With Electron Focusing Or Intensity Control Means Patents (Class 378/138)
  • Publication number: 20070258564
    Abstract: In a method for stabilizing the size of a focal spot of an X-ray tube and contrast modulation function of a X-ray tube, the tube has a cathode comprising a concentrator and a heating filament. It has an anode is placed so as to be facing the cathode. With the filament, the cathode produces an electron beam bombarding the focal spot of the anode. A bias voltage is applied between a terminal of the filament and a terminal of the concentrator. The tube has means to measure the size of the focal spot and the function of contrast modulation. It also has means to regulate the size of the focal spot and the contrast modulation function by means of a bias voltage.
    Type: Application
    Filed: April 19, 2007
    Publication date: November 8, 2007
    Inventors: Christelle Gaudin, Philippe Blin
  • Patent number: 7289603
    Abstract: A shield structure and focal spot control assembly is provided for use in connection with an x-ray device that includes an anode and cathode disposed in a vacuum enclosure in a spaced apart arrangement so that a target surface of the anode is positioned to receive electrons emitted by the cathode. The shield structure is configured to be interposed between the anode and the cathode and includes an interior surface that defines an aperture or other opening through which the electrons are passed from the cathode to the target surface of the anode. Additionally, fluid passageways defined in connection with the shield structure enable cooling of the shield structure. Finally, a magnetic device disposed proximate the cathode facilitates control of the location of the focal spot on the target surface of the anode.
    Type: Grant
    Filed: September 3, 2004
    Date of Patent: October 30, 2007
    Assignee: Varian Medical Systems Technologies, Inc.
    Inventors: Gregory C. Andrews, James R. Boye
  • Patent number: 7286644
    Abstract: Systems, methods and devices for implementing automatic control of focal spot Z axis positioning are disclosed for use with an x-ray device having an x-ray tube positioned within a housing and configured for thermal communication with a temperature control system. Control circuitry, and a position sensing device configured to determine the distance between the focal spot and a reference point related to the x-ray device, are coupled with a control module. The position sensing device sends information concerning the relative distance between the focal spot and the reference point to the control module which compares the received information with a predetermined desired distance. If the received information varies by an unacceptably large margin from the desired distance, the control module sends a corresponding signal to the control circuitry which causes the temperature control system to implement an appropriate change to a heat transfer parameter associated with the x-ray device.
    Type: Grant
    Filed: April 28, 2004
    Date of Patent: October 23, 2007
    Assignee: Varian Medical Systems Technologies, Inc.
    Inventor: Gregory C. Andrews
  • Patent number: 7280637
    Abstract: A cathode cup is provided. The cathode cup includes one or more pockets; and one or more filaments associated with the one or more pockets. A same number of pockets as filaments are present. Each pocket is associated with exactly one filament and is configured to have a length that is tailored to a length of the filament. The cathode cup can be used in an X-ray system having an anode and a cathode. A method of electron beam shaping is provided. The method includes the following steps. A computer-simulated model of a cathode cup is created. The model is used to predict focal spot dimensions. The predicted focal spot dimensions are compared to desired focal spot dimensions. The steps of creating, using and comparing are repeated until the predicted focal spot dimensions match the desired focal spot dimensions. A cathode cup is created based on the computer-simulated model.
    Type: Grant
    Filed: March 28, 2006
    Date of Patent: October 9, 2007
    Inventors: Jizhong Chen, Sergio Lemaitre, Brian Douglas Lounsberry
  • Patent number: 7266179
    Abstract: An x-ray radiator with an anode accommodated in a housing such that it can rotate around an axis has a device for determination of the position of an x-ray-emitting focal spot on the anode. To increase the measurement precision, the device includes a collimator aligned on the focal spot.
    Type: Grant
    Filed: May 20, 2005
    Date of Patent: September 4, 2007
    Assignee: Siemens Aktiengesellschaft
    Inventors: Josef Deuringer, Ronald Dittrich, Jörg Freudenberger, Peter Schardt, Jens Uecker
  • Patent number: 7257194
    Abstract: A cathode head is provide that is suitable for use in an x-ray device that includes an anode having a target surface configured and arranged to receive electrons emitted by the cathode head. The cathode head may be constructed of magnetic or non-magnetic material and includes an emitter block carrying a filament that defines a longitudinal axis about which is disposed one or more magnetic coils. The filament is configured and arranged to emit an electron beam that defines a focal spot on the target surface of the anode. The magnetic coil, or coils, disposed about the longitudinal axis defined by the filament generate a magnetic field that enables control of the location of the focal spot on the target surface of the anode.
    Type: Grant
    Filed: February 9, 2004
    Date of Patent: August 14, 2007
    Assignee: Varian Medical Systems Technologies, Inc.
