With Movable Electrode Patents (Class 378/135)
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Patent number: 11665806Abstract: The present disclosure relates to a downhole tool that includes a first photon flux detector disposed at a first radial position about a longitudinal axis of the downhole tool that measures a first signal indicative of an x-ray flux of the x-ray photons. The downhole tool also includes a second photon flux detector disposed at a second radial position about the longitudinal axis of the downhole tool that measures a second signal indicative of the x-ray flux of the x-ray photons. Further, the downhole tool includes a controller communicatively coupled to the first photon flux detector and the second photon flux detector that determines a condition associated with the electron beam based at least in part on a relative x-ray flux from the first photon flux detector and the second photon flux detector.Type: GrantFiled: December 20, 2019Date of Patent: May 30, 2023Assignee: SCHLUMBERGER TECHNOLOGY CORPORATIONInventors: Jani Reijonen, Vincent Ernst
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Patent number: 11443913Abstract: An X-ray radiator and an X-ray assembly are disclosed. The X-ray radiator according to an embodiment has an evacuated X-ray tube housing, mounted to be rotatable about a rotation axis, the X-ray tube housing including an anode and an electron source. The anode is arranged within the X-ray tube housing non-rotatably relative to the X-ray tube housing and is configured to generate X-ray radiation via electrons impacting upon a focal spot of the anode, the electron source being mounted substantially stationary within the X-ray tube housing relative to the rotation axis. The electron source has a main emitter and at least one subsidiary emitter for emitting electrons. The electron emission of the main emitter and/or of the at least one subsidiary emitter is controllable such that a spatial movement of the focal spot due to a movement of the electron source is reduced.Type: GrantFiled: May 26, 2021Date of Patent: September 13, 2022Assignee: Siemens Healthcare GmbHInventor: Anja Fritzler
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Patent number: 11315750Abstract: An anode target comprises: a plurality of target structures, used for receiving an electron beam emitted by a cathode to generate a ray, the plurality of target structures being of three-dimensional structures having bevels; a copper cooling body, used for bearing the target structures and comprising an oxygen-free copper cooling body; a cooling oil tube, used for cooling the anode target; and a shielding layer, used for achieving a shielding effect and comprising a tungsten shielding layer. The anode target, the ray light source, the computed tomography scanning device, and the imaging method in the present application are able to enable all target spots on the anode target to be distributed on a straight line, imaging quality of a ray system is improved, and complexity of an imaging system is reduced.Type: GrantFiled: June 1, 2018Date of Patent: April 26, 2022Assignees: Nuctech Company Limited, TSINGHUA UNIVERSITYInventors: Chengjun Tan, Wenhui Huang, Chuanxiang Tang, Qingxiu Jin, Dongsheng Zhang, Qun Luo, Donghai Liu, Luming Zhang, Peidong Wu
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Patent number: 8983037Abstract: An X-ray tube with a rotatable anode for generating X-rays and an X-ray apparatus and a method for balancing the rotary anode of an X-ray tube include balancing of the rotary anode applicable to an anode mounted inside an X-ray tube. The rotatable anode includes an anode disc fixedly mounted to a rotatably driven support body, which is rotatably supported by a bearing arrangement. The anode includes at least one balancing cavity to adjust the center of gravity of the anode. The balancing cavity is partly filled with a balancing material being solid at operating temperature of the X-ray tube and liquid at a higher temperature. The balancing method includes determining an imbalance of the anode; heating liquefy balancing material; dislocating the balancing material inside the balancing cavity to compensate the imbalance; and cooling to solidify the balancing material.Type: GrantFiled: September 8, 2010Date of Patent: March 17, 2015Assignee: Koninklijke Philips N.V.Inventors: Rolf Karl Otto Behling, Christoph Bathe
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Publication number: 20140314208Abstract: The present invention relates to balancing of a rotating anode. In order to provide a facilitated balancing of a rotating anode allowing balancing also in a state where the rotating anode disk is mounted inside an X-ray tube, an adjustment device (54) for balancing a rotating anode disk in an operating state is provided. The adjustment device comprises at least a first plurality (72) of balancing elements (74), wherein the balancing elements are attached to at least one circular ring structure (76), and wherein the balancing elements each comprise a balancing portion (80) mounted to the circular ring structure via a bending portion (82).Type: ApplicationFiled: November 28, 2012Publication date: October 23, 2014Inventor: Marcus Walter Foellmer
