Patents by Inventor Tetsutaro Inoue
Tetsutaro Inoue 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: 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: 20070111040Abstract: A magnetic recording medium having a non-magnetic support and a magnetic layer formed thereon, wherein the magnetic layer comprises a ferromagnetic powder, a binder and a non-magnetic inorganic powder, and wherein at least 95% of the non-magnetic powder particles contained in the magnetic layer have a particle size of 0.05 to 0.013 ?m, provide that the non-magnetic powder particles are those found in a field of view of 1.8 ?m×2.4 ?m when the surface of the magnetic layer is observed with a scanning electron microscope at a magnification of 50,000 times.Type: ApplicationFiled: January 10, 2007Publication date: May 17, 2007Inventors: Ken Yoshimura, Tetsutaro Inoue
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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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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: 7175927Abstract: A magnetic recording medium having a non-magnetic support and a magnetic layer formed thereon, wherein the magnetic layer comprises a ferromagnetic powder, a binder and a non-magnetic inorganic powder, and wherein at least 95% of the non-magnetic powder particles contained in the magnetic layer have a particle size of 0.05 to 0.013 ?m, provide that the non-magnetic powder particles are those found in a field of view of 1.8 ?m×2.4 ?m when the surface of the magnetic layer is observed with a scanning electron microscope at a magnification of 50,000 times.Type: GrantFiled: November 9, 2004Date of Patent: February 13, 2007Assignee: Hitachi Maxell, Ltd.Inventors: Ken Yoshimura, Tetsutaro Inoue
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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: 20060141140Abstract: A magnetic recording medium comprising a flexible support, a lower non-magnetic layer comprising a non-magnetic powder and a binder formed on the flexible support, and an upper magnetic layer comprising a ferromagnetic powder and a binder formed on the lower non-magnetic layer, wherein the upper magnetic layer has a SFD value of 0.5 or less, the magnetic powder contained in the upper magnetic layer has an average major axis length of 80 nm or less, and a SFD value of the upper magnetic layer is 1.2 times or less the initial SFD value after the magnetic recording medium is stored at a temperature of 60° C. and a relative humidity of 90% RH for 90 days.Type: ApplicationFiled: March 15, 2006Publication date: June 29, 2006Inventors: Tetsutaro INOUE, Ken Yoshimura, Chikako Kurusumi
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Publication number: 20060003191Abstract: 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: ApplicationFiled: August 31, 2005Publication date: January 5, 2006Inventors: Sadamu Kuse, Tsugihiro Doi, Tetsutaro Inoue, Mikio Kishimoto
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Publication number: 20050277001Abstract: A magnetic recording medium comprising a flexible support, a lower non-magnetic layer comprising a non-magnetic powder and a binder formed on the flexible support, and an upper magnetic layer comprising a ferromagnetic powder and a binder formed on the lower non-magnetic layer, wherein the upper magnetic layer has a SFD value of 0.5 or less, the magnetic powder contained in the upper magnetic layer has an average major axis length of 80 nm or less, and a SFD value of the upper magnetic layer is 1.2 times or less the initial SFD value after the magnetic recording medium is stored at a temperature of 60° C. and a relative humidity of 90% RH for 90 days.Type: ApplicationFiled: August 22, 2003Publication date: December 15, 2005Inventors: Tetsutaro Inoue, Ken Yoshimura, Chikako Kurusumi
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Publication number: 20050276999Abstract: 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: ApplicationFiled: February 21, 2003Publication date: December 15, 2005Inventors: Sadamu Kuse, Tsugihiro Doi, Tetsutaro Inoue, Mikio Kishimoto, Yuji Sasaki, Hideaki Watanabe
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Publication number: 20050254162Abstract: 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: May 16, 2005Publication date: November 17, 2005Applicant: HITACHI MAXELL, LTD.Inventors: Masao Okafuji, Tsugihiro Doi, Tetsutaro Inoue, Hiroyuki Mitsuhashi, Seigi Kawarai, Sadamu Kuse
