Patent US5227667A successfully refreshed from Google Patents.
US5227667A
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Microwave proximity switch
Assignee: Omron Corp
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Filing: 1991-12-16
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Granted: 1993-07-13
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Expires: 2011-12-16
Abstract
Abstract A microwave proximity detector includes a microwave oscillator circuit having a dielectric resonator, or having a micro strip line as an inductor thereof so as to sense a change in an oscillation frequency or output from the oscillator circuit caused by a variation in an impedance of a circuit including the dielectric resonator, or of the micro strip line, due to a loss which takes place in a leakage magnetic field from the micro strip line when an object approaches the leakage magnetic field, thereby detecting an object in the neighborhood of the switch.
Inventors
- 👤 Takaharu Takinami
- 👤 Koichi Tsujino
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:58
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/94; H03K17/945; H03K17/95; G; G01; G01V; G01V3/00; G01V3/08; G01V3/10; G01V3/101; G01V3/102
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
82 words
A microwave proximity detector, comprising: a microwave oscillation circuit comprising an inductive element and a capacitive element tuned to resonate at a microwave frequency, said inductive element comprising a microstrip line terminated with a capacitor and which generates a leakage magnetic field; means for sensing a change in the microwave oscillation frequency of the microwave oscillation circuit when an object approaches the leakage magnetic field of the microstrip line; and output means for outputting a signal indicative of said change in frequency.
Claim 2
Dependent Claim
82 words
A microwave proximity detector, comprising: a microwave oscillation circuit comprising an inductive element and a capacitive element tuned to resonate at a microwave frequency, said inductive element comprising a microstrip line terminated with a capacitor and which generates a leakage magnetic field; means for sensing a change in the microwave oscillation frequency of the microwave oscillation circuit when an object approaches the leakage magnetic field of the microstrip line; and output means for outputting a signal indicative of said change in frequency.
Claim 3
Dependent Claim
25 words
A microwave proximity detector as claimed in claim 1, wherein the change in oscillation frequency includes an interruption of oscillation of the microwave oscillation circuit.
Claim 4
Dependent Claim
20 words
A microwave proximity detector as claimed in claim 1, further comprising a dielectric resonator magnetically coupled with said microstrip line.
Claim 5
Dependent Claim
23 words
A microwave proximity detector as claimed in claim 3, wherein said dielectric resonator is mounted adjacent said microstrip line on a dielectric substrate.
Claim 6
Dependent Claim
32 words
A microwave proximity detector as claimed in claim 4, wherein the dielectric resonator generates a leakage magnetic field due to transverse mode resonance caused by the magnetic coupling with the microstrip line.
Claim 7
Dependent Claim
38 words
A microwave proximity detector as claimed in claim 1, wherein the microstrip line has a length less than one quarter of the wavelength of the microwave oscillation frequency of the microwave oscillation circuit when no object is present.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-07-12 | 1997-01-11 | 1997-07-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-07-12 | 2001-01-11 | 2001-07-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-07-12 | 2005-01-11 | 2005-07-13 | $7700.00 | Window Closed / Lapsed |