Patent US3858307A successfully refreshed from Google Patents.
US3858307A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrostatic transducer
Assignee: Panasonic Holdings Corp
•
Filing: 1973-03-05
•
Granted: 1975-01-07
•
Expires: 1993-03-05
Abstract
Abstract A method of permanently polarizing a vibratile film of an electrostatic transducer wherein an unpolarized film having a vibratile electrode on one side is disposed in a housing opposite a stationary electrode. A saturation polarizing voltage is applied across the vibratile and stationary electrodes to cause a ferroelectric phenomenon due to absorbed surface charges to occur in the vibratile film thereby permanently polarizing the vibratile film.
Inventors
- 👤 Hisashi Yoshimura
- 👤 Nobuhisa Atoji
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:33
CPC Classifications
H; H04; H04R; H04R19/00; H04R19/01; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49005
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
164 words
A method of polarizing a vibratile film of an electrostatic transducer, the vibratile film being permanently polarized after assembly into a housing of the transducer, comprising the steps of: preparing an unpolarized vibratile film of a plastic material capable of readily undergoing permanent polarization, depositing a vibratile electrode of metal on one surface of said vibratile film, said vibratile electrode being vibratile with said vibratile film, assembling into a housing of the transducer said vibratile film on which said vibratile electrode is deposited, disposing in said housing a stationary electrode of metal opposite to said vibratile film and spaced therefrom so as to define an air layer, and then applying across said vibratile and stationary electrodes a saturation polarizing voltage without heating said vibratile film, said saturation polarizing voltage causing ferroelectric phenomena in said vibratile film due to absorbed surface changes to maximize the residual charge on said vibratile film after the removal of said saturation polarizing voltage, thereby polarizing permanently said vibratile film.
Claim 2
Independent Claim
164 words
A method of polarizing a vibratile film of an electrostatic transducer, the vibratile film being permanently polarized after assembly into a housing of the transducer, comprising the steps of: preparing an unpolarized vibratile film of a plastic material capable of readily undergoing permanent polarization, depositing a vibratile electrode of metal on one surface of said vibratile film, said vibratile electrode being vibratile with said vibratile film, assembling into a housing of the transducer said vibratile film on which said vibratile electrode is deposited, disposing in said housing a stationary electrode of metal opposite to said vibratile film and spaced therefrom so as to define an air layer, and then applying across said vibratile and stationary electrodes a saturation polarizing voltage without heating said vibratile film, said saturation polarizing voltage causing ferroelectric phenomena in said vibratile film due to absorbed surface changes to maximize the residual charge on said vibratile film after the removal of said saturation polarizing voltage, thereby polarizing permanently said vibratile film.
Claim 3
Dependent Claim
26 words
A method according to claim 1, wherein the plastic material is selected from a group consisting of polyethylene terephthalate, a polyimide resin and fluorine compound resin.
Claim 4
Dependent Claim
16 words
A method according to claim 1, wherein the saturation polarizing voltage is applied for several seconds.
References Cited (Backward Citations)
US3705312A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-01-06 | 1978-07-08 | 1979-01-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-06 | 1982-07-08 | 1983-01-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-06 | 1986-07-08 | 1987-01-07 | $7700.00 | Window Closed / Lapsed |