Patents by Inventor Naoto Murao
Naoto Murao 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: 7433154Abstract: A cleaning tape comprising a support and a coating layer containing powder and a binder, wherein a surface of the coating layer has a central line average roughness of from 5 to 25 nm and has protrusions having height of 25 nm or more in number of from 60 to 1,700/105 ?m2, the surface of the coating layer being a surface of the cleaning tape.Type: GrantFiled: September 2, 2005Date of Patent: October 7, 2008Assignee: FUJIFILM CorporationInventors: Naoto Murao, Tomohiro Ichikawa
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Publication number: 20070224456Abstract: A magnetic recording medium including: a nonmagnetic support; a smoothing layer containing a polymer; a nonmagnetic layer formed by coating a first solution containing nonmagnetic powder and a binder on the smoothing layer and drying the coated first solution; and a magnetic layer formed by coating a second solution containing ferromagnetic powder, inorganic powder and a binder on the nonmagnetic layer and drying the coated second solution, in this order.Type: ApplicationFiled: March 27, 2007Publication date: September 27, 2007Applicant: FUJIFILM CorporationInventors: Naoto Murao, Youhei Aritoshi
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Patent number: 7166377Abstract: In one aspect, the magnetic recording medium comprises a nonmagnetic layer comprising a nonmagnetic powder and a binder and a magnetic layer comprising a ferromagnetic powder and a binder in this order on a nonmagnetic support. The quantity of metal ions comprised in the nonmagnetic powder is equal to or less than 40 ppm/g. In a second aspect, the magnetic recording medium comprises a nonmagnetic layer comprising a nonmagnetic powder and a binder and a magnetic layer comprising a ferromagnetic powder and a binder in this order on a nonmagnetic support. The abrasiveness of the magnetic layer against a ferrite bar is equal to or less than 2×10?5 ?m/m. In both aspects, the quantity of metal ions extracted from the magnetic layer is equal to or less than 0.5 ppm/m2·100 mL.Type: GrantFiled: May 23, 2005Date of Patent: January 23, 2007Assignee: Fuji Photo Film Co., Ltd.Inventor: Naoto Murao
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Patent number: 7044837Abstract: A method for cleaning a magnetic head using a cleaning tape comprising a substrate and a cleaning layer, wherein the cleaning tape has a stiffness of 2 or less in a width direction, and the magnetic head has trenches substantially parallel to a sliding direction of the cleaning tape.Type: GrantFiled: October 28, 2003Date of Patent: May 16, 2006Assignee: Fuji Photo Film Co., Ltd.Inventors: Naoto Murao, Hiroyuki Tahara
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Patent number: 7041396Abstract: Provided is a magnetic recording medium affording good head contact and high output in addition to excellent head abrasion characteristics acceptable to high data transmission rates. The magnetic recording medium comprises a nonmagnetic layer comprising a nonmagnetic powder and a binder and a magnetic layer comprising a ferromagnetic powder and a binder in this order on a support. Said magnetic layer comprises an abrasive in a quantity of 2 to 5 weight percent with respect to the ferromagnetic powder, the number of protrusions having a height of 3 to 7 nm per 23,000 ?m2 of a surface of the magnetic layer, measured by a non-contact three-dimensional structure analyzing microscope, ranges from 50 to 200, and said magnetic layer has a microindentation hardness ranging from 40 to 80 kg/mm2 at a load of 6 mgf.Type: GrantFiled: September 10, 2004Date of Patent: May 9, 2006Assignee: Fuji Photo Film Co., Ltd.Inventors: Tomohiro Ichikawa, Naoto Murao
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Publication number: 20060066997Abstract: A cleaning tape comprising a support and a coating layer containing powder and a binder, wherein a surface of the coating layer has a central line average roughness of from 5 to 25 nm and has protrusions having height of 25 nm or more in number of from 60 to 1,700/105 ?m2, the surface of the coating layer being a surface of the cleaning tape.Type: ApplicationFiled: September 2, 2005Publication date: March 30, 2006Inventors: Naoto Murao, Tomohiro Ichikawa
