Patents by Inventor Bradley D. Canfield
Bradley D. Canfield has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 10383203Abstract: Technology is described for calibrating a deflected position of a central ray of an x-ray tube to a radiation imager. An x-ray system includes an x-ray tube and a tube control unit (TCU). The x-ray tube includes a cathode that includes an electron emitter configured to emit an electron beam, an anode configured to receive the electron beam and generate x-rays with a central ray from electrons of the electron beam colliding on a focal spot of the anode, and a steering magnetic multipole between the cathode and the anode that is configured to produce a steering magnetic field from a steering signal. At least two poles of the steering magnetic multipole are on opposite sides of the electron beam. The TCU includes at least one steering driver configured to generate the steering signal. The TCU is configured to convert a position correction value to the steering signal.Type: GrantFiled: April 28, 2016Date of Patent: August 13, 2019Assignee: VAREX IMAGING CORPORATIONInventors: Michael Meiler, Bradley D Canfield, Colton B Woodman, Inwoo Yoon
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Patent number: 10383202Abstract: Technology is described for electronically aligning a central ray of an x-ray tube to a radiation detector. In an example, an x-ray system includes an x-ray tube and a tube control unit (TCU). The x-ray tube includes a cathode that includes an electron emitter configured to emit an electron beam, an anode configured to receive the electron beam and generate x-rays with a central ray from electrons of the electron beam colliding on a focal spot of the anode, and a steering magnetic multipole between the cathode and the anode that is configured to produce a steering magnetic field from a steering signal. At least two poles of the steering magnetic multipole are on opposite sides of the electron beam. The TCU includes at least one steering driver configured to generate the steering signal. The TCU is configured to convert an offset value to the steering signal.Type: GrantFiled: April 28, 2016Date of Patent: August 13, 2019Assignee: VAREX IMAGING CORPORATIONInventors: Bradley D Canfield, Michael Meiler, Colton B Woodman, Inwoo Yoon
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Publication number: 20190237286Abstract: An X-ray tube can include: a cathode including an electron emitter that emits an electron beam; an anode configured to receive the emitted electrons of the electron beam; a first magnetic quadrupole between the cathode and the anode; a second magnetic quadrupole between the first magnetic quadrupole and the anode; a magnetic dipole between the cathode and anode; and a power supply system operably coupled with the first magnetic quadrupole, second magnetic quadrupole, and magnetic dipole, the power supply system being configured to: produce a first focusing magnetic quadrupole field at the first magnetic quadrupole; produce a second focusing magnetic quadrupole field at the second magnetic quadrupole; and produce a steering magnetic dipole field at the magnetic dipole configured to deflect the electron beam in order to shift a focal spot of the electron beam on the anode.Type: ApplicationFiled: July 16, 2018Publication date: August 1, 2019Inventors: Bradley D. Canfield, Colton B. Woodman
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Patent number: 10269529Abstract: A method of designing an electron emitter can include: determining a desired cross-sectional profile of an electron emission from an electron emitter and inputting parameters of the electron emitter into a computer; determining a desired temperature profile for the electron emitter that emits the desired cross-sectional profile; and determining desired emitter dimensions for a defined electrical current through the electron emitter that produces the desired temperature profile with the computer based on the input parameters of the electron emitter. The emitter dimensions can include: each rung width dimension; each first gap segment dimension; each second gap segment dimension; and each web dimension. The emitter can include: a plurality of elongate rungs connected together in a planar pattern; a plurality of corners; a first gap between adjacent non-connected elongate rungs; a second gap between adjacent non-connected elongate rungs; and one or more cutouts between a corner apex and corner nadir.Type: GrantFiled: May 22, 2017Date of Patent: April 23, 2019Assignee: Varex Imaging CorporationInventors: Bradley D. Canfield, Colton B. Woodman
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Patent number: 10181389Abstract: An X-ray tube can include: a cathode including an electron emitter that emits an electron beam; an anode configured to receive the electron beam; a first magnetic quadrupole between the cathode and the anode and having a first yoke with four first pole projections extending from the first yoke and oriented toward a central axis of the first yoke and each of the four first pole projections having a first quadrupole electromagnetic coil; a second magnetic quadrupole between the first magnetic quadrupole and the anode and having a second yoke with four second pole projections extending from the second yoke and oriented toward a central axis of the second yoke and each of the four second pole projections having a second quadrupole electromagnetic coil; and at least one steering coil collocated with a quadrupole on a pole projection.Type: GrantFiled: March 17, 2015Date of Patent: January 15, 2019Assignee: VAREX IMAGING CORPORATIONInventors: Bradley D. Canfield, Colton B. Woodman
