Koninklijke Philips Corporation N.v.

Picker International, Inc.

Marconi Medical Systems, Inc.

Jason P Harris

Gerald James Carlson

Daniel E Kuzniar

Lester Donald Miller

Salvatore G Perno

Mark S Maska

Todd Russell Bittner

An x-ray tube comprising a first electrode and a second electrode. The first and second electrodes are located in operative relationship with one another to generate x-rays when the electrodes are energized at their respective operating potential. An evacuated envelope encloses the first and second electrodes. The evacuated envelope includes a first envelope wall portion, a second envelope wall portion and an envelope weld member comprising an electrical conductor. The envelope weld member is in electrical communication so as to be at operating potential of one of the first and second electrodes when the x-ray tube is energized. The envelope weld member is adapted for vacuum tight joining to the first envelope wall portion and to the second envelope wall portion. The envelope weld member has an integral corona shield portion.

X-ray tube envelope with integral corona shield

A dual filament x-ray tube assembly ( ) includes an evacuated envelope ( ) having an anode ( ) disposed at a first end of the evacuated envelope ( ) and a cathode assembly ( ) disposed at a second end of the evacuated envelope ( ). The cathode assembly includes a variable-length filament assembly ( ) which emits electron beams for impingement on the anode ( ) at focal spots having varying lengths. The cathode assembly ( ) further includes a cathode cup ( ) which is subdivided into a plurality of electrically insulated deflection electrodes ( ). A filament select circuit ( ) selectively and individually heats a portion of the variable-length filament assembly ( ). Electron beams emitted from the filament assembly ( ) are electrostatically focused and controlled by applying potentials to different ones of the deflection electrodes ( ). The x-ray tube assembly ( ) provides longer focal spots for thick-slice scanning applications and shorter focal spots for thin-slice scanning applications along with the benefit of electrostatic focusing and control.

Dual filament, electrostatically controlled focal spot for x-ray tubes

A rotation monitoring system ( ) detects the rotational speed of an anode ( ) of an x-ray tube during use. The system ( ) includes a detector ( ), which detects a pulse of secondary x-rays generated by the interaction of a stream (C) of electrons with a known defect ( ) on a surface ( ) of the anode. The detector may be position inside or outside a vacuum envelope ( ) of the x-ray tube. The stream of electrons is supplied by a secondary source ( ), separate from a main source ( ) of electrons used to generate the primary or working x-ray beam (B) of the x-ray tube. A single pulse is detected with each rotation of the anode, providing a simple method of calculation of the anode rotation speed. Preferably, a feed back loop is used to correct the rotational speed of the anode so that overheating of the anode is avoided and the useful life of the x-ray tube is extended.

Pulse detection system for X-ray tubes

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

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

Jason P Harris