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Publication number: 20050266276Abstract: In one aspect, the magnetic recording medium comprises a nonmagnetic layer comprising a nonmagnetic powder and a binder and a magnetic layer comprising a ferromagnetic powder and a binder in this order on a nonmagnetic support. The quantity of metal ions comprised in the nonmagnetic powder is equal to or less than 40 ppm/g. In a second aspect, the magnetic recording medium comprises a nonmagnetic layer comprising a nonmagnetic powder and a binder and a magnetic layer comprising a ferromagnetic powder and a binder in this order on a nonmagnetic support. The abrasiveness of the magnetic layer against a ferrite bar is equal to or less than 2×10?5 ?m/m. In both aspects, the quantity of metal ions extracted from the magnetic layer is equal to or less than 0.5 ppm/m2·100 mL.Type: ApplicationFiled: May 23, 2005Publication date: December 1, 2005Inventor: Naoto Murao
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Publication number: 20050079389Abstract: Provided is a magnetic recording medium affording good head contact and high output in addition to excellent head abrasion characteristics acceptable to high data transmission rates. The magnetic recording medium comprises a nonmagnetic layer comprising a nonmagnetic powder and a binder and a magnetic layer comprising a ferromagnetic powder and a binder in this order on a support. Said magnetic layer comprises an abrasive in a quantity of 2 to 5 weight percent with respect to the ferromagnetic powder, the number of protrusions having a height of 3 to 7 nm per 23,000 ?m2 of a surface of the magnetic layer, measured by a non-contact three-dimensional structure analyzing microscope, ranges from 50 to 200, and said magnetic layer has a microindentation hardness ranging from 40 to 80 kg/mm2 at a load of 6 mgf.Type: ApplicationFiled: September 10, 2004Publication date: April 14, 2005Inventors: Tomohiro Ichikawa, Naoto Murao
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Publication number: 20040137833Abstract: A method for cleaning a magnetic head using a cleaning tape comprising a substrate and a cleaning layer, wherein the cleaning tape has a stiffness of 2 or less in a width direction, and the magnetic head has trenches substantially parallel to a sliding direction of the cleaning tape.Type: ApplicationFiled: October 28, 2003Publication date: July 15, 2004Applicant: FUJI PHOTO FILM CO., LTD.Inventors: Naoto Murao, Hiroyuki Tahara
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Patent number: 6729570Abstract: A tape reel (10) is so constructed that an upper flange (12) and a lower flange (13) are respectively provided at an upper and a lower ends of a cylindrical reel hub (11) around which a magnetic tape (20) is wound, and a maximum value of a distance from the upper flange (12) and the lower flange (13) to lateral ends of the magnetic tape (20) is set to be 0.5 mm or more, and less than 1.0 mm. The magnetic tape (20) includes a nonmagnetic substrate (21), a magnetic layer (22) provided on one face of the nonmagnetic substrate and a back layer (23) provided on the other face of the nonmagnetic substrate, and in a state where the magnetic tape is wound around the tape reel (10), a distance (U1+D1) from the upper flange (12) and the lower flange (13) to lateral ends of the back layer (23) is larger than a distance (U2+D2) from the upper flange (12) and the lower flange (13) to lateral ends of the nonmagnetic substrate (21) or lateral ends of the magnetic layer (22).Type: GrantFiled: August 16, 2001Date of Patent: May 4, 2004Assignee: Fuji Photo Film Co., Ltd.Inventors: Naoto Murao, Makoto Sato, Mitsugu Yamagishi, Kiyoo Morita
