Patents by Inventor Mikio Ohno
Mikio Ohno 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: 7381485Abstract: A magnetic recording tape comprising a nonmagnetic support and a magnetic layer containing ferromagnetic powder and a binder, wherein the nonmagnetic support has an intrinsic viscosity of from 0.40 to 0.60 dl/g and a number average molecular weight of from 12,000 to 24,000, and a distance between an apex of a maximum convexity and a valley of a maximum concavity of the nonmagnetic support on a cross section of an edge of the tape made by cutting the tape in a transverse direction is 2 ?m or less in the transverse direction.Type: GrantFiled: February 4, 2005Date of Patent: June 3, 2008Assignee: FUJIFILM CorporationInventors: Tatsuo Ishikawa, Mikio Ohno, Tomohiro Ichikawa
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Patent number: 7368189Abstract: A magnetic recording medium comprising: a magnetic layer containing ferromagnetic powder and a binder; a nonmagnetic support; and a back coat layer, in this order, wherein the nonmagnetic support contains polyester having an intrinsic viscosity of from 0.40 to 0.60 dl/g and a number average molecular weight of from 12,000 to 24,000, a surface of the magnetic layer on a side not having the nonmagnetic support has a surface roughness Ra of from 1 to 5 nm, and a surface of the back coat layer on a side not having the nonmagnetic support has a surface roughness Ra of from 6 to 20 nm.Type: GrantFiled: January 26, 2005Date of Patent: May 6, 2008Assignee: FUJIFILM CorporationInventors: Mikio Ohno, Tatsuo Ishikawa, Tomohiro Ichikawa
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Patent number: 7361422Abstract: A leader tape in which an non-magnetic under layer that contains a powder and a binder and a magnetic upper layer are sequentially laminated on at least one side of a support, a center line average roughness (Ra) of a surface of the support is from 30 to 50 nm, and a center line average roughness (Ra) of the multi layer coated surface is larger than that (Ra) of an opposite surface of the support, and the difference is at most 4 nm.Type: GrantFiled: March 28, 2005Date of Patent: April 22, 2008Assignee: FUJIFILM CorporationInventors: Masatoshi Takahashi, Mikio Ohno
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Patent number: 7349182Abstract: A magnetic recording medium for being used in a write/read system in which a difference of track width between write track width and read track width is smaller than 10 ?m, which comprises: a magnetic layer containing ferromagnetic powder and a binder; a nonmagnetic support; and a backcoating layer, in this order, at least one of the magnetic layer and the backcoating layer having servo signals for tracking control pre-recorded therein, wherein the nonmagnetic support is a film of a polyester having an intrinsic viscosity of 0.40 to 0.60 dl/g and a number average molecular weight of 12000 to 24000.Type: GrantFiled: February 4, 2005Date of Patent: March 25, 2008Assignee: FUJIFILM CorporationInventors: Mikio Ohno, Tomohiro Ichikawa, Tatsuo Ishikawa
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Publication number: 20080017741Abstract: An object is to provide a leader tape which suppresses the increase of dropout resulting from imprinting of the drive reel or leader block part due to storage for a long time or running at a high temperature and hardly causes the edge damage of a magnetic tape, and also provide a magnetic tape cartridge using the leader tape. 1) A leader tape LT including a support having provided on at least one surface thereof a coating layer, wherein Ra on at least one surface of the leader tape is from 10 to 60 nm and the maximum curving amount in the longitudinal direction is 3 mm/m or less; and 2) a magnetic tape cartridge including a cartridge case; and a single reel or a plurality of reels, each reel being rotatably housed in the cartridge case and having a magnetic tape wound therearound, in which the magnetic tape has a leader tape of 1), the leader tape being jointed to an leading end of the magnetic tape and drawn out into a magnetic recording and reproducing apparatus while leading the magnetic tape.Type: ApplicationFiled: April 13, 2004Publication date: January 24, 2008Inventors: Tomohiro Ichikawa, Mikio Ohno, Kiyomi Ejiri
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Patent number: 7045227Abstract: A magnetic recording medium comprising: a nonmagnetic support; an undercoat layer containing a compound polymerizable by radiation exposure; and a magnetic layer containing ferromagnetic powder and a binder, in this order wherein the undercoat layer has a thickness of from 0.1 to 1 ?m, the binder contains a polyurethane resin having a glass transition temperature of from 100 to 200° C., the magnetic layer has a thickness of from 20 to 150 nm, and an average particle size of the ferromagnetic powder is from 20 to 60 nm.Type: GrantFiled: March 19, 2004Date of Patent: May 16, 2006Assignee: Fuji Photo Film Co., Ltd.Inventors: Tatsuo Ishikawa, Mikio Ohno
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Patent number: 6991862Abstract: In one aspect, the magnetic recording medium comprises a magnetic layer comprising a ferromagnetic powder and a binder and said binder comprises polyurethane resin having a glass transition temperature of 100 to 200° C. 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 and at least the binder comprised in said magnetic layer comprises polyurethane resin having a glass transition temperature of 100 to 200° C. In both aspects, said magnetic layer has a thickness equal to or less than 0.15 ?m, said ferromagnetic powder has a mean major axis length or a mean plate diameter of 60 nm or less, and said magnetic layer has a coercivity of 159 to 239 kA/m in a longitudinal or in-plane direction.Type: GrantFiled: March 29, 2004Date of Patent: January 31, 2006Assignee: Fuji Photo Film Co., Ltd.Inventors: Mikio Ohno, Tatsuo Ishikawa
