Patents by Inventor Takafumi Ishitsu

Takafumi Ishitsu 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).

  • Publication number: 20240023912
    Abstract: To provide a radiation imaging device which, even when a subpixel fails during operation of the photon counting detector, can correct an output signal of the pixel including the failed subpixel. A radiation imaging device that has a photon counting detector to count radiation photons and can correct an output signal of a pixel including a failed subpixel even if the subpixel fails during operation of the photon counting detector. The photon counting detector comprises: a pixel comprised of a plurality of subpixels; a data processing section that calculates an output signal of the pixel according to the number of radiation photons counted in each of the subpixels; and a failure detection section that detects a failure of the subpixel according to the number of radiation photons counted in the subpixel and outputs the position of the failed subpixel.
    Type: Application
    Filed: April 28, 2023
    Publication date: January 25, 2024
    Inventors: Takafumi Ishitsu, Isao Takahashi
  • Publication number: 20230076183
    Abstract: A radiographic imaging apparatus and a radiation detector are provided, which are capable of sufficiently reducing the sensitivity difference between pixels even if the incident photon rate is high. A radiographic imaging apparatus includes: a radiation source for irradiating an object with radiation; a plurality of detection element modules each having a semiconductor layer that generates electrical charges depending on photon energy of the radiation, and a photon counting circuit for counting the electrical charges for each pixel; and a collimator that is disposed between the radiation source and the semiconductor layer, and has a plurality of walls forming a plurality of passage holes through which the radiation passes.
    Type: Application
    Filed: August 9, 2022
    Publication date: March 9, 2023
    Inventors: Masafumi Onouchi, Takafumi Ishitsu
  • Patent number: 11567016
    Abstract: There is provided a radiographic imaging apparatus capable of alignment of a detector with a collimator with a position of a radiation source fixed. The radiographic imaging apparatus includes the radiation source which irradiates a subject with radioactive rays, a plurality of detecting elements which detect photons in the radioactive rays, and a collimator which is disposed between the radiation source and the detecting elements and has a plurality of walls which form a plurality of passing holes that the radioactive rays pass. The detecting element and the collimator are aligned with each other in a direction which is orthogonal to a direction that the subject is irradiated with the radioactive rays such that a ratio or a difference between output signals from the detecting elements which are mutually adjacent with the wall being interposed falls within a predetermined range.
    Type: Grant
    Filed: April 16, 2021
    Date of Patent: January 31, 2023
    Assignee: FUJIFILM HEALTHCARE CORPORATION
    Inventors: Masafumi Onouchi, Takafumi Ishitsu
  • Patent number: 11523783
    Abstract: There are provided a radiation detector module, a radiation detector, and a radiographic imaging apparatus which make it possible to increase the row number while suppressing a length in a body-axis direction. The radiation detector module includes a detector substrate on which a scintillator, a photodiode, and AD conversion chips are loaded, and a control substrate which supplies power to the detector substrate and controls the operation of an AD conversion unit (AFE) of each AD conversion chip of the detector substrate. The plurality of radiation detector modules configure a radiation detector which suppresses the length in the body-axis direction by connecting together the two substrates so as to form a two-stage structure by stacking connectors.
    Type: Grant
    Filed: April 14, 2021
    Date of Patent: December 13, 2022
    Assignee: FUJIFILM HEALTHCARE CORPORATION
    Inventors: Tatsuhiko Hayashi, Takafumi Ishitsu, Masafumi Onouchi
  • Publication number: 20220074872
    Abstract: There is provided a radiographic imaging apparatus capable of alignment of a detector with a collimator with a position of a radiation source fixed. The radiographic imaging apparatus includes the radiation source which irradiates a subject with radioactive rays, a plurality of detecting elements which detect photons in the radioactive rays, and a collimator which is disposed between the radiation source and the detecting elements and has a plurality of walls which form a plurality of passing holes that the radioactive rays pass. The detecting element and the collimator are aligned with each other in a direction which is orthogonal to a direction that the subject is irradiated with the radioactive rays such that a ratio or a difference between output signals from the detecting elements which are mutually adjacent with the wall being interposed falls within a predetermined range.