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Publication number: 20050196645Abstract: A magnetic tape having excellent high recording density characteristics, good durability and good servo-tracking characteristics, which comprises a non-magnetic support, a magnetic layer formed on one surface of the non-magnetic support and containing a magnetic powder, a primer layer provided between the non-magnetic support and the magnetic layer and containing a non-magnetic powder, and a back coat layer formed on the other surface of the non-magnetic support, wherein the non-magnetic powder is goethite particles having an average particle size in a range of from 5 nm to 100 nm and the magnetic tape has an edge weave amount of 1.0 ?m or less.Type: ApplicationFiled: February 9, 2005Publication date: September 8, 2005Applicant: HITACHI MAXELL, LTD.Inventors: Tsugihiro Doi, Shinji Sakata, Tetsutaro Inoue, Sadamu Kuse
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Publication number: 20050170214Abstract: There is provided a magnetic recording medium comprising a flexible non-magnetic substrate, and a magnetic layer containing magnetic particles, formed on at least one surface of the flexible non-magnetic substrate, and this magnetic recording medium is characterized in that an uppermost layer formed on the side of the magnetic layer is a non-magnetic layer with a thickness of 1 to 50 nm, which contains a resin and has a surface roughness (P-V) of 2 to 20 nm. This magnetic recording medium is excellent in high density recording performance, and is highly reliable in durability.Type: ApplicationFiled: November 24, 2004Publication date: August 4, 2005Applicant: HITACHI MAXELL, LTD.Inventors: Tsugihiro Doi, Tetsutaro Inoue, Hisanobu Mikamo, Seigi Kawarai, Sadamu Kuse
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Publication number: 20050153170Abstract: There is provided a magnetic tape comprising a non-magnetic support, and a primer layer and a magnetic layer both formed on a surface of the non-magnetic support, and a backcoat layer formed on the other surface of the non-magnetic support, wherein the magnetic layer contains magnetic powder which comprises needle-like iron-based magnetic particles, and has a thickness of 0.09 ?m or less; and the primer layer contains non-magnetic powder which comprises plate-like non-magnetic oxide particles with an average particle size of 10 to 100 nm. Further, the thermal expansion coefficient of the magnetic layer in the tape widthwise direction is (0 to 8)×10?6/° C., and the humidity expansion coefficient of the magnetic layer in the tape widthwise direction is (0 to 10)×10?6/% RH; and the amount of edge weave which is formed on either of the edges of the tape serving as the side of reference for the feeding of the tape is 0.8 ?m or less.Type: ApplicationFiled: July 16, 2003Publication date: July 14, 2005Applicant: HITACHI MAXELL, LTD.Inventors: Tetsutaro Inoue, Tsugihiro Doi, Mikio Kishimoto
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Publication number: 20050142386Abstract: There is provided a magnetic tape of coating type, which comprises a lower non-magnetic layer containing non-magnetic powder and a binder, and an upper magnetic layer containing ferromagnetic powder and a binder, formed in this order on a surface of a tape-form non-magnetic support. This magnetic tape has an intermediate binder layer consisting essentially of a binder, which is provided just under the upper magnetic layer and which 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 just under the magnetic layer can be controlled. As a result, the PW50 value of a solitary waveform and modulation noise can be reduced, and thus, the magnetic tape show excellent C/N characteristics.Type: ApplicationFiled: July 2, 2003Publication date: June 30, 2005Applicant: HITACHI MAXELL, LTD.Inventors: Tetsutaro Inoue, Tsugihiro Doi
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Publication number: 20050100762Abstract: A magnetic recording medium having a non-magnetic support and a magnetic layer formed thereon, wherein the magnetic layer comprises a ferromagnetic powder, a binder and a non-magnetic inorganic powder, and wherein at least 95% of the non-magnetic powder particles contained in the magnetic layer have a particle size of 0.05 to 0.013 ?m, provide that the non-magnetic powder particles are those found in a field of view of 1.8 ?m×2.4 ?m when the surface of the magnetic layer is observed with a scanning electron microscope at a magnification of 50,000 times.Type: ApplicationFiled: November 9, 2004Publication date: May 12, 2005Inventors: Ken Yoshimura, Tetsutaro Inoue
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Publication number: 20040110037Abstract: 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 &mgr;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: ApplicationFiled: March 10, 2003Publication date: June 10, 2004Inventors: Sadamu Kuse, Tsugihiro Doi, Tetsutaro Inoue, Mikio Kishimoto
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Publication number: 20040089564Abstract: 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: March 18, 2003Publication date: May 13, 2004Inventors: Sadamu Kuse, Tsugihiro Doi, Tetsutaro Inoue, Mikio Kishimoto, Yuji Sasaki, Hideaki Watanabe