Apparatus and method for detecting and imaging metal
First Claim
1. An imaging metal detector for forming an image of metallic objects in an imaged plane having a longest side, comprising:
- a sensor ring including of a plurality of sensors wrapped around ferrite stubs mounted on a ferrite loop, said loop arranged to substantially surround said imaged plane, each sensor having a central axis directed inwardly from said loop into said imaged plane, each said sensor switchably coupled to a transmitter and to a receiver, each sensor having a diameter at most 1/20 times the longest side of the imaged plane such that transformer coupling effects are dominated by radar diffraction effects;
a transmit mux having an address input and a plurality of outputs, one of said plurality of outputs switchably coupled to each sensor, said transmit mux also coupled to a computer for receiving a transmit address code;
a transmitter coupled to said input of said transmit mux;
a receiver mux having at least one output and a plurality of inputs, one of said plurality of inputs coupled to each sensor, said receiver mux also coupled to said computer for receiving a receive address code;
at least one receiver coupled to said at least one output of said receiver mux, said at least one receiver having an output coupled to said computer;
the computer being programmed to;
provide said transmit address codes to said transmit mux and said receive address codes to said receiver mux; and
receive image data from said at least one receiver and to process that data to generate a metal image indicating the distribution of metal in the imaged plane; and
a monitor coupled to said computer and adapted to display said metal image.
1 Assignment
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Accused Products
Abstract
This invention relates to the field of metal detectors. More particularly, it relates to an imaging metal detector for imaging the metal on subjects passing through a spatial plane providing the specific location, shape and mass of the metal object. This invention makes use of an array of active sensors to transmit and receive magnetic beams and a computer for generating an image of the metal object based upon the data received from the sensors. Through the use of this invention it is possible to scan several subjects at the same time and generate a two- or three-dimensional image of any metal object on the subject as well as precise location, mass and type of metal contained in the object.
47 Citations
36 Claims
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1. An imaging metal detector for forming an image of metallic objects in an imaged plane having a longest side, comprising:
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a sensor ring including of a plurality of sensors wrapped around ferrite stubs mounted on a ferrite loop, said loop arranged to substantially surround said imaged plane, each sensor having a central axis directed inwardly from said loop into said imaged plane, each said sensor switchably coupled to a transmitter and to a receiver, each sensor having a diameter at most 1/20 times the longest side of the imaged plane such that transformer coupling effects are dominated by radar diffraction effects; a transmit mux having an address input and a plurality of outputs, one of said plurality of outputs switchably coupled to each sensor, said transmit mux also coupled to a computer for receiving a transmit address code; a transmitter coupled to said input of said transmit mux; a receiver mux having at least one output and a plurality of inputs, one of said plurality of inputs coupled to each sensor, said receiver mux also coupled to said computer for receiving a receive address code; at least one receiver coupled to said at least one output of said receiver mux, said at least one receiver having an output coupled to said computer; the computer being programmed to; provide said transmit address codes to said transmit mux and said receive address codes to said receiver mux; and receive image data from said at least one receiver and to process that data to generate a metal image indicating the distribution of metal in the imaged plane; and a monitor coupled to said computer and adapted to display said metal image. - View Dependent Claims (2, 3, 4, 5)
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6. A method of detecting the presence and distribution of metal in an imaged plane, comprising:
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providing a sensor ring including a plurality of transceiver sensors each said sensors having a relatively small diameter to maximum side length ratio such that transformer coupling effects are dominated by radar diffraction effects, a transmitter, a receiver, a computer, and a monitor; transmitting a signal from selected ones of said transceiver sensor in turn and receiving corresponding received signals from other selected ones of the transceiver sensors and providing information representative of said received signals to said computer; repeating said transmitting and receiving steps using a different transmitter in said transmitting step until a sufficient number of attenuated signals have been calculated to generate an image of said metal of a resolution not less than 2.0 to 0.25 inches; and generating a metal image of said metal from the information provided to the computer; and displaying said metal image on said monitor. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A method of detecting the presence and distribution of metal in an imaged plane having a maximum side length, comprising:
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providing a sensor loop including a plurality of sensors having a relatively small diameter to maximum side length ratio such that transformer coupling effects are dominated by radar diffraction effects; transmitting a signal from at least one said sensor to at least one other sensor; receiving an attenuated signal at said at least one other sensor and providing information representative of said attenuated signal; repeating said transmitting and receiving steps using a different transmitter in said transmitting step until a sufficient number of attenuated signals have been received to generate an image of said metal of desired detail; and generating a metal image of said metal from the representative information provided. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
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31. An imaging metal detector for forming an image of metallic objects in an imaged plane having a maximum side length, comprising:
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a sensor ring having a plurality of sensors wrapped around ferrite stubs mounted on a ferrite loop, said loop arranged to substantially surround said imaged plane, each sensor having a central axis directed inwardly from said loop into said imaged plane, each sensor having a relatively small diameter to maximum side length ratio such that transformer coupling effects are dominated by radar diffraction effects; a transmitter having an address input and a plurality of outputs, one of said plurality of outputs switchably coupled to each sensor; and a receiver having at least one output and a plurality of inputs, one of said plurality of inputs switchably coupled to each sensor. - View Dependent Claims (32, 33, 34, 35, 36)
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Specification