X-ray imaging apparatus and x-ray tube

An X-ray imaging apparatus, comprising:

• an X-ray tube including at least a first electron irradiation unit and a second electron irradiation unit for irradiating electrons to different focal positions on a target;
• a detector for detecting X-rays emitted from the X-ray tube;
• a subject placement unit arranged between the X-ray tube and the detector, for placing a subject thereon;
• a rotation mechanism for rotating one of an imaging unit including the X-ray tube and the detector, and the subject placement unit, so as to change an imaging angle of the subject;
• and
• a control unit for acquiring a plurality of projection image data at each of a plurality of the imaging angles from the detector, and for generating a CT image based on the acquired plurality of projection image data,
• wherein the control unit performs:
• a control to cause electrons to be irradiated simultaneously from the first electron irradiation unit and the second electron irradiation unit for each of the plurality of the imaging angles;
• and
• a control to make a first relative focal position of the first electron irradiation unit with respect to the subject at a first imaging angle, a second relative focal position of the second electron irradiation unit with respect to the subject at the first imaging angle, a third relative focal position of the first electron irradiation unit with respect to the subject at a second imaging angle, and a fourth relative focal position of the second electron irradiation unit with respect to the subject at the second imaging angle different from each other so as not to overlap.