Various methods and systems are provided for an x-ray imaging system. In one example, an x-ray tube of the imaging system includes a rotor with a core forming a continuous unit with at least one of a retention sleeve and a bearing assembly sleeve. The rotor further includes one or more magnets disposed in the core and maintained in place by the retention sleeve.

Methods and systems are provided for increasing a quality of computed tomography (CT) images generated by a CT system by altering a shape of a focal spot of an X-ray emitter of the CT system. In one embodiment, a method comprises controlling the CT system to focus a beam of electrons generated by a cathode of the CT system at a plurality of focal spots on a surface of an target of the CT system; generating a composite focal spot from the plurality of focal spots; and obtaining projection data of the CT system with the composite focal spot. For example, two focal spots may be combined to generate the composite focal spot. By combining focal spots to generate composite focal spots, a quality of a resulting view produced by the CT system may be increased.

A method is for spatially influencing a focal spot of an X-ray source that generates X-ray radiation, to an associated X-ray source, to an associated system and to an associated computer program product. The method according to at least one embodiment includes: producing a focal spot on an anode by way of an electron emitter including a plurality of emitter segments, individually controllable to emit electrons; determining at least one actual value of a spatial extent and/or of a position of the produced focal spot; comparing the at least one actual value with a specified reference value of the focal spot; and controlling the emitter segments based upon the comparison of the at least one actual value and the reference value such that the at least one actual value converges toward the reference value, thereby spatially influencing the focal spot of the X-ray source that generates X-ray radiation.

Various methods and systems are provided for an x-ray imaging system. In one example, an x-ray tube of the imaging system includes a rotor with a core forming a continuous unit with at least one of a retention sleeve and a bearing assembly sleeve. The rotor further includes one or more magnets disposed in the core and maintained in place by the retention sleeve.

A rotary anode driving device includes a DC power supply, an inverter circuit which is connected to the DC power supply and includes a plurality of switching elements and, the inverter circuit generates an AC voltage from a DC voltage of the DC power supply, and outputs the AC voltage to a stator coil which generates a rotating magnetic field of an X-ray tube; a pulse width modulation (PWM) waveform generator configured to generate an AC voltage of two phases or three phases as the AC voltage from the DC voltage by performing PWM control of the switching elements of the inverter circuit; and a capacitor connected in series to an input side of a stator coil of at least one phase of the stator coil, the capacitor having an electrostatic capacitance constituting a series resonant circuit with the stator coil to which the capacitor is connected.

A rotary anode driving device includes a DC power supply, an inverter circuit which is connected to the DC power supply and includes a plurality of switching elements and, the inverter circuit generates an AC voltage from a DC voltage of the DC power supply, and outputs the AC voltage to a stator coil which generates a rotating magnetic field of an X-ray tube; a pulse width modulation (PWM) waveform generator configured to generate an AC voltage of two phases or three phases as the AC voltage from the DC voltage by performing PWM control of the switching elements of the inverter circuit; and a capacitor connected in series to an input side of a stator coil of at least one phase of the stator coil, the capacitor having an electrostatic capacitance constituting a series resonant circuit with the stator coil to which the capacitor is connected.

The X-ray imaging apparatus includes: a main power supply operation unit for switching ON/OFF of power supply to the X-ray imaging apparatus; a braking unit for decelerating a rotation speed of the anode to a predetermined braking speed lower than a resonance range which is a rotation speed of the anode at which resonance occurs in the X-ray tube; and a non-braking stop prediction unit configured to detect a predetermined situation in which a non-braking stop state is predicted, the non-braking stop state being a state in which the main power supply operation unit is operated to be turned to an OFF state without decelerating the rotating anode by the braking unit. The non-braking stop prediction unit activates the braking unit by detecting the predetermined situation to decrease the rotation speed of the anode to the braking speed.

A computer tomography x-ray tube for generating pulsed x-rays is presented. The x-ray tube comprises an anode and an electron emission unit for generating a pulsed electron beam onto the anode. Furthermore, a rotation mechanism for rotating the anode characterized in that the rotation mechanism is configured for rotating the anode with an angular velocity that varies in time is comprised. The rotation mechanism may also be configured for rotating the anode such that the variation of the angular velocity in time is a continuous oscillation around a mean angular velocity ω.sub.0 in time. In a preferred embodiment the angular velocity ω (t) varies in time according to the following formula:

ω(t)=ω.sub.0+Δω sin Ωt,

wherein ω.sub.0 is a mean angular velocity. In a particular embodiment, the grid switch for generating the pulsed electron beam is comprised and the x-ray tube may be embodied as a stereo tube, in which two focal spots of electron beams are generated in an alternating manner.

A computer tomography x-ray tube for generating pulsed x-rays is presented. The x-ray tube comprises an anode and an electron emission unit for generating a pulsed electron beam onto the anode. Furthermore, a rotation mechanism for rotating the anode characterized in that the rotation mechanism is configured for rotating the anode with an angular velocity that varies in time is comprised. The rotation mechanism may also be configured for rotating the anode such that the variation of the angular velocity in time is a continuous oscillation around a mean angular velocity ω.sub.0 in time. In a preferred embodiment the angular velocity ω (t) varies in time according to the following formula:

ω(t)=ω.sub.0+Δω sin Ωt,

wherein ω.sub.0 is a mean angular velocity. In a particular embodiment, the grid switch for generating the pulsed electron beam is comprised and the x-ray tube may be embodied as a stereo tube, in which two focal spots of electron beams are generated in an alternating manner.

Some embodiments include a system, comprising: an enclosure configured to enclose a vacuum; a cathode disposed within the enclosure; an anode disposed within the enclosure configured to receive a beam of electrons from the cathode; a motor disposed within the enclosure and configured to rotate the anode in response to a drive input; and a circuit electrically connected to the drive input, and configured to generate a phase signal based on a voltage of the drive input and a current of the drive input, the phase signal indicating a phase difference between the voltage of the drive input and the current of the drive input.