Patents by Inventor Toru Yokohata
Toru Yokohata 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: 10248142Abstract: A cooling apparatus includes: a pump transports a refrigerant; and a controller controls a discharge amount of the pump depending on a calorific value of a heat generating body. And a cooling method includes: measuring a calorific value of a heat generating body; and controlling a discharge amount of a pump, which transports a refrigerant used for cooling the heat generating body, depending on the calorific value.Type: GrantFiled: May 18, 2016Date of Patent: April 2, 2019Assignee: FUJITSU LIMITEDInventors: Toru Yokohata, Hiroshi Ishikawa
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Publication number: 20160353614Abstract: A cooling apparatus includes: a pump transports a refrigerant; and a controller controls a discharge amount of the pump depending on a calorific value of a heat generating body. And a cooling method includes: measuring a calorific value of a heat generating body; and controlling a discharge amount of a pump, which transports a refrigerant used for cooling the heat generating body, depending on the calorific value.Type: ApplicationFiled: May 18, 2016Publication date: December 1, 2016Applicant: FUJITSU LIMITEDInventors: Toru Yokohata, Hiroshi ISHIKAWA
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Publication number: 20150156921Abstract: An electrical system comprising a plurality of sets of electrical devices and cooling units that respectively cool the electrical devices, wherein: each of the cooling units includes a tank that is connected via a connection pipe to another tank of another of the cooling units and that stores coolant; a heat exchanger that cools the coolant from the tank; and a pump that feeds the coolant, which has been cooled by the heat exchanger, via a circulation pipe to the tank, the heat exchanger, and a cooler that cools a respective one of the electrical devices.Type: ApplicationFiled: November 24, 2014Publication date: June 4, 2015Applicant: FUJITSU LIMITEDInventor: Toru YOKOHATA
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Patent number: 8738869Abstract: A storage system is disclosed that stores data across plural storage devices. The storage system includes plural modules. Each of the modules includes a storage device including a data storage section that has plural slice areas to store data elements one in each, and a control-information storage section that stores control information of the plural slice areas, a communications-function section having a function of sending and receiving the data elements stored in the slice areas in the data storage section. The modules communicate with each other to replicate the data element stored in the slice area into an unused slice area in another module so as to have data redundancy.Type: GrantFiled: May 31, 2005Date of Patent: May 27, 2014Assignee: Fujitsu LimitedInventors: Kazutaka Ogihara, Masahisa Tamura, Toru Yokohata, Satoshi Ikuta, Yasuo Noguchi, Riichiro Take
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Patent number: 8296512Abstract: A recording method for a disk device includes the following steps. Sequential data is written into the medium along the track in a predetermined radial direction. Information indicating an end position along the track where the end of the sequential data is written into is stored. The information is read when additional sequential data is to be written into the medium. The additional data is written from a position along the track next to the end position indicated by the information in the predetermined radial direction. The information is updated so as to indicate an end position along the track where the end of the additional sequential data is written into.Type: GrantFiled: January 27, 2009Date of Patent: October 23, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Toru Yokohata, Hitoshi Komoriya, Takayuki Kawabe
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Patent number: 7774572Abstract: The present invention relates to a system capable of carrying out efficient and stable system operation control even if a usage rate of the entire system varies under a situation in which the characteristics of storage units, such as maximum available total capacity and speed performance, are largely different from each other. Therefore, the system according to the present invention is composed of a monitor unit for monitoring information on a total volume of data stored in each of the storage units or in all the storage units, an index value calculating unit for calculating an index value on the basis of the monitor result and a location unit for distributively locating or relocating logical storage areas in physical storage areas on a plurality of storage units on the basis of the calculated index value.Type: GrantFiled: June 29, 2004Date of Patent: August 10, 2010Assignee: Fujitsu LimitedInventors: Toru Yokohata, Atsuo Iida, Arata Ejiri, Mitsuhiko Ohta, Riichiro Take, Kazutaka Ogihara, Yasuo Noguchi
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Publication number: 20090190251Abstract: A recording method for a disk device includes the following steps. Sequential data is written into the medium along the track in a predetermined radial direction. Information indicating an end position along the track where the end of the sequential data is written into is stored. The information is read when additional sequential data is to be written into the medium. The additional data is written from a position along the track next to the end position indicated by the information in the predetermined radial direction. The information is updated so as to indicate an end position along the track where the end of the additional sequential data is written into.Type: ApplicationFiled: January 27, 2009Publication date: July 30, 2009Applicant: FUJITSU LIMITEDInventors: Toru Yokohata, Hitoshi Komoriya, Takayuki Kawabe
