Patents by Inventor Hitoshi Kishi
Hitoshi Kishi 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: 7123456Abstract: A combined stripe of a magnetoresistive (MR) film and domain control stripe layers can be formed below a photoresist film on the surface of a substratum. An insulating base layer is then formed to extend over the surface of the substratum. The insulating base layer is allowed to cover over the photoresist film, the magnetoresistive film and the domain control stripe layers on the substratum. When the photoresist film is removed, the insulating base layer remains on the substratum. The insulating base layer keeps contacting the side surface of the magnetoresistive film. The magnetoresistive film can be kept covered with the insulating base layer at the side surface during a subsequent etching process. Any chemical reaction can be avoided between the magnetoresistive film and the etching gas employed in the etching process. The resulting magnetoresistive head element is allowed to exhibit an ideal characteristic in the magnetoresistive effect.Type: GrantFiled: February 16, 2001Date of Patent: October 17, 2006Assignee: Fujitsu LimitedInventors: Chikayoshi Kamata, Hitoshi Kishi
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Patent number: 7116533Abstract: A magnetoresistive sensor including the following layers, in order: a first conductor layer; a first antiferromagnetic layer; a first pinned ferromagnetic layer; a first nonmagnetic intermediate layer; a free ferromagnetic layer; a second nonmagnetic intermediate layer; a second pinned ferromagnetic layer; a second antiferromagnetic layer; and a second conductor layer. Alternatively, the magnetoresistive sensor may include the following layers, in order: a first conductor layer; a first free ferromagnetic layer; a first nonmagnetic intermediate layer; a first pinned ferromagnetic layer; an antiferromagnetic layer; a second pinned ferromagnetic layer; a second nonmagnetic intermediate layer; a second free ferromagnetic layer; and a second conductor layer.Type: GrantFiled: January 6, 2006Date of Patent: October 3, 2006Assignee: Fujitsu LimitedInventors: Yoshihiko Seyama, Atsushi Tanaka, Keiichi Nagasaka, Yutaka Shimizu, Shin Eguchi, Hitoshi Kanai, Reiko Kondo, Hitoshi Kishi, Junya Ikeda
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Publication number: 20060119989Abstract: Disclosed herein is a spin valve magnetoresistive sensor including a first conductor layer, a free ferromagnetic layer provided on the first conductor layer, a nonmagnetic intermediate layer provided on the free ferromagnetic layer, a pinned ferromagnetic layer provided on the nonmagnetic intermediate layer, an antiferromagnetic layer provided on the pinned ferromagnetic layer, and a second conductor layer provided on the antiferromagnetic layer. At least one of the free ferromagnetic layer and the pinned ferromagnetic layer has a thickness larger than that providing a maximum resistance change rate or resistance change amount in the case of passing a current in an in-plane direction of the at least one layer. That is, the thickness of at least one of the free ferromagnetic layer and the pinned ferromagnetic layer falls in the range of 3 nm to 12 nm.Type: ApplicationFiled: January 6, 2006Publication date: June 8, 2006Inventors: Yoshihiko Seyama, Atsushi Tanaka, Keiichi Nagasaka, Yutaka Shimizu, Shin Eguchi, Hitoshi Kanai, Reiko Kondo, Hitoshi Kishi, Junya Ikeda
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Patent number: 6995960Abstract: Disclosed herein is a spin valve magnetoresistive sensor including a first conductor layer, a free ferromagnetic layer provided on the first conductor layer, a nonmagnetic intermediate layer provided on the free ferromagnetic layer, a pinned ferromagnetic layer provided on the nonmagnetic intermediate layer, an antiferromagnetic layer provided on the pinned ferromagnetic layer, and a second conductor layer provided on the antiferromagnetic layer. At least one of the free ferromagnetic layer and the pinned ferromagnetic layer has a thickness larger than that providing a maximum resistance change rate or resistance change amount in the case of passing a current in an in-plane direction of the at least one layer. That is, the thickness of at least one of the free ferromagnetic layer and the pinned ferromagnetic layer falls in the range of 3 nm to 12 nm.Type: GrantFiled: March 28, 2001Date of Patent: February 7, 2006Assignee: Fujitsu LimitedInventors: Yoshihiko Seyama, Atsushi Tanaka, Keiichi Nagasaka, Yutaka Shimizu, Shin Eguchi, Hitoshi Kanai, Reiko Kondo, Hitoshi Kishi, Junya Ikeda
