Patent US4295010A successfully refreshed from Google Patents.
US4295010A
Expired / Lapsed
US
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Plural piezoelectric polymer film acoustic transducer
Assignee: Lectret SA
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Filing: 1980-02-22
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Granted: 1981-10-13
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Expires: 2000-02-22
Abstract
Abstract An acoustic transducer with a plurality of metal-coated piezoelectric polymer films as an oscillator, adjacent film pairs being physically connected near their centers.
Inventors
- 👤 Preston V. Murphy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:14
CPC Classifications
H; H04; H04R; H04R17/00; H04R17/005; H04R2499/00; H04R2499/10; H04R2499/11; Y; Y10; Y10S; Y10S310/00; Y10S310/80
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
49 words
An acoustic transducer comprising: a hollow support member, and a plurality of metal-coated piezoelectric polymer films to act as an oscillator, said films being spaced apart at their peripheries, mounted at said peripheries to said support member, and physically connected to at least one adjacent film near their centers.
Claim 2
Dependent Claim
49 words
An acoustic transducer comprising: a hollow support member, and a plurality of metal-coated piezoelectric polymer films to act as an oscillator, said films being spaced apart at their peripheries, mounted at said peripheries to said support member, and physically connected to at least one adjacent film near their centers.
Claim 3
Dependent Claim
37 words
The transducer of claim 1 wherein said transducer is for generating sound and said films are electrically connected in parallel and with polarities selected to cause said films to move in the same direction under electrical excitation.
Claim 4
Dependent Claim
44 words
The transducer of claim 1 wherein said transducer is for converting sound into an electrical signal and said films are electrically connected in series and with polarities selected to cause the voltage outputs of each of said films to add when said films oscillate.
Claim 5
Dependent Claim
25 words
The transducer of claim 1, 2 or 3 in which said films are physically connected together near their centers by a dot of epoxy adhesive.
Claim 6
Dependent Claim
36 words
The transducer of claim 1 in which two of said films are flat cone-shaped, one cone is inverted with respect to the other, and said two films are physically connected at the apex of the cones.
Claim 7
Dependent Claim
25 words
The transducer of claim 4 in which each said piezoelectric film comprises an inner layer of polarized polyvinylidene fluoride coated on both surfaces with gold.
Claim 8
Dependent Claim
21 words
The transducer of claim 1 wherein said films are even in number and adjacent films are physically connected near their centers.
Claim 9
Dependent Claim
24 words
The transducer of claim 7 wherein said films are four in number and each of the four films are physically connected near their centers.
Claim 10
Dependent Claim
11 words
The transducer of claim 8 wherein said films are flat cone-shaped.
Claim 11
Dependent Claim
21 words
The transducer of claim 5 or 9 wherein the half cone angle of each said cone is greater than 1.20 radians.
Claim 12
Dependent Claim
19 words
The transducer of claim 10 wherein the half cone angle of each said cone is greater than 1.50 radians.
Claim 13
Dependent Claim
22 words
The transducer of claim 1, 5, or 9 wherein the overall thickness of each said film is from 5 to 30 microns.
Claim 14
Dependent Claim
22 words
The transducer of claim 1, 5, or 9 wherein the natural resonant frequency of said transducer is set at below 6000 Hz.
Claim 15
Dependent Claim
21 words
The transducer of claim 13 wherein the natural resonant frequency of said transducer is set at from 2000 to 5000 Hz.
Claim 16
Dependent Claim
36 words
The transducer of claim 1, 5, or 9 wherein said hollow member has a cylindrical interior to which said film peripheries are mounted and said cylindrical interior has a diameter of from 30 to 60 mm.
References Cited (Backward Citations)
US3832580A
Cited
US3792204A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-10-12 | 1985-04-13 | 1985-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-12 | 1989-04-13 | 1989-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-12 | 1993-04-13 | 1993-10-13 | $7700.00 | Window Closed / Lapsed |