Systems, methods, and apparatus for detection of metal objects in a predetermined space
US9726518B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 8, 2013 |
| Grant date | Aug 8, 2017 |
| Priority date | — |
| Expiry date | Sep 1, 2034 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY04S30/14
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
This disclosure provides systems, methods and apparatus for detecting foreign objects. In one aspect an apparatus for detecting a presence of an object is provided. The apparatus includes a resonant circuit having a resonant frequency. The resonant circuit includes a sense circuit including an electrically conductive structure. The apparatus further includes a coupling circuit coupled to the sense circuit. The apparatus further includes a detection circuit coupled to the sense circuit via the coupling circuit. The detection circuit is configured to detect the presence of the object in response to detecting a difference between a measured characteristic that depends on a frequency at which the resonant circuit is resonating and a corresponding characteristic that depends on the resonant frequency of the resonant circuit. The coupling circuit is configured to reduce a variation of the resonant frequency by the detection circuit in the absence of the object.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.