Patents by Inventor Tatsuya Nagata
Tatsuya Nagata 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).
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Patent number: 8517948Abstract: An ultrasound diagnostic apparatus 1 causes discharge means 4 to apply a discharge pulse (having a peak value equal to or greater than a collapse voltage) between electrodes of an ultrasound transducer 20 a plurality of time while inverting the polarity of the discharge pulse each time, to thereby accelerate discharge of the charge accumulated in the diaphragm of the ultrasound transducer 20, so that a transmission-reception sensitivity offset can be caused to quickly approach zero. The charge is discharged instantaneously. That is, it is possible to quickly calibrate a transmission-reception sensitivity drift stemming from time-course accumulation of charge flowing into the diaphragm between the electrodes upon application of a DC bias thereto.Type: GrantFiled: October 25, 2006Date of Patent: August 27, 2013Assignee: Hitachi Medical CorporationInventors: Katsunori Asafusa, Tatsuya Nagata
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Publication number: 20130172750Abstract: In order to obtain a high-resolution ultrasound diagnostic image while reducing the back side reflection of a ultrasound irradiated to the side opposite to the ultrasound transmission direction of an ultrasound transmission/reception device, disclosed is an ultrasound probe, wherein a substrate is provided thereon with a cavity, insulation layers having the cavity therebetween, and an upper layer electrode and a lower layer electrode having the cavity and the insulation layers therebetween, so as to form an ultrasound vibration element, the substrate is held by a backing with a low-modulus member therebetween, and a direct voltage and a alternating voltage are applied between the electrodes to vibrate the ultrasound vibration element, and wherein a mechanical impedance by the substrate and the low-modulus member has a substantially equal value as an acoustic impedance of the backing.Type: ApplicationFiled: August 19, 2011Publication date: July 4, 2013Applicant: HITACHI MEDICAL CORPORATIONInventors: Yasuhiro Yoshimura, Tatsuya Nagata, Akifumi Sako
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Patent number: 8198782Abstract: An ultrasonic transducer includes a first electrode, a second electrode, an insulating film disposed between the first and second electrodes, and a cavity disposed between the first and second electrodes. The insulating film includes a projection extending in the cavity, and a portion of the cavity is disposed between the projection and the first electrode. A portion of one of the first electrode and the second electrode has an opening corresponding to a position of the projection of the insulating film when viewed in plan view.Type: GrantFiled: March 1, 2010Date of Patent: June 12, 2012Assignee: Hitachi, Ltd.Inventors: Shuntaro Machida, Hiroyuki Enomoto, Yoshitaka Tadaki, Tatsuya Nagata
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Patent number: 8132462Abstract: The receive sensitivity of an ultrasound array transducer structured with a diaphragm electro-acoustic transducer (101) being a basic unit is affected by change in a charge amount with elapsed time due to leakage or the like, which causes drift of the primary beam sensitivity, degradation in the acoustic SN ratio due to a rise in the acoustic noise level, and degradation in the directivity of an ultrasound beam. To addressing this problem, a charge controller (charge monitor 211) is provided to control charge in an electro-acoustic transducer (101). A charge monitoring section (102) monitors the change in the charge amount. When change in the charge amount is small, transmit sensitivity or receive sensitivity is calibrated by a controller (104) by, for example, multiplying a receive signal by a calibration coefficient corresponding to the change amount. Further, when the change in the charge amount is large, for example, charges can be re-emitted from a charge emitter (103).Type: GrantFiled: January 30, 2006Date of Patent: March 13, 2012Assignee: Hitachi Medical CorporationInventors: Takashi Azuma, Shinichiro Umemura, Tatsuya Nagata, Hiroshi Fukuda, Shuntaro Machida, Toshiyuki Mine
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Patent number: 7969067Abstract: There is provided an ultrasound probe including a first substrate having a silicon substrate and an ultrasound transmit-receive element, an acoustic lens disposed over an upper surface of the first substrate, and a damping layer disposed under the first substrate, in which a second substrate is disposed between a lower surface of the first substrate and an upper surface of the damping layer, and the second substrate is made of a material having approximately the same linear expansion coefficient and acoustic impedance as the silicon substrate of the first substrate. With this structure, it is possible to provide the ultrasound probe which can prevent damage to the silicon substrate due to temperature change and has excellent transmission/reception performance and structure reliability while reducing noise by reflected waves in transmission and reception.Type: GrantFiled: November 14, 2006Date of Patent: June 28, 2011Assignee: Hitachi Medical CorporationInventors: Takanori Aono, Tatsuya Nagata, Katsunori Asafusa, Takashi Kobayashi, Naoya Kanda
