US3835264A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor transducer comprising an electret
Assignee: Telefonaktiebolaget LM Ericsson AB
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Filing: 1972-09-28
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Granted: 1974-09-10
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Expires: 1992-09-28
Abstract
Abstract The invention relates to an electromechanical transducer comprising an electret one side of which faces a control surface of a semiconductor element and the other side of which faces a a movable control electrode to the semiconductor element. The control surface of the semiconductor element is, according to a first plane geometrical pattern, divided into a surface part responsive to an external field and into another surface part not responsive to an external field while the surface of the movable control electrode is divided into an electrically conducting surface part and into an electrically non-conducting surface part according to a second plane geometrical pattern which substantially corresponds to said first plane geometrical pattern. The control electrode is movable in parallel in relation to the field responsive control surface in order to vary the degree of overlapping between said first and second plane geometrical patterns and thereby generate a change in the inherent resistance of the semiconductor element.
Inventors
- 👤 S Overby
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:56
CPC Classifications
H; H04; H04R; H04R19/00; H04R19/01
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
274 words
An electromechanical transducer comprising: a planar semiconductor element of a first type of semiconductor material having a control surface with a central region and at least two annular regions concentric with said central region, said central region and said annular regions being of a second and complementary type of semiconductor material, first terminal means connected to said central region, second terminal means connected to the annular region most remote from said central region; a planar control electrode disposed parallel to and spaced from said planar semiconductor element, and opposite said control surface, said control electrode comprising at least two concentric annular elements of conductive material, one of said annular elements being contoured to be substantially congruent with the area between the two annular regions of said planar semiconductor element, the other of said annular elements being contoured to be substantially congruent with the area between the central region and the annular region adjacent thereof of said planar semiconductor element, and means for conductively connecting said annular elements; a planar electret disposed between and parallel to said planar semiconductor element and said planar control electrode; and means for relatively moving said planar control electrode and said planar semiconductor element relative to each other in a direction parallel to the plane of said electret to vary the degree of overlap between the regions of the second type of semiconductor material of said planar semiconductor element and the annular elements of said planar control electrode and thereby the capacitance therebetween so that the electric field influencing said control surface varies to vary the inherent resistance between said first and second terminal means of said planar semiconductor element.
Claim 2
Dependent Claim
274 words
An electromechanical transducer comprising: a planar semiconductor element of a first type of semiconductor material having a control surface with a central region and at least two annular regions concentric with said central region, said central region and said annular regions being of a second and complementary type of semiconductor material, first terminal means connected to said central region, second terminal means connected to the annular region most remote from said central region; a planar control electrode disposed parallel to and spaced from said planar semiconductor element, and opposite said control surface, said control electrode comprising at least two concentric annular elements of conductive material, one of said annular elements being contoured to be substantially congruent with the area between the two annular regions of said planar semiconductor element, the other of said annular elements being contoured to be substantially congruent with the area between the central region and the annular region adjacent thereof of said planar semiconductor element, and means for conductively connecting said annular elements; a planar electret disposed between and parallel to said planar semiconductor element and said planar control electrode; and means for relatively moving said planar control electrode and said planar semiconductor element relative to each other in a direction parallel to the plane of said electret to vary the degree of overlap between the regions of the second type of semiconductor material of said planar semiconductor element and the annular elements of said planar control electrode and thereby the capacitance therebetween so that the electric field influencing said control surface varies to vary the inherent resistance between said first and second terminal means of said planar semiconductor element.
Claim 3
Dependent Claim
26 words
The electromechanical transducer of claim 1 wherein said planar control electrode is fixed to the surface of said planar electret remote from said planar semiconductor material.
Claim 4
Dependent Claim
30 words
The electromechanical transducer of claim 1 wherein said planar control electrode and said control surface are separated by said planar electret and an air gap greater than 10 6 meters.
Claim 5
Dependent Claim
41 words
The electromechanical transducer of claim 1 further comprising a diaphragm mechanically connected to said planar semiconductor element so that movement of said diaphragm moves said planar control electrode with respect to said control surface whereby the electromechanical transducer is a microphone.
References Cited (Backward Citations)
US3436492A
Cited
US3356915A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-09 | 1978-03-11 | 1978-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-09 | 1982-03-11 | 1982-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-09 | 1986-03-11 | 1986-09-10 | $7700.00 | Window Closed / Lapsed |