically insulating, photoresist coating on said supporting surface; (b) masking a multitude of preselected discrete pedestal areas in a preselected array distributed over said supporting surface to define non-pedestal areas, said pedestal areas being separated by said non-pedestal areas; (c) directing a sensitizing wave against said supporting surface to expose one of said areas of said supporting surface; (d) photographically removing said photoresist coating from said non-pedestal areas whereby pieces of said photoresist coating remain on said pedestal areas; (e) spray etching said supporting surface with a solution reactive with only said supporting surface; and, (f) leaving said photoresist coating on said pedestal areas.
Claim 34
Independent Claim
98 words
A method of producing a generally flat membrane supporting surface as an electrically conducting portion of a backplate of an electrostatic pressure wave transducer, said transducer comprising said backplate and a relatively flexible membrane, said method comprising the steps of: (a) applying an electrically insulating coating on said supporting surface; (b) removing selected areas of said insulating coating and said supporting surface underlaying selected areas of said insulating coating to a preselected depth; and, (c) leaving said insulating coating on said supporting surface in remaining areas of said supporting surface whereby insulating coating topped support pedestals are provided.
Claim 35
Independent Claim
98 words
A method of producing a generally flat membrane supporting surface as an electrically conducting portion of a backplate of an electrostatic pressure wave transducer, said transducer comprising said backplate and a relatively flexible membrane, said method comprising the steps of: (a) applying an electrically insulating coating on said supporting surface; (b) removing selected areas of said insulating coating and said supporting surface underlaying selected areas of said insulating coating to a preselected depth; and, (c) leaving said insulating coating on said supporting surface in remaining areas of said supporting surface whereby insulating coating topped support pedestals are provided.
Claim 36
Dependent Claim
29 words
The method of claim 26 wherein said removing step (b) includes undercutting whereby said insulating coating on said supporting surface remaining after said removing step overhangs said support pedestals.
Claim 37
Dependent Claim
62 words
The method of claim 26 wherein said insulating coating is a photosensitive coating and step (b) comprises: (b1) masking said photosensitive coating on said supporting surface to establish pedestal areas and non-pedestal areas; (b2) exposing said masked photosensitive coating; (b3) removing said photosensitive coating from said non-pedestal areas; and, (b4) removing said supporting surface underlaying said non-pedestal areas to a preselected depth.
Claim 38
Dependent Claim
15 words
The method of claim 28 wherein said step (b4) comprises chemically etching said supporting surface.
Claim 39
Dependent Claim
37 words
The method of claim 29 wherein said etching is continued until said support pedestals comprise an insulating coating of a first area supported on a supporting surface pedestal of a second area smaller than said first area.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-12-11 | 1993-06-12 | 1993-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-11 | 1997-06-12 | 1997-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-11 | 2001-06-12 | 2001-12-12 | $7700.00 | Window Closed / Lapsed |