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Patent number: 7944114Abstract: The present invention provides an ultrasonic transducer device to send and receive ultrasonic waves, comprising a semiconductor substrate, a lower electrode disposed on the semiconductor substrate, a gap disposed on the lower electrode, a third insulation film disposed on the gap, an upper electrode disposed on the third insulation film, a fourth insulation film disposed on the upper electrode, a wiring layer disposed on the fourth insulation film, and a fifth insulation film disposed on the wiring layer. The upper electrode is electrically connected to the wiring layer with penetrating wires.Type: GrantFiled: May 13, 2008Date of Patent: May 17, 2011Assignee: Hitachi, Ltd.Inventors: Yasuhiro Yoshimura, Tatsuya Nagata
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Publication number: 20110071396Abstract: An ultrasonic probe is provided with a CMUT chip having a plurality of transducer elements that change electromechanical coupling coefficients or sensitivities in accordance with a bias voltage to transmit and receive ultrasonic waves, an electric conducting layer formed on the ultrasonic irradiation side of the CMUT chip, an acoustic lens arranged on the ultrasonic irradiation side of the CMUT chip, an insulating layer formed in the direction opposite to the ultrasonic irradiation side of the acoustic lens, a housing unit that stores the CMUT chip in which the electric conducting layer and the insulating layer are fixed with an adhesive and the acoustic lens, wherein the insulating layer is formed by the material that includes at least either silicon oxide or paraxylene to prevent a solvent of the adhesive from soaking into the adhered portion.Type: ApplicationFiled: May 13, 2009Publication date: March 24, 2011Applicant: HITACHI MEDICAL CORPORATIONInventors: Shuzo Sano, Yasuhiro Yoshimura, Tatsuya Nagata, Makoto Fukada, Akifumi Sako
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Patent number: 7862952Abstract: According to the present invention, there is provided a membrane electrode composite module including a membrane electrode composite formed by sandwiching both surfaces of an electrolyte membrane between gas diffusion electrodes, an anode current collecting plate having fuel flow holes through which fuel flows, and a cathode current collecting plate having oxygen flow holes through which oxygen flows, wherein both surfaces of the membrane electrode composite are sandwiched between the anode current collecting plate and the cathode current collecting plate, the membrane electrode composite module further including films made of a synthetic resin (a first film and a second film) which are a base of the anode current collecting plate and a base of the cathode current collecting plate.Type: GrantFiled: July 8, 2005Date of Patent: January 4, 2011Assignees: Hitachi, Ltd., Hitachi Cable, Ltd.Inventors: Ryuji Kohno, Tatsuya Nagata, Makoto Kitano, Masahiro Seido, Kazuhiko Nakagawa
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Patent number: 7860258Abstract: A transducer for transmitting and receiving ultrasonic waves to a diaphragm-based ultrasonic transducer device using silicon as a base material. An electro-acoustic transducer device which can have a first electrode formed on top of, or inside, a substrate and having a thin film provided on top of the substrate. The device can also have a second electrode formed on top of, or inside, the thin film. A void layer can be provided between the first electrode and the second electrode. A charge-storage layer can be provided between the first electrode and the second electrode. A source electrode and a drain electrode can also be provided for measuring a quantity of electricity stored in the charge-storage layer.Type: GrantFiled: July 24, 2006Date of Patent: December 28, 2010Assignee: Hitachi, Ltd.Inventors: Takashi Azuma, Shin-ichiro Umemura, Tatsuya Nagata, Hiroshi Fukuda, Shuntaro Machida, Toshiyuki Mine
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Patent number: 7817811Abstract: The present invention aims to stabilize sound-electricity conversion characteristics of a diaphragm-type sound-electricity conversion device as well as to decrease the noise level of an ultrasonic diagnostic apparatus using the sound-electricity conversion device. The sound-electricity conversion device is configured by a capacitor cell including a lower electrode formed on a silicon substrate and an upper electrode over the lower electrode, the lower and upper electrodes sandwiching a cavity. An electrode short-circuit prevention film is formed on the upper electrode on the cavity side. The electrode short-circuit prevention film is formed of a material with an electrical time constant shorter than 1 second and longer than 10 microseconds, such as silicon nitride containing a stoichiometrically excessive amount of silicon.Type: GrantFiled: January 30, 2006Date of Patent: October 19, 2010Assignee: Hitachi, Ltd.Inventors: Shinichiro Umemura, Takashi Azuma, Tatsuya Nagata, Hiroshi Fukuda, Toshiyuki Mine, Syuntaro Machida