    Inventor: Ricky Smith
  • Patent number: 7212610
    Abstract: An initial image (the image of a slit plate 5 imaged when adjusted to an optimal focal diameter) is stored in a storage section 72 of an X-ray tube adjusting apparatus 7. An acquisition section 74 acquires a test image (the image of the slit plate 5 imaged at the time of adjusting the focal diameter). A presentation section 76 presents the initial image and an image representing the luminance on the initial image (showing a contrast ?a between a slit portion 764a and a residual area portion 766a in the initial image) and the test image and an image representing the luminance on the test image (showing a contrast ?b between a slit portion 764b and a residual area portion 766b in the initial image) simultaneously (in a comparable manner).
    Type: Grant
    Filed: April 4, 2003
    Date of Patent: May 1, 2007
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Masayoshi Ishikawa, Takane Yokoi, Tsutomu Nakamura, Yutaka Ochiai, Kinji Takase
  • Patent number: 7209544
    Abstract: An x-ray tube cathode assembly (28) includes a support arm (36) comprising a first metal. A ceramic insulator (70, 82) has a first metalized surface (72, 86) wherein the metalized surfaces comprise a desired amount of the first metal. A first member of filler material (90) is in contact with the support arm (36) and the first metalized surface (72, 86) of the ceramic insulator (70, 82), the first member of filler material comprising at least a second metal (96a, 96b) wherein a first alloy system (FIG. 5) comprising the first and second metals includes an alloy minimum point percentage composition (P) of the first and second metals having a first alloy system minimum melting point (M) for the alloy minimum point percentage composition that is lower than both of the melting point of the first metal and second metal.
    Type: Grant
    Filed: February 20, 2004
    Date of Patent: April 24, 2007
    Assignee: Koninklijke Philips Electronics, N.V.
    Inventors: Paul Xu, George Awad, Salvatore Perno, Qing K. Lu
  • Patent number: 7206381
    Abstract: An x-ray tube (1) irradiates an electron beam from a cathode (18) to impact a target (36) and emit x-rays. When the x-ray tube (1) operates, the magnet portion (40) is rotated every fixed time period and positioned at a prescribed rotation position. Due to the rotation of the magnet portion (40), the magnetic field formed by the permanent magnets (42) changes and the irradiation position on the target (36) of the electron beam moves. As a result, the electron beam is irradiated at a new position on the target (36) and the same amount of x-ray as the initial performance is generated.
    Type: Grant
    Filed: January 9, 2004
    Date of Patent: April 17, 2007
    Assignees: Toshiba Electron Tube & Devices Co., Ltd., Kabushiki Kaisha Toshiba
    Inventors: Takashi Shimono, Katsunori Shimizu
  • Patent number: 7136455
    Abstract: An electron emitter assembly and a method for adjusting a size of electron beams are provided. The electron emitter assembly includes a laser configured to emit a first light beam. The electron emitter assembly further includes a lens assembly configured to receive the first light beam. The lens assembly is configured to adjust a size of the first light beam between a first predetermined size and a second predetermined size larger than the first predetermined size. The lens assembly emits the first light beam toward a photo-cathode. The photo-cathode is configured to emit a first electron beam having a third predetermined size when the first light beam having the first predetermined size contacts the photo-cathode. The photo-cathode is further configured to emit a second electron beam having a fourth predetermined size when the first light beam having the second predetermined size contacts the photo-cathode.
    Type: Grant
    Filed: November 2, 2004
    Date of Patent: November 14, 2006
    Assignee: General Electric Company
    Inventors: Bruce Matthew Dunham, John Scott Price, Colin R. Wilson
  • Patent number: 7123688
    Abstract: The invention relates to an X-ray tube which includes a device for at least substantially protecting an object to be examined against the incidence of undesirable X-rays (E) which can be produced notably by the decay of a residual or surplus charge present in a high-voltage circuit after an X-ray exposure. To this end there is provided at least one device (341, 342) for deflecting and/or defocusing the electron beam (E) produced by the residual and/or surplus charge in such a manner that at least it is not incident to a significant extent on a region (22) of an anode (2) wherefrom X-rays excited thereby are directed towards an object to be examined.
    Type: Grant
    Filed: May 23, 2003
    Date of Patent: October 17, 2006
    Assignee: Koninklijke Philips Electronics, N.V.
    Inventor: Hans Negle
  • Patent number: 7085354
    Abstract: This invention provides an X-ray tube apparatus which can output X-rays of a dose suitable for radioscopy for a long time. In the apparatus, small focus filaments are provided on respective sides of a large focus filament, such that they have almost equal distances from the center of the large focus filament, and the inclination angles of converging electrodes surrounding the respective small focus filaments with respect to a cathode main body are set to almost equal angles within a range of 20 to 40°.
