EP0119706A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Improved polarizing of material
Assignee: AT&T Inc
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Filing: 1984-02-06
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Granted: —
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Expires: 2004-02-06
Abstract
Abstract Electrically polarizable material (12), e.g. PVDP (film) is poled by appliyng an electric field across the film. Insulation is provided on the surface of the film. In a typical embodiment a compliant dielectric annulus (10) insulates the polarized region from the edges of the film. This substantially eliminates breakdown at the edges of the film, allowing increased poling voltages. The technique can reduce poling time to typically a few seconds at room temperature, as compared to minutes or hours by prior art techniques, some of which required elevated temperatures.
Inventors
- 👤 Heinz Von Seggern
- 👤 Tsuey Tang Wang
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 02:11
CPC Classifications
H; H01; H01G; H01G7/00; H01G7/02; H01G7/021; H01G7/023; H10; H10N; H10N30/00; H10N30/01; H10N30/04; H10N30/045; H10N30/09; H10N30/098; H10N30/80; H10N30/85; H10N30/857
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
74 words
A method of polarizing a sheet (12,42) of polarizable material by steps comprising applying an electric field across a portion of said sheet CHARACTERIZED BY insulating at least during said polarizing, at least one edge of said sheet from said portion by means of a dielectric (10,45) contacting a surface of said sheet between said portion and said edge, whereby the voltage that can be applied to said sheet without breakdown is substantially increased.
Claim 2
Independent Claim
74 words
A method of polarizing a sheet (12,42) of polarizable material by steps comprising applying an electric field across a portion of said sheet CHARACTERIZED BY insulating at least during said polarizing, at least one edge of said sheet from said portion by means of a dielectric (10,45) contacting a surface of said sheet between said portion and said edge, whereby the voltage that can be applied to said sheet without breakdown is substantially increased.
Claim 3
Dependent Claim
14 words
The method according to claim 1, CHARACTERIZED IN THAT said dielectric comprises compliant material.
Claim 4
Dependent Claim
20 words
The method according to claim 2, CHARACTERIZED IN THAT said contacting is accomplished by pressing said dielectric onto said sheet.
Claim 5
Dependent Claim
18 words
The method according to claim 1, CHARACTERIZED IN THAT said dielectric is an annulus that surrounds said portion.
Claim 6
Dependent Claim
20 words
The method according to claim 1, CHARACTERIZED IN THAT said polarizable material is poly (vinylidene fluoride) or a copolymer thereof.
Claim 7
Dependent Claim
34 words
The method according to claim 5, CHARACTERIZED IN THAT said poly (vinylidene fluoride) or copolymer thereof is in the form of a film having a thickness in the range of 6 to 150 micrometers.
Claim 8
Dependent Claim
32 words
The method according to claim 6. CHARACTERIZED IN THAT said polarizing is accomplished with an electric field greater than 3 000,000 volts/cm. or greater than 4,000,000 volts/cm. or greater than 5,000,000 volts/cm.
Claim 9
Independent Claim
47 words
The method according to any one of preceding claims, 1 - 7, CHARACTERIZED IN THAT said sheet of polarizable material is a biaxially oriented film of poly (vinylidene fluoride) wherein the value of the piezoelectric strain coefficient (d31) achieved by said polarizing is at least 5 pC/N.
Claim 10
Independent Claim
39 words
The method according to any one of preceding claims 1 - 8, CHARACTERIZED IN THAT said sheet of polarizable material is a film of poly (vinylidene fluoride), and said poling is accomplished for a time less than 10 seconds.
Claim 11
Dependent Claim
16 words
The method according to claim 9, CHARACTERZED IN THAT said poling is accomplished at room temperature.
Claim 12
Independent Claim
41 words
The method according to any one of preceding claims 1 - 10 CHARACTERIZED BY insulating a multiplicity of interior portions of said sheet from each other by dielectric material contacting a surface of said sheet between said portions during said polarizing.
Claim 13
Independent Claim
33 words
The method according to any one of preceding claims 1 - 11, CHARACTERIZED IN THAT said portion of said material has at least one surface metallized prior to said applying an electric field.
Claim 14
Independent Claim
23 words
The method according to any one of preceding claims 1 - 12, CHARACTERIZED BY removing said dielectric from said sheet after said polarizing.
Claim 15
Independent Claim
26 words
The method according to any one of preceding claims 1 - 12, CHARACTERIZED IN THAT said dielectric is not removed from said sheet after said polarizing.
Claim 16
Dependent Claim
18 words
A sheet of material polarized by the method according to any one of preceding claims 1 - 14.
References Cited (Backward Citations)
No citation records indexed.
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