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Patent number: 10026586Abstract: An X-ray tube can include: a cathode planar emitter that emits an inhomogeneous electron beam; an anode to receive the electron beam; a first magnetic quadrupole having a first yoke with four evenly distributed first pole projections extending from the first yoke and oriented toward a central axis of the first yoke and each of the four first pole projections having a first quadrupole electromagnetic coil; a second magnetic quadrupole having a second yoke with four evenly distributed second pole projections extending from the second yoke and oriented toward a central axis of the second yoke and each of the four second pole projections having a second quadrupole electromagnetic coil; and at least one coil of a first pair of opposing coils with alternating current offset from the power supply.Type: GrantFiled: March 17, 2015Date of Patent: July 17, 2018Assignee: VAREX IMAGING CORPORATIONInventors: Bradley D. Canfield, Colton B. Woodman
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Patent number: 10008359Abstract: An X-ray tube can include: a cathode including an electron emitter; an anode configured to receive the emitted electrons; a first magnetic quadrupole between the cathode and the anode and having a first quadrupole yoke with four first quadrupole pole projections extending from the first quadrupole yoke and oriented toward a central axis of the first quadrupole yoke and each of the four first quadrupole pole projections having a first quadrupole electromagnetic coil; a second magnetic quadrupole between the first magnetic quadruple and the anode and having a second quadrupole yoke with four second quadrupole pole projections extending from the second quadrupole yoke and oriented toward a central axis of the second quadrupole yoke and each of the four second quadrupole pole projections having a second quadrupole electromagnetic coil; and a magnetic dipole between the cathode and anode and having a dipole yoke with four dipole electromagnetic coils.Type: GrantFiled: March 9, 2015Date of Patent: June 26, 2018Assignee: VAREX IMAGING CORPORATIONInventors: Bradley D. Canfield, Colton B. Woodman
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Patent number: 9916961Abstract: An X-ray tube comprising: a cathode including an emitter; an anode; a first magnetic quadrupole formed on a first yoke and having a magnetic quadrupole gradient for focusing an electron beam in a first direction and defocusing the beam in a second direction; a second magnetic quadrupole formed on a second yoke and having a magnetic quadrupole gradient for focusing the electron beam in the second direction and defocusing the electron beam in the first direction; wherein a combination of the first and second magnetic quadrupoles provides a net focusing effect in both first and second directions of a focal spot of the electron beam; and a pair of opposing quadrupole electromagnetic coils having alternating current offset being configured to deflect the electron beam in order to shift the focal spot of the electron beam on a target.Type: GrantFiled: March 17, 2015Date of Patent: March 13, 2018Assignee: VAREX IMAGING CORPORATIONInventor: Bradley D. Canfield
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Publication number: 20170318652Abstract: Technology is described for calibrating a deflected position of a central ray of an x-ray tube to a radiation imager. An x-ray system includes an x-ray tube and a tube control unit (TCU). The x-ray tube includes a cathode that includes an electron emitter configured to emit an electron beam, an anode configured to receive the electron beam and generate x-rays with a central ray from electrons of the electron beam colliding on a focal spot of the anode, and a steering magnetic multipole between the cathode and the anode that is configured to produce a steering magnetic field from a steering signal. At least two poles of the steering magnetic multipole are on opposite sides of the electron beam. The TCU includes at least one steering driver configured to generate the steering signal. The TCU is configured to convert a position correction value to the steering signal.Type: ApplicationFiled: April 28, 2016Publication date: November 2, 2017Inventors: Michael Meiler, Bradley D. Canfield, Colton B. Woodman, Inwoo Yoon
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Publication number: 20170318651Abstract: Technology is described for electronically aligning a central ray of an x-ray tube to a radiation detector. In an example, an x-ray system includes an x-ray tube and a tube control unit (TCU). The x-ray tube includes a cathode that includes an electron emitter configured to emit an electron beam, an anode configured to receive the electron beam and generate x-rays with a central ray from electrons of the electron beam colliding on a focal spot of the anode, and a steering magnetic multipole between the cathode and the anode that is configured to produce a steering magnetic field from a steering signal. At least two poles of the steering magnetic multipole are on opposite sides of the electron beam. The TCU includes at least one steering driver configured to generate the steering signal. The TCU is configured to convert an offset value to the steering signal.Type: ApplicationFiled: April 28, 2016Publication date: November 2, 2017Inventors: Bradley D. Canfield, Michael Meiler, Colton B. Woodman, Inwoo Yoon
