Patents by Inventor Tatsuya Isomura
Tatsuya Isomura 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: 6238492Abstract: A soft magnetic thin micro-crystalline film of FeaTbNc (at %) wherein T is at least one of Zr, Hf, Ti, Nb, Ta, V, Mo, and W and 0<b≦20, and 0<c≦22 except the range of b≦7.5 and c≦5, shows low coercivity Hc of 80-400 Am−1 (1-5 Oe) which is stable upon heating at elevated temperatures for glass bonding. This film is produced by crystallizing an amorphous alloy film of the similar composition at 350-650° C. to a crystal grain size up to 30 nm to provide uniaxial anisotropy and increased magnetic permeability at a higher frequency. It can also provide low magnetostriction around &lgr;s=0. A composite magnetic head is made using this thin film. A diffusion preventive SiO2 layer is disposed between ferrite cores, and this thin film in the magnetic head prevents an interdiffusion layer and suppresses beat in the output signal.Type: GrantFiled: October 24, 1997Date of Patent: May 29, 2001Assignee: Fuji Photo Film Co., Ltd.Inventors: Kanji Nakanishi, Osamu Shimizu, Satoshi Yoshida, Masaaki Katayama, Tatsuya Isomura
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Patent number: 6183568Abstract: A soft magnetic thin micro-crystalline film of FeaBbNc (at %) wherein B is at least one of Zr, Hf, Ti, Nb, Ta, V, Mo and W, and 0<b≦20 and 0<c≦22 except the range of b≦7.5 and c≦5, shows low coercivity Hc of 80-400 Am−1 (1-5 Oe) which is stable upon heating at elevated temperature for glass bonding. This film is produced by crystallizing an amorphous alloy film of the similar composition at 350-650° C. to a crystal grain size up to 30 nm to provide uniaxial anisotropy and increased magnetic permeability at higher frequency. It can also provide low magnetostriction around &lgr;s=0. Composite magnetic head is made using this thin film. Diffusion preventive SiO2 layer disposed between ferrite core and this thin film in the magnetic head prevents an interdiffusion layer and suppress beat in the output signal.Type: GrantFiled: January 6, 1994Date of Patent: February 6, 2001Assignee: Fuji Photo Film Co., Ltd.Inventors: Kanji Nakanishi, Osamu Shimizu, Satoshi Yoshida, Masaaki Katayama, Tatsuya Isomura
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Patent number: 5772797Abstract: A soft magnetic thin micro-crystalline film of FeT.sub.b N.sub.c (at %) wherein T is at least one of Zr, Hf, Ti, Nb, Ta, V, Mo and W, and 0<b<20 and 0<c<22 except the range of b.ltoreq.7.5 and c.ltoreq.5, shows low coercivity Hc of 80-400 Am.sup.-1 (1-5 Oe) which is stable upon heating at elevated temperature for glass bonding.This film is produced by crystallizing an amorphous alloy film of the similar composition at 350.degree.-650.degree. C. to a crystal grain size up to 30 nm to provide uniaxial anisotropy and increased magnetic permeability at higher frequency. It can also provide low magnetostriction around .gamma.s=0.Composite magnetic head is made using this thin film. Diffusion preventive SiO.sub.2 layer disposed between ferrite core and this thin film in the magnetic head prevents an interdiffusion layer and suppress beat in the output signal.Type: GrantFiled: January 2, 1997Date of Patent: June 30, 1998Assignee: Fuji Photo Film Co., Ltd.Inventors: Kanji Nakanishi, Osamu Shimizu, Satoshi Yoshida, Masaaki Katayama, Tatsuya Isomura
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Patent number: 5606219Abstract: A xenon electronic flash tube has a transparent glass tube body. Xe gas is enclosed in the tube body. An anode is projected inside the tube body. A cathode, inside the tube body, is projected toward the anode, and includes base metal material and a Cs compound having a characteristic of emitting electrons, such as Cs.sub.2 Ta.sub.2 O.sub.6.Type: GrantFiled: October 10, 1995Date of Patent: February 25, 1997Assignee: Fuji Photo Film Co., Ltd.Inventors: Tsutomu Tobita, Tatsuya Isomura, Hideaki Takeuchi
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Patent number: 5421915Abstract: A soft magnetic thin micro-crystalline film of FeT.sub.b N.sub.c (at %) wherein T is at least one of Zr, Hf, Ti, Nb, Ta, V, Mo and W, and 0<b.ltoreq.20 and 0<c.ltoreq.22 except the range of b.ltoreq.7.5 and c.ltoreq.5, exhibits low coercivity Hc of 80-400 Am.sup.-1 (1-5 Oe) which is stable upon heating at elevated temperature for glass bonding.This film is produced by crystallizing an amorphous alloy film of the similar composition at 350.degree.-650.degree. C. to a crystal grain size up to 30 nm to provide uniaxial anisotropy and increased magnetic permeability at higher frequency. It can also provide low magnetostriction around .lambda.s=0.Composite magnetic head is made using this thin film. Diffusion preventive SiO.sub.2 layer disposed between ferrite core and this thin film in the magnetic head prevents an interdiffusion layer and suppress beat in the output signal.Type: GrantFiled: May 5, 1992Date of Patent: June 6, 1995Assignee: Fuji Photo Film Co., Ltd.Inventors: Kanji Nakanishi, Osamu Shimizu, Satoshi Yoshida, Masaaki Katayama, Tatsuya Isomura
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Patent number: 5227940Abstract: A composite magnetic head comprises a pair of magnetic core halves each including a core block formed of an oxide magnetic material and a soft magnetic thin film disposed on said core block interposed with a reaction inhibiting layer, said core halves abutting to each other so that a magnetic gap is defined between the ends of said soft magnetic thin films. The magnetic head has a size relation bcd/a.ltoreq.0.2.times.10.sup.-10 m.sup.2 wherein a is a gap length, measured along the proceeding direction of a magnetic recording medium, c a gap depth, d a gap width as measured along the track width and b is a thickness of said reaction inhibiting layer. Wavy (beat) noise of output signal due to the psuedo gap produced by the reaction inhibiting layer is effectively suppressed.Type: GrantFiled: July 11, 1991Date of Patent: July 13, 1993Assignee: Fuji Photo Film Co., Ltd.Inventors: Tatsuya Isomura, Osamu Shimizu, Satoshi Yoshida, Kanji Nakanishi
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Patent number: 5117321Abstract: A soft magnetic thin micro-crystalline film of Fe.sub.a B.sub.b N.sub.c (at %) wherein B is at least one of Zr, Hf, Ti, Nb, Ta, V, Mo and W, and O<b.ltoreq.20 and O<c.ltoreq.22 except the range of b.ltoreq.7.5 and c.ltoreq.5, shows low coercivity Hc of 80-400 Am.sup.-1 (1-5 Oe) which is stable upon heating at elevated temperature for glass bonding.This film is produced by crystallizing an amorphous alloy film of the similar composition of 350.degree.-650.degree. C. to a crystal grain size up to 30 nm to provide uniaxial anisotropy and increased magnetic permeability at higher frequency. It can also provide low magnetostriction around .lambda.s= .Composite magnetic head is made using this thin film. Diffusion preventive SiO.sub.2 layer disposed between ferrite core and this thin film in the magnetic head prevents an interdiffusion layer and suppress beat in the output signal.Type: GrantFiled: January 26, 1990Date of Patent: May 26, 1992Assignee: Fuji Photo Film Co., Ltd.Inventors: Kanji Nakanishi, Osamu Shimizu, Satoshi Yoshida, Masaaki Katayama, Tatsuya Isomura