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Publication number: 20140270084Abstract: An x-ray transmission device includes two surfaces in frictional contact within a low fluid pressure environment provided by a housing substantially opaque to x-rays. Materials of the two surfaces are selected such that the frictional contact generates relative charging between the surfaces. The housing includes a window substantially transparent to x-rays, and an electron target, for example a metal, is on an interior surface of the window. The electron target faces the surface that is relatively negatively charged, such that electrons accelerated from that surface, or accelerated due to the negative charge of that surface strike the electron target to generate x-rays, which may be transmitted through the window.Type: ApplicationFiled: March 15, 2013Publication date: September 18, 2014Inventor: Carlos G. Camara
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Publication number: 20140126698Abstract: The present invention relates to the generation of multiple energy X-ray radiation. In order to provide multiple energy X-ray radiation with increased switching frequencies, a rotating anode (10) for an X-ray tube is provided with an anode body (12), a circular focal track (14), and an axis of rotation (16). The focal track is provided on the anode body and comprises at least one first focal track portion (18) and at least one second focal track portion (20). Transition portions (22) are provided between the at least one first and second focal track portions. The at least one first focal track portion is inclined towards an X-ray radiation projection direction (24) of the X-ray tube.Type: ApplicationFiled: June 4, 2012Publication date: May 8, 2014Applicant: KONINKLIJKE PHILIPS N.V.Inventor: Rolf Karl Otto Behling
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Publication number: 20130070903Abstract: The invention relates to an X-ray tube (12) with a rotatable anode (30) for generating X-rays and an X-ray apparatus (10) with such an X-ray tube and a method for balancing a rotary anode of an X-ray tube. In order to provide a balancing of the rotary anode applicable to an anode mounted inside an X-ray tube, an X-ray tube with a rotatable anode (30) for generating X-rays is provided, wherein the anode comprises an anode disc (32) fixedly mounted to a rotatably driven support body (44, 46), which support body is rotatably supported by a bearing arrangement (34). The anode comprises at least one balancing cavity (70) to adjust the center of gravity of the anode, which balancing cavity (70) is partly filled with a balancing material (72) being solid at operating temperature of the X-ray tube and liquid at a higher temperature.Type: ApplicationFiled: September 8, 2010Publication date: March 21, 2013Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V.Inventors: Rolf Karl Otto Behling, Christoph Bathe
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Patent number: 8126117Abstract: A multi-beam x-ray system includes an x-ray source which emits x-rays and a housing with a first part and a second part. The second part is moveable relative to the first part and includes a plurality of optics of different performance characteristics. Each optic, through the movement of the second part relative to the first part, is positioned to a working position so that the optic receives the x-rays from the x-ray source and directs the x-rays with the desired performance attributes to a desired location.Type: GrantFiled: February 3, 2010Date of Patent: February 28, 2012Assignee: Rigaku Innovative Technologies, Inc.Inventors: Boris Verman, Michael Young, Licai Jiang
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Publication number: 20110188636Abstract: A multi-beam x-ray system includes an x-ray source which emits x-rays and a housing with a first part and a second part. The second part is moveable relative to the first part and includes a plurality of optics of different performance characteristics. Each optic, through the movement of the second part relative to the first part, is positioned to a working position so that the optic receives the x-rays from the x-ray source and directs the x-rays with the desired performance attributes to a desired location.Type: ApplicationFiled: February 3, 2010Publication date: August 4, 2011Applicant: Rigaku Innovative Technologies, Inc.Inventors: Boris Verman, Michael Young, Licai Jiang