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Patent number: 6961222Abstract: A flux guide type includes a magnetoresistive device for reading a signal flux, and a flux guide for transmitting the signal flux to the magnetoresistive device. The flux guide includes a laminated film that includes a ferromagnetic layer, a non-magnetic layer and a ferromagnetic layer in this order, and the two ferromagnetic layers in the flux guide have antiparallel directions of magnetization with respect to the non-magnetic layer.Type: GrantFiled: October 30, 2002Date of Patent: November 1, 2005Assignee: Fujitsu LimitedInventor: Hitoshi Kishi
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Patent number: 6954341Abstract: A magneto-resistive magnetic sensor has an overlay-type structure and includes a cap layer on a top surface of a magneto-resistive structure and a pair of electrodes provided on said cap layer with a separation from each other, wherein there is interposed an oxidation-resistant conductive film underneath each electrode, such that the oxidation-resistant conductive film is sandwiched between the cap film and the electrode.Type: GrantFiled: December 27, 2000Date of Patent: October 11, 2005Assignee: Fujitsu LimitedInventors: Chikayoshi Kamata, Hitoshi Kishi
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Publication number: 20030151857Abstract: A flux guide type includes a magnetoresistive device for reading a signal flux, and a flux guide for transmitting the signal flux to the magnetoresistive device, wherein the flux guide includes a laminated film that includes a ferromagnetic layer, a non-magnetic layer and a ferromagnetic layer in this order, and the two ferromagnetic layers in the flux guide have antiparallel directions of magnetization with respect to the non-magnetic layer.Type: ApplicationFiled: October 30, 2002Publication date: August 14, 2003Applicant: FUJITSU LIMITEDInventor: Hitoshi Kishi
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Patent number: 6410843Abstract: A solar cell module according to this invention comprises a front surface member which is transparent, a rear surface member, a plurality of two-side incidence type solar cells sealed between the front surface member and the rear surface member, a connecting member which is conductive for electrically connecting the solar cells in series or in parallel, and a reflecting surface for reflecting light incident from the front surface member to a space between the solar cells which are adjacent each other and for introducing reflected light to a rear surface of the solar cell.Type: GrantFiled: November 21, 2000Date of Patent: June 25, 2002Assignee: Sanyo Electric Co., Ltd.Inventors: Hitoshi Kishi, Kenji Uchihashi, Seiichi Kiyama
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Patent number: 6364961Abstract: A method is disclosed for magnetizing a magnetic system including a ferromagnetic layer magnetized in a first direction and an anti-ferromagnetic layer provided on said ferromagnetic layer in exchange coupling therewith. The method includes a first thermal annealing process including the sub-steps of annealing the magnetic system in a first annealing state, and applying a magnetic field to the magnetic system in a second direction different from the first direction, while maintaining the magnetic system in the first annealing state. A second thermal annealing process includes the sub-steps of annealing the magnetic system after the first thermal annealing process, to a second annealing state, and applying a magnetic field in a third direction different from the second direction while maintaining the magnetic system in the second annealing state.Type: GrantFiled: November 5, 1999Date of Patent: April 2, 2002Assignee: Fujitsu LimitedInventors: Keiichi Nagasaka, Yutaka Shimizu, Hitoshi Kishi, Atsushi Tanaka
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Publication number: 20020034055Abstract: Disclosed herein is a spin valve magnetoresistive sensor including a first conductor layer, a free ferromagnetic layer provided on the first conductor layer, a nonmagnetic intermediate layer provided on the free ferromagnetic layer, a pinned ferromagnetic layer provided on the nonmagnetic intermediate layer, an antiferromagnetic layer provided on the pinned ferromagnetic layer, and a second conductor layer provided on the antiferromagnetic layer. At least one of the free ferromagnetic layer and the pinned ferromagnetic layer has a thickness larger than that providing a maximum resistance change rate or resistance change amount in the case of passing a current in an in-plane direction of the at least one layer. That is, the thickness of at least one of the free ferromagnetic layer and the pinned ferromagnetic layer falls in the range of 3 nm to 12 nm.Type: ApplicationFiled: March 28, 2001Publication date: March 21, 2002Applicant: FUJITSU LIMITEDInventors: Yoshihiko Seyama, Atsushi Tanaka, Keiichi Nagasaka, Yutaka Shimizu, Shin Eguchi, Hitoshi Kanai, Reiko Kondo, Hitoshi Kishi, Junya Ikeda
