Patents by Inventor Hiroyasu Yoshizawa
Hiroyasu Yoshizawa 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: 7692456Abstract: A semiconductor integrated circuit having a plurality of ultrasound pulsers corresponding to a plurality of respective channels, and integrally formed on a small area. The ultrasound pulsers each include a MOSFET gate drive circuit in which an input voltage pulse is converted into a current pulse, and the current pulse is converted again into a voltage pulse on the basis of a high potential side voltage +HV, and a low potential side voltage ?HV, applied to a transducer drive circuit, and in which a voltage level shift in the input voltage pulse is attained, and a voltage pulse swing is generated by the MOSFET gate drive circuit on the basis of the high potential side voltage +HV, and the low potential side voltage ?HV. The MOSFET gate drive circuit is DC-coupled with the transducer drive circuit.Type: GrantFiled: December 17, 2007Date of Patent: April 6, 2010Assignee: Hitachi, Ltd.Inventors: Satoshi Hanazawa, Hiroyasu Yoshizawa
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Publication number: 20080238532Abstract: With an ultrasound pulser suitable for application to a medical ultrasound system, and so forth, a high voltage power supply of a transducer drive circuitry, on both high potential and low potential sides, is rendered variable in a range of 0 V on the order of ±200 V, thereby implementing a semiconductor integrated circuit wherein a plurality of the ultrasound pulsers corresponding to a plurality of channels, respectively, are integrally formed on a small area.Type: ApplicationFiled: December 17, 2007Publication date: October 2, 2008Inventors: Satoshi Hanazawa, Hiroyasu Yoshizawa
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Patent number: 7372330Abstract: A variable gain amplifier of such configuration that can yield continuously and log-linearly variable gains in relation to control voltage and, at the same time, that does not use an attenuator, an element which otherwise would entail cause of increased noise. The amplifier includes a plurality of gm amplifiers connected in parallel with input signal, exponential multipliers connected respectively to the gm amplifiers, a control section to vary the multiplication coefficient of the exponential multipliers according to the external gain control signal, and an I-V converter circuit to aggregate current output after multiplication and convert the aggregated current output to voltage. A continuously variable gain characteristic can be obtained without the use of an attenuator but by varying multiplication coefficient according to control voltage.Type: GrantFiled: July 12, 2006Date of Patent: May 13, 2008Assignee: Hitachi, Ltd.Inventors: Hiroyasu Yoshizawa, Satoshi Hanazawa
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Patent number: 7239467Abstract: The storage media recording/writing system includes a media drive circuit, a head retaining means, a head moving means, a head drive circuit, a signal processing circuit, and a controller to control these. The head drive circuit possesses a first semiconductor integrated circuit having an amplifier that amplifies the read signal from the head, and a second semiconductor integrated circuit placed between the first semiconductor integrated circuit and the signal processing circuit, which has a circuit that receives write data from the signal processing circuit and generates a drive signal to drive a write head. Further, the first semiconductor integrated circuit is mounted on a part near the front of the head retaining means, and the second semiconductor integrated circuit is installed on the side of the moving means.Type: GrantFiled: April 29, 2004Date of Patent: July 3, 2007Assignee: Hitachi, Ltd.Inventors: Hiroyasu Yoshizawa, Yoichiro Kobayashi, Toshio Shinomiya, Noriyuki Fujii, Masaki Yoshinaga
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Publication number: 20070121237Abstract: A magnetic disk apparatus-purpose reproducing circuit capable of performing a high speed and under stable condition. In the magnetic disk apparatus-purpose reproducing circuit equipped with: a bias circuit for applying a bias voltage with respect to an MR (Magneto-Resistive) head, an amplification circuit for amplifying an output of the MR head, capacitors C0 and C1 for cutting a DC component contained in the output of the MR head, and a conductor amplifier for applying an input bias of the amplifier, a shortcircuit-purpose switch S0 for charging the DC cut capacitors are further provided. When a mode transition from a write mode to a read mode occurs, the shortcircuit-purpose switch S0 is turned ON so as to charge the DC cut capacitors, so that a mode transition characteristic capable of establishing a high speed characteristic and a stable characteristic can be obtained.Type: ApplicationFiled: November 28, 2006Publication date: May 31, 2007Inventors: Hiroyasu Yoshizawa, Yoichiro Kobayashi, Toshio Shinomiya