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Patent number: 7965818Abstract: Disclosed herein is an x-ray field emission apparatus, system and method, the apparatus having a hollow probe held at vacuum; a cathode enclosed within the probe, the cathode producing an electron stream when connected to a high negative potential; an anode enclosed within the probe and separated from the cathode by a gap, said the providing a target for the electron stream; and a shield assembly comprising a hollow shield electrode positioned within the probe and about the cathode.Type: GrantFiled: December 17, 2008Date of Patent: June 21, 2011Assignee: Minnesota Medical Physics LLCInventors: Ali Jaafar, Victor I. Chornenky
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Patent number: 7835501Abstract: According to an exemplary embodiment an x-ray tube comprises a cathode, rotable disc anode, and a focal spot modulating unit, wherein the cathode is adapted to emit an electron beam, and wherein the focal spot modulating unit is adapted to modulate the electron beam in such a way that an intensity distribution of the electron beam on a focal spot on the anode is asymmetric such that the intensity of the electron beam on the focal spot is higher at the front of the focal spot with respect to the rotation direction.Type: GrantFiled: October 9, 2007Date of Patent: November 16, 2010Assignee: Koninklijke Philips Electronics N.V.Inventors: Stefan Hauttmann, Rainer Pietig, Jeroen Jan Lambertus Horikx
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Patent number: 7778391Abstract: A field emission cathode has a field emitter and an extraction grid, and the field emitter and the extraction grid can be moved relative to one another. Such a field emission cathode is highly durable and exhibits a longer lifespan. An x-ray tube has a field emission cathode composed of a field emitter and an extraction grid that can be moved relative to one another. Such an x-ray tube is highly durable and exhibits a longer lifespan.Type: GrantFiled: June 4, 2009Date of Patent: August 17, 2010Assignee: Siemens AktiengesellschaftInventors: Jens Fuerst, Stefan Popescu, Georg Wittmann
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Patent number: 7759663Abstract: A radiation source having self-shading electrodes is disclosed. Debris originating from the electrodes is reduced. The path from the electrodes to the EUV optics is blocked by part of the electrodes themselves (termed self-shading). This may significantly reduce the amount of electrode-generated debris.Type: GrantFiled: December 6, 2006Date of Patent: July 20, 2010Assignee: ASML Netherlands B.V.Inventors: Maarten Marinus Johannes Wilhelmus Van Herpen, Wouter Anthon Soer
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Publication number: 20100008470Abstract: According to an exemplary embodiment an x-ray tube comprises a cathode, rotable disc anode, and a focal spot modulating unit, wherein the cathode is adapted to emit an electron beam, and wherein the focal spot modulating unit is adapted to modulate the electron beam in such a way that an intensity distribution of the electron beam on a focal spot on the anode is asymmetric such that the intensity of the electron beam on the focal spot is higher at the front of the focal spot with respect to the rotation direction.Type: ApplicationFiled: October 9, 2007Publication date: January 14, 2010Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V.Inventors: Stefan Hauttmann, Rainer Pietig, Jeroen Jan Lambertus Horikx
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Patent number: 7518134Abstract: A radiation source is disclosed that includes an anode and a cathode that are configured and arranged to create a discharge in a substance in a discharge space between the anode and the cathode and to form a plasma so as to generate electromagnetic radiation, the anode and the cathode being rotatably mounted around an axis of rotation, the cathode being arranged to hold a liquid metal. The radiation source further includes an activation source arranged to direct an energy beam onto the liquid metal so as to vaporize part of the liquid metal and a liquid metal provider arranged to supply additional liquid metal so as to compensate for the vaporized part of the liquid metal.Type: GrantFiled: December 6, 2006Date of Patent: April 14, 2009Assignee: ASML Netherlands B.V.Inventors: Vladimir Vitalevitch Ivanov, Vadim Yevgenyevich Banine, Konstantin Nikolaevitch Koshelev, Vladimir Mihailovitch Krivtsun
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Patent number: 7479646Abstract: An extreme ultraviolet source with wide-angle vapor containment and reflux is described. In the optical output directions radiating from the source plasma there is an array of tapered buffer gas heat pipes, with wick structures in the walls. In directions toward the insulators separating the discharge electrodes there are disc-shaped buffered gas heat pipes that prevent metal vapor from condensing on these insulators. A preferred electrode configuration has three electrode discs that operate in the star pinch mode. Another electrode configuration comprises two electrode discs and supports a pseudospark discharge. The star pinch variant of this source has efficiently generated 13.5 nm radiation with lithium vapor and helium buffer gas.Type: GrantFiled: December 11, 2006Date of Patent: January 20, 2009Assignee: PLEX LLCInventor: Malcolm W. McGeoch