    Type: Grant
    Filed: September 3, 2004
    Date of Patent: August 1, 2006
    Assignees: Toshiba Electron Tube & Devices Co., Ltd., Kabushiki Kaisha Toshiba
    Inventor: Masaji Kanagami
  • Patent number: 7068749
    Abstract: A stationary CT system comprising at least one annular x ray source assembly comprising a plurality of respective x ray sources spaced along the annular x ray source assembly. Each of the x ray sources comprises a respective stationary x ray target, an electron beam focusing chamber; an x ray channel; an electron beam source disposed in a spaced apart relationship with respect to the respective stationary x ray target; a vacuum chamber disposed in between the electron beam focusing chamber and an insulating chamber where the insulating chamber houses the electron beam source; a radiation window at a pre-defined angular displacement from the respective stationary x ray target and the x ray channel; and a target substrate attached to the respective stationary x ray target.
    Type: Grant
    Filed: May 19, 2003
    Date of Patent: June 27, 2006
    Assignee: General Electric Company
    Inventors: Manohar Gopalaswamy Kollegal, Colin Richard Wilson, Bernard Patrick Bewlay, Mark Gilbert Benz
  • Patent number: 7046767
    Abstract: An object of the invention is to provide a high-resolution transmission type X-ray tube. With an X-ray imaging device according to the present invention, electron lens forming part 100A includes a central axis part 131, which is formed at the interior of a yoke 130, and an outer peripheral part 133, which defines the outer periphery of yoke 130. A part of a front end part 135 of central axis part 131 becomes a magnetic pole 110 that is positioned at the side of an electron gun. A first opening 111 is defined by magnetic pole 110. A part of a front end part 137 of outer peripheral part 133 becomes a magnetic pole 120 that is positioned at the side of a target 300. A second opening 121 is defined by magnetic pole 120. The value of diameter d2 of second opening 121 is greater than the value of diameter d1 of first opening 111.
    Type: Grant
    Filed: May 30, 2002
    Date of Patent: May 16, 2006
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Tomoyuki Okada, Yoshitoshi Ishihara
  • Patent number: 7027559
    Abstract: A method and apparatus for generating x-ray beams are described. In one embodiment, the method includes operating a cathode to operating a cathode to generate an electron beam, directing the electron beam from the cathode through a selectable shaped aperture in an accelerating electrode, and impinging the electron beam at a low angle on an anode surface to form a focal spot on the anode surface.
    Type: Grant
    Filed: December 10, 2003
    Date of Patent: April 11, 2006
    Assignee: General Electric Company
    Inventors: Colin Richard Wilson, Amy Linsebigler Smentkowski, Lembit Salasoo
  • Patent number: 6985557
    Abstract: The present invention provides apparatus and method for providing a stabilized x-ray output from a field emission x-ray apparatus by monitoring the operating current and adjusting the gap between the anode and cathode to stabilize the output.
    Type: Grant
    Filed: March 19, 2003
    Date of Patent: January 10, 2006
    Assignee: Minnesota Medical Physics LLC
    Inventor: Ali Jaafar
  • Patent number: 6968039
    Abstract: A cathode (38) for an imaging tube (33) is provided. The cathode (38) includes an emitter (74) that emits an electron beam (98) to a focal spot (46) on an anode (44). A backing member (76) is electrically disposed on a second side (78) of the emitter (74) and contributes in formation of the electron beam (98). A deflection electrode (82) is electrically disposed between the backing member (76) and the anode (44) and adjusts position of the focal spot (46) on the anode (44). A non-contact x-ray source component position measuring system (32) is also provided. The position measuring system (32) includes an electromagnetic source (18) having an electromagnetic radiation source component (42) and a probe (50) that directs an emission signal (52) at and receives a return signal from the electromagnetic radiation source component (42). A controller (28) generates the emission signal (52) and determines position of the electromagnetic radiation source component (42) in response to the return signal (54).
    Type: Grant
    Filed: August 4, 2003
    Date of Patent: November 22, 2005
    Assignee: GE Medical Systems Global Technology Co., LLC
    Inventors: Sergio Lemaitre, John Scott Price
  • Patent number: 6944268
    Abstract: An X-ray generator comprises a cathode electrode (15), a grid electrode (17) for controlling an electron beam (e) generated by the cathode electrode (15), a focus electrode (18) for focusing the electron beam (e), and an anode target (14) for emitting X rays by the collision of the electron beam (e). A bias voltage (Vb) is impressed between the cathode electrode (15) and the grid electrode (17) from a bias voltage generating section (20). A tube voltage (Vt) is impressed on the anode target (13) from a tube voltage generating section (19). A voltage dividing section (31) divides the tube voltage (Vt) to generate a focus voltage (Vf). The effect of a variation in voltage on the formation of a focal point of the electron beam is suppressed by impressing such a focus voltage (Vf) on the focus electrode (18).
