Patents by Inventor Tsugihiro Doi
Tsugihiro Doi 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: 9231272Abstract: The electrode of the present invention includes a current collector and an active material-containing layer formed on one side or both sides of the current collector. The active material-containing layer has a thickness of 20 to 200 ?m per one side of the current collector, and diethyl carbonate permeates the active material-containing layer at a rate of 0.1 g/(cm2·min) or higher. Further, the method for producing an electrode of the present invention includes the steps of: forming an electrode precursor by forming an active material-containing layer on one side or both sides of a current collector; and compressing the electrode precursor. In the electrode precursor forming step, the active material-containing layer is formed such that the active material-containing layer has a higher porosity in a portion close to the current collector then in other portions.Type: GrantFiled: February 28, 2012Date of Patent: January 5, 2016Assignee: HITACHI MAXELL, LTD.Inventors: Hiroyuki Mitsuhashi, Tsugihiro Doi
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Publication number: 20120237821Abstract: The electrode of the present invention includes a current collector and an active material-containing layer formed on one side or both sides of the current collector. The active material-containing layer has a thickness of 20 to 200 ?m per one side of the current collector, and diethyl carbonate permeates the active material-containing layer at a rate of 0.1 g/(cm2·min) or higher. Further, the method for producing an electrode of the present invention includes the steps of: forming an electrode precursor by forming an active material-containing layer on one side or both sides of a current collector; and compressing the electrode precursor. In the electrode precursor forming step, the active material-containing layer is formed such that the active material-containing layer has a higher porosity in a portion close to the current collector then in other portions.Type: ApplicationFiled: February 28, 2012Publication date: September 20, 2012Inventors: Hiroyuki MITSUHASHI, Tsugihiro DOI
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Patent number: 7593177Abstract: In a recording/reproducing method of a magnetic tape in a tracking servo system, a recording density of each data track is increased while inhibiting occurrence of a recording/reproducing error caused by a size change of a magnetic tape in the width direction. Data tracks are each set to have a smaller track width stepwise as closer to servo tracks (41T-1 to 41T-5 etc.) in the width direction of a magnetic tape 1. With such a setting, the width of the data tracks (A1-41T-1 to A1-41T-5 etc.) closest to the servo tracks (41T-1 to 41T-5) can be minimized, thereby enabling a significant increase in number of the data tracks.Type: GrantFiled: June 29, 2007Date of Patent: September 22, 2009Assignee: Hitachi Maxell, Ltd.Inventors: Masao Okafuji, Tsugihiro Doi, Tetsutaro Inoue, Hiroyuki Mitsuhashi, Seigi Kawarai, Sadamu Kuse
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Patent number: 7545597Abstract: In a recording/reproducing method of a magnetic tape in a tracking servo system, a recording density of each data track is increased while inhibiting occurrence of a recording/reproducing error caused by a size change of a magnetic tape in the width direction. Data tracks are each set to have a smaller track width stepwise as closer to servo tracks (41T-1 to 41T-5 etc.) in the width direction of a magnetic tape 1. With such a setting, the width of the data tracks (A1-41T-1 to A1-41T-5 etc. ) closest to the servo tracks (41T-1 to 41T-5) can be minimized, thereby enabling a significant increase in number of the data tracks.Type: GrantFiled: November 22, 2006Date of Patent: June 9, 2009Assignee: Hitachi Maxell, Ltd.Inventors: Masao Okafuji, Tsugihiro Doi, Tetsutaro Inoue, Hiroyuki Mitsuhashi, Seigi Kawarai, Sadamu Kuse
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Patent number: 7522381Abstract: A recording medium built-in cartridge of the present invention includes: a case; a recording medium housed in the case; and at least one humidity control member disposed in the case and including at least one humidity control material that absorbs moisture in the case when a humidity in the case is a first humidity or higher and emits the moisture to the case when the humidity in the case is a second humidity or lower, the second humidity being lower than the first humidity.Type: GrantFiled: March 16, 2006Date of Patent: April 21, 2009Assignee: Hitachi Maxell, Ltd.Inventors: Teruo Sogabe, Tsugihiro Doi
