Patent ID: 8457282

Claim:
An x-ray tube arranged to move during an exposure period comprising: a cathode for providing an electron stream; an anode comprising a target for receiving the electron stream and generating a photon stream in response thereto; a focusing cup which focuses the electron stream on the anode during the exposure period; a port for passing the photon stream out of the x-ray tube, wherein the cathode, anode and port together define a static focal spot of the x-ray tube, the static focal spot directed at an object during the exposure period to provide an effective focal spot at the object; and a controller coupled to at least one of the anode, the cathode and focusing cup, wherein the x-ray tube moves in a first direction during an exposure period and the controller moves the static focal spot in a second direction, opposite from the first direction and synchronous with the movement of the x-ray tube to minimize a size of the effective focal spot at the object; and wherein the x-ray tube operates in two modes, a first mode providing the photon stream with a relatively smaller static focal spot for a relatively longer exposure period than in a second mode.