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Patent number: 7522360Abstract: Provided is a new apparatus for measuring a flying height of a head requiring none of a specific magnetization pattern, that is, ahead flying height measurement apparatus for use within a disk drive including a reading head, including: a signal replay unit 300 for replaying a signal from the reading head; filter units 320 and 322, being connected to the signal replay unit, for filtering the replayed signal; amplitude detection units 330 and 332, being connected to each of the filter units, for detecting a maximum amplitude or a representative value close thereto from the filtered replayed signal; and a calculation unit 340 for calculating a flying height of the reading head within the disk drive by using the maximum amplitude, or the representative value close thereto, which is detected by the amplitude detection unit.Type: GrantFiled: July 6, 2006Date of Patent: April 21, 2009Assignee: Fujitsu LimitedInventors: Takahiro Imamura, Toru Yokohata
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Publication number: 20080266692Abstract: A data writing method to write data on a disk in a disk device. The data is written in one radial direction. The method includes detecting a first deviation amount from a center in a current track and sector in the direction of a track on which data was previously written. A second deviation amount from the center in the current track and sector in the direction of a track on which data will be subsequently written is also detected. Data is written on the current track when the first deviation amount is equal to or smaller than a first threshold and the second deviation amount is equal to or smaller than a second threshold.Type: ApplicationFiled: April 25, 2008Publication date: October 30, 2008Applicant: FUJITSU LIMITEDInventors: Hitoshi Komoriya, Michinaga Yamagishi, Toru Yokohata
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Publication number: 20080239581Abstract: An AC power source is connected to a write coil mounted on a head slider for determination of contact of a head slider with a storage medium. The AC power source outputs the alternating current having a specific frequency. A measuring circuit measures a sequence of indices for the alternating current supplied to the write coil. A component corresponding to the specific frequency is extracted from the sequence of the indices. This serves to eliminate components corresponding to frequencies other than the specific frequency, namely noise. A detecting circuit detects contact between the head slider and the storage medium based on a change in the amplitude of the sequence appearing at the specific frequency. The contact can thus reliably be detected between the head slider and the storage medium.Type: ApplicationFiled: August 23, 2007Publication date: October 2, 2008Applicant: FUJITSU LIMITEDInventors: Yoshiaki Ikai, Takahiro Imamura, Tohru Fujimaki, Toru Yokohata
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Patent number: 7369341Abstract: Firstly, in order to check the noise level of a device, DC erasure is applied to a magnetic recording medium and the magnetic recording medium is read. Then, a test signal including a first order component and a third order harmonic frequency is written into the magnetic recording medium. The written test signal is read and Fourier transform is applied to the read signal to obtain the respective amplitude of the first order and third order harmonic components. Then, it is determined whether the amplitude of the third order harmonic component is sufficiently large compared with the obtained noise level. If the amplitude is sufficiently large, the flying height of the head is estimated using both the first order and third order harmonic components. If the amplitude is not sufficiently large, the flying height of the head is estimated using only the first order component.Type: GrantFiled: June 29, 2006Date of Patent: May 6, 2008Assignee: Fujitsu LimitedInventors: Toru Yokohata, Takahiro Imamura, Atsuo Iida
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Patent number: 7365931Abstract: A method of detecting a gap between a head and a recording medium in an information-recording/reproducing apparatus that uses the head to record and reproduce information in and from the recording medium. In the method, the gap between the head and the recording medium is alternately increased and decreased, thereby gradually reducing the gap between the head and the recording medium. A detection signal is detected from which to determine a contact between the head or a slider supporting the head and the recording medium. When it is determined that the head or the slider has contacted the recording medium, the head is stopped and moved away from the recording medium to a prescribed position, and data representing a distance the head has moved to contact the recoding medium is acquired.Type: GrantFiled: August 30, 2006Date of Patent: April 29, 2008Assignee: Fujitsu LimitedInventors: Yoshiaki Ikai, Atsuo Iida, Takahiro Imamura, Tohru Fujimaki, Toru Yokohata
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Publication number: 20080074797Abstract: A first wiring connects a first actuator to a controlling circuit on a head slider. The second wiring connects the second actuator to the first wiring in parallel with the first actuator. A first rectifying element is inserted in the first wiring. A second rectifying element is inserted in the second wiring. When electric voltage is applied to the first and second wiring in a first direction, the electric voltage acts on the first wiring. Only the first actuator is allowed to receive the electric voltage. When electric voltage is applied to the first and second wiring in a second direction opposite to the first direction, the electric voltage acts on the second wiring. Only the second actuator is allowed to receive the electric voltage in the second direction.Type: ApplicationFiled: July 25, 2007Publication date: March 27, 2008Applicant: FUJITSU LIMITEDInventors: Yoshiaki Ikai, Toru Yokohata, Takahiro Imamura, Kenrou Yamamoto