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Publication number: 20050253010Abstract: A leader tape in which an non-magnetic under layer that contains a powder and a binder and a magnetic upper layer are sequentially laminated on at least one side of a support, a center line average roughness (Ra) of a surface of the support is from 30 to 50 nm, and a center line average roughness (Ra) of the multi layer coated surface is larger than that (Ra) of an opposite surface of the support, and the difference is at most 4 nm.Type: ApplicationFiled: March 28, 2005Publication date: November 17, 2005Inventors: Masatoshi Takahashi, Mikio Ohno
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Publication number: 20050211814Abstract: A leader tape where an non-magnetic under layer that contains a powder and a binder and a magnetic upper layer are sequentially laminated on at least one face of a support, in which F5 values of the support in a machine direction (MD) and in a transverse direction (TD) are from 80 to 120 MPa respectively, the F5 value in MD is larger than that in TD, and a difference between the F5 value in MD and that in TD is 15 MPa or less.Type: ApplicationFiled: March 28, 2005Publication date: September 29, 2005Inventors: Masatoshi Takahashi, Mikio Ohno
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Publication number: 20050214594Abstract: A leader tape has, on at least one face of a support, a coating layer that contains a powder and a binder, which is characterized in that the center line average roughness (Ra) of at least one face of the leader tape is from 10 to 60 nm, the leader tape is used in a magnetic recording and reproduction device where the line recording density is at least 100 kfci, and the difference between the recording track width and the reproduction track width is from 0 to 16 ?m.Type: ApplicationFiled: March 28, 2005Publication date: September 29, 2005Inventor: Mikio Ohno
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Publication number: 20050214525Abstract: A leader tape has, on at least one face of a support, a coating layer that contains a powder and a binder, which is characterized in that a center line average roughness (Ra) of at least one face of the leader tape is from 10 to 60 nm, and the leader tape is used for binding to a magnetic tape having a thickness of 3 to 11 ?m.Type: ApplicationFiled: March 28, 2005Publication date: September 29, 2005Inventor: Mikio Ohno
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Publication number: 20050202289Abstract: A magnetic recording tape comprising a nonmagnetic support and a magnetic layer containing ferromagnetic powder and a binder, wherein the nonmagnetic support has an intrinsic viscosity of from 0.40 to 0.60 dl/g and a number average molecular weight of from 12,000 to 24,000, and a distance between an apex of a maximum convexity and a valley of a maximum concavity of the nonmagnetic support on a cross section of an edge of the tape made by cutting the tape in a transverse direction is 2 ?m or less in the transverse direction.Type: ApplicationFiled: February 4, 2005Publication date: September 15, 2005Inventors: Tatsuo Ishikawa, Mikio Ohno, Tomohiro Ichikawa
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Publication number: 20050175866Abstract: A magnetic recording medium for being used in a write/read system in which a difference of track width between write track width and read track width is smaller than 10 ?m, which comprises: a magnetic layer containing ferromagnetic powder and a binder; a nonmagnetic support; and a backcoating layer, in this order, at least one of the magnetic layer and the backcoating layer having servo signals for tracking control pre-recorded therein, wherein the nonmagnetic support is a film of a polyester having an intrinsic viscosity of 0.40 to 0.60 dl/g and a number average molecular weight of 12000 to 24000.Type: ApplicationFiled: February 4, 2005Publication date: August 11, 2005Inventors: Mikio Ohno, Tomohiro Ichikawa, Tatsuo Ishikawa
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Publication number: 20050173577Abstract: Disclosed is a tape drive system which can wind magnetic tapes in proper alignment and which minimizes the possibility of tape impressions on magnetic tapes even if the core of the take-up reel has step heights on its peripheral surface. The tape drive system includes a tape-shaped recording medium having a head edge where a leader tape is formed to prevent tape impressions from being formed on the tape-shaped recording medium itself; a plurality of grooves formed on a flange of the take-up reel or the supply reel, the grooves for directing an airflow to an outside of the flange upon winding of the tape-shaped recording medium; and the leader tape having a surface of a center line average roughness ranging from 10 nm to 60 nm and a total thickness ranging from 10 ?m to 40 ?m while being wounded around or the take-up reel.Type: ApplicationFiled: December 29, 2004Publication date: August 11, 2005Inventor: Mikio Ohno
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Publication number: 20050170213Abstract: A magnetic recording medium comprising: a magnetic layer containing ferromagnetