Koninklijke Philips Corporation N.V.

Picker International, Inc.

Marconi Medical Systems, Inc.

Gerald James Carlson

Kevin Charles Kraft

Lester Donald Miller

Paul Xu

Jason P Harris

Qing Kelvin Lu

Daniel E Kuzniar

Thomas R Miller

Min He

Ming-Wei Paul Xu

Gereon Vogtmeier

Cheryl L Panasik

Rainer Pietig

Christoph Loef

Allan D Kautz

Salvatore G Perno

Robert B Campbell

Todd Russell Bittner

Patrick P McNally

Norman E Wandke

Martin Kimutai Duerr

Qing Lu

Jose A Buan

For the generation of multiple-energy X-ray radiation, an X-ray tube () for generating multiple-energy X-ray radiation includes an anode () and a filter (). At least a first () and a second focal spot position () are offset from each other in an offset direction () transverse to an X-ray radiation projection direction. The filter includes a first plurality () of first portions () with first filtering characteristics for X-ray radiation and a second plurality () of second portions () with second filtering characteristics for X-ray radiation. The filter is a directional filter adapted in a such a way that at least a first X-ray beam () emanating from the first focal spot position at least partly passes through the filter unit via the first portions, and a second X-ray beam () emanating from the second focal spot position passes obliquely through the first and the second portions when passing through the filter unit.

Multiple focal spot X-ray radiation filtering

An anode () is formed by building a carbon, such as a carbon reinforced carbon composite, or other ceramic substrate (). A ductile, refractory metal is electroplated on the ceramic substrate to form a refractory metal carbide layer () and a ductile refractory metal layer (), at least on a focal track portion (). A high-Z refractory metal is vacuum plasma sprayed on the ductile refractory metal layer to form a vacuum plasma sprayed high-Z refractory metal layer (), at least on the focal track portion.

Anode disk element with refractory interlayer and VPS focal track

A method () creates a braze joint () between an anode plate () and a piece of graphite () of an x-ray tube (). The method () includes receiving () the anode plate () and the piece of graphite (). A barrier layer () and a braze layer () are arranged () between the anode plate () and the piece of graphite (), where the barrier layer () is between the piece of graphite () and the brazing layer (). The barrier layer () is heated () with the braze layer () to create the braze joint () between the anode plate () and the piece of graphite ().

Brazed X-ray tube anode

The present invention relates to X-ray generating technology in general, in particular, it relates to an anode disk element () for an X-ray generating device (). The generation of electromagnetic radiation may be considered to be quite inefficient, since a substantial part of energy applied to a focal track is converted to heat rather than X-radiation. Thus, a limiting factor in the operation of X-ray tubes is the cooling of the anode element and more specifically the focal track. In the present invention, an anode disk element is provided, with an improved dissipation of heat from the focal track. Thus, the anode disk element may sustain increased heat while maintaining structural integrity. The anode disk element () comprises at least a first surface () and a second surface (), with the first surface () comprising a focal track () and the second surface () comprising a conductive coating (). The anode disk element () is rotatable about a rotational axis () with the focal track () being rotationally symmetrical to the rotational axis (). The first surface () comprising the focal track () and the second surface () comprising the conductive coating () are adjacently arranged.

Anode disk element comprising a conductive coating

An anode disk element for the generation of X-rays that provides improved dissipation of heat from a focal track includes an anisotropic thermal conductivity. The anode disk element includes a focal track and at least one heat dissipating element. The anode disk element is rotatable about a rotational axis with the focal track being rotationally symmetrical to the rotational axis. The at least one heat dissipating element is configured for heat dissipation from the focal track in the direction of reduced thermal conductivity of the anode disk element.

Anode disk element comprising a heat dissipating element

An x-ray tube assembly ( ) includes a housing ( ) and an insert frame ( ) supported within the housing ( ), such that the insert frame ( ) defines a substantially evacuated envelope in which a cathode assembly ( ) and a rotating anode assembly ( ) operate to produce x-rays. The rotating anode assembly ( ) includes an anode target plate ( ) coupled to a rotor ( ) and bearing shaft ( ), which is rotatably supported within a bearing housing ( ), by a plurality of ball bearings ( ). A heat barrier ( ) substantially surrounds the bearing housing ( ) and is coupled, along with the bearing housing ( ) to an anode cold plate ( ). The anode cold plate ( ) includes a grooved cover ( ), a basin ( ), and a plurality of corrugated fins ( ) disposed therein. Coupling both the bearing housing ( ) and the heat barrier ( ) to the anode cold plate ( ) provides an effective means for cooling the bearing assembly ( ).

X-ray tube anode cold plate

An x-ray tube ( ) includes an evacuated envelope ( ). Mounted within the evacuated envelope are a cathode ( ) and a rotatbly supported anode ( ). A rotor ( ) is included for rotatably driving the anode. The rotor ( ) is electrically insulated from the anode ( ) by a disk ( ) comprised of an insulating material.

High voltage isolated rotor drive for rotating anode x-ray tube

A cooling oil circuit (D) circulates cooling oil over an x-ray tube absorbing its waste heat. A refrigeration circuit (E) then cools the cooling oil. A heat buffer ( ) absorbing peak heat loads from the cooling fluid when the x-ray tube is generating x-rays. Valves ( ) regulate a relative amount of cooling oil entering the heat buffer to increase heat transfer efficiency. The heat buffer enables the system to handle peak heat loads with a smaller, more condensed refrigeration system, by absorbing heat during operation of the x-ray tube and releasing heat between operations.