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Publication number: 20070253092Abstract: A method of detecting a gap between a head and a recording medium in an information-recording/reproducing apparatus that uses the head to record and reproduce information in and from the recording medium. In the method, the gap between the head and the recording medium is alternately increased and decreased, thereby gradually reducing the gap between the head and the recording medium. A detection signal is detected from which to determine a contact between the head or a slider supporting the head and the recording medium. When it is determined that the head or the slider has contacted the recording medium, the head is stopped and moved away from the recording medium to a prescribed position, and data representing a distance the head has moved to contact the recoding medium is acquired.Type: ApplicationFiled: August 30, 2006Publication date: November 1, 2007Applicant: FUJITSU LIMITEDInventors: Yoshiaki Ikai, Atsuo Iida, Takahiro Imamura, Tohru Fujimaki, Toru Yokohata
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Publication number: 20070230013Abstract: Firstly, in order to check the noise level of a device, DC erasure is applied to a magnetic recording medium and the magnetic recording medium is read. Then, a test signal including a first order component and a third order harmonic frequency is written into the magnetic recording medium. The written test signal is read and Fourier transform is applied to the read signal to obtain the respective amplitude of the first order and third order harmonic components. Then, it is determined whether the amplitude of the third order harmonic component is sufficiently large compared with the obtained noise level. If the amplitude is sufficiently large, the flying height of the head is estimated using both the first order and third order harmonic components. If the amplitude is not sufficiently large, the flying height of the head is estimated using only the first order component.Type: ApplicationFiled: June 29, 2006Publication date: October 4, 2007Applicant: FUJITSU LIMITEDInventors: Toru Yokohata, Takahiro Imamura, Atsuo Iida
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Publication number: 20070230001Abstract: In an inspection for judging acceptance of a recording and reproduction head used in a recording and reproduction device, quality information indicating quality of a data signal of a head unit and flying height information indicating flying height of the head unit are acquired, and acceptance of the head unit is judged by a combination of the quality and the flying height.Type: ApplicationFiled: July 6, 2006Publication date: October 4, 2007Applicant: FUJITSU LIMITEDInventors: Takahiro Imamura, Hiroyuki Kubotera, Toru Yokohata
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Publication number: 20070211361Abstract: Provided is a new apparatus for measuring a flying height of a head requiring none of a specific magnetization pattern, that is, ahead flying height measurement apparatus for use within a disk drive including a reading head, including: a signal replay unit 300 for replaying a signal from the reading head; filter units 320 and 322, being connected to the signal replay unit, for filtering the replayed signal; amplitude detection units 330 and 332, being connected to each of the filter units, for detecting a maximum amplitude or a representative value close thereto from the filtered replayed signal; and a calculation unit 340 for calculating a flying height of the reading head within the disk drive by using the maximum amplitude, or the representative value close thereto, which is detected by the amplitude detection unit.Type: ApplicationFiled: July 6, 2006Publication date: September 13, 2007Applicant: FUJITSU LIMITEDInventors: Takahiro Imamura, Toru Yokohata
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Publication number: 20070127147Abstract: In a contact detecting apparatus that detects contact of a head with a recording medium, a signal writing unit writes onto the recording medium, a signal that includes at least one predetermined frequency component; and a contact detecting unit detects the contact of the head with the recording medium based on an amplitude of the predetermined frequency component, by reading the signal written on the recording medium while changing a spacing between the head and the recording medium.Type: ApplicationFiled: March 23, 2006Publication date: June 7, 2007Applicant: FUJITSU LIMITEDInventors: Toru Yokohata, Takeshi Iwase, Takahisa Ueno, Seigo Igaki, Takahiro Imamura
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Publication number: 20070127148Abstract: In a contact detecting apparatus that detects contact of a head with a recording medium, a signal writing unit writes onto the recording medium, a signal that includes at least one predetermined frequency component; and a contact detecting unit detects the contact of the head with the recording medium based on an amplitude of the predetermined frequency component, by reading the signal written on the recording medium while changing a spacing between the head and the recording medium.Type: ApplicationFiled: September 20, 2006Publication date: June 7, 2007Applicant: FUJITSU LIMITEDInventors: Toru Yokohata, Takeshi Iwase, Takahisa Ueno, Seigo Igaki, Takahiro Imamura, Tohru Fujimaki
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Patent number: 7057385Abstract: A magnetic recording medium inspection method detects small protrusions that constitute defects on the surface of a magnetic recording medium. The method includes flying a glide inspection head at a predetermined height over the surface of the moving magnetic recording medium; detecting a contact duration time during which the glide head is in contact with a protrusion on the surface of the magnetic recording medium using a contact detection sensor attached to the glide inspection head; and determining the small protrusion based on the contact duration time.Type: GrantFiled: March 12, 2003Date of Patent: June 6, 2006Assignee: Fujitsu LimitedInventors: Toru Yokohata, Takahiro Imamura, Toshiya Fujita, Yojiro Ochiai, Masahiro Ozeki, Naoki Satake