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Publication number: 20080277599Abstract: A device constructed to generate radiation includes a liquid bath, and a pair of electrodes. At least a part of one of the electrodes is formed by a cable part moveable with respect to the liquid bath. The device also includes an actuator arranged to move the cable part from a liquid-adhering position to an ignition position, and an ignition source configured to trigger a discharge produced radiating plasma from the liquid adherent to the cable part, when the cable part is in the ignition position, by a discharge between the electrodes. The liquid-adhering position is a position for adhering a liquid from the bath to the part of the electrode.Type: ApplicationFiled: May 9, 2007Publication date: November 13, 2008Applicant: ASML NETHERLANDS B.V.Inventors: Wouter Anthon Soer, Maarten Marinus Johannes Wilhelmus Van Herpen
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Patent number: 7035377Abstract: To solve a difference in an emitting directions by switching the types of X-rays. An X-ray generator comprises: an anticathode unit 3 in which a plurality of anticathode parts 2 (2A and 2B) that emit X-rays by collision of thermoelectrons are disposed side by side; a cathode 4 for releasing the thermoelectrons toward the anticathode parts 2A and 2B on the anticathode unit 3; and a cathode moving mechanism that switches the anticathode parts, against which the thermoelectrons from the cathode 4 collide by moving the cathode 4 along the diction of aligning anticathode parts 2A and 2B.Type: GrantFiled: January 28, 2005Date of Patent: April 25, 2006Assignee: Bruker AXS K.K.Inventor: Chuji Katayama
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Patent number: 6275567Abstract: The invention relates to a rotary-anode X-ray tube which includes a sleeve bearing which is composed of an inner and an outer bearing segment, the outer bearing segment including intermediate pieces and a holder on which the intermediate pieces bear so as to transfer the bearing forces. Suitable shaping of the external surfaces of the intermediate pieces and the inner surfaces of the holder which contact these outer surfaces ensures that the intermediate pieces become aligned with the bearing surfaces on the inner bearing segment. This strongly reduces the complexity of manufacture.Type: GrantFiled: September 10, 1998Date of Patent: August 14, 2001Assignee: U.S. Philips CorporationInventor: Ulrich Hove
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Patent number: 6164820Abstract: X-ray examination installation, particularly for computed tomography for mammography, has a rotating bulb x-ray tube with a cathode-side drive as its x-ray source, with the tube being oriented so that its anode faces toward the exposure side or actuation side of the system. The distance between the x-ray beam exit window of the tube, and the exposure side or actuation side of the system, thus is made small.Type: GrantFiled: May 6, 1999Date of Patent: December 26, 2000Assignee: Siemens AktiengesellschaftInventors: Erich Hell, Detlef Mattern, Peter Schardt
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Patent number: 5581591Abstract: An x-ray tube includes an anode (A) and an envelope (C). A cathode assembly (B) which is supported in the envelope on a bearing (32) emits a beam of electrons which strike the anode forming a focal spot. The anode rotates (D) relative to the cathode such that focal spot follows a generally annular path along a beveled track (14). If the axis of the anode and the cathode assembly are screwed or offset, the focal spot path is not circular and wobbles. An adjustment assembly (60) adjusts the relative positions of the anode, the cathode and the envelope to adjust the anode and cathode assembly axes. The adjustment assembly also includes one or more electrodes (102, 108) which adjust the position of the focal spot. An angular position encoder (106) identifies an angular orientation of the anode. A control circuit (110) applies an electrostatic potential to the electrodes to move the focal spot such that it stays on a constant plane of the leveled anode surface.Type: GrantFiled: November 28, 1994Date of Patent: December 3, 1996Assignee: Picker International, Inc.Inventors: James E. Burke, Lester Miller, Salvatore Perno, Norman E. Wandke
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Patent number: 5526396Abstract: An X-ray tube, comprising a cathode arrangement which includes an electron emitter connected to supporting pins which in turn are connected to the cathode structure via a respective fixing element. Particularly simple adjustment of the position of the filament is achieved in that the fixing elements are connected to the cathode structure in a first region and to the associated supporting pin in a second region which is remote from the first region, and that the fixing elements comprise a deformation zone between the first and the second region, deformation of said zone enabling adjustment of the position of the electron emitter relative to the cathode structure.Type: GrantFiled: July 8, 1994Date of Patent: June 11, 1996Assignee: U.S. Philips CorporationInventor: Heinz-Jurgen Jacob