    Type: Grant
    Filed: August 29, 2002
    Date of Patent: September 13, 2005
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Takashi Shimono
  • Patent number: 6885728
    Abstract: A compact X-ray source is disclosed, improving controllability and insulation from unwanted high voltage effects. In one aspect, an active variable conductance device (130, 330) connected in series with the cathode is used in a closed loop, feedback arrangement to control the cathode beam current; the current flowing through the device to the cathode being directly sensed and compared with a desired current level. The result of the comparison is used to control the conductance of the device, thereby directly influencing the cathode current. A second aspect provides an extension of a Faraday cage, whereby the secondary winding of a transformer used to supply power to components within the cage is shielded within a coaxial, tubular member connected to the cage and extending outwardly from it.
    Type: Grant
    Filed: July 23, 2001
    Date of Patent: April 26, 2005
    Assignee: X-Tek Systems Limited
    Inventors: Roger Hadland, Alan Copeland Crawley, Ian George Haig, Paul Justin Keanly
  • Patent number: 6831964
    Abstract: An x-ray radiation source in which a focused electron beam impinges upon a target positioned in front of the focal point of the electron beam and the radiation emitted by the target travels through the aperture of an aperture diaphragm with the aperture disposed at the focal point of the electron beam.
    Type: Grant
    Filed: August 16, 2001
    Date of Patent: December 14, 2004
    Assignee: Quanta Vision, Inc.
    Inventors: Pavel Ivanovich Lazarev, Oleg Valentinovich Komardin
  • Patent number: 6816573
    Abstract: The voltage applied to a first grid electrode 71 of an X-ray tube 11 by a grid voltage control section 110 is controlled with reference to a predetermined negative voltage from a negative voltage generating section 112 when an object 5 to be inspected does not exist in an imaging area (irradiation area of an X-ray from an X-ray source 1) so that the pulse outputted from a pulse generator 105 is in its OFF state, and is controlled with reference to a reference positive voltage from a reference voltage generating section 115 when the object 5 to be inspected exists in the imaging area in the X-ray image intensifier 2 (irradiation area of the X-ray from the X-ray source 1) so that the pulse outputted from the pulse generator 105 is in its ON state, whereby both of the cutoff voltage and grid operating voltage are applied in a stable state.
    Type: Grant
    Filed: August 31, 2001
    Date of Patent: November 9, 2004
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Masayuki Hirano, Hiroki Kawakami
  • Publication number: 20040218723
    Abstract: An object of the invention is to provide a high-resolution transmission type X-ray tube. With an X-ray imaging device according to the present invention, electron lens forming part 100A includes a central axis part 131, which is formed at the interior of a yoke 130, and an outer peripheral part 133, which defines the outer periphery of yoke 130. A part of a front end part 135 of central axis part 131 becomes a magnetic pole 110 that is positioned at the side of an electron gun. A first opening 111 is defined by magnetic pole 110. A part of a front end part 137 of outer peripheral part 133 becomes a magnetic pole 120 that is positioned at the side of a target 300. A second opening 121 is defined by magnetic pole 120. The value of diameter d2 of second opening 121 is greater than the value of diameter d1 of first opening 111.
    Type: Application
    Filed: June 15, 2004
    Publication date: November 4, 2004
    Inventors: Tomoyuki Okada, Yoshitoshi Ishihara
  • Patent number: 6810110
    Abstract: An x-ray tube having sensors, magnets, and/or active compensation means operatively coupled thereto or integrated therein for aligning its electron beam with an external magnetic field. Permanent magnets positioned behind the anode and cathode respectively or electromagnets are used to produce a strong, properly aligned internal magnetic field. The x-ray tube is thus less sensitive to other magnetic fields that are not parallel to the anode-cathode axis. The x-ray tube can be mounted in a manner that it can pivot, allowing it to move and align itself. The x-ray tube can also be mounted such that a torque can be sensed. This sensed mechanical force is then used as an input to determine current applied to electromagnetic coils arranged to oppose a transverse magnetic field.
    Type: Grant
    Filed: November 27, 2002
    Date of Patent: October 26, 2004
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Norbert J. Pelc, Zhifei Wen
  • Patent number: 6807248
    Abstract: A multisource type X-ray CT apparatus including a fixed sensor array, a fixed vacuum chamber, and an X-ray generation unit. The X-ray generation unit includes a cathode and an anode which are fixed in the vacuum chamber so as to surround the sensor array, a gate array including a plurality of grid electrodes which are densely fixed between the cathode and anode and which include holes for passing the electron beams, a power source which applies a bias voltage to the grid electrodes of the gate array, and a controller which controls the power supply operation from the power source so as to select the grid electrode suitable for image pickup from the gate array in accordance with an image pickup portion of the subject and to release the bias voltage applied to the selected grid electrode.