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Patent number: 7494728Abstract: A magnetic tape comprising a non-magnetic support, a magnetic layer containing magnetic powder which is formed on one side of the non-magnetic support, a primer layer containing non-magnetic powder which is formed between the non-magnetic support and the magnetic layer, and a backcoat layer containing non-magnetic powder which is formed on the other side of the non-magnetic support, wherein the magnetic layer contains the magnetic powder which comprises plate, granular or ellipsoidal magnetic particles with a particle diameter of 5 to 50 nm, and has a thickness of 0.09 ?m or less, and wherein at least one of the primer layer and the backcoat layer contains non-magnetic plate particles with a particle diameter of 10 to 100 nm.Type: GrantFiled: March 10, 2003Date of Patent: February 24, 2009Assignee: Hitachi Maxell, Ltd.Inventors: Sadamu Kuse, Tsugihiro Doi, Tetsutaro Inoue, Mikio Kishimoto
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Patent number: 7445858Abstract: A magnetic recording medium comprising a non-magnetic support, at least one primer layer formed on one surface of the non-magnetic support, comprising a non-magnetic powder and a binder resin, at least one magnetic layer formed on the primer layer, comprising a magnetic powder and a binder resin, and a back layer formed on the other surface of the non-magnetic support, wherein the magnetic powder contained in the uppermost layer of the magnetic layer is a rare earth metal-iron type magnetic powder of substantially spherical or ellipsoidal particles comprising a rare earth element and iron or a transition metal which comprises iron, and has a number average particle size of 5 to 50 nm and an average axis ratio of 1 to 2, and the total thickness of the magnetic recording medium is less than 6 ?m. This magnetic recording medium can achieve an excellent block error rate.Type: GrantFiled: March 19, 2007Date of Patent: November 4, 2008Assignee: Hitachi Maxell, Ltd.Inventors: Sadamu Kuse, Tsugihiro Doi, Tetsutaro Inoue, Mikio Kishimoto, Yuji Sasaki, Hideaki Watanabe
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Publication number: 20080107921Abstract: A magnetic recording medium comprising a non-magnetic support; at least one lower magnetic layer containing magnetic powder and a binder resin, which is formed on one side of the non-magnetic support with or without a non-magnetic primer layer interposed between the non-magnetic support and the lower magnetic layer; at least one non-magnetic intermediate layer containing non-magnetic powder and a binder resin, which is formed on the lower magnetic layer; at least one upper magnetic layer containing magnetic powder and a binder resin, which is formed on the non-magnetic intermediate layer; and a back layer which is formed on the other side of the non-magnetic support, characterized in that the magnetic powder contained in the uppermost magnetic layer of the upper magnetic layer is iron type magnetic powder which comprises substantially spherical or ellipsoidal particles with a number-average particle diameter of 5 to 50 nm and an average axial ratio of 1 to 2, each of said particles containing iron or containiType: ApplicationFiled: June 21, 2007Publication date: May 8, 2008Applicant: HITACHI MAXELL, LTD.Inventors: Sadamu Kuse, Tsugihiro Doi, Tetsutaro Inoue, Mikio Kishimoto, Yuji Sasaki, Hideaki Watanabe
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Patent number: 7309040Abstract: There is provided a magnetic tape cartridge, including a cartridge (1) composed of a top cartridge (2) and a bottom cartridge (3), a reel (5) rotatably disposed in the cartridge (1), and a magnetic tape (4) wound onto the reel (5), in which a width (w) of the magnetic tape (4) is over 12.65 mm, a thickness (h) of the cartridge (1) is 32 mm or less, and the width (w) of the magnetic tape is 60% to 90% of the thickness (h) of the cartridge (1).Type: GrantFiled: August 31, 2005Date of Patent: December 18, 2007Assignee: Hitachi Maxell, Ltd.Inventors: Teruo Sogabe, Tsugihiro Doi
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Publication number: 20070285832Abstract: In a recording/reproducing method of a magnetic tape in a tracking servo system, a recording density of each data track is increased while inhibiting occurrence of a recording/reproducing error caused by a size change of a magnetic tape in the width direction. Data tracks are each set to have a smaller track width stepwise as closer to servo tracks (41T-1 to 41T-5 etc.) in the width direction of a magnetic tape 1. With such a setting, the width of the data tracks (A1-41T-1 to A1-41T-5 etc.) closest to the servo tracks (41T-1 to 41T-5) can be minimized, thereby enabling a significant increase in number of the data tracks.Type: ApplicationFiled: June 29, 2007Publication date: December 13, 2007Inventors: Masao Okafuji, Tsugihiro Doi, Tetsutaro Inoue, Hiroyuki Mitsuhashi, Seigi Kawarai, Sadamu Kuse