    Type: Application
    Filed: April 16, 2021
    Publication date: March 10, 2022
    Inventors: Masafumi ONOUCHI, Takafumi ISHITSU
  • Publication number: 20220054098
    Abstract: There are provided a radiation detector module, a radiation detector, and a radiographic imaging apparatus which make it possible to increase the row number while suppressing a length in a body-axis direction. The radiation detector module includes a detector substrate on which a scintillator, a photodiode, and AD conversion chips are loaded, and a control substrate which supplies power to the detector substrate and controls the operation of an AD conversion unit (AFE) of each AD conversion chip of the detector substrate. The plurality of radiation detector modules configure a radiation detector which suppresses the length in the body-axis direction by connecting together the two substrates so as to form a two-stage structure by stacking connectors.
    Type: Application
    Filed: April 14, 2021
    Publication date: February 24, 2022
    Inventors: Tatsuhiko HAYASHI, Takafumi ISHITSU, Masafumi ONOUCHI
  • Patent number: 11169284
    Abstract: The present invention provides a radiation imaging apparatus capable of maintaining the quality of an image obtained even when a dose incident on a radiation detector changes suddenly. The present invention is a radiation imaging apparatus including a radiation source, a radiation detector to detect radiation emitted from the radiation source, and a cooling unit to cool the radiation detector; and is characterized in that the radiation detector has a counting circuit to output a number of photons in radiation counted per unit time as a photon counting rate, and the cooling unit controls a coolability of the radiation detector in response to the photon counting rate.
    Type: Grant
    Filed: December 18, 2019
    Date of Patent: November 9, 2021
    Assignee: HITACHI, LTD.
    Inventors: Masafumi Onouchi, Takafumi Ishitsu, Fumito Watanabe
  • Patent number: 11029423
    Abstract: To provide a radiation imaging system which is adapted to downsize a photon counting radiation detector including a semiconductor layer for detecting photons of radiation and a collimator for suppressing incidence of scattered rays, and which ensures high voltage resistance. The radiation imaging system includes: a radiation source; a radiation detector; and a support portion for supporting the radiation source and the radiation detector in opposed relation. The system has a structure wherein the radiation detector includes a plurality of detecting element modules arranged in an arcuate form. The detecting element module includes a base fixed to the support portion; a semiconductor layer; a high-voltage wire for supplying high voltage to the semiconductor layer; a collimator for suppressing scattered rays, and a supporting column disposed at place within a predetermined distance from the semiconductor layer.
    Type: Grant
    Filed: March 4, 2020
    Date of Patent: June 8, 2021
    Assignee: HITACHI, LTD.
    Inventors: Masafumi Onouchi, Takafumi Ishitsu, Fumito Watanabe
  • Publication number: 20200408939
    Abstract: To provide a radiation imaging system which is adapted to downsize a photon counting radiation detector including a semiconductor layer for detecting photons of radiation and a collimator for suppressing incidence of scattered rays, and which ensures high voltage resistance. The radiation imaging system includes: a radiation source; a radiation detector; and a support portion for supporting the radiation source and the radiation detector in opposed relation. The system has a structure wherein the radiation detector includes a plurality of detecting element modules arranged in an arcuate form. The detecting element module includes a base fixed to the support portion; a semiconductor layer; a high-voltage wire for supplying high voltage to the semiconductor layer; a collimator for suppressing scattered rays, and a supporting column disposed at place within a predetermined distance from the semiconductor layer.
    Type: Application
    Filed: March 4, 2020
    Publication date: December 31, 2020
    Applicant: Hitachi, Ltd.
    Inventors: Masafumi Onouchi, Takafumi Ishitsu, Fumito Watanabe
  • Publication number: 20200225368
    Abstract: The present invention provides a radiation imaging apparatus capable of maintaining the quality of an image obtained even when a dose incident on a radiation detector changes suddenly. The present invention is a radiation imaging apparatus including a radiation source, a radiation detector to detect radiation emitted from the radiation source, and a cooling unit to cool the radiation detector; and is characterized in that the radiation detector has a counting circuit to output a number of photons in radiation counted per unit time as a photon counting rate, and the cooling unit controls a coolability of the radiation detector in response to the photon counting rate.
    Type: Application
    Filed: December 18, 2019
    Publication date: July 16, 2020
    Applicant: Hitachi, Ltd.
