US3742152A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ultrasonic transducers
Assignee: Bpifrance Financement SA
•
Filing: 1971-11-22
•
Granted: 1973-06-26
•
Expires: 1991-11-22
Abstract
Abstract A condenser has two plates capable of vibrating, separated from one another by a thin electrostatically charged dielectric. One of the plates is in contact with the propagation medium of the ultrasonic waves. The two plates are connected to an electrical emitter and/or receiver. The dielectric is permanently charged by prior treatment and an external DC voltage is applied between the plates in reverse sense to that used for charging the dielectric. The two electrostatic fields so created are added in effect.
Inventors
- 👤 J Lewiner
- 👤 P Biquard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:07
CPC Classifications
B; B06; B06B; B06B1/00; B06B1/02; B06B1/0292; G; G01; G01H; G01H11/00; G01H11/06
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
114 words
Ultrasonic transducer of the electrostatic type comprising a condenser with two plates capable of vibrating, a thin electrostatically charged dielectric separating said plates, one of said two plates being placed in contact with the medium in which the ultrasonic waves to be emitted and/or received are propagated and the two plates being connected to an electrical emitter and/or receiver circuit, said dielectric being permanently electrostatically charged by prior treatment and an external DC voltage being applied between said plates in the reverse sense to that which has served for charging the dielectric so that the two electrostatic fields created respectively by the permanent charge of the dielectric and by this external polarization are added.
Claim 2
Dependent Claim
114 words
Ultrasonic transducer of the electrostatic type comprising a condenser with two plates capable of vibrating, a thin electrostatically charged dielectric separating said plates, one of said two plates being placed in contact with the medium in which the ultrasonic waves to be emitted and/or received are propagated and the two plates being connected to an electrical emitter and/or receiver circuit, said dielectric being permanently electrostatically charged by prior treatment and an external DC voltage being applied between said plates in the reverse sense to that which has served for charging the dielectric so that the two electrostatic fields created respectively by the permanent charge of the dielectric and by this external polarization are added.
Claim 3
Dependent Claim
39 words
Ultrasonic transducer according to claim 1, wherein the dielectric is constituted by a solid thin sheet whose thickness is comprised between 3 and 70 microns, which sheet is separated from the facing plates by very thin layers of air.
References Cited (Backward Citations)
GB1147423A
Cited
US3544733A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-25 | 1976-12-25 | 1977-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-25 | 1980-12-25 | 1981-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-25 | 1984-12-25 | 1985-06-26 | $7700.00 | Window Closed / Lapsed |