    Type: Grant
    Filed: November 25, 2002
    Date of Patent: October 19, 2004
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Kazumasa Mihara, Susumu Urano, Keiichi Hori, Shin Ogura
  • Patent number: 6801599
    Abstract: A cathode assembly (18, 216) for an x-ray tube (1) includes a base (60, 220) to which a filament (66) is mounted. A pair of deflectors (82, 84) are carried by the base for deflecting a beam (A) of electrons generated by the filament. Metal tubes (130, 132) are mounted in bores (106) of insulator blocks (104, 105). Metalized ends (150) of the insulator blocks are brazed into bores (122, 222, 224) in the base. A rod (130, 132) attached to the deflector is slid into the tube and the deflector's position and alignment are gauged and accurately set. The rod and tube are crimped to set the deflector position then welded.
    Type: Grant
    Filed: February 19, 2002
    Date of Patent: October 5, 2004
    Assignee: Koninklijke Philips Electronics, N.V.
    Inventors: Allan D. Kautz, Salvatore G. Perno
  • Patent number: 6778633
    Abstract: An X-ray generator comprises an evacuated and sealed X-ray tube, containing an electron gun and an X-ray target. An electron beam is produced by the electron gun in which the cathode is at negative high voltage, the electron gun consisting of a filament just inside the aperture of a Wehnelt grid which is biased negatively with respect to the filament. Two sets of beam deflection coils, are employed in two planes, mounted between the anode of the electron gun and the focussing lens to center the beam. Between the focussing lens and the target is an air-cored quadripole magnet which acts as a stigmator in that it turns the circular cross-section of the beam into an elongated one. This quadripole can be rotated about the tube axis so as to adjust the orientation of the line focus. The beam can be moved about on the target surface by controlling the currents in the four coils of the quadripole.
    Type: Grant
    Filed: January 28, 2002
    Date of Patent: August 17, 2004
    Assignee: BEDE Scientific Instruments Limited
    Inventors: Neil Loxley, Mark Taylor, John Leonard Wall, Graham Vincent Fraser
  • Patent number: 6775354
    Abstract: An X-ray tube subsystem including an X-ray tube and a grid voltage supply that reduces high voltage breakdown events. The X-ray tube provides a grid bias connection, a filament bias connection, and an anode bias connection. The grid voltage supply is connected to the grid bias connection and is adapted to produce an ion collection voltage substantially less than an electron beam focus voltage.
    Type: Grant
    Filed: September 20, 2000
    Date of Patent: August 10, 2004
    Assignee: GE Medical Systems Global Technology Company, LLC
    Inventor: Richard Michael Roffers
  • Publication number: 20040120462
    Abstract: A method and apparatus for generating x-ray beams are described.
    Type: Application
    Filed: December 10, 2003
    Publication date: June 24, 2004
    Applicant: General Electric Company
    Inventors: Colin Richard Wilson, Amy Linsebigler Smentkowski, Lembit Salasoo
  • Publication number: 20040114722
    Abstract: An X-ray generator comprises a cathode electrode (15), a grid electrode (17) for controlling an electron beam (e) generated by the cathode electrode (15), a focus electrode (18) for focusing the electron beam (e), and an anode target (14) for emitting X rays by the collision of the electron beam (e). A bias voltage (Vb) is impressed between the cathode electrode (15) and the grid electrode (17) from a bias voltage generating section (20). A tube voltage (Vt) is impressed on the anode target (13) from a tube voltage generating section (19). A voltage dividing section (31) divides the tube voltage (Vt) to generate a focus voltage (Vf). The effect of a variation in voltage on the formation of a focal point of the electron beam is suppressed by impressing such a focus voltage (Vf) on the focus electrode (18).
    Type: Application
    Filed: September 4, 2003
    Publication date: June 17, 2004
    Inventor: Takashi Shimono
  • Patent number: 6735282
    Abstract: An X-ray tube 1 includes spacer 8 which is cylindrical so it does not block electrons 80 directed from a grid electrode 72 toward a focusing electrode 25, and which has one end 8b fixed to the grid electrode 72 and the other end 8c abutting against the focusing electrode 25. The distance between the grid electrode 72 and focusing electrode 25 is set to a predetermined distance by the spacer 8.
    Type: Grant
    Filed: January 6, 2003
    Date of Patent: May 11, 2004
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Tadaoki Matsushita, Tutomu Inazuru
  • Publication number: 20040081283
    Abstract: Certain embodiments include a computed tomography system including an electron beam source for generating an electron beam, an ion clearing electrode for removing ions from the electron beam using electrical fields, an ion trap for allowing ions to accumulate in a downstream region of the electron beam so that the ions do not drift upstream, a beam tube for housing the ion trap, and a grounded tube conforming an effective electrical radius of the beam tube to the physical radius of the grounded tube to reduce spherical aberrations in the electron beam. Certain embodiments include a method for correcting spherical aberration in an electron beam including producing an electron beam, removing ions from the electron beam using electrical fields, and allowing ions to accumulate in a downstream portion of the electron beam using an ion trap and a grounded tube. The grounded tube adjusts a range of spherical aberration correction of the ion trap.
