Patents by Inventor Johannes Walk

Johannes Walk has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 9265135
    Abstract: A method and an associated apparatus for controlling a heating current flowing through an emitter of a pulsed X-ray tube during pulse pauses are provided. The heating current is controlled by comparing a measured actual value of the heating current with a predefinable desired value of the heating current. A low-pass filtering of the actual value of the heating current is effected before the comparison. A time constant of the low-pass filtering is equal to a thermal time constant of the emitter. A correction of the actual value of the heating current is provided before the low-pass filtering by a first correction value. The first correction value is determined such that a tube current control during the pulses is not compensated for by the heating current control in the pulse pauses.
    Type: Grant
    Filed: January 9, 2014
    Date of Patent: February 16, 2016
    Assignee: Siemens Aktiengesellschaft
    Inventors: Rudolf Auernhammer, Andreas Böhme, Johannes Walk
  • Patent number: 9042518
    Abstract: A method for asynchronous operation of a rotary anode of an x-ray emitter, where a torque is exerted onto the rotary anode by an electromagnetic alternating field of a stator with a first frequency is provided. The method includes increasing the first frequency to a second frequency. The second frequency is a whole number multiple of an x-ray trigger frequency. The method also includes simultaneously changing an output of the alternating field such that a rotational frequency of the rotary anode remains unchanged.
    Type: Grant
    Filed: August 1, 2013
    Date of Patent: May 26, 2015
    Assignee: Siemens Aktiengesellschaft
    Inventors: Jens Fürst, Andreas Körner, Johannes Walk
  • Publication number: 20140192961
    Abstract: A method and an associated apparatus for controlling a heating current flowing through an emitter of a pulsed X-ray tube during pulse pauses are provided. The heating current is controlled by comparing a measured actual value of the heating current with a predefinable desired value of the heating current. A low-pass filtering of the actual value of the heating current is effected before the comparison. A time constant of the low-pass filtering is equal to a thermal time constant of the emitter. A correction of the actual value of the heating current is provided before the low-pass filtering by a first correction value. The first correction value is determined such that a tube current control during the pulses is not compensated for by the heating current control in the pulse pauses.
    Type: Application
    Filed: January 9, 2014
    Publication date: July 10, 2014
    Inventors: Rudolf Auernhammer, Andreas Böhme, Johannes Walk
  • Patent number: 8774366
    Abstract: The present embodiments improve the radiation monochromy of an x-ray device with a control electrode for controlling a flow of electrons generated between a cathode and an anode. A correction voltage is generated in accordance with a correction function. This correction voltage is used for correction of a voltage applied between the anode and the cathode in terms of a constant voltage, even in the period of control using the control electrode. The voltage applied between the anode and the cathode is corrected with the generated correction voltage.
    Type: Grant
    Filed: October 29, 2010
    Date of Patent: July 8, 2014
    Assignee: Siemens Aktiengesellschaft
    Inventor: Johannes Walk
  • Publication number: 20140037067
    Abstract: A method for asynchronous operation of a rotary anode of an x-ray emitter, where a torque is exerted onto the rotary anode by an electromagnetic alternating field of a stator with a first frequency is provided. The method includes increasing the first frequency to a second frequency. The second frequency is a whole number multiple of an x-ray trigger frequency. The method also includes simultaneously changing an output of the alternating field such that a rotational frequency of the rotary anode remains unchanged.
    Type: Application
    Filed: August 1, 2013
    Publication date: February 6, 2014
    Inventors: Jens Fürst, Andreas Körner, Johannes Walk
  • Patent number: 8391441
    Abstract: The present embodiments specify a method and an associated X-ray facility for estimating a radiation dose of an X-ray that is generated by an X-ray source and penetrates an object under examination. First dose values of the X-ray are determined by measurement in an automatic exposure control chamber. A second dose value is determined by estimating the radiation dose that is emitted by an X-ray source in a dead time of the automatic exposure control chamber. The estimated radiation dose is determined by the first dose value and the second dose value last determined being added. The second dose value represents a correction value for a non-measurable dose during the dead time of the automatic exposure control chamber that is taken into account when determining the estimated radiation dose.
    Type: Grant
    Filed: August 5, 2011
    Date of Patent: March 5, 2013
    Assignee: Siemens Aktiengesellschaft
    Inventors: Johannes Walk, Marcel Wellnitz
  • Publication number: 20120195408
    Abstract: The present embodiments specify a method and an associated X-ray facility for estimating a radiation dose of an X-ray that is generated by an X-ray source and penetrates an object under examination. First dose values of the X-ray are determined by measurement in an automatic exposure control chamber. A second dose value is determined by estimating the radiation dose that is emitted by an X-ray source in a dead time of the automatic exposure control chamber. The estimated radiation dose is determined by the first dose value and the second dose value last determined being added. The second dose value represents a correction value for a non-measurable dose during the dead time of the automatic exposure control chamber that is taken into account when determining the estimated radiation dose.
    Type: Application
    Filed: August 5, 2011
    Publication date: August 2, 2012
    Inventors: Johannes Walk, Marcel Wellnitz
  • Publication number: 20110103552
    Abstract: The present embodiments improve the radiation monochromy of an x-ray device with a control electrode for controlling a flow of electrons generated between a cathode and an anode. A correction voltage is generated in accordance with a correction function. This correction voltage is used for correction of a voltage applied between the anode and the cathode in terms of a constant voltage, even in the period of control using the control electrode. The voltage applied between the anode and the cathode is corrected with the generated correction voltage.
    Type: Application
    Filed: October 29, 2010
    Publication date: May 5, 2011
    Inventor: Johannes Walk