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Patent number: 5475729Abstract: A toroidal x-ray tube (I) is supported and selectively positioned by a gantry (II). The x-ray tube includes a toroidal housing (A) in which a rotor (30) is rotatably mounted. One or more cathodes (C) are mounted on the rotor for generating an electron beam which strikes an anode (B) to generate a beam of x-rays which passes through a window (20) and strikes an annular ring of detectors (160). A grid bias control circuit (100) selectively applies a continuously adjustable bias to a grid (36) for regulating the electron current, hence the intensity of the x-ray beam. A scintillating optical fiber (110) extends around the exterior of the window. The scintillation optical fiber includes fluorescent dopant (116) which convert a very small fraction of the x-rays into optical light which is transmitted along the fibers to an opto-electric transducer (118). The opto-electric transducer is connected with the grid bias control circuit.Type: GrantFiled: April 8, 1994Date of Patent: December 12, 1995Assignee: Picker International, Inc.Inventors: Rodney A. Mattson, Theodore A. Resnick
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Patent number: 5438605Abstract: A toroidal x-ray tube housing (A) is composed of multiple sections which are clamped together and sealed by elastomeric gaskets (128). An annular anode (B) is mounted to the housing with coolant passages (12, 14) extending thereadjacent. A rotor (30) is rotated within the toroidal housing by a motor (60). At least one cathode assembly (C) is mounted to the rotor adjacent the anode. The rotor is supported by magnetic bearings (40) whose active coils are separated from the vacuum region by a magnetic window (48). Alternately, a series of vanes (136, 138) are provided to divide the vacuum chamber into a high vacuum region (132) adjacent the cathode and anode and a low vacuum region (134) adjacent the motor (60) and bearings (40, 150, 152) for rotatably supporting the rotor within the housing. An active vacuum pump, preferably a ion pump (112) and a getter (114) are hermetically sealed into the vacuum region for maintaining the vacuum.Type: GrantFiled: December 6, 1993Date of Patent: August 1, 1995Assignee: Picker International, Inc.Inventors: James E. Burke, Lester Miller
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Patent number: 5384820Abstract: A housing (A) which has a radiation transmissive window (52) defines a coolant oil reservoir (50). An x-ray tube (B) is mounted within the cooling oil reservoir. The x-ray tube includes a vacuum envelope having a cylindrical wall portion (10). A cylindrical sleeve (70) is mounted around the cylindrical wall (10) defining a narrow coolant oil gap (100). In one embodiment, a motor (16) rotates the vacuum envelope and an anode (14). The cylindrical sleeve (70) and the cylindrical rotating vacuum envelope wall portion (10) with the cooling oil film in the gap define a journal bearing which minimizes the horsepower requirements of the motor (16). A diaphragm (102) is expanded to reduce the thickness of the coolant oil film in the journal bearing gap. The cylindrical sleeve (70) is preferably constructed of a radiation blocking material such that the body of coolant oil (50) is shielded from x-rays (42).Type: GrantFiled: July 16, 1993Date of Patent: January 24, 1995Assignee: Picker International, Inc.Inventor: James E. Burke
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Patent number: 5291538Abstract: An evacuated envelope (C) which is connected with an anode (A), has a cathode assembly (B) rotatably mounted inside. Magnets (44, 46) hold the cathode assembly stationary as the anode and envelope rotate. A ferrite core transformer (60) includes a ferrite core primary (66) stationarily mounted exterior to the envelope. A secondary (64) is mounted to the cathode assembly interior to the envelope. The secondary winding includes a ferrite core (70), a portion of which is surrounded by a ceramic, dielectric bobbin (76). The bobbin includes walls or ridges (78) which define a spiral groove (80) therearound in which an uninsulated electric wire (82) is received. The uninsulated electric wire is connected with a cathode filament (52). The primary winding has a ferrite core (90) that has about five times the cross section as the secondary ferrite core to compensate for a low, about 20%, coupling efficiency between the primary and secondary windings.Type: GrantFiled: June 3, 1993Date of Patent: March 1, 1994Assignee: Picker International. Inc.Inventors: James E. Burke, Lester Miller, Salvatore G. Perno