Heat removal from high power CT x-ray tubes using heat buffer and refrigeration techniques

A high energy x-ray tube includes an evacuated chamber ( ) containing a rotor ( ) which rotates an anode ( ) through a stream of electrons (A) in order to generate an x-ray beam (B). The rotor includes a bearing assembly (C) having a hollow bearing shaft ( ) centrally aligned with a longitudinal axis (Z) of the rotor. The bearing shaft includes an interior annular wall ( ) having an inner surface which defines a central bore ( ). The bearing shaft has an outer surface ( ), which with an inner surface of the bearing shaft, defines an annular chamber ( ). An opening ( ) is provided at the forward end of the annular wall to provide access from the central bore to the annular chamber. During exhaust processing, baking cycles, and normal operation of the x-ray tube, a pump ( ) forces a cooling medium through the central bore, through the opening of the annular wall, and into the annular chamber. The cooling medium exits through channels ( ). While in the annular chamber, the cooling medium cools a plurality of forward and rearward lubricated bearings ( F, R) located adjacent an outer surface of the hollow bearing shaft.

Internal bearing cooling using forced air

An x-ray tube (,) comprising a cathode (,) and an anode (,) in operative relationship with the cathode (,). The anode (,) is mounted on a stem (,). The x-ray tube includes at least one bearing (,) rotatably receiving the stem (,). The at least one bearing (,) has an outer bearing race (,) in an outer race member, an inner bearing race (,) and a plurality of bearing members (,) operatively disposed between the inner and outer bearing races. The x-ray tube (,) also includes an evacuated envelope (,) which encloses the tube components and receives the outer race member of the at least one bearing (,) in thermally conductive contact along an inner surface (,).

Oil cooled bearing assembly

A CT scanner includes a stationary gantry (,) defining an examination region (,) and a rotating gantry (,) which rotates about the examination region. At least two x-ray tubes (,), each capable of producing a beam of radiation directed through the examination region, are mounted to the rotating gantry. The x-ray tubes are switchably connected to an electrical power supply (,). X-rays are detected by an arc of x-ray detectors (,) which generate signals indicative of the radiation received. These signals are processed by a reconstruction processor (,) into an image representation. A thermal calculator (,) estimates when an anode in one of the x-ray tubes (,) reaches a selected temperature. The thermal calculator (,) controls a switch (,) which is electrically connected between the x-ray tubes and the power supply. The switch selectively switches power from the power supply alternately to the x-ray tubes. Each time the thermal calculator estimates that the anode of one of the x-ray tubes has reached selected temperature, that tube is switched off and the other tube is switched on.

Method and apparatus to increase the operational time of a tomographic scanner

An x-ray tube includes an envelope defining an evacuated chamber in which an anode assembly is rotatably mounted to a bearing assembly and interacts with a cathode assembly for production of x-rays. The x-ray tube further includes a heat shield disposed in the envelope. The heat shield serves to reduce heat radiating from the anode assembly which is transferred to the bearing assembly or otherwise serves to insulate the bearing assembly from such radiated heat. The heat shield is brazed or otherwise bonded to the anode assembly and is comprised of a material having a low emissivity so that a minimum amount of heat radiates through the heat shield.

Target integral heat shield for x-ray tubes

An x-ray tube includes an envelope defining an evacuated chamber and having a window transmissive to x-rays. An anode assembly and a cathode assembly operate within the envelope to produce x-rays which travel through the window transmissive to x-rays towards a patient or subject under examination. A shield transmissive to x-rays is coupled to the envelope and positioned such that x-rays traveling through the window transmissive to x-rays must first travel through the shield. The shield prevents substantially all secondary electrons created during the production of x-rays from coming into contact with the window transmissive to x-rays thereby preventing excessive heating of the window transmissive to x-rays. An electrode defined by the envelope in a region proximate the window transmissive to x-rays may additionally or alternatively be used to prevent secondary electrons from reaching the window transmissive to x-rays.

X-ray tube window heat shield

A rotating assembly 79 includes an anode assembly 55 coupled to a shaft 70 and a rotor 75 including a rotor body 77. The anode assembly 55 includes an elongated neck portion 58 and is rotated via the shaft 70 about an axis of rotation 65 in an x-ray tube 12. The shaft 70 is mounted by a straddle bearing assembly 68 having a bearing housing 100. The bearing housing 100 includes a first elongated portion 101 and second elongated portion 102, and a base portion 103. The first elongated portion 101 and the second elongated portion 102 each pass through a center of mass C of the rotating assembly 79 and define an cooling duct 119 for removing heat from the anode assembly 55 during operations. A first bearing 90a and a second bearing 90b are disposed in the bearing housing 100 on opposite sides of the center of mass C of the rotating assembly 79. The first bearing 90a and the second bearing 90b are received between inner races 82a, 82b defined by the shaft 70 and outer races 92a, 92b defined by an outer bearing member 94 adjacent the second elongated portion 102. The second bearing 90b is positioned such that it is always in a closer thermal conductive path to a peripheral edge of the anode assembly 55 than the first bearing 90a regardless of an amount of load of the rotating assembly 79 supported by the first or second bearing.

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Aurora, IL, United States of America

Gerald James Carlson