Patents by Inventor Yukinori Ikegawa
Yukinori Ikegawa 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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Publication number: 20040042117Abstract: The thin film magnetic head has stable recording characteristics. The thin film magnetic head of the present invention comprises: lower and upper magnetic poles; an insulating layer formed between the magnetic poles, the insulating layer having a apex part; a coil formed in the insulating layer; and a gap layer formed between the magnetic poles faced each other. The coil is provided in a concave part of the lower magnetic pole. The concave part is filled with a first insulating layer. A high magnetic permeability layer is formed on the lower magnetic pole which faces the upper magnetic pole. The gap layer is formed on the high magnetic permeability layer. A second insulating layer is formed on the first insulating layer. A third insulating layer is formed on the second insulating layer and has the apex part.Type: ApplicationFiled: January 21, 2003Publication date: March 4, 2004Applicant: FUJITSU LIMITEDInventor: Yukinori Ikegawa
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Patent number: 6614620Abstract: A thin film magnetic head includes an upper magnetic pole maintaining a constant thickness in a range determined by the so-called gap depth. A thinner film portion is defined in the upper magnetic pole in a range rearward of the range determined by the gap depth. The thinner film portion has a reduced thickness smaller than the constant thickness. The upper magnetic pole starts to enlarge the core width in the lateral direction at the rear end of the region determined by the so-called neck height. The neck height smaller than the gap depth serves to establish a reduction in the thickness of the upper magnetic pole after the upper magnetic pole gets larger in the lateral direction. A magnetic saturation can reliably be prevented at the thinner film portion in the upper magnetic pole. The front end of the upper magnetic pole is allowed to receive a larger quantity of a magnetic flux. It is possible to reliably enhance a magnetic field for recordation in the thin film magnetic head.Type: GrantFiled: February 6, 2001Date of Patent: September 2, 2003Assignee: Fujitsu LimitedInventors: Ikuya Tagawa, Tomoko Kutsuzawa, Hideo Niwa, Yukinori Ikegawa, Yoshinori Ohtsuka, Hiroshi Maeda, Takashi Sekikawa, Hiroki Fujimoto
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Patent number: 6510024Abstract: There is provided a magnetic head which is able to enhance the magnetic field intensity to be generated by shaping a magnetic pole, and a method of manufacturing the same. The method of manufacturing a magnetic head, comprising the steps of forming a lower recording magnetic pole and an upper recording magnetic pole, and trimming partially an elongated pole in the vicinity of a floating surface of the upper recording magnetic pole and an upper portion of the lower recording magnetic pole positioned below and around the elongated pole by an ion milling method, wherein a core width of the elongated pole can be adjusted.Type: GrantFiled: July 17, 2001Date of Patent: January 21, 2003Assignee: Fujitsu LimitedInventors: Yoshinori Otsuka, Ikuya Tagawa, Yukinori Ikegawa, Tomoko Kutsuzawa, Yuji Uehara, Minoru Hasegawa
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Publication number: 20020048116Abstract: A thin film magnetic head includes an upper magnetic pole maintaining a constant thickness in a range determined by the so-called gap depth. A thinner film portion is defined in the upper magnetic pole in a range rearward of the range determined by the gap depth. The thinner film portion has a reduced thickness smaller than the constant thickness. The upper magnetic pole starts to enlarge the core width in the lateral direction at the rear end of the region determined by the so-called neck height. The neck height smaller than the gap depth serves to establish a reduction in the thickness of the upper magnetic pole after the upper magnetic pole gets larger in the lateral direction. A magnetic saturation can reliably be prevented at the thinner film portion in the upper magnetic pole. The front end of the upper magnetic pole is allowed to receive a larger quantity of a magnetic flux. It is possible to reliably enhance a magnetic field for recordation in the thin film magnetic head.Type: ApplicationFiled: February 6, 2001Publication date: April 25, 2002Applicant: FUJITSU LIMITEDInventors: Ikuya Tagawa, Tomoko Kutsuzawa, Hideo Niwa, Yukinori Ikegawa, Yoshinori Ohtsuka, Hiroshi Maeda, Takashi Sekikawa, Hiroki Fujimoto
