Patent US4356049A successfully refreshed from Google Patents.
US4356049A
Expired / Lapsed
US
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Method of manufacturing an electret device
Assignee: Toshiba Corp
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Filing: 1981-03-10
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Granted: 1982-10-26
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Expires: 2001-03-10
Abstract
Abstract A method of manufacturing an electret device which comprises the step of causing a pressure deformation jig whose surface is provided with numerous minute convex and concave regions to abut against the surface of a raw dielectric material for an electret and later be removed therefrom, thereby forming minute stretched and contracted region on the surface of said dielectric material.
Inventors
- 👤 Sakae Tamura
- 👤 Hiromi Yoshida
- 👤 Takehiko Kotoh
- 👤 Masami Kobayashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:15
CPC Classifications
H; H01; H01G; H01G7/00; H01G7/02; H01G7/021; H01G7/023; Y; Y10; Y10T; Y10T156/00; Y10T156/10; Y10T156/1002; Y10T156/1039; Y10T156/1041; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49226; Y10T428/00; Y10T428/24; Y10T428/24479
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
100 words
A method of manufacturing an electret device, which comprises the steps of: laminating a conductive member with a dielectric polymer film; and later causing a pressure deformation jig whose surface is provided with plural projections defining numerous minute convex and concave regions to abut against the surface of said dielectric polymer film with a pressure of 100 to 750 kg/cm 2 to thereby plastically deform the dielectric film in forming minute stretched and compressed concave and convex regions, said projections having walls inclined at an angle a, wherein 95°<a<120°; and removing said jig from the surface of the dielectric film.
Claim 2
Independent Claim
100 words
A method of manufacturing an electret device, which comprises the steps of: laminating a conductive member with a dielectric polymer film; and later causing a pressure deformation jig whose surface is provided with plural projections defining numerous minute convex and concave regions to abut against the surface of said dielectric polymer film with a pressure of 100 to 750 kg/cm 2 to thereby plastically deform the dielectric film in forming minute stretched and compressed concave and convex regions, said projections having walls inclined at an angle a, wherein 95°<a<120°; and removing said jig from the surface of the dielectric film.
Claim 3
Dependent Claim
43 words
The method according to claim 1, wherein: said conductive member is laminated with said dielectric polymer film having a thickness of 50-150 microns, and said jig is provided with a pressure deformation surface having 2000-7500 minute convex and concave regions per square centimeter.
Claim 4
Dependent Claim
44 words
The method according to claim 1, further comprising: irradiating positively charged particles on the surface of the dielectric polymer film which is provided with the minute stretched and compressed regions and is negatively charged beforehand, thereby causing said surface to be eventually positively charged.
Claim 5
Dependent Claim
16 words
The method according to claim 1 wherein said dielectric polymer film comprises: a tetrafluorethylene-hexafluoropropylene copolymer film.
Claim 6
Dependent Claim
23 words
The method according to claim 1, wherein said dielectric polymer film comprises: a polymer selected from the group consisting of polytetrafluorethylene and polyperfluoroalkoxide.
Claim 7
Dependent Claim
41 words
The method according to claim 1, wherein said dielectric polymer film comprises: a polymer selected from the group consisting of polyethylene terephthalate, polyimide, polyvinyl chloride and polyvinylidine fluoride laminated with a polymer selected from the group consisting of tetrafluoroethylene-hexafluoropropylene and polytetrafluoroethylene.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-10-25 | 1986-04-26 | 1986-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-25 | 1990-04-26 | 1990-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-25 | 1994-04-26 | 1994-10-26 | $7700.00 | Window Closed / Lapsed |