Patent US4764690A successfully refreshed from Google Patents.
US4764690A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electret transducing
Assignee: RTI Technologies Pte Ltd
•
Filing: 1986-06-18
•
Granted: 1988-08-16
•
Expires: 2006-06-18
Abstract
Abstract A backplate assembly for an electret transducer including a backplate, an electret layer covering one surface of the backplate, and a peripheral spacer on the same side of the backplate as the electret layer and around the entire periphery of the electret layer, the spacer being secured to the backplate by a thin layer of material of the electret layer located and compressed between the spacer and the backplate, the thin layer being substantially thinner than the electret layer. Also disclosed is using a peripheral ring to support a diaphragm spaced from a housing wall via support members extending from the ring.
Inventors
- 👤 Preston V. Murphy
- 👤 Kurt Hubschi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 18:39
CPC Classifications
H; H04; H04R; H04R19/00; H04R19/01; H04R25/00; H04R25/60; H04R25/604; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49005; Y10T29/49226
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
79 words
A backplate assembly for an electret transducer comprising a backplate, an electret layer covering one surface of said backplate, and a peripheral spacer on the same side of the backplate as said electret layer and around the entire periphery of said electret layer, said spacer being secured to said backplate by a thin layer of material of said electret layer located and compressed between said spacer and said backplate, said thin layer being substantially thinner than said electret layer.
Claim 2
Dependent Claim
79 words
A backplate assembly for an electret transducer comprising a backplate, an electret layer covering one surface of said backplate, and a peripheral spacer on the same side of the backplate as said electret layer and around the entire periphery of said electret layer, said spacer being secured to said backplate by a thin layer of material of said electret layer located and compressed between said spacer and said backplate, said thin layer being substantially thinner than said electret layer.
Claim 3
Dependent Claim
35 words
The assembly of claim 1 wherein said spacer can move no further than said backplate resulting in an effective spacer height equal to the height of said spacer minus the thickness of said electret layer.
Claim 4
Dependent Claim
13 words
The assembly of claim 1 wherein said electret layer is made of Teflon.
Claim 5
Dependent Claim
25 words
The assembly of claim 1 wherein said thin layer is 2 microns or less in thickness, and said spacer is greater than 25 microns thick.
Claim 6
Dependent Claim
27 words
The assembly of claim 4 wherein said thin layer is less than or equal to 1 micron thick, and said spacer is more than 40 microns thick.
Claim 7
Independent Claim
82 words
A method of making a backplate assembly comprising providing a sandwich of a backplate, an electret layer covering one surface of said backplate, and a peripheral spacer on the same side of the backplate as said electret and around the entire periphery of said electret layer, and applying sufficient pressure and temperature to cause the majority of electret layer material between said spacer and said backplate to be displaced outward, resulting in a very thin layer between said spacer and said backplate.
Claim 8
Independent Claim
82 words
A method of making a backplate assembly comprising providing a sandwich of a backplate, an electret layer covering one surface of said backplate, and a peripheral spacer on the same side of the backplate as said electret and around the entire periphery of said electret layer, and applying sufficient pressure and temperature to cause the majority of electret layer material between said spacer and said backplate to be displaced outward, resulting in a very thin layer between said spacer and said backplate.
Claim 9
Dependent Claim
30 words
The method of claim 6 wherein said pressure is sufficiently high such that further increases in pressure do not result in a substantially thinner layer between the spacer and backplate.
Claim 10
Dependent Claim
13 words
The method of claim 7 wherein said electret layer is made of Teflon.
Claim 11
Dependent Claim
25 words
The method of claim 7 wherein said thin layer is 2 microns or less in thickness, and said spacer is greater than 25 microns thick.
Claim 12
Dependent Claim
27 words
The method of claim 8 wherein said thin layer is less than or equal to 1 micron thick, and said spacer is more than 40 microns thick.
Claim 13
Dependent Claim
85 words
A transducer including a backplate assembly comprising a backplate, an electret layer covering one surface of said backplate, a peripheral spacer on the same side of the backplate as said electret layer and around the entire periphery of said electret layer, said spacer being secured to said backplate by a thin layer of material of said electret layer compressed between said spacer and said backplate, said thin layer being substantially thinner than said electret layer, and a diaphragm spaced from said backplate by said spacer.
Claim 14
Dependent Claim
85 words
A transducer including a backplate assembly comprising a backplate, an electret layer covering one surface of said backplate, a peripheral spacer on the same side of the backplate as said electret layer and around the entire periphery of said electret layer, said spacer being secured to said backplate by a thin layer of material of said electret layer compressed between said spacer and said backplate, said thin layer being substantially thinner than said electret layer, and a diaphragm spaced from said backplate by said spacer.
Claim 15
Dependent Claim
71 words
An electret transducer comprising a housing defining an entry port to a chamber therein, a diaphragm in said chamber, and a diaphragm support including a pheripheral ring, one side of said ring being secured to said diaphragm and another side of said ring being secured to support members, said support members spacing said ring from a wall of said housing and providing an unobstructed path between said port and said diaphragm.
Claim 16
Dependent Claim
71 words
An electret transducer comprising a housing defining an entry port to a chamber therein, a diaphragm in said chamber, and a diaphragm support including a pheripheral ring, one side of said ring being secured to said diaphragm and another side of said ring being secured to support members, said support members spacing said ring from a wall of said housing and providing an unobstructed path between said port and said diaphragm.
Claim 17
Dependent Claim
22 words
The transducer of claim 12 wherein said support members are a pair of parallel bars extending between and spaced from said ring.
Claim 18
Dependent Claim
24 words
The transducer of claim 13 wherein said bars are spaced from each other by a distance greater than the width of said entry port.
Claim 19
Dependent Claim
36 words
The transducer of claim 14 wherein said housing has large sides parallel to said diaphragm and thin sides perpendicular to said large sides, and said entry port is located at a thin side of said housing.
Claim 20
Dependent Claim
13 words
The transducer of claim 14 wherein said entry port directly faces said diaphragm.
References Cited (Backward Citations)
US3436492A
Cited
US4014091A
Cited
US3772133A
Cited
US3963881A
Cited
US3943304A
Cited
US4063050A
Cited
US4249043A
Cited
US4160881A
Cited
US4236051A
Cited
US4268725A
Cited
US4331840A
Cited
US4447678A
Cited
US4418246A
Cited
US4542264A
Cited
US4621171A
Cited
US4442324A
Cited
US4567382A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-08-16 | 1992-02-15 | 1992-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-16 | 1996-02-15 | 1996-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-16 | 2000-02-15 | 2000-08-16 | $7700.00 | Window Closed / Lapsed |