X-ray tube

Claim 2

An X-ray tube including an envelope and an anode movable with respect thereto, a source of a beam of energy, for example an electron beam, arranged to impinge on said anode to generate X-radiation substantially at a region of contact with said anode and means for moving said anode in a predetermined manner relative to said tube envelope to move said region of contact relative to said tube envelope to scan the generated X-radiation in a predetermined manner relative to said tube envelope.

Claim 3

An X-ray tube according to claim 1 in which said anode is rotatable about an axis and is formed with a peripheral surface at a variable radius from said axis and said means for moving comprises means for rotating said anode about said axis to move said region of contact relative to the tube envelope.

Claim 4

An X-ray tube according to claim 2 in which the anode is a disc with a substantially elliptical plan form perpendicular to said axis.

Claim 5

An X-ray tube according to claim 2 in which the periphery of the anode includes one or more sections of substantially equiangular spiral form in a plane perpendicular to said axis.

Claim 6

An X-ray tube according to claim 2 in which the periphery of the anode includes one or more sections of substantially constant radius about said axis in a plane substantially perpendicular thereto.

Claim 7

An X-ray tube according to claim 2 in which said source includes means for directing said beam of energy along a path intersecting said anode at a tangent to a circle concentric with said axis.

Claim 8

An X-ray tube according to claim 2 in which said means for moving includes means for rotating said anode about said axis at a substantially constant angular velocity.

Claim 9

An X-ray tube according to claim 1 in which said anode is formed with a surface shaped so that the movement of said region of contact comprises a series of steady movements in one direction with a rapid flyback in the other direction therebetween.

Claim 10

An X-ray generating tube comprising an evacuated envelope, an anode mounted inside the envelope for rotation about an anode axis and having a peripheral surface at least partially surrounding said axis, a source of an electron beam propagating at least some of the time along a beam axis fixed with respect to the envelope and impinging on said peripheral surface at an area which moves along the peripheral surface upon rotation of the anode about said anode axis, said peripheral surface being irregularly shaped to cause said area of impingement of the electron beam to move with respect to the envelope upon rotation of the anode, said peripheral surface being made of a material generating X-ray radiation when said electron beam impinges thereon, said X-ray radiation originating at the area of impingement and propagating away from the anode, and means for rotating the anode about the anode axis to thereby move the area of impingement relative to the envelope and scan the X-ray radiation relative to the envelope in a manner determined by the shape of the peripheral surface and the anode rotation.

Claim 11

An X-ray generating tube comprising an evacuated envelope, an anode mounted inside the envelope for rotation about an anode axis and having a peripheral surface at least partially surrounding said axis, a source of an electron beam propagating at least some of the time along a beam axis fixed with respect to the envelope and impinging on said peripheral surface at an area which moves along the peripheral surface upon rotation of the anode about said anode axis, said peripheral surface being irregularly shaped to cause said area of impingement of the electron beam to move with respect to the envelope upon rotation of the anode, said peripheral surface being made of a material generating X-ray radiation when said electron beam impinges thereon, said X-ray radiation originating at the area of impingement and propagating away from the anode, and means for rotating the anode about the anode axis to thereby move the area of impingement relative to the envelope and scan the X-ray radiation relative to the envelope in a manner determined by the shape of the peripheral surface and the anode rotation.