    Type: Application
    Filed: October 23, 2002
    Publication date: April 29, 2004
    Inventor: Roy Edward Rand
  • Patent number: 6727658
    Abstract: An electron beam generating apparatus for generating a plurality of electron beams, which includes: a plurality of cathodes for generating thermoelectrons; a cathode power supply unit for applying negative voltage to the cathodes so as to emit the thermoelectrons from the cathodes; a plurality of grids, which correspond to the plurality of cathodes respectively, for focusing the thermoelectrons emitted from each of the plurality of cathodes, and shaping the plurality of electron beams; and an insulator on which the plurality of cathodes and the plurality of grids are attached.
    Type: Grant
    Filed: March 7, 2003
    Date of Patent: April 27, 2004
    Assignee: Advantest Corporation
    Inventors: Yoshihisa Ooae, Yoichi Shimizu, Takamasa Satoh, Takeshi Haraguchi
  • Publication number: 20040022361
    Abstract: A method and apparatus for an x-ray tube having an emitter and a differentially biased emitter-cup cathode configured to provide an electron beam of substantially greater perveance and beam compression ratio than otherwise obtainable with conventional cathode designs is disclosed. The method and apparatus include a cathode assembly opposing an anode and spaced apart therefrom. The cathode is maintained during operation of the x-ray tube at a negative potential with respect to the anode. The cathode assembly includes an emitter for emitting an electron beam to a focal spot on the anode during operation of the x-ray tube and a cathode front member having an aperture defined by the cathode front member on a first side of the emitter. A backing is disposed on a second side of the emitter and is operably connected to the cathode front member via a backing insulator. The cathode further includes a means for applying a differential bias in the cathode assembly to variably change the focal spot size.
    Type: Application
    Filed: July 30, 2002
    Publication date: February 5, 2004
    Inventor: Sergio Lemaitre
  • Patent number: 6687333
    Abstract: A system for generating tunable pulsed monochromatic X-rays includes a tabletop laser emitting a light beam that is counter-propagated against an electron beam produced by a linear accelerator. X-ray photon pulses are generated by inverse Compton scattering that occurs as a consequence of the “collision” that occurs between the electron beam and IR photons generated by the laser. The system uses a novel pulse structure comprising, for example, a single micropulse. In this way, pulses of very short X-rays are generated that are controllable on an individual basis with respect to their frequency, energy level, “direction,” and duration.
    Type: Grant
    Filed: September 28, 2001
    Date of Patent: February 3, 2004
    Assignee: Vanderbilt University
    Inventors: Frank E. Carroll, Robert H. Traeger, Marcus H. Mendenhall, James W. Waters, Glenn Edwards, Charles A. Brau
  • Patent number: 6670625
    Abstract: A method and apparatus are disclosed for reducing variation in a spot size of an electron beam at a target due to multipole aberrations in an electron beam tomography (EBT) scanner. A magnitude of a DC voltage applied to a positive ion electrode (PIE) within the EBT scanner is adjusted and an orientation of a non-circular aperture of the PIE is aligned with respect to the electron beam. A profile of the spot size is monitored while adjusting the magnitude of the DC voltage and while aligning the orientation of the non-circular aperture of the PIE until the variation in the spot size is sufficiently reduced.
    Type: Grant
    Filed: June 18, 2002
    Date of Patent: December 30, 2003
    Assignee: GE Medical Systems Global Technology Company, LLC
    Inventors: Roy E. Rand, Khem Garewal
  • Patent number: 6665371
    Abstract: A measurement apparatus has a first detector for measuring an intensity such that a sheet-shaped beam of synchrotron radiation is integrated over the entire range of the beam in the thickness direction thereof; a second detector for measuring the intensity of the beam at two points where positions along the direction are different; and a calculating device for calculating the magnitude of the beam in the direction on the basis of the detections by the first and second detectors.
    Type: Grant
    Filed: May 31, 2000
    Date of Patent: December 16, 2003
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hideyuki Chinju, Yutaka Watanabe, Akira Miyake, Nobuaki Ogushi
  • Patent number: 6661876
    Abstract: A mobile, miniature x-ray source includes a low-power consumption cathode element for mobility, and an anode optic creating a field free region to prolong the life of the cathode element. An electric field is applied to an anode and a cathode that are disposed on opposite sides of an evacuated tube. The anode includes a target material to produce x-rays in response to impact of electrons. The cathode includes a cathode element to produce electrons that are accelerated towards the anode in response to the electric field between the anode and the cathode. The tube can have a length less than approximately 3 inches, and a diameter or width less than approximately 1 inch. The cathode element can include a low-power consumption cathode element with a low power consumption less than approximately 1 watt. The power source can include a battery power source. A field-free region can be positioned at the anode to resist positive ion acceleration back towards the cathode element.
