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US 4,675,891 AGranted
X-ray apparatus with focus position control
AssigneeThomson-CGR
InventorsAndre Plessis, Jacques Leguen
Life of this patent
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Abstract
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.
Claims12
An X-ray apparatus having focus position control, comprising:
- an X-ray tube having:
- (a) a rotary anode on which a focus is formed;
- (b) a rotor coupled in rotation with the rotary anode for rotating the anode about a longitudinal axis;
- (c) magnetic bearings for movably supporting the rotor;
- electronic means for controlling the magnetic bearings to move the rotor along the longitudinal axis;
- means for sensing the position of the focus for supplying a difference signal to the electronic means, the difference signal corresponding to a position variation of the focus along a control axis parallel to the longitudinal axis;
- wherein the difference signal is compared with a reference signal for controlling the magnetic bearings to move the rotor along the longitudinal axis in a direction opposite to the direction in which the position variation of the focus was affected, so as to control and stabilize the position of the focus.
4 more elements
Dependencies are inferred from the claim text.