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Patent number: 5274690Abstract: An x-ray tube includes an anode (A) and envelope (C) which are rotated (D) at a relatively high rate of speed. A cathode assembly (B) is supported in the envelope on a bearing (32). In order to hold the cathode assembly stationary, a magnetic susceptor (40) having periodic projections (44) is disposed with the projections closely adjacent an outer peripheral wall (20) of the envelope. A plurality of permanent magnets (52) are mounted on a stationary keeper (50), each magnet adjacent one of the susceptor projections. Preferably, the magnets have alternating polarity such that magnetic flux lines (54) flow between adjacent magnets through the magnetic susceptor.Type: GrantFiled: December 9, 1992Date of Patent: December 28, 1993Assignee: Picker International, Inc.Inventors: James E. Burke, Lester Miller, Salvatore G. Perno
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Patent number: 5268955Abstract: A toroidal x-ray tube housing (A) has an evacuated interior. An annular anode (B) is connected with the housing closely adjacent the window such that a cooling fluid passage (12) is defined in intimate thermal communication with the anode. A cathode assembly (32) is mounted within the evacuated housing or an annular ring (30) that rotates an electron beam (22) around the large diameter annular anode. In the embodiment of FIGS. 1 and 2, the annular ring is magnetically levitated (40) and rotated by a motor (50). A collimator (62) and filter (64) are rotated with the cathode assembly closely adjacent an electron emitter or cathode cup (32) such that the generated x-rays are collimated and filtered within the x-ray tube. Preferably, a plurality of cathode cups (120) are provided, whose operation is selected by a series of magnetically controlled switches (76). The cathode cup is insulated (106) from the annular ring and isolated by a transformer (104, 112) from the filament current control switches.Type: GrantFiled: April 8, 1992Date of Patent: December 7, 1993Assignee: Picker International, Inc.Inventors: James E. Burke, Lester Miller
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Patent number: 5241577Abstract: An anode (A) closes one end of an evacuated envelope (C) and a cathode end plate (22) closes the other. A cathode assembly (B) is mounted on a bearing (40) in the evacuated envelope such that the envelope and cathode can undergo relative rotation. A motor (38) rotates the anode and envelope while a pair of magnets (44, 46) hold the cathode assembly stationary. Bearing (40) functions as a current path from a current source (72) to the primary windings of a transformer (58). Another bearing (94) provides a return current path from the transformer to the current source. The secondary windings of the transformer are connected with a cathode filament (52). The transformer enables a relatively low ampere current to pass through the bearings to limit cathodic damage to the bearings, yet provides sufficient amperage to the filament to cause thermionic emission.Type: GrantFiled: January 6, 1992Date of Patent: August 31, 1993Assignee: Picker International, Inc.Inventors: James E. Burke, Salvatore G. Perno
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Patent number: 5200985Abstract: A cathode assembly (B) including cathode filaments (52, 54) remain stationary in the interior of a rotating evacuated envelope (C). The cathode filaments generate a beam of electrons (12) which strike an annular anode surface (10) that rotates with the envelope to generate a beam of x-rays (14). Electrical power from an AC electrical source (62) is conveyed across a circularly cylindrical peripheral side wall (20) of the envelope by pairs of concentric capacitive ring members (64, 70); (66, 72). One of the cathode filaments is selected either with (i) reed switches (82, 84), (ii) by bringing a selected one of the filaments and the capacitor rings into resonance at the frequency of the AC electrical source with a switch (86) and inductance (88a, 88b), or (iii) with a third pair of annular capacitive members (100, 102).Type: GrantFiled: January 6, 1992Date of Patent: April 6, 1993Assignee: Picker International, Inc.Inventor: Lester Miller
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Patent number: 5179583Abstract: An X-ray tube for a CT apparatus comprises a ring-shaped vacuum tube containing a fixed cathode having a thermion emitting surface, a ring-shaped fixed anode, and a ring-shaped rotatable cathode interposed between the fixed cathode and fixed anode. The rotatable cathode defines a thermion receiving surface opposed to the thermion emitting surface, and a thermion emitting portion opposed to the fixed anode. Thermions are emitted from the thermion emitting portion toward the fixed anode while the rotatable cathode is suspended to non-contact state and rotated at high speed. With the thermions being accelerated and colliding on the fixed anode, an X-ray is generated toward the center of the vacuum tube. The X-ray generating position moves at high speed along a circumferential surface of the fixed anode with rotation of the rotatable cathode.Type: GrantFiled: April 30, 1991Date of Patent: January 12, 1993Assignee: Shimadzu CorporationInventor: Shiro Oikawa