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Patent number: 7291409Abstract: A magnetic recording medium comprising a non-magnetic support, at least one primer layer formed on one surface of the non-magnetic support, comprising a non-magnetic powder and a binder resin, at least one magnetic layer formed on the primer layer, comprising a magnetic powder and a binder resin, and a back layer formed on the other surface of the non-magnetic support, wherein the magnetic powder contained in the uppermost layer of the magnetic layer is a rare earth metal-iron type magnetic powder of substantially spherical or ellipsoidal particles comprising a rare earth element and iron or a transition metal which comprises iron, and has a number average particle size 5 to 50 nm and an average axis ratio of 1 to 2, and the total thickness of the magnetic recording medium is less than 6 ?m. This magnetic recording medium can achieve an excellent block error rate, which cannot be realized with magnetic recording media comprising conventional acicular magnetic powders.Type: GrantFiled: February 21, 2003Date of Patent: November 6, 2007Assignee: Hitachi Maxell, Ltd.Inventors: Sadamu Kuse, Tsugihiro Doi, Tetsutaro Inoue, Mikio Kishimoto, Yuji Sasaki, Hideaki Watanabe
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Patent number: 7267896Abstract: A magnetic recording medium comprising a non-magnetic support; at least one lower magnetic layer containing magnetic powder and a binder resin, which is formed on one side of the non-magnetic support with or without a non-magnetic primer layer interposed between the non-magnetic support and the lower magnetic layer; at least one non-magnetic intermediate layer containing non-magnetic powder and a binder resin, which is formed on the lower magnetic layer; at least one upper magnetic layer containing magnetic powder and a binder resin, which is formed on the non-magnetic intermediate layer; and a back layer which is formed on the other side of the non-magnetic support, characterized in that the magnetic powder contained in the uppermost magnetic layer of the upper magnetic layer is iron type magnetic powder which comprises substantially spherical or ellipsoidal particles with a number-average particle diameter of 5 to 50 nm and an average axial ratio of 1 to 2, each of said particles containing iron or containiType: GrantFiled: March 18, 2003Date of Patent: September 11, 2007Assignee: Hitachi Maxell, Ltd.Inventors: Sadamu Kuse, Tsugihiro Doi, Tetsutaro Inoue, Mikio Kishimoto, Yuji Sasaki, Hideaki Watanabe
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Patent number: 7259935Abstract: A magnetic tape having a lower non-magnetic layer containing non-magnetic powder and a binder, and an upper magnetic layer containing ferromagnetic powder and a binder, formed on a surface of a tape-form non-magnetic support. This magnetic tape has an intermediate binder layer, which is under the upper magnetic layer and has an average dry thickness of 10 to less than 50 nm. The average dry thickness of the upper magnetic layer is 5 to 100 nm, and the squareness ratio of the upper magnetic layer in the lengthwise direction is 0.8 or more. In this magnetic tape, the thickness of the magnetic layer and the fluctuation at the interface between the magnetic layer and the intermediate binder layer under the magnetic layer can be controlled. As a result, the PW50 value of a solitary waveform and modulation noise can be reduced. Thus, the magnetic tape shows excellent C/N characteristics.Type: GrantFiled: July 2, 2003Date of Patent: August 21, 2007Assignee: Hitachi Maxell, Ltd.Inventors: Tetsutaro Inoue, Tsugihiro Doi
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Patent number: 7253988Abstract: In a recording/reproducing method of a magnetic tape in a tracking servo system, a recording density of each data track is increased while inhibiting occurrence of a recording/reproducing error caused by a size change of a magnetic tape in the width direction. Data tracks are each set to have a smaller track width stepwise as closer to servo tracks (41T-1 to 41T-5 etc.) in the width direction of a magnetic tape 1. With such a setting, the width of the data tracks (A1-41T-1 to A1-41T-5 etc.) closest to the servo tracks (41T-1 to 41T-5) can be minimized, thereby enabling a significant increase in number of the data tracks.Type: GrantFiled: November 22, 2006Date of Patent: August 7, 2007Assignee: Hitachi Maxell, Ltd.Inventors: Masao Okafuji, Tsugihiro Doi, Tetsutaro Inoue, Hiroyuki Mitsuhashi, Seigi Kawarai, Sadamu Kuse
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Publication number: 20070159722Abstract: A magnetic recording medium comprising a non-magnetic support, at least one primer layer formed on one surface of the non-magnetic support, comprising a non-magnetic powder and a binder resin, at least one magnetic layer formed on the primer layer, comprising a magnetic powder and a binder resin, and a back layer formed on the other surface of the non-magnetic support, wherein the magnetic powder contained in the uppermost layer of the magnetic layer is a rare earth metal-iron type magnetic powder of substantially spherical or ellipsoidal particles comprising a rare earth element and iron or a transition metal which comprises iron, and has a number average particle size of 5 to 50 nm and an average axis ratio of 1 to 2, and the total thickness of the magnetic recording medium is less than 6 ?m. This magnetic recording medium can achieve an excellent block error rate, which cannot be realized with magnetic recording media comprising conventional acicular magnetic powders.Type: ApplicationFiled: March 19, 2007Publication date: July 12, 2007Applicant: Hitachi Maxell, Ltd.Inventors: Sadamu KUSE, Tsugihiro Doi, Tetsutaro Inoue, Mikio Kishimoto, Yuji Sasaki, Hideaki Watanabe