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Publication number: 20010050830Abstract: There is provided a magnetic head which is able to enhance the magnetic field intensity to be generated by shaping a magnetic pole, and a method of manufacturing the same. The method of manufacturing a magnetic head, comprising the steps of forming a lower recording magnetic pole and an upper recording magnetic pole, and trimming partially an elongated pole in the vicinity of a floating surface of the upper recording magnetic pole and an upper portion of the lower recording magnetic pole positioned below and around the elongated pole by an ion milling method, wherein a core width of the elongated pole can be adjusted.Type: ApplicationFiled: July 17, 2001Publication date: December 13, 2001Applicant: Fujitsu LimitedInventors: Yoshinori Otsuka, Ikuya Tagawa, Yukinori Ikegawa, Tomoko Kutsuzawa, Yuji Uehara, Minoru Hasegawa
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Patent number: 6282776Abstract: There is provided a magnetic head which is able to enhance the magnetic field intensity to be generated by shaping a magnetic pole, and a method of manufacturing the same. The method of manufacturing a magnetic head, comprising the steps of forming a lower recording magnetic pole and an upper recording magnetic pole, and trimming partially an elongated pole in the vicinity of a floating surface of the upper recording magnetic pole and an upper portion of the lower recording magnetic pole positioned below and around the elongated pole by an ion milling method, wherein a core width of the elongated pole can be adjusted.Type: GrantFiled: November 25, 1998Date of Patent: September 4, 2001Assignee: Fujitsu LimitedInventors: Yoshinori Otsuka, Ikuya Tagawa, Yukinori Ikegawa, Tomoko Kutsuzawa, Yuji Uehara, Minoru Hasegawa
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Patent number: 6104575Abstract: A planar thin-film magnetic head including a lower magnetic pole having a first end portion and a second end portion, and an upper magnetic pole having a first end portion magnetically joined to the first end portion of the lower magnetic pole and a second end portion. A gap is defined between the second end portion of the lower magnetic pole and the second end portion of the upper magnetic pole. The thin-film magnetic head further includes a coil having a center positioned in the vicinity of the gap and spirally formed so as to pass between the upper magnetic pole and the lower magnetic pole. The coil is embedded in an insulating layer.Type: GrantFiled: February 2, 1998Date of Patent: August 15, 2000Assignee: Fujitsu LimitedInventors: Yukinori Ikegawa, Michiaki Kanamine
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Patent number: 6088908Abstract: In a method for forming a horizontal head slider having a media opposing surface flying above or coming into contact with a recording medium, a film-like surface of a head for recording/reproducing information provided in parallel to the media opposing surface, and a rail portion provided on the media opposing surface for generating a pressure for ensuring stable flying or contact. The rail portion has a planar portion and a taper portion, and all of the shaping accuracy of the bottom surface of the slider and the rail, the adhesive property to a sacrificial layer overlaid thereon and the surface smoothness of the rail surface are enhanced. When the rail portion is formed, a part of mold for the planar portion is prepared by a metallic layer 2 and a mold for the taper portion is prepared by a photoresist layer 3, and a sacrificial layer 4, a media opposing surface layer 6 and a slider body layer 6 are formed thereon in this order.Type: GrantFiled: March 19, 1998Date of Patent: July 18, 2000Assignee: Fujitsu LimitedInventors: Takahiro Imamura, Yukinori Ikegawa
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Patent number: 6083410Abstract: A plan or vertical type thin film magnetic head is produced by a process comprising the steps of: forming a gap separator layer of a non-magnetic material on the surface of a substrate, while the forming process is not limited to plating; forming a mask layer on the gap layer; patterning the mask layer to form a shield; etching the gap layer, while the shield functions as a mask, thereby forming a gap wall having a width narrower than that of the shield independent of the resolution degree of the resist; forming a magnetic pole layer of a soft magnetic material on the surface of the substrate by exposing the resist at a time, thereby the formed magnetic pole layer being separated by the gap wall; and, utilizing the gap wall as a magnetic pole gap of the magnetic pole layer.Type: GrantFiled: October 17, 1997Date of Patent: July 4, 2000Assignee: Fujitsu Ltd.Inventors: Yukinori Ikegawa, Takao Koshikawa, Yoshinori Ohtsuka