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Patent number: 4679219Abstract: An X-ray tube is disclosed, which comprises an evacuated envelope having a cathode assembly and an anode assembly provided at the opposite ends of the envelope such that they face each other. The cathode assembly includes a spiral filament for generating an electron beam with a beam axis. One of the terminal ends of the spiral filament is located in the proximity of the center thereof. The anode assembly includes a conical target with a tip corresponding to the beam axis, for radiating X-rays in all directions. When a current flows with the filament of the X-ray tube, the temperature of the filament is reduced for a central portion thereof to reduce the density of electrons emitted from the central portion, thus preventing overheating of the tip of the conical target.Type: GrantFiled: June 12, 1985Date of Patent: July 7, 1987Assignee: Kabushiki Kaisha ToshibaInventor: Hidemichi Ozaki
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Patent number: 4675891Abstract: The invention relates to an X-ray apparatus with focus position control, the focus being formed on the anode of an X-ray tube with magnetic bearings. The X-ray apparatus comprises a focus position sensing device cooperating with electronic means associated with the magnetic bearings, in order to control the position of the focus by displacing a rotor under the action of the magnetic bearings.Type: GrantFiled: June 25, 1985Date of Patent: June 23, 1987Assignee: Thomson-CGRInventors: Andre Plessis, Jacques Leguen
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Patent number: 4669102Abstract: A method and a device for operating and focusing a tomographic x-ray unit using an electron beam and embodying at least one electron gun (1), an anode (2) at which the gun is aimed as well as the x-ray detectors (5) needed to produce a tomographic photograph. In order to construct a device with a sufficiently short exposure time and capable of taking tomographic photographs of fast-moving objects, it is particularly characteristic of this invention that an electron beam (8) emitted by an electron gun (1) is roughly deflected at a hole (4) in the focusing plane (3) which, by means of focusing field lines, draws the electrons into the hole, focuses and accelerates the electron beam which strikes the surface of the anode (2), generating an x-ray source, and that the focusing hole (4) is moved in regard to the anode (2) to generate a series of x-ray sources needed to produce a "layerwise" tomographic photograph of the object under examination.Type: GrantFiled: April 18, 1984Date of Patent: May 26, 1987Assignee: Puumalaisen Tutkimuslaitos OyInventor: Pertti Puumalainen
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Patent number: 4563769Abstract: In an X-ray generator device a target member emitting X-rays by electron bombardment is arranged in a rod-shaped tubular probe and is provided with a conically tapering front part facing a comparatively narrow aperture in a controlling electron beam diaphragm for the purpose of forming a substantially punctiform radiation source. The position of the target member is adjusted by securing the rod-shaped target member at a part of its length reckoned from its opposite, rearmost end in a central bore of an oblong cylindrical target carrier positioned coaxially in the probe, said target carrier being only at its foremost end connected with the wall of the probe, thereby allowing fine adjustment of the target member with respect to said aperture by displacement of said opposite end of the target carrier in a radial plane in the probe, e.g. by means of wedge means formed as adjusting screws in the annular channel between the target carrier and the inner wall of the probe.Type: GrantFiled: December 21, 1982Date of Patent: January 7, 1986Assignee: Andrex Radiation Products A/SInventor: Jens U. Madsen
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Patent number: 4357555Abstract: An X-ray tube having a rotary anode which is supported by a bearing system comprising an axial magnetic bearing and at least one radial sleeve bearing. In operation, mutually cooperating metal (e.g. W or Mo) supporting faces of the sleeve bearing are separated by a liquid layer wetting the supporting faces. The liquid layer consists of a metal or a metal alloy, such as Ga or a Ga alloy, whose vapor pressure at 300.degree. C. is below 10.sup.-5 N/m.sup.2, and which does not attack the supporting faces to any substantial extent. The tube has a long life, produces little noise during operation, and is of relatively simple construction.Type: GrantFiled: May 8, 1980Date of Patent: November 2, 1982Assignee: U.S. Philips CorporationInventors: Jan Gerkema, Evert M. H. Kamerbeek