X-ray tube diagnostic system including a circuit to generate a phase signal and/or an indication of a status of a motor

Patent metadata

Field	Value
Publication number	US-11051388-B2
Application number	US-201816024841-A
Country	US
Kind code	B2
Filing date	Jun 30, 2018
Priority date	Jun 30, 2018
Publication date	Jun 29, 2021
Grant date	Jun 29, 2021

Abstract

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.

First claim

The invention claimed is:

1. 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.

2. The system of claim 1 , wherein:
the drive input is a three-phase input including a first voltage, a second voltage, and a third voltage, each with a phase difference from the other voltages;
the circuit further comprises a first comparator configured to generate a first pulse based on a comparison with the first voltage and the second voltage; and
the circuit is configured to generate the phase signal based on the first pulse.

3. The system of claim 2 , wherein the circuit further comprises:
a second comparator configured to generate a second pulse based on a current associated with the first voltage; and
a logic circuit configured to generate the phase signal in response to the first pulse and the second pulse.

4. The system of claim 1 , wherein:
the drive input is a single-phase input;
the voltage of the drive input is a voltage of the single-phase input; and
the current of the drive input is a current of the single-phase input.

5. The system of claim 1 , further comprising a diagnostic circuit configured to receive the phase signal and generate an indication of a status of the motor in response to the phase signal.

6. The system of claim 5 , further comprising:
a rotatable gantry including the enclosure; and
an accelerometer configured to measure an acceleration of the rotatable gantry;
wherein the diagnostic circuit is configured to generate the indication of the status of the motor in response to the acceleration of the rotatable gantry.

7. The system of claim 5 , wherein the diagnostic circuit is configured to:
compare the phase signal to a range based on a previous state of the phase signal; and
generate the indication of the status of the motor in response to the comparison.

8. The system of claim 7 , wherein:
the range is based on at least one of a frequency of rotation of the motor and centripetal acceleration of a rotatable gantry including the enclosure.

9. The system of claim 5 , wherein the diagnostic circuit is further configured to:
measure a time from startup to steady state of the phase signal; and
generate the indication of the status of the motor in response to the time from startup to steady state of the phase signal.

10. The system of claim 5 , wherein the diagnostic circuit is further configured to:
measure a rate of change of the phase signal from startup to steady state; and
generate the indication of the status of the motor in response to the rate of change of the phase signal from startup to steady state.

11. 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 and receive a drive input;
a sensor configured to receive a signal from the motor; and
a circuit electrically connected to the sensor, and configured to:
measure a time associated with the signal; and
generate an indication of a status of the motor in response to the time.

12. The system of claim 11 , wherein the time associated with the signal is a time from when power supplied to the motor is deactivated until the signal from the motor passes a threshold.

13. The system of claim 12 , wherein:
the sensor is an acoustic sensor; and
the signal received from the motor is an acoustic signal sensed by the acoustic sensor.

14. The system of claim 12 , wherein:
the sensor is a voltage sensor; and
the signal received from the motor is a voltage sensed by the voltage sensor.

15. The system of claim 12 , wherein:
the sensor is a current sensor coupled to the cathode; and
the signal received from the motor is a current sensed by the current sensor.

16. The system of claim 11 , wherein the time associated with the signal is a time from when power is supplied to the motor until the signal from the motor reaches a steady state.

17. The system of claim 11 , wherein the signal from the motor is a phase shift between a voltage driving the motor and a current associated with the voltage.

18. The system of claim 11 , wherein the circuit is configured to:
measure a rate of change of the signal from the motor from when power is supplied to the motor until the signal from the motor reaches a steady state; and
generate the indication of the status of the motor in response to the rate of change.

19. A system, comprising:
means for operating a motor within an enclosure of an x-ray tube enclosing a vacuum;
means for measuring a phase shift between a voltage and a current driving a motor during operation; and
means for generating an indication of a status of the motor in response to the phase shift.

20. The system of claim 19 , further comprising:
means for changing operating conditions of the x-ray tube to new operating conditions; and
means for generating the indication of the status of the motor in response to the new operating conditions.

Assignees

• Varex Imaging Corp

Inventors

• Richmond Michelle
• Virshup Gary F
• Jones Dan

Classifications

• H05G1/66

  Circuit arrangements for X-ray tubes with target movable relatively to the anode · CPC title

• H01J35/1024

  Rolling bearings · CPC title

• H05G1/54

  Protecting {or lifetime prediction}(overload protection combined with control H05G1/46) · CPC title

• H01J2235/1026

  Means (motors) for driving the target (anode) · CPC title

• H01J35/10

  Rotary anodes; Arrangements for rotating anodes; Cooling rotary anodes · CPC title