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Patent number: 9779907Abstract: A cathode head can include: a first electron emitter filament having a first size; a first grid pair defining walls of a first filament slot having the first filament therein, each grid member of the first grid pair being electronically coupled to different voltage sources; a second electron emitter filament; and a second grid pair defining walls of a second filament slot having the first electron emitter therein, each grid member of the second grid pair being electronically coupled to different voltage sources. The first grid pair can have a first and second grid members; and the second grid pair can have the second grid member and a third grid member. The first grid member and third grid member are electronically coupled to the same voltage source and the second grid member being electronically coupled to a different voltage source.Type: GrantFiled: January 28, 2015Date of Patent: October 3, 2017Assignee: VAREX IMAGING CORPORATIONInventor: Bradley D. Canfield
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Publication number: 20170256379Abstract: A method of designing an electron emitter can include: determining a desired cross-sectional profile of an electron emission from an electron emitter and inputting parameters of the electron emitter into a computer; determining a desired temperature profile for the electron emitter that emits the desired cross-sectional profile; and determining desired emitter dimensions for a defined electrical current through the electron emitter that produces the desired temperature profile with the computer based on the input parameters of the electron emitter. The emitter dimensions can include: each rung width dimension; each first gap segment dimension; each second gap segment dimension; and each web dimension. The emitter can include: a plurality of elongate rungs connected together in a planar pattern; a plurality of corners; a first gap between adjacent non-connected elongate rungs; a second gap between adjacent non-connected elongate rungs; and one or more cutouts between a corner apex and corner nadir.Type: ApplicationFiled: May 22, 2017Publication date: September 7, 2017Inventors: Bradley D. Canfield, Colton B. Woodman
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Patent number: 9659741Abstract: An electron emitter can include: a plurality of elongate rungs connected together end to end from a first emitter end to a second emitter end in a plane so as to form a planar pattern; a plurality of corners, wherein each elongate rung is connected to another elongate rung through a corner having a corner apex and an opposite corner nadir; a first gap between adjacent non-connected elongate rungs, wherein the first gap extends from the first emitter end to a middle rung; a second gap between adjacent non-connected elongate rungs, wherein the second gap extends from the second emitter end to the middle rung, wherein the first gap does not intersect the second gap; and one or more cutouts at one or more of the corners of the plurality of corners between the corner apex and corner nadir or at the corner nadir.Type: GrantFiled: March 17, 2015Date of Patent: May 23, 2017Assignee: VAREX IMAGING CORPORATIONInventors: Bradley D. Canfield, Colton B. Woodman
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Publication number: 20160268095Abstract: An X-ray tube can include: a cathode including an electron emitter; an anode configured to receive the emitted electrons; a first magnetic quadrupole between the cathode and the anode and having a first quadrupole yoke with four first quadrupole pole projections extending from the first quadrupole yoke and oriented toward a central axis of the first quadrupole yoke and each of the four first quadrupole pole projections having a first quadrupole electromagnetic coil; a second magnetic quadrupole between the first magnetic quadruple and the anode and having a second quadrupole yoke with four second quadrupole pole projections extending from the second quadrupole yoke and oriented toward a central axis of the second quadrupole yoke and each of the four second quadrupole pole projections having a second quadrupole electromagnetic coil; and a magnetic dipole between the cathode and anode and having a dipole yoke with four dipole electromagnetic coils.Type: ApplicationFiled: March 9, 2015Publication date: September 15, 2016Inventors: Bradley D. Canfield, Colton B. Woodman