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Publication number: 20070075774Abstract: A variable gain amplifier of such configuration that can yield continuously and log-linearly variable gains in relation to control voltage and, at the same time, that does not use an attenuator, an element which otherwise would entail cause of increased noise. The amplifier includes a plurality of gm amplifiers connected in parallel with input signal, exponential multipliers connected respectively to the gm amplifiers, a control section to vary the multiplication coefficient of the exponential multipliers according to the external gain control signal, and an I-V converter circuit to aggregate current output after multiplication and convert the aggregated current output to voltage. A continuously variable gain characteristic can be obtained without the use of an attenuator but by varying multiplication coefficient according to control voltage.Type: ApplicationFiled: July 12, 2006Publication date: April 5, 2007Inventors: Hiroyasu Yoshizawa, Satoshi Hanazawa
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Patent number: 7082004Abstract: The present invention provides a disk storage system with a low error rate, which is suitable for reduction in size. The other end of the signal line, which is connected with a read head at one end, is connected with a head bias circuit to apply a sense current to the read head and a pair of first and second capacitance elements for allowing the read signal element formed by the read head to pass, a loop is provided for amplifying the read signal obtained through the first and second capacitance elements by supplying the read signal to an input terminal of a differential amplifying circuit and for converting the amplified signal into the current by transconductance and providing a positive feedback of the amplified signal to the input terminal of the differential amplifying circuit.Type: GrantFiled: January 12, 2005Date of Patent: July 25, 2006Assignee: Hitachi, Ltd.Inventors: Shinya Kajiyama, Hiroyasu Yoshizawa, Yoichiro Kobayashi, Ichiro Somada
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Publication number: 20050180041Abstract: The present invention provides a disk storage system with a low error rate, which is suitable for reduction in size. The other end of the signal line, which is connected with a read head at one end, is connected with a head bias circuit to apply a sense current to the read head and a pair of first and second capacitance elements for allowing the read signal element formed by the read head to pass, a loop is provided for amplifying the read signal obtained through the first and second capacitance elements by supplying the read signal to an input terminal of a differential amplifying circuit and for converting the amplified signal into the current by transconductance and providing a positive feedback of the amplified signal to the input terminal of the differential amplifying circuit.Type: ApplicationFiled: January 12, 2005Publication date: August 18, 2005Inventors: Shinya Kajiyama, Hiroyasu Yoshizawa, Yoichiro Kobayashi, Ichiro Somada
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Publication number: 20050128619Abstract: A magnetic head driving circuit includes a main driving circuit symmetrical with respect to a centered recording coil, and at least two pairs of adding circuits, each pair including a positive pulse adding circuit and a negative pulse superposed circuit symmetrical with respect to the centered coil. And, by reversing the direction of the magnetic head coil current, at least one of the adding circuits is made to operate and make it as a magnetic head driving circuit for adding a potential equal to or higher than the power supply, thereby to drive as a sub-driving circuit arranged symmetrically with respect to the centered coil, which promotes the reversal of the magnetic head coil current, and which drives stably with a central potential of the coil at about the disk potential.Type: ApplicationFiled: February 4, 2005Publication date: June 16, 2005Inventors: Yasuyuki Ookuma, Kenji Maio, Yoichiro Kobayashi, Hiroyasu Yoshizawa
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Patent number: 6867936Abstract: A magnetic head driving circuit includes a main driving circuit symmetrical with respect to a centered recording coil, and at least two pairs of adding circuits, each pair including a positive pulse adding circuit and a negative pulse superposed circuit symmetrical with respect to the centered coil. And, by reversing the direction of the magnetic head coil current, at least one of the adding circuits is made to operate and make it as a magnetic head driving circuit for adding a potential equal to or higher than the power supply, thereby to drive as a sub-driving circuit arranged symmetrically with respect to the centered coil, which promotes the reversal of the magnetic head coil current, and which drives stably with a central potential of the coil at about the disk potential.Type: GrantFiled: August 30, 2001Date of Patent: March 15, 2005Assignee: Hitachi, Ltd.Inventors: Yasuyuki Ookuma, Kenji Maio, Yoichiro Kobayashi, Hiroyasu Yoshizawa