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Publication number: 20100148594Abstract: An ultrasonic transducer includes a first electrode, a second electrode, an insulating film disposed between the first and second electrodes, and a cavity disposed between the first and second electrodes. The insulating film includes a projection extending in the cavity, and a portion of the cavity is disposed between the projection and the first electrode. A portion of one of the first electrode and the second electrode has an opening corresponding to a position of the projection of the insulating film when viewed in plan view.Type: ApplicationFiled: March 1, 2010Publication date: June 17, 2010Inventors: Shuntaro Machida, Hiroyuki Enomoto, Yoshitaka Tadaki, Tatsuya Nagata
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Patent number: 7675221Abstract: Disclosed is an improved construction of an ultrasonic transducer, wherein a charge is not easily injected into an insulating film even when the bottom of a membrane comes in contact with a lower electrode, and a manufacturing method thereof without using the wafer laminating technique. The ultrasonic transducer includes a lower electrode; a cavity layer formed on the first electrode; an insulating film covering the cavity layer; and an upper electrode formed on the insulating film, wherein, the cavity layer includes projections formed into an insulating film protruded from the cavity layer. In addition, an opening is formed into the upper electrode, and this upper electrode having the opening formed therein is deposited at a position not being superposed with the projections of the insulating film when seen from the top.Type: GrantFiled: July 20, 2006Date of Patent: March 9, 2010Assignee: Hitachi, Ltd.Inventors: Shuntaro Machida, Hiroyuki Enomoto, Yoshitaka Tadaki, Tatsuya Nagata
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Patent number: 7667374Abstract: In an ultrasonic transducer including a gap between an upper electrode and a lower electrode on a silicon substrate, it is made possible to reduce or adjust warpage of an above-gap membrane vibrated by electrostatic actuation due to internal stress. A fourth insulating film and a fifth insulating film of films positioned above the gap which is a cavity required for transmitting and receiving ultrasonic are respectively a silicon oxide film for compression stress and a silicon nitride film for tensile stress. Therefore, compression stress and tensile stress cancel each other, so that warpage of the above-gap membrane is reduced. An amount of warpage can be adjusted by adjusting a film thickness of the fourth insulating film and a film thickness of the fifth insulating film.Type: GrantFiled: January 23, 2007Date of Patent: February 23, 2010Assignee: Hitachi, Ltd.Inventors: Takanori Aono, Tatsuya Nagata, Hiroyuki Enomoto, Shuntaro Machida
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Publication number: 20090301199Abstract: The receive sensitivity of an ultrasound array transducer structured with a diaphragm electro-acoustic transducer (101) being a basic unit is affected by change in a charge amount with elapsed time due to leakage or the like, which causes drift of the primary beam sensitivity, degradation in the acoustic SN ratio due to a rise in the acoustic noise level, and degradation in the directivity of an ultrasound beam. To addressing this problem, a charge controller (charge monitor 211) is provided to control charge in an electro-acoustic transducer (101). A charge monitoring section (102) monitors the change in the charge amount. When change in the charge amount is small, transmit sensitivity or receive sensitivity is calibrated by a controller (104) by, for example, multiplying a receive signal by a calibration coefficient corresponding to the change amount. Further, when the change in the charge amount is large, for example, charges can be re-emitted from a charge emitter (103).Type: ApplicationFiled: January 30, 2006Publication date: December 10, 2009Inventors: Takashi Azuma, Shinichiro Umemura, Tatsuya Nagata, Hiroshi Fukuda, Shuntaro Machida, Toshiyuki Mine
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Publication number: 20090299192Abstract: An ultrasound diagnostic apparatus 1 causes discharge means 4 to apply a discharge pulse (having a peak value equal to or greater than a collapse voltage) between electrodes of an ultrasound transducer 20 a plurality of time while inverting the polarity of the discharge pulse each time, to thereby accelerate discharge of the charge accumulated in the diaphragm of the ultrasound transducer 20, so that a transmission-reception sensitivity offset can be caused to quickly approach zero. The charge is discharged instantaneously. That is, it is possible to quickly calibrate a transmission-reception sensitivity drift stemming from time-course accumulation of charge flowing into the diaphragm between the electrodes upon application of a DC bias thereto.Type: ApplicationFiled: October 25, 2006Publication date: December 3, 2009Inventors: Katsunori Asafusa, Tatsuya Nagata
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Publication number: 20090175477Abstract: A vibration transducer (e.g. a condenser microphone) having a high sensitivity is constituted of a housing composed of an airtight material having a through-hole, a vibration conversion die (e.g. a microphone die) which is attached to the interior surface of the housing at the prescribed position embracing the through-hole in plan view, and a barrier diaphragm composed of an airtight material whose external periphery is attached to the exterior surface of the housing in an airtight manner oppositely to the prescribed position. The barrier diaphragm has a vibration area which is larger than the sectional area of the through-hole. A space allowing the barrier diaphragm to vibrate is formed between the barrier diaphragm and the exterior surface of the housing, wherein the distance between the barrier diaphragm and the exterior surface of the housing can be gradually reduced from the vibration axis to the external periphery.Type: ApplicationFiled: August 14, 2008Publication date: July 9, 2009Applicant: Yamaha CorporationInventors: Yukitoshi Suzuki, Toshihisa Suzuki, Kunimasa Muroi, Tatsuya Nagata
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Publication number: 20090069688Abstract: There is provided an ultrasound probe including a first substrate having a silicon substrate and an ultrasound transmit-receive element, an acoustic lens disposed over an upper surface of the first substrate, and a damping layer disposed under the first substrate, in which a second substrate is disposed between a lower surface of the first substrate and an upper surface of the damping layer, and the second substrate is made of a material having approximately the same linear expansion coefficient and acoustic impedance as the silicon substrate of the first substrate. With this structure, it is possible to provide the ultrasound probe which can prevent damage to the silicon substrate due to temperature change and has excellent transmission/reception performance and structure reliability while reducing noise by reflected waves in transmission and reception.Type: ApplicationFiled: November 14, 2006Publication date: March 12, 2009Applicant: HITACHI MEDICAL CORPORATIONInventors: Takanori Aono, Tatsuya Nagata, Katsunori Asafusa, Takashi Kobayashi, Naoya Kanda
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Publication number: 20080284287Abstract: The present invention provides an ultrasonic transducer device to send and receive ultrasonic waves, comprising a semiconductor substrate, a lower electrode disposed on the semiconductor substrate, a gap disposed on the lower electrode, a third insulation film disposed on the gap, an upper electrode disposed on the third insulation film, a fourth insulation film disposed on the upper electrode, a wiring layer disposed on the fourth insulation film, and a fifth insulation film disposed on the wiring layer. The upper electrode is electrically connected to the wiring layer with penetrating wires.Type: ApplicationFiled: May 13, 2008Publication date: November 20, 2008Inventors: Yasuhiro YOSHIMURA, Tatsuya Nagata
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Patent number: 7345892Abstract: In a memory module, reference potential connecting patterns are disposed on high frequency signal lines and/or on the extension lines extending from the terminal ends of the signal lines as well as a shield cover for covering semiconductor memory chips is disposed on the substrate, and the reference potential connecting patterns are connected to the shield cover through metal cover contact parts.Type: GrantFiled: May 20, 2005Date of Patent: March 18, 2008Assignees: NEC Corporation, Renesas Eastern Japan Semiconductor, Inc., Elpida Memory, Inc.Inventors: Masaharu Imazato, Atsushi Nakamura, Takayuki Watanabe, Kensuke Tsuneda, Mitsuaki Katagiri, Hiroya Shimizu, Tatsuya Nagata
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Patent number: 7298081Abstract: A display apparatus is disclosed with a vacuum seal member which has a shell structure. The display apparatus includes an anode substrate, a planar cathode substrate forming an electron emitting chamber vacuously sealed between the cathode substrate and the anode substrate, electron sources formed on the cathode substrate, phosphors formed on the anode substrate, and a vacuum seal member forming a pressure balancing chamber on the back of the electron emitting chamber side of the cathode substrate. The vacuum seal member is placed covering the back of the electron emitting chamber side, and has a shell structure for receiving the atmospheric pressure.Type: GrantFiled: May 19, 2005Date of Patent: November 20, 2007Assignee: Hitachi, Ltd.Inventors: Takeshi Terasaki, Atsushi Kazama, Makoto Kitano, Tatsuya Nagata, Takashi Fujimura