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Patent number: 6686024Abstract: A magnetic recording medium is formed from a non-magnetic support, and a magnetic layer formed on the support and including mainly a binder resin and a ferromagnetic metal powder including mainly Fe. The magnetic layer includes an abrasive and a lubricant. The abrasive present on the surface of the magnetic layer satisfies the relationship 0.01≦H15/H10≦0.3 where H10 denotes the number of particles per unit area having a height less than 10 nm (particles/&mgr;m2) and H5 denotes the number of particles per unit area having a height equal to or greater than 15 nm (particles/&mgr;m2). The magnetic recording medium has a surface lubricant index of 3 to 11. The height of the abrasive particles can be controlled by, for example, a blade treatment using an abrasive tape (LTBL system) or a diamond powder-studded rotating roll (DWBL system).Type: GrantFiled: April 25, 2002Date of Patent: February 3, 2004Assignee: Fuji Photo Film Co., Ltd.Inventors: Mikio Ohno, Naoto Murao, Toshichika Aoki, Hiroaki Araki
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Patent number: 6653001Abstract: Provided is a thin magnetic tape with good tracking and very little output variation in VTRs. The magnetic tape comprises a flexible support, a magnetic layer provided on one side of said flexible support and a backcoat layer provided on the reverse side of said flexible support. The magnetic tape has a stiffness equal to or less than 70 mg·mm2 in the width direction, an average meandering amount of a tape edge trajectory traced by each of both end in the width direction of said tape observed from the direction perpendicular to said magnetic layer surface is equal to or less than 15 &mgr;m in every end, and an intensity of a meandering component having a cycle of 20 to 200 mm is equal to or less than 30 percent of the intensity of a meandering component having a cycle of 20 to 10,000 mm.Type: GrantFiled: October 26, 2001Date of Patent: November 25, 2003Assignee: Fuji Photo Film Co., Ltd.Inventors: Naoto Murao, Mikio Ohno, Nobuyoshi Asada, Youichi Hayata
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Patent number: 6607156Abstract: A 2 reel type data storage magnetic tape cassette (20) is provided with reels (28, 30) around which a magnetic recording medium (26) is wound. The magnetic recording medium (26) includes a support, a non-magnetic layer comprising a non-magnetic powder and a binder on one surface of the support, a magnetic layer comprising a ferromagnetic metal powder and a binder on top of the non-magnetic layer, and a back layer comprising a carbon black powder and a binder on the other side of the support. The magnetic tape cassette (20) is further provided with a rotating guide roller (36) made of a resin within the cassette (20). The rotating guide roller (36) has a ten-point average roughness Rz of 3.0 to 4.5 &mgr;m and is in contact with the surface of the magnetic layer having a center plane average roughness SRa of 2.0 to 3.5 nm.Type: GrantFiled: April 18, 2002Date of Patent: August 19, 2003Assignee: Fuji Photo Film Co., Ltd.Inventors: Naoto Murao, Hiroaki Araki, Tomohiro Ichikawa
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Publication number: 20030062438Abstract: A 2 reel type data storage magnetic tape cassette (20) is provided with reels (28, 30) around which a magnetic recording medium (26) is wound. The magnetic recording medium (26) includes a support, a non-magnetic layer comprising a non-magnetic powder and a binder on one surface of the support, a magnetic layer comprising a ferromagnetic metal powder and a binder on top of the non-magnetic layer, and a back layer comprising a carbon black powder and a binder on the other side of the support. The magnetic tape cassette (20) is further provided with a rotating guide roller (36) made of a resin within the cassette (20). The rotating guide roller (36) has a ten-point average roughness Rz of 3.0 to 4.5 &mgr;m and is in contact with the surface of the magnetic layer having a center plane average roughness SRa of 2.0 to 3.5 nm.Type: ApplicationFiled: April 18, 2002Publication date: April 3, 2003Applicant: FUJI PHOTO FILM CO., LTD.Inventors: Naoto Murao, Hiroaki Araki, Tomohiro Ichikawa