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Patent number: 5870262Abstract: A method is disclosed for producing a magneto-resistive effect type thin film magnetic head including a thin film coil, a pair of magnetic poles and an insulation layer consisting of a thermosetting resin for electrically insulating mutually between the thin film coil and the magnetic poles. A photoresist material is used as the thermosetting resin. A thermal treatment of the thermosetting resin is conducted in an atmosphere including at least oxygen, in such a manner that a film stress of the insulation layer after thermal treatment is within a range of -10 MPa to +25 MPa.Type: GrantFiled: November 21, 1996Date of Patent: February 9, 1999Assignee: Fujitsu LimitedInventors: Yukinori Ikegawa, Mutsuo Yoshinami, Eiji Shimizu, Keiji Watanabe
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Patent number: 5777827Abstract: A magneto-resistive (MR) head has an MR layer in a space formed by shield layers by providing a distance enough to protect magnetic flux, flowing through the MR layer from a recording medium through a gap formed by the shield layers, from leaking out to the shield layers. A flux guide is provided between the MR layer and the gap, and has an end magnetically connected to the MR, extending over an effective area of the MR head, and another end having a width a little narrower than a width of track of the recording medium. A side of the MR layer, opposite to the side connected with the flux guide layer is placed in a narrow space formed at a corner of the space. Magnetic flux leaked from the gap due to a sense current flowing through the MR layer is eliminated by making a current flow through a recording coil layer or through an electrically conductive layer placed in the space.Type: GrantFiled: September 6, 1996Date of Patent: July 7, 1998Assignee: Fujitsu LimitedInventors: Yoshifumi Mizoshita, Takao Koshikawa, Hitoshi Kanai, Junichi Kane, Yoshinori Otsuka, Yukinori Ikegawa
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Patent number: 5717630Abstract: A magnetic memory device comprises: a vertically magnetic recording medium; a probe formed of an electrically conductive as well as soft-magnetic material, a pointed end of the probe faces the magnetically recording medium across a gap; a magnetic flux detecting element for detecting a magnetic flux caught by the probe, where the magnetic flux is from a data recorded on the magnetically recording medium; a vertical controller for keeping the gap constant by the use of a tunnel current flowing via said gap into the probe while a voltage is applied across the gap; and a scan mechanism for scanning the probe along the magnetically recording medium. The magnetic memory device may further comprises an exciting coil for magnetizing the probe so as to write a data in the magnetically recording medium. The probe may be recessed from the scanning position when the probe is not in operation.Type: GrantFiled: April 12, 1996Date of Patent: February 10, 1998Assignee: Fujitsu LimitedInventors: Takao Koshikawa, Yukinori Ikegawa, Hiroshi Maeda, Yoshinori Ohtsuka, Takahiro Imamura, Yoshifumi Mizoshita
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Patent number: 5583726Abstract: A magneto-resistive (MR) head has an MR layer in a space formed by shield layers by providing a distance enough to protect magnetic flux, flowing through the MR layer from a recording medium through a gap formed by the shield layers, from leaking out to the shield layers. A flux guide is provided between the MR layer and the gap and has an end magnetically connected to the MR extending over an effective area of the MR head, and another end having a width a little narrower than a width of track of the recording medium. A side of the MR layer, opposite to the side connected with the flux guide layer is placed in a narrow space formed at a corner of the space. Magnetic flux leaked from the gap due to a sense current flowing through the MR layer is eliminated by making a current flow through a recording coil layer or through an electrically conductive layer placed in the space.Type: GrantFiled: May 5, 1995Date of Patent: December 10, 1996Assignee: Fujitsu LimitedInventors: Yoshifumi Mizoshita, Takao Koshikawa, Hitoshi Kanai, Junichi Kane, Yoshinori Otsuka, Yukinori Ikegawa