Patents by Inventor Tsutomu Chikamatsu
Tsutomu Chikamatsu 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: 9702945Abstract: A magnetic measurement device which can measure the magnetic characteristics in a microregion of a thin plate magnetic sample. After a magnetic sample is applied by a magnetic field and magnetized accordingly, by scanning the magnetic sample using a measuring part, the magnetic flux leakage in the magnetic sample can be measured. The magnetic flux leaks outside by magnetizing a first region and a second region of the magnetic sample in reciprocally opposite directions and reducing the demagnetizing field. Specifically, a magnetic field generating part with at least a pair of magnetic poles is used to perform the magnetization of multiple poles, or the magnetic field generating part applies a damped oscillation magnetic field to perform the magnetization, or a local magnetic field generating part which applies an alternating magnetic field and scans the surface of the sample at the same time is used to perform the magnetization.Type: GrantFiled: December 13, 2012Date of Patent: July 11, 2017Assignee: TDK CORPORATIONInventors: Kenichi Suzuki, Tsutomu Chikamatsu, Akio Ogawa, Kyung-ku Choi, Ryuji Hashimoto
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Patent number: 9354285Abstract: A magnetic measurement device which measures coercivity and coercivity distribution in a microregion of a thin plate magnetic sample with high coercivity. A magnetic sample is applied with a magnetic field in a first direction and magnetized, a second magnetic field is applied in a direction opposite to the first, a measuring part scans the sample, measuring magnetic flux leakage due to remnant magnetization in the sample. The intensity of the second magnetic field is gradually increased while the measuring part repeats the measurement to obtain the second magnetic field wherein the magnitude of the leakage from the sample reaches the maximum level, and when a magnetic field equivalent to the coercivity is applied to the sample and about half of the magnetization is reversed, the sample's coercivity is obtained based on the determination that the demagnetizing field Hd reaches the minimum level and the leakage reaches the maximum level.Type: GrantFiled: December 13, 2012Date of Patent: May 31, 2016Assignee: TDK CORPORATIONInventors: Kenichi Suzuki, Tsutomu Chikamatsu, Akio Ogawa, Kyung-ku Choi, Ryuji Hashimoto
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Publication number: 20150070005Abstract: A magnetic measurement device which measures coercivity and coercivity distribution in a microregion of a thin plate magnetic sample with high coercivity. A magnetic sample is applied with a magnetic field in a first direction and magnetized, a second magnetic field is applied in a direction opposite to the first, a measuring part scans the sample, measuring magnetic flux leakage due to remnant magnetization in the sample. The intensity of the second magnetic field is gradually increased while the measuring part repeats the measurement to obtain the second magnetic field wherein the magnitude of the leakage from the sample reaches the maximum level, and when a magnetic field equivalent to the coercivity is applied to the sample and about half of the magnetization is reversed, the sample's coercivity is obtained based on the determination that the demagnetizing field Hd reaches the minimum level and the leakage reaches the maximum level.Type: ApplicationFiled: December 13, 2012Publication date: March 12, 2015Inventors: Kenichi Suzuki, Tsutomu Chikamatsu, Akio Ogawa, Kyung-ku Choi, Ryuji Hashimoto
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Publication number: 20140375308Abstract: A magnetic measurement device which can measure the magnetic characteristics in a microregion of a thin plate magnetic sample. After a magnetic sample is applied by a magnetic field and magnetized accordingly, by scanning the magnetic sample using a measuring part, the magnetic flux leakage in the magnetic sample can be measured. The magnetic flux leaks outside by magnetizing a first region and a second region of the magnetic sample in reciprocally opposite directions and reducing the demagnetizing field. Specifically, a magnetic field generating part with at least a pair of magnetic poles is used to perform the magnetization of multiple poles, or the magnetic field generating part applies a damped oscillation magnetic field to perform the magnetization, or a local magnetic field generating part which applies an alternating magnetic field and scans the surface of the sample at the same time is used to perform the magnetization.Type: ApplicationFiled: December 13, 2012Publication date: December 25, 2014Inventors: Kenichi Suzuki, Tsutomu Chikamatsu, Akio Ogawa, Kyung-ku Choi, Ryuji Hashimoto
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Patent number: 8138754Abstract: The characteristics of thin-film magnetic heads are evaluated by measuring, in a step and repeat method and apparatus, the magnetic field generated by the respective heads in a bar including multiple heads.Type: GrantFiled: May 18, 2009Date of Patent: March 20, 2012Assignee: TDK CorporationInventors: Akio Ogawa, Tsutomu Chikamatsu, Kazuyuki Kobayashi, Haruhiko Yamaguchi, Kazunori Matsuiwa, Masaki Ohashi, Kazuyoshi Nakajima, Kiyotaka Shindo
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Patent number: 7764466Abstract: A thin-film magnetic head where the closure is bonded with sufficiently high adhesive strength by the adhesive layer thinner than conventional and that is free from the problem of fine dusts, is provided. The head comprises: a substrate having an element-formed surface and an opposed-to-medium surface; at least one magnetic head element provided on/above the element-formed surface; an overcoat layer formed on the element-formed surface; an etching pattern formed on a part of an upper surface of the overcoat layer, the whole or a part of the etching pattern being filled up by adhesive; a closure provided on the etching pattern of the overcoat layer; and an opening portion formed close to an edge on the opposite side to the opposed-to-medium surface of an adhesive surface of the closure, being a portion exposed from the closure of the etching pattern.Type: GrantFiled: October 27, 2006Date of Patent: July 27, 2010Assignee: TDK CorporationInventors: Mitsuyoshi Kawai, Tomonaga Nishikawa, Tsutomu Chikamatsu, Makoto Yoshida
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Publication number: 20090284857Abstract: The characteristics of thin-film magnetic heads are evaluated by measuring, in a step and repeat method and apparatus, the magnetic field generated by the respective heads in a bar including multiple heads.Type: ApplicationFiled: May 18, 2009Publication date: November 19, 2009Applicant: TDK CORPORATIONInventors: Akio Ogawa, Tsutomu Chikamatsu, Kazuyuki Kobayashi, Haruhiko Yamaguchi, Kazunori Matsuiwa, Masaki Ohashi, Kazuyoshi Nakajima, Kiyotaka Shindo
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Publication number: 20070109683Abstract: A thin-film magnetic head where the closure is bonded with sufficiently high adhesive strength by the adhesive layer thinner than conventional and that is free from the problem of fine dusts, is provided. The head comprises: a substrate having an element-formed surface and an opposed-to-medium surface; at least one magnetic head element provided on/above the element-formed surface; an overcoat layer formed on the element-formed surface; an etching pattern formed on a part of an upper surface of the overcoat layer, the whole or a part of the etching pattern being filled up by adhesive; a closure provided on the etching pattern of the overcoat layer; and an opening portion formed close to an edge on the opposite side to the opposed-to-medium surface of an adhesive surface of the closure, being a portion exposed from the closure of the etching pattern.Type: ApplicationFiled: October 27, 2006Publication date: May 17, 2007Applicant: TDK CorporationInventors: Mitsuyoshi KAWAI, Tomonaga Nishikawa, Tsutomu Chikamatsu, Makoto Yoshida