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Publication number: 20040202066Abstract: The storage media recording/writing system includes a media drive circuit, a head retaining means, a head moving means, a head drive circuit, a signal processing circuit, and a controller to control these. The head drive circuit possesses a first semiconductor integrated circuit having an amplifier that amplifies the read signal from the head, and a second semiconductor integrated circuit placed between the first semiconductor integrated circuit and the signal processing circuit, which has a circuit that receives write data from the signal processing circuit and generates a drive signal to drive a write head. Further, the first semiconductor integrated circuit is mounted on a part near the front of the head retaining means, and the second semiconductor integrated circuit is installed on the side of the moving means.Type: ApplicationFiled: April 29, 2004Publication date: October 14, 2004Applicant: Hitachi, Ltd.Inventors: Hiroyasu Yoshizawa, Yoichiro Kobayashi, Toshio Shinomiya, Noriyuki Fujii, Masaki Yoshinaga
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Patent number: 6762896Abstract: The storage media recording/writing system includes a media drive circuit, a head retaining means, a head moving means, a head drive circuit, a signal processing circuit, and a controller to control these. The head drive circuit possesses a first semiconductor integrated circuit having an amplifier that amplifies the read signal from the head, and a second semiconductor integrated circuit placed between the first semiconductor integrated circuit and the signal processing circuit, which has a circuit that receives write data from the signal processing circuit and generates a drive signal to drive a write head. Further, the first semiconductor integrated circuit is mounted on a part near the front of the head retaining means, and the second semiconductor integrated circuit is installed on the side of the moving means.Type: GrantFiled: July 12, 2001Date of Patent: July 13, 2004Assignee: Hitachi, Ltd.Inventors: Hiroyasu Yoshizawa, Yoichiro Kobayashi, Toshio Shinomiya, Noriyuki Fujii, Masaki Yoshinaga
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Publication number: 20030142432Abstract: There is provided a semiconductor integrated circuit for magnetic recording including a write circuit which may be operated with the power supply voltage of 5V system without any problem on the dielectric strength thereof and also assures high speed data write operation to media of the magnetic recording system and a high-speed and highly reliable storage media reading system which has employed the same semiconductor integrated circuit. The write circuit described above is configured to apply a drive voltage to a head through superimposition so that a write current generates over-shoot when the current is inverted by providing the write head with a voltage and moreover a protection element is provided to protect a switch MOSFET for the current switching from a high voltage which is applied to the write head when the current is inverted.Type: ApplicationFiled: December 30, 2002Publication date: July 31, 2003Applicant: Hitachi, Ltd.Inventors: Hiroyasu Yoshizawa, Yoichiro Kobayashi
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Publication number: 20020118479Abstract: The storage media recording/writing system includes a media drive circuit, a head retaining means, a head moving means, a head drive circuit, a signal processing circuit, and a controller to control these. The head drive circuit possesses a first semiconductor integrated circuit having an amplifier that amplifies the read signal from the head, and a second semiconductor integrated circuit placed between the first semiconductor integrated circuit and the signal processing circuit, which has a circuit that receives write data from the signal processing circuit and generates a drive signal to drive a write head. Further, the first semiconductor integrated circuit is mounted on a part near the front of the head retaining means, and the second semiconductor integrated circuit is installed on the side of the moving means.Type: ApplicationFiled: July 12, 2001Publication date: August 29, 2002Inventors: Hiroyasu Yoshizawa, Yoichiro Kobayashi, Toshio Shinomiya, Noriyuki Fujii, Masaki Yoshinaga
