SYSTEMS, METHODS, AND APPARATUS FOR DETECTION OF METAL OBJECTS IN A PREDETERMINED SPACE
First Claim
1. An apparatus for detecting a presence of an object, the apparatus comprising:
- a resonant circuit having a resonant frequency, the resonant circuit comprising a sense circuit comprising an electrically conductive structure;
a coupling circuit coupled to the sense circuit; and
a detection circuit coupled to the sense circuit via the coupling circuit, the detection circuit 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, and the coupling circuit configured to reduce a variation of the resonant frequency by the detection circuit in the absence of the object.
2 Assignments
0 Petitions
Accused Products
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.
-
Citations
48 Claims
-
1. An apparatus for detecting a presence of an object, the apparatus comprising:
-
a resonant circuit having a resonant frequency, the resonant circuit comprising a sense circuit comprising an electrically conductive structure; a coupling circuit coupled to the sense circuit; and a detection circuit coupled to the sense circuit via the coupling circuit, the detection circuit 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, and the coupling circuit configured to reduce a variation of the resonant frequency by the detection circuit in the absence of the object. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
-
-
23. A method for detecting a presence of an object, the method comprising:
-
applying a signal to a resonant circuit having a resonant frequency, the resonant circuit comprising a sense circuit comprising an electrically conductive structure, a coupling circuit is coupled to the sense circuit; and detecting the presence of the object via a detection circuit coupled to the sense circuit via the coupling circuit 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 configured to reduce a variation of the resonant frequency by the detection circuit in the absence of the object. - View Dependent Claims (24, 25, 26)
-
-
27. An apparatus for detecting a presence of an object, the apparatus comprising:
-
means for resonating at a resonant frequency; means for detecting the presence of the object in response to detecting a difference between a measured characteristic that depends on a frequency at which the resonating means is resonating and a corresponding characteristic that depends on the resonant frequency of the resonating means; and means for reducing variation of the resonant frequency by the detection means in the absence of the object. - View Dependent Claims (28, 29, 30)
-
-
31. An apparatus for detecting a presence of an object, the apparatus comprising:
-
a first sense circuit comprising a first electrically conductive structure, at least the first sense circuit forming a first resonant circuit having a first resonant frequency; a second sense circuit comprising a second electrically conductive structure, at least the second sense circuit forming a second resonant circuit having a second resonant frequency, the second resonant frequency different than the first resonant frequency; and a detection circuit coupled to the first and second sense circuits, the detection circuit configured detect the presence of the object in response to detecting; a difference between a first measured characteristic that depends on a frequency at which the first resonant circuit is resonating and a first corresponding characteristic that depends on the first resonant frequency, or a difference between a second measured characteristic that depends on a frequency at which the second resonant circuit is resonating and a second corresponding characteristic that depends on the second resonant frequency. - View Dependent Claims (32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42)
-
-
43. A method for detecting a presence of an object, the method comprising:
-
applying a first signal to a first sense circuit comprising a first electrically conductive structure, at least the first sense circuit forming a first resonant circuit having a first resonant frequency; applying a second signal to a second sense circuit comprising a second electrically conductive structure, at least the second sense circuit forming a second resonant circuit having a second resonant frequency, the second resonant frequency different than the first resonant frequency; and detecting the presence of the object via a detection circuit in response to detecting; a difference between a first measured characteristic that depends on a frequency at which the first resonant circuit is resonating and a first corresponding characteristic that depends on the first resonant frequency, or a difference between a second measured characteristic that depends on a frequency at which the second resonant circuit is resonating and a second corresponding characteristic that depends on the second resonant frequency. - View Dependent Claims (44, 45)
-
-
46. An apparatus for detecting a presence of an object, the apparatus comprising:
-
a first means for resonating at a first resonant frequency; a second means for resonating at a second resonant frequency, the second resonant frequency different than the first resonant frequency; and means for detecting the presence of the object in response to detecting; a difference between a first measured characteristic that depends on a frequency at which the first resonating means is resonating and a first corresponding characteristic that depends on the first resonant frequency, or a difference between a second measured characteristic that depends on a frequency at which the second resonating means is resonating and a second corresponding characteristic that depends on the second resonant frequency. - View Dependent Claims (47, 48)
-
Specification