    Inventors: Masafumi ONOUCHI, Takafumi ISHITSU, Fumito WATANABE
  • Patent number: 10299746
    Abstract: A radiation imaging apparatus provided with a detector capable of improving correction accuracy at a high counting rate. The present invention is provided with: grids that remove scattered beams that emanate from an object; and a plurality of detector sub-pixels arranged so as to divide the gap between the grids into three or more segments, wherein the area of each of the detector sub-pixels located below the wall surface of the grids is larger than that of each of the other detector sub-pixels in a planar view. The size of each of the detector sub-pixels not located below the wall surface of the grids is expressed as (Pg?Tg?Lsplit×2)/N, where Pg represents the pitch between the grids, Tg represents the thickness of each of the grids, and N represents the number of segments formed by the detector sub-pixels between the grids.
    Type: Grant
    Filed: December 21, 2016
    Date of Patent: May 28, 2019
    Assignee: Hitachi, Ltd.
    Inventors: Takafumi Ishitsu, Isao Takahashi, Kazuma Yokoi, Makoto Satou
  • Patent number: 10292669
    Abstract: To improve performance in Photon Counting CT, pixel miniaturization, a reduction in circuit dead time, and dealing with scattered radiation and charge sharing are important. In addition, because the number of circuits increases, a reduction in power consumption of each circuit is important. Under these constraints, circuitry that deals with the scattered radiation is provided. Each pixel includes a circuit that determines whether radiation has been detected by another, adjacent pixel at the same time, and counters that count the radiation are switched on the basis of the result of the determination. On the basis of this result, counts of non-coincident events are primarily used, and coincident counts are used after being corrected, for reconstruction data.
    Type: Grant
    Filed: March 18, 2016
    Date of Patent: May 21, 2019
    Assignee: Hitachi, Ltd.
    Inventors: Takafumi Ishitsu, Isao Takahashi, Kazuma Yokoi
  • Publication number: 20180368790
    Abstract: A radiation imaging apparatus provided with a detector capable of improving correction accuracy at a high counting rate. The present invention is provided with: grids that remove scattered beams that emanate from an object; and a plurality of detector sub-pixels arranged so as to divide the gap between the grids into three or more segments, wherein the area of each of the detector sub-pixels located below the wall surface of the grids is larger than that of each of the other detector sub-pixels in a planar view. The size of each of the detector sub-pixels not located below the wall surface of the grids is expressed as (Pg?Tg?Lsplit×2)/N, where Pg represents the pitch between the grids, Tg represents the thickness of each of the grids, and N represents the number of segments formed by the detector sub-pixels between the grids.
    Type: Application
    Filed: December 21, 2016
    Publication date: December 27, 2018
    Inventors: Takafumi ISHITSU, Isao TAKAHASHI, Kazuma YOKOI, Makoto SATOU
  • Publication number: 20180049707
    Abstract: To improve performance in Photon Counting CT, pixel miniaturization, a reduction in circuit dead time, and dealing with scattered radiation and charge sharing are important. In addition, because the number of circuits increases, a reduction in power consumption of each circuit is important. Under these constraints, circuitry that deals with the scattered radiation is provided. Each pixel includes a circuit that determines whether radiation has been detected by another, adjacent pixel at the same time, and counters that count the radiation are switched on the basis of the result of the determination. On the basis of this result, counts of non-coincident events are primarily used, and coincident counts are used after being corrected, for reconstruction data.
    Type: Application
    Filed: March 18, 2016
    Publication date: February 22, 2018
    Inventors: Takafumi ISHITSU, Isao TAKAHASHI, Kazuma YOKOI
  • Patent number: 9757077
    Abstract: When two detector panels are rotationally moved around the entire circumference of a region of interest and projection images of the region of interest are captured during the rotational movement, the respective detector panels are moved along the tangential direction of the rotational movement to a position where the union of the capturing ranges of the projection images captured by the respective detector panels covers the entire region of interest. The projection images captured by the respective detector panels are used to reconstruct a transaxial image of the region of interest.
    Type: Grant
    Filed: October 29, 2014
    Date of Patent: September 12, 2017
    Assignee: Hitachi, Ltd.