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Publication number: 20020030951Abstract: A combined stripe of a magnetoresistive (MR) film and domain control stripe layers can be formed below a photoresist film on the surface of a substratum. An insulating base layer is then formed to extend over the surface of the substratum. The insulating base layer is allowed to cover over the photoresist film, the magnetoresistive film and the domain control stripe layers on the substratum. When the photoresist film is removed, the insulating base layer remains on the substratum. The insulating base layer keeps contacting the side surface of the magnetoresistive film. The magnetoresistive film can be kept covered with the insulating base layer at the side surface during a subsequent etching process. Any chemical reaction can be avoided between the magnetoresistive film and the etching gas employed in the etching process. The resulting magnetoresistive head element is allowed to exhibit an ideal characteristic in the magnetoresistive effect.Type: ApplicationFiled: February 16, 2001Publication date: March 14, 2002Applicant: FUJITSU LIMITEDInventors: Chikayoshi Kamata, Hitoshi Kishi
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Patent number: 6355115Abstract: A method is disclosed for fabricating a spin-valve magnetic head including a layered body of a first ferromagnetic layer having a first easy axis of magnetization extending in a first direction, a non-magnetic layer formed on the first ferromagnetic layer, a second ferromagnetic layer provided on the non-magnetic layer, and an anti-ferromagnetic layer provided on the second ferromagnetic layer in exchange coupling therewith. The method includes a first thermal annealing process with the steps of annealing the layered body in a first annealing state and applying a magnetic field to the layered body in a second direction different from the first direction, while maintaining the layered body in the first annealing state.Type: GrantFiled: November 5, 1999Date of Patent: March 12, 2002Assignee: Fujitsu LimitedInventors: Keiichi Nagasaka, Yutaka Shimizu, Hitoshi Kishi, Atsushi Tanaka
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Patent number: 6327121Abstract: The invention provides a GMR head in which an adequate bias point may be set for the free magnetic layer 12 of the GMR head by suppressing the static magnetic field in the free magnetic layer which arises from a pinned magnetic layer 14 of the GMR head. The GMR head comprises a sensor section 10, a magnetic field correction section 20 disposed laterally adjacent to the sensor section 10. The sensor section 10 includes, in addition to the free magnetic layer 12 and the pinned magnetic layer 14, an intermediate layer 13 and an anti-ferromagnetic layer 15 in a specific arrangement. The magnetic field correction section 20 may have the same structure as the sensor section 10.Type: GrantFiled: November 13, 1998Date of Patent: December 4, 2001Assignee: Fujitsu LimitedInventors: Keiichi Nagasawa, Yutaka Shimizu, Hitoshi Kishi, Atsushi Tanaka, Reiko Kondoh
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Publication number: 20010026424Abstract: A magneto-resistive magnetic sensor has an overlay-type structure and includes a cap layer on a top surface of a magneto-resistive structure and a pair of electrodes provided on said cap layer with a separation from each other, wherein there is interposed an oxidation-resistant conductive film underneath each electrode, such that the oxidation-resistant conductive film is sandwiched between the cap film and the electrode.Type: ApplicationFiled: December 27, 2000Publication date: October 4, 2001Applicant: FUJITSU LIMITEDInventors: Chikayoshi Kamata, Hitoshi Kishi
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Patent number: 6291764Abstract: The present invention prevents an increase in an overvoltage and increases an optimum operating voltage of a power inverter. A photovoltaic power generation device is provided with a solar cell device 1, a power inverter 2 for inverting output from the solar cell device 1 into AC power, a current path circuit 3 connected in parallel between the solar cell device 1 and the power inverter 2, and a current detection circuit 4 for detecting a current feeding back to the solar cell device 1. When a current detected by the current detection circuit 4 reaches beyond a predetermined current value, the current path circuit 3 is cut off.Type: GrantFiled: March 23, 2000Date of Patent: September 18, 2001Assignee: Sanyo Electronics Co., Ltd.Inventors: Takeo Ishida, Ryuzo Hagihara, Hitoshi Kishi