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Publication number: 20070097541Abstract: In a recording/reproducing method of a magnetic tape in a tracking servo system, a recording density of each data track is increased while inhibiting occurrence of a recording/reproducing error caused by a size change of a magnetic tape in the width direction. Data tracks are each set to have a smaller track width stepwise as closer to servo tracks (41T-1 to 41T-5 etc.) in the width direction of a magnetic tape 1. With such a setting, the width of the data tracks (A1-41T-1 to A1-41T-5 etc. ) closest to the servo tracks (41T-1 to 41T-5) can be minimized, thereby enabling a significant increase in number of the data tracks.Type: ApplicationFiled: November 22, 2006Publication date: May 3, 2007Inventors: Masao OKAFUJI, Tsugihiro Doi, Tetsutaro Inoue, Hiroyuki Mitsuhashi, Seigi Kawarai, Sadamu Kuse
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Patent number: 7212372Abstract: There is provided a magnetic tape, to be used at a running speed of at least 4,000 mm/sec., wherein servo signals for controlling tracking are recorded on the magnetic layer or the backcoat layer, and wherein the difference between the recording track width and the reproducing track width is 16 ?m or less, characterized in that the value of [?/(Tw?Tr)] is 0.2 or less, wherein a [?m] is an amount of a weave occurring on one of both edges of the magnetic tape and on the side of reference for the running of the tape; Tw [?m] is a recording track width; and Tr [?m] is a reproducing track width; and that a coefficient of humidity expansion in the tape widthwise direction is (0 to 14)×10?6/% RH; and a coefficient of thermal expansion in the tape widthwise direction is (0 to 10)×10?6/° C.Type: GrantFiled: August 13, 2002Date of Patent: May 1, 2007Assignee: Hitachi Maxell, Ltd.Inventors: Ken Yoshimura, Tsugihiro Doi
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Publication number: 20070086109Abstract: In a recording/reproducing method of a magnetic tape in a tracking servo system, a recording density of each data track is increased while inhibiting occurrence of a recording/reproducing error caused by a size change of a magnetic tape in the width direction. Data tracks are each set to have a smaller track width stepwise as closer to servo tracks (41T-1 to 41T-5 etc.) in the width direction of a magnetic tape 1. With such a setting, the width of the data tracks (A1-41T-1 to A1-41T-5 etc.) closest to the servo tracks (41T-1 to 41T-5) can be minimized, thereby enabling a significant increase in number of the data tracks.Type: ApplicationFiled: November 22, 2006Publication date: April 19, 2007Inventors: Masao Okafuji, Tsugihiro Doi, Tetsutaro Inoue, Hiroyuki Mitsuhashi, Seigi Kawarai, Sadamu Kuse
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Patent number: 7170709Abstract: In a recording/reproducing method of a magnetic tape in a tracking servo system, a recording density of each data track is increased while inhibiting occurrence of a recording/reproducing error caused by a size change of a magnetic tape in the width direction. Data tracks are each set to have a smaller track width stepwise as closer to servo tracks (41T-1 to 41T-5 etc.) in the width direction of a magnetic tape 1. With such a setting, the width of the data tracks (A1-41T-1 to A1-41T-5 etc.) closest to the servo tracks (41T-1 to 41T-5) can be minimized, thereby enabling a significant increase in number of the data tracks.Type: GrantFiled: May 16, 2005Date of Patent: January 30, 2007Assignee: Hitachi Maxell, Ltd.Inventors: Masao Okafuji, Tsugihiro Doi, Tetsutaro Inoue, Hiroyuki Mitsuhashi, Seigi Kawarai, Sadamu Kuse
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Publication number: 20060208122Abstract: A recording medium built-in cartridge of the present invention includes: a case; a recording medium housed in the case; and at least one humidity control member disposed in the case and including at least one humidity control material that absorbs moisture in the case when a humidity in the case is a first humidity or higher and emits the moisture to the case when the humidity in the case is a second humidity or lower, the second humidity being lower than the first humidity.Type: ApplicationFiled: March 16, 2006Publication date: September 21, 2006Inventors: Teruo Sogabe, Tsugihiro Doi