    Inventors: Atsuro Suzuki, Yuichiro Ueno, Takafumi Ishitsu, Wataru Takeuchi, Isao Takahashi
  • Publication number: 20160374633
    Abstract: When two detector panels are rotationally moved around the entire circumference of a region of interest and projection images of the region of interest are captured during the rotational movement, the respective detector panels are moved along the tangential direction of the rotational movement to a position where the union of the capturing ranges of the projection images captured by the respective detector panels covers the entire region of interest. The projection images captured by the respective detector panels are used to reconstruct a transaxial image of the region of interest.
    Type: Application
    Filed: October 29, 2014
    Publication date: December 29, 2016
    Applicant: Hitachi, Ltd.
    Inventors: Atsuro SUZUKI, Yuichiro UENO, Takafumi ISHITSU, Wataru TAKEUCHI, Isao TAKAHASHI
  • Publication number: 20160348270
    Abstract: A crucible provided with a holding section (12) for holding a raw material (20), an initial distillate recovery section (14) for recovering an initial distillate (24) when the raw material (20) held in the holding section (12) has been vaporized, a main distillate condensing section (16) for condensing a main distillate when the raw material (20) held in the holding section (12) has been vaporized, and a crystal growing section (18) for holding the main distillate (30) comprising a raw material melt (28) condensed by the main distillate condensing section (16) and producing crystals when crystals are grown from the held main distillate (30) is used as a crucible (10) for crystal growth used to grow crystals. This makes it possible to raise the efficiency of manufacturing crystals while achieving high purification of a raw material for semiconductor crystals.
    Type: Application
    Filed: October 8, 2014
    Publication date: December 1, 2016
    Inventors: Takayuki KANDA, Shinya KOMINAMI, Yuichiro UENO, Takafumi ISHITSU, Tomoyuki SEINO, Isao TAKAHASHI
  • Patent number: 9390823
    Abstract: There is provided is a radiation image acquiring device which corrects a positional displacement between a collimator and a detector and obtains an image without artifacts. The device includes a detector (21) to measure a radiation; a collimator (26) including a through-hole (27) having one or more detectors (21) disposed therein and configured to limit an incident direction of the radiation; a positional displacement measuring unit configured to measure a positional displacement between the detector (21) and the collimator (26) by use of a profile of a radiation source measured by the detector (21) based on the radiation source disposed corresponding to a predetermined detector (21).
    Type: Grant
    Filed: October 3, 2013
    Date of Patent: July 12, 2016
    Assignee: Hitachi, Ltd.
    Inventors: Atsuro Suzuki, Takafumi Ishitsu, Isao Takahashi, Wataru Takeuchi, Keiji Kobashi
  • Publication number: 20150262721
    Abstract: There is provided is a radiation image acquiring device which corrects a positional displacement between a collimator and a detector and obtains an image without artifacts. The device includes a detector (21) to measure a radiation; a collimator (26) including a through-hole (27) having one or more detectors (21) disposed therein and configured to limit an incident direction of the radiation; a positional displacement measuring unit configured to measure a positional displacement between the detector (21) and the collimator (26) by use of a profile of a radiation source measured by the detector (21) based on the radiation source disposed corresponding to a predetermined detector (21).
    Type: Application
    Filed: March 10, 2013
    Publication date: September 17, 2015
    Inventors: Atsuro Suzuki, Takafumi Ishitsu, Isao Takahashi, Wataru Takeuchi, Keiji Kobashi
  • Patent number: 9057789
    Abstract: A radiation measuring device includes: a detector that detects radiation; a preamplifier that amplifies a signal outputted from the detector; a shaping amplifier that shapes the waveform of the signal outputted from the preamplifier; an A/D converter that converts the analog signal output from the shaping amplifier to a digital signal; and a digital data processing unit that calculates digital signal output from the A/D converter, wherein energy information of the radiation inputted to the detector is obtained from a pulse height of the pulse signal processed by the preamplifier and the shaping amplifier, and the pulse height of the current pulse is corrected in the digital data processing unit by performing an arithmetic operation using the pulse height information of the current pulse digitalized by the A/D converter, the generation time information of the preceding pulse, and the pulse height information of the preceding pulse.
    Type: Grant
    Filed: August 4, 2011
    Date of Patent: June 16, 2015
    Assignee: HITACHI, LTD.
    Inventors: Tomoyuki Seino, Yuichiro Ueno, Takafumi Ishitsu