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Patent number: 6157523Abstract: A spin valve magnetoresistive head includes a first soft magnetic layer and a second soft magnetic layer having larger internal stress than that of the first magnetic layer. The larger internal stress of the second soft magnetic layer is created by injecting the second soft magnetic layer with a selected type of ion. Also included in the head is a nonmagnetic layer formed between the first soft magnetic layer and the second soft magnetic layer.Type: GrantFiled: September 6, 1995Date of Patent: December 5, 2000Assignee: Fujitsu LimitedInventors: Hideyuki Kikuchi, Kazuo Kobayashi, Hitoshi Kishi, Mitsuru Otagiri
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Patent number: 6074535Abstract: The present invention relates to a method of fabricating a magnetoresistive head formed by laminating a magnetic layer and a nonmagnetic metal layer including a silver film and used for converting change in magnetic field into change of resistivity of the device. A method of fabricating a magnetoresistive head upon laminating on a substrate a plurality of magnetic layers arranged to put nonmagnetic metal layer therebetween and a bias magnetic layer formed adjacent to one of the magnetic layers to give a magnetization of the specified direction to the magnetic layer, comprising the steps of setting film thicknesses of the nonmagnetic metal layers to be formed, and forming the nonmagnetic metal layers under a condition where temperature of the substrate is held within a temperature range less than an upper limit of a film forming temperature not to cause pin holes in the nonmagnetic metal layer.Type: GrantFiled: October 31, 1997Date of Patent: June 13, 2000Assignee: Fujitsu LimitedInventors: Hitoshi Kishi, Kazuo Kobayashi, Yasuhiro Kitade, Mitsuru Otagiri, Hideyuki Kikuchi
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Patent number: 6034845Abstract: A spin-valve magnetic head has a first ferromagnetic layer with a first easy axis of magnetization extending in a first direction, and a second ferromagnetic layer provided on, and separated from, the first ferromagnetic layer. The second ferromagnetic layer has a magnetization in a second direction substantially perpendicular to the first direction. The magnetization defines a line in the second direction. An anti-ferromagnetic layer provided on the second ferromagnetic layer is exchange coupled to the second ferromagnetic layer. The second ferromagnetic layer has a second easy axis of magnetization extending in a direction intersecting the line in the second direction.Type: GrantFiled: February 17, 1998Date of Patent: March 7, 2000Assignee: Fujitsu LimitedInventors: Keiichi Nagasaka, Yutaka Shimizu, Hitoshi Kishi, Atsushi Tanaka
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Patent number: 6007643Abstract: A magnetoresistive head in which an antiferromagnetic material having superior corrosion resistance is used is disclosed. In the magnetoresistive head, a pair of anti-ferromagnetic layers 24a and 24b are formed while contacting with a soft magnetic layer 23, and the antiferromagnetic layers 24a and 24b are made of a PdMn film.Type: GrantFiled: August 29, 1997Date of Patent: December 28, 1999Assignee: Fujitsu LimitedInventors: Hitoshi Kishi, Kazuo Kobayashi, Atsushi Tanaka, Yasuhiro Kitade, Yuko Miyake, Mitsuru Otagiri
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Patent number: 5951785Abstract: The present invention is directed to a photo-voltaic apparatus comprising a photo-voltaic module having a plurality of photo-voltaic cells, and an inverter for converting a direct current output generated from the photo-voltaic cells into an alternating current and outputting the alternating current, the inverter being mounted on a surface opposite to the light receiving surface of the photo-voltaic module with a clearance provided therebetween, so that heat self-generated by the inverter can be efficiently radiated, and heat from the photo-voltaic module is not transferred to the inverter.Type: GrantFiled: January 29, 1997Date of Patent: September 14, 1999Assignee: Sanyo Electric Co., Ltd.Inventors: Kenji Uchihashi, Takeo Ishida, Hitoshi Kishi, Ryuzo Hagihara