    Type: Grant
    Filed: July 29, 2002
    Date of Patent: December 9, 2003
    Assignee: Moxtek, Inc.
    Inventors: Clark Turner, Arturo Reyes, Hans K. Pew, Mark W. Lund, Michael Lines, Paul Moody, Sergei Voronov
  • Patent number: 6658085
    Abstract: A medical examination installation has an MR system and an X-ray system that has an X-ray radiator with an X-ray tube and a solid-state X-ray image detector for producing X-ray exposures. The X-ray system has sensors for the acquisition of the location dependency of the stray field of the MR system in the three spatial axes, and coils for compensation of the stray field, and a computer that uses the output signal of the sensors to calculate a current for the coils which cause the stray field to be reduced in the region of the electron beams of the X-ray tube.
    Type: Grant
    Filed: August 6, 2001
    Date of Patent: December 2, 2003
    Assignee: Siemens Aktiengesellschaft
    Inventor: Hartmut Sklebitz
  • Publication number: 20030099327
    Abstract: An X-ray tube 1 includes spacer 8 which is cylindrical so it does not block electrons 80 directed from a grid electrode 72 toward a focusing electrode 25, and which has one end 8b fixed to the grid electrode 72 and the other end 8c abutting against the focusing electrode 25. The distance between the grid electrode 72 and focusing electrode 25 is set to a predetermined distance by the spacer 8.
    Type: Application
    Filed: January 6, 2003
    Publication date: May 29, 2003
    Applicant: Hamamatsu Photonics K.K.
    Inventors: Tadaoki Matsushita, Tutomu Inazuru
  • Patent number: 6570958
    Abstract: The invention relates to an X-ray system/generator in which after the end of an X-ray exposure the grid of th X-ray tube is blocke4d as long as the X-ray exposure is read out from a detector (or as long a film or a PCR is removed from the X-rays). After read out, the grid is released so that the system capacitance may be discharged via the X-ray tube. Thereby over-exposure due to energy stored in the sytem- and cable capacities is avoided (which is a problem especially for thin objects), and the system may be switched from a tube with grid to a tube without grid without problems.
    Type: Grant
    Filed: July 18, 2002
    Date of Patent: May 27, 2003
    Assignee: Koninklijke Philips Electronics N.V.
    Inventor: Joachim Brendler
  • Publication number: 20030086533
    Abstract: Thin film thickness measurement accuracy in x-ray reflectometry systems can be enhanced by minimizing scattering and beam spreading effects. An oblong x-ray beam can be produced by shaping the electron beam in an x-ray microfocus tube, or by creating a target with a metal strip having the desired beam cross section. The elongation allows the beam direction dimension to be substantially reduced, without causing overheating of the target. By blocking portions of the x-ray beam focused on the thin film and generating reflectivity curves in increments, the effects of scattering can be minimized.
    Type: Application
    Filed: November 7, 2001
    Publication date: May 8, 2003
    Inventors: Gary Janik, Jeffrey Moore
  • Publication number: 20030043966
    Abstract: An X-ray emission device and method for a radiology apparatus comprises a cathode and a rotating anode, the anode being provided with a roughly cylindrical surface. The device forms a beam of electrons that bombards a portion of the roughly cylindrical surface of the anode that constitutes the focal point of emission of the X-rays. The position of the focal point of the anode relative to a reference position is dynamically controlled.
    Type: Application
    Filed: August 14, 2002
    Publication date: March 6, 2003
    Inventors: Philippe Blin, Xavier Le Pennec, Frederic Dahan
  • Patent number: 6526122
    Abstract: An X-ray tube 1 includes spacer 8 which is cylindrical so it does not block electrons 80 directed from a grid electrode 72 toward a focusing electrode 25, and which has one end 8b fixed to the grid electrode 72 and the other end 8c abutting against the focusing electrode 25. The distance between the grid electrode 72 and focusing electrode 25 is set to a predetermined distance by the spacer 8.
    Type: Grant
    Filed: January 8, 2001
    Date of Patent: February 25, 2003
    Assignee: Hamamatsu Photonics K.K.
    Inventors: Tadaoki Matsushita, Tutomu Inazuru
  • Publication number: 20030002628
    Abstract: A field emission array electron source (12) is used to generate an electron beam in a x-ray generating device (10). The field emission array operates at room temperature and has a life expectancy in excess of 12,000 hours and provides a robust, efficient emitter for generating an electron beam in a x-ray generating device cathode (10).