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Publication number: 20030054201Abstract: A magnetic recording medium is formed from a non-magnetic support, and a magnetic layer formed on the support and including mainly a binder resin and a ferromagnetic metal powder including mainly Fe. The magnetic layer includes an abrasive and a lubricant. The abrasive present on the surface of the magnetic layer satisfies the relationship 0.01≦H15/H10≦0.3 where H10 denotes the number of particles per unit area having a height less than 10 nm (particles/&mgr;m2) and H5 denotes the number of particles per unit area having a height equal to or greater than 15 nm (particles/&mgr;m2). The magnetic recording medium has a surface lubricant index of 3 to 11. The height of the abrasive particles can be controlled by, for example, a blade treatment using an abrasive tape (LTBL system) or a diamond powder-studded rotating roll (DWBL system).Type: ApplicationFiled: April 25, 2002Publication date: March 20, 2003Applicant: FUJI PHOTO FILM CO., LTD.Inventors: Mikio Ohno, Naoto Murao, Toshichika Aoki, Hiroaki Araki
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Publication number: 20020197513Abstract: The present invention aims to provide a magnetic recording medium having excellent head contact and output suitable for high data transfer rates and having excellent high-speed sliding durability suitable for high-density recording.Type: ApplicationFiled: December 15, 2000Publication date: December 26, 2002Inventors: Naoto Murao, Hiroaki Araki
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Publication number: 20020155324Abstract: Provided is a thin magnetic tape with good tracking and very little output variation in VTRs. The magnetic tape comprises a flexible support, a magnetic layer provided on one side of said flexible support and a backcoat layer provided on the reverse side of said flexible support. The magnetic tape has a stiffness equal to or less than 70 mg.mm2 in the width direction, an average meandering amount of a tape edge trajectory traced by each of both end in the width direction of said tape observed from the direction perpendicular to said magnetic layer surface is equal to or less than 15 &mgr;m in every end, and an intensity of a meandering component having a cycle of 20 to 200 mm is equal to or less than 30 percent of the intensity of a meandering component having a cycle of 20 to 10,000 mm.Type: ApplicationFiled: October 26, 2001Publication date: October 24, 2002Inventors: Naoto Murao, Mikio Ohno, Nobuyoshi Asada, Youichi Hayata
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Patent number: 5922483Abstract: A magnetic recording medium having a total thickness of not more than 11 .mu.m is disclosed, comprising a non-magnetic support having a magnetic layer comprising a ferromagnetic powder dispersed in a binder provided on one surface of the non-magnetic support and a back layer provided on the other surface of the non-magnetic support, wherein the non-magnetic support has a longitudinal Young's modulus (E.sub.MD) and a crosswise Young's modulus (E.sub.TD) such that the sum of E.sub.MD and E.sub.TD is not less than 1,200 kg/mm.sup.2 and the ratio of E.sub.MD to E.sub.TD is from 1/1 to 1/3 and an intrinsic viscosity of from 0.50 to 0.60 and the magnetic layer comprises a polyurethane resin with a weight-average molecular weight of from 30,000 to 60,000 having a component having a molecular weight of not more than 5,000 in an amount of not more than 4.5%.Type: GrantFiled: February 18, 1997Date of Patent: July 13, 1999Assignee: Fuji Photo Film Co., Ltd.Inventors: Masatoshi Takahashi, Naoto Murao, Nobuyoshi Asada, Noburo Hibino
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Patent number: 5827599Abstract: In the present invention, the anti-scrapability of the back layer of a magnetic recording medium is improved to reduce the frequency of occurrence of powder fall onto the surface of the magnetic layer and clogging between the magnetic head and the surface of the magnetic layer. As a result, a magnetic recording medium which is extremely less susceptible to dropout can be provided. A novel tape-shaped magnetic recording medium is provided which is obtained by longitudinally slitting a nonmagnetic support having on one side thereof a magnetic layer comprising a ferromagnetic powder dispersed in a binder and on the other side a back layer, wherein the edge face of said back layer doesn't protrude from the vertical line tangent to the highest protrusion on the slit section of said nonmagnetic support.Type: GrantFiled: November 8, 1996Date of Patent: October 27, 1998Assignee: Fuji Photo Film Co., Ltd.Inventors: Naoto Murao, Masatoshi Takahashi, Nobuyoshi Asada, Jun-ichi Nakamigawa, Nobuyuki Kobayashi