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Publication number: 20160217965Abstract: A cathode head can include: a first electron emitter filament having a first size; a first grid pair defining walls of a first filament slot having the first filament therein, each grid member of the first grid pair being electronically coupled to different voltage sources; a second electron emitter filament; and a second grid pair defining walls of a second filament slot having the first electron emitter therein, each grid member of the second grid pair being electronically coupled to different voltage sources. The first grid pair can have a first and second grid members; and the second grid pair can have the second grid member and a third grid member. The first grid member and third grid member are electronically coupled to the same voltage source and the second grid member being electronically coupled to a different voltage source.Type: ApplicationFiled: January 28, 2015Publication date: July 28, 2016Inventor: Bradley D. Canfield
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Publication number: 20150187538Abstract: An X-ray tube can include: a cathode including an electron emitter that emits an electron beam; an anode configured to receive the electron beam; a first magnetic quadrupole between the cathode and the anode and having a first yoke with four first pole projections extending from the first yoke and oriented toward a central axis of the first yoke and each of the four first pole projections having a first quadrupole electromagnetic coil; a second magnetic quadrupole between the first magnetic quadrupole and the anode and having a second yoke with four second pole projections extending from the second yoke and oriented toward a central axis of the second yoke and each of the four second pole projections having a second quadrupole electromagnetic coil; and at least one steering coil collocated with a quadrupole on a pole projection.Type: ApplicationFiled: March 17, 2015Publication date: July 2, 2015Inventors: Bradley D. Canfield, Colton B. Woodman
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Publication number: 20150187530Abstract: An electron emitter can include: a plurality of elongate rungs connected together end to end from a first emitter end to a second emitter end in a plane so as to form a planar pattern; a plurality of corners, wherein each elongate rung is connected to another elongate rung through a corner having a corner apex and an opposite corner nadir; a first gap between adjacent non-connected elongate rungs, wherein the first gap extends from the first emitter end to a middle rung; a second gap between adjacent non-connected elongate rungs, wherein the second gap extends from the second emitter end to the middle rung, wherein the first gap does not intersect the second gap; and one or more cutouts at one or more of the corners of the plurality of corners between the corner apex and corner nadir or at the corner nadir.Type: ApplicationFiled: March 17, 2015Publication date: July 2, 2015Inventors: Bradley D. Canfield, Colton B. Woodman
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Publication number: 20150187537Abstract: An X-ray tube comprising: a cathode including an emitter; an anode; a first magnetic quadrupole formed on a first yoke and having a magnetic quadrupole gradient for focusing an electron beam in a first direction and defocusing the beam in a second direction; a second magnetic quadrupole formed on a second yoke and having a magnetic quadrupole gradient for focusing the electron beam in the second direction and defocusing the electron beam in the first direction; wherein a combination of the first and second magnetic quadrupoles provides a net focusing effect in both first and second directions of a focal spot of the electron beam; and a pair of opposing quadrupole electromagnetic coils having alternating current offset being configured to deflect the electron beam in order to shift the focal spot of the electron beam on a target.Type: ApplicationFiled: March 17, 2015Publication date: July 2, 2015Inventor: Bradley D. Canfield
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Publication number: 20150187536Abstract: An X-ray tube can include: a cathode planar emitter that emits an inhomogeneous electron beam; an anode to receive the electron beam; a first magnetic quadrupole having a first yoke with four evenly distributed first pole projections extending from the first yoke and oriented toward a central axis of the first yoke and each of the four first pole projections having a first quadrupole electromagnetic coil; a second magnetic quadrupole having a second yoke with four evenly distributed second pole projections extending from the second yoke and oriented toward a central axis of the second yoke and each of the four second pole projections having a second quadrupole electromagnetic coil; and at least one coil of a first pair of opposing coils with alternating current offset from the power supply.Type: ApplicationFiled: March 17, 2015Publication date: July 2, 2015Inventors: Bradley D. Canfield, Colton B. Woodman
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Patent number: 8451976Abstract: A cathode assembly for an x-ray tube. In one example embodiment, a cathode assembly includes a cathode head, a filament, and first and second focusing tabs. The cathode head defines a recess having first and second open ends, a slot within the recess, and first and second tab stops within the recess. The filament is positioned within the slot. The first focusing tab is positioned in the first open end of the recess abutting the first tab stop. The second focusing tab is positioned in the second open end of the recess abutting the second tab stop.Type: GrantFiled: July 30, 2010Date of Patent: May 28, 2013Assignee: Varian Medical Systems, Inc.Inventor: Bradley D. Canfield