    Type: Application
    Filed: June 27, 2001
    Publication date: January 2, 2003
    Inventors: Colin R. Wilson, Bruce M. Dunham, John Scott Price
  • Patent number: 6480572
    Abstract: A dual filament x-ray tube assembly (16) includes an evacuated envelope (52) having an anode (54) disposed at a first end of the evacuated envelope (52) and a cathode assembly (62) disposed at a second end of the evacuated envelope (52). The cathode assembly includes a variable-length filament assembly (72, 74; 100) which emits electron beams for impingement on the anode (54) at focal spots having varying lengths. The cathode assembly (62) further includes a cathode cup (64, 66, 68; 110, 112) which is subdivided into a plurality of electrically insulated deflection electrodes (64, 66, 68; 110, 112). A filament select circuit (80) selectively and individually heats a portion of the variable-length filament assembly (72, 74). Electron beams emitted from the filament assembly (72, 74) are electrostatically focused and controlled by applying potentials to different ones of the deflection electrodes (64, 66, 68; 110, 112).
    Type: Grant
    Filed: March 9, 2001
    Date of Patent: November 12, 2002
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Jason P. Harris, Salvatore Perno
  • Patent number: 6459766
    Abstract: A photon generator includes an electron gun for emitting an electron beam, a laser for emitting a laser beam, and an interaction ring wherein the laser beam repetitively collides with the electron beam for emitting a high energy photon beam therefrom in the exemplary form of x-rays. The interaction ring is a closed loop, sized and configured for circulating the electron beam with a period substantially equal to the period of the laser beam pulses for effecting repetitive collisions.
    Type: Grant
    Filed: April 17, 2000
    Date of Patent: October 1, 2002
    Assignee: Brookhaven Science Associates, LLC
    Inventor: Triveni Srinivasan-Rao
  • Publication number: 20020122531
    Abstract: The invention provides a scheme in accordance with which a linear accelerator may be operated in two or more resonance (or standing wave) modes to produce charged particle beams over a wide range of output energies so that diagnostic imaging and therapeutic treatment may be performed on a patient using the same device. In this way, the patient may be diagnosed and treated, and the results of the treatment may be verified and documented, without moving the patient. This feature reduces alignment problems that otherwise might arise from movement of the patient between diagnostic and therapeutic exposure machines. In addition, this feature reduces the overall treatment time, thereby reducing patient discomfort.
    Type: Application
    Filed: March 5, 2001
    Publication date: September 5, 2002
    Applicant: SIEMENS MEDICAL SYSTEMS, INC.
    Inventor: Kenneth Whitham
  • Patent number: 6438207
    Abstract: An x-ray tube having a cathode and an anode disposed within an evacuated housing is disclosed. The cathode is spaced apart from a target surface formed on the anode and the anode is placed at a positive voltage relative to the cathode so that electrons emitted from the cathode accelerate towards and strike the target surface at a focal spot. The resulting collision produces x-rays. The cathode assembly includes a cathode support base, upon which is mounted a filament for emitting electrons. A first focusing mechanism focuses the emitted electrons into an electron beam. In illustrated embodiments, a pair of deflector plates are also supported upon the cathode support base. Voltage potentials are applied to the deflector plates so as to create a deflection region which alters the trajectory of the electron beam and thereby reposition the focal spot on the anode target.
    Type: Grant
    Filed: September 14, 1999
    Date of Patent: August 20, 2002
    Assignee: Varian Medical Systems, Inc.
    Inventors: Charles Lynn Chidester, Mark Alan Heber
  • Patent number: 6433498
    Abstract: A mini-blind actuator has a motor and a housing that holds the motor and a dc battery. The rotor of the motor is coupled to the baton of the mini-blind for rotating the baton and thereby opening or closing the slats of the mini-blind. Alternatively, the rotor is coupled to the tilt rod of the blind to rotate the tilt rod and thereby open or close the slats of the mini-blind. A control signal generator generates a control signal for completing the electrical circuit between the battery and the motor. The control signal can be generated in response to a predetermined amount of daylight or in response to a user-generated remote command signal. The actuator can be used to rotate the slats of horizontal or vertical blinds, or the sections of a pleated shade. Or, the actuator can be used to rotate the hollow rotatable tube of a roll-up shade.
    Type: Grant
    Filed: April 14, 2000
    Date of Patent: August 13, 2002
    Assignee: Harmonic Design, Inc.
    Inventors: Douglas R. Domel, Winston G. Walker
  • Patent number: 6426996
    Abstract: In order to produce X-ray radiographic images consistently with high quality regardless of the magnitude of body thickness or motion of an examined site, a radiographic irradiation time threshold readout section 4 reads a radiographic irradiation time threshold Th corresponding to an examined site input by an operator out of a radiographic irradiation time threshold table 3, and an irradiation condition determining section 5 and radiographic irradiation time comparing section 6 select a larger radiographic focus size as the radiographic focus size for an X-ray tube 1 if Th<radiographic irradiation time Ts, and select a smaller radiographic focus size if Th radiographic irradiation time Ts.
    Type: Grant
    Filed: October 11, 2000
    Date of Patent: July 30, 2002
    Assignee: GE Medical Systems Global Technology Company, LLC
    Inventors: Yoshio Moribe, Akira Izuhara