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Publication number: 20020105746Abstract: A magnetic head driving circuit includes a main driving circuit symmetrical with respect to a centered recording coil, and at least two pairs of adding circuits, each pair including a positive pulse adding circuit and a negative pulse superposed circuit symmetrical with respect to the centered coil. And, by reversing the direction of the magnetic head coil current, at least one of the adding circuits is made to operate and make it as a magnetic head driving circuit for adding a potential equal to or higher than the power supply, thereby to drive as a sub-driving circuit arranged symmetrically with respect to the centered coil, which promotes the reversal of the magnetic head coil current, and which drives stably with a central potential of the coil at about the disk potential.Type: ApplicationFiled: August 30, 2001Publication date: August 8, 2002Inventors: Yasuyuki Ookuma, Kenji Maio, Yoichiro Kobayashi, Hiroyasu Yoshizawa
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Patent number: 6169777Abstract: In a fuel transport container, basket has a basket hole including at least two adjacent inner side walls to be fit to a fuel assembly for housing the fuel assembly element in the basket hole. The fuel assembly element is directly housed in the basket hole of the basket. The fuel assembly housed in the basket hole is slid by bias means toward the two adjacent inner side walls thereof without pushing the fuel assembly thereby biasing the housed fuel assembly so that the fuel assembly element is in contact with the two adjacent inner side walls of the basket hole.Type: GrantFiled: July 1, 1998Date of Patent: January 2, 2001Assignee: Kabushiki Kaisha ToshibaInventors: Hiroyasu Yoshizawa, Tamotsu Ozawa
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Patent number: 6134290Abstract: In a transport container, at least one fuel assembly containing element including at least one fuel assembly is housed in a container having an inner surface portion to be fit to the at least one fuel assembly containing element. The inner surface portion has a predetermined shape substantially corresponding to a fit portion of the at least one fuel assembly containing element. The at least one fuel assembly containing element is pushed by a support against the inner surface portion of the container along a fixed support direction. Therefore, the fit portion of the at least one fuel assembly containing element is fit to the inner surface portion of the container so that the at least one fuel assembly containing element is fixedly supported to the container.Type: GrantFiled: February 7, 2000Date of Patent: October 17, 2000Assignee: Kabushiki Kaisha ToshibaInventors: Hiroyasu Yoshizawa, Tamotsu Ozawa, Satoshi Hirayama
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Patent number: 6128360Abstract: In a fuel protective apparatus having a fuel assembly, the fuel protective apparatus is hoisted up by using a hoisting accessory. The fuel protective apparatus includes a fuel protective container for housing the fuel assembly. The fuel protective container has an opening portion to which the hoisting accessory is accessed. An attachment jig member is fixedly secured to the fuel protective container so as to be engaged to the hoisting accessory accessed to the opening portion.Type: GrantFiled: March 5, 1998Date of Patent: October 3, 2000Assignee: Kabushiki Kaisha ToshibaInventors: Hiroyasu Yoshizawa, Tamotsu Ozawa, Satoshi Hirayama
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Patent number: 6108392Abstract: In a transport container, at least one fuel assembly is housed in a container having an inner surface portion to be fit to the at least one fuel assembly. The inner surface portion has a predetermined shape substantially corresponding to a fit portion of the at least one fuel assembly. The at least one fuel assembly is pushed against the inner surface portion of the container along a fixedly support direction. Therefore, the fit portion of the at least one fuel assembly is fit to the inner surface portion of the container so that the at least one fuel assembly is fixedly supported to the container.Type: GrantFiled: January 21, 1998Date of Patent: August 22, 2000Assignee: Kabushiki Kaisha ToshibaInventors: Hiroyasu Yoshizawa, Tamotsu Ozawa, Satoshi Hirayama
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Patent number: 5542832Abstract: A fluid compressor having a rotational force transmitting mechanism. The mechanism comprises an Oldam portion, an Oldam ring and a second cylinder gearing. The Oldam portion is integral with a piston. The Oldam ring has a first pair of key grooves and a second pair of key grooves. The key grooves of the first pair extend at right angles to those of the second pair. The second cylinder bearing is fitted in the cylinder and has two projections fitted in the key grooves of the second pair. The Oldam ring is made of silicon nitride ceramic.Type: GrantFiled: September 15, 1994Date of Patent: August 6, 1996Assignee: Kabushiki Kaisha ToshibaInventors: Yoshinori Sone, Takayoshi Fujiwara, Takashi Honjo, Takuya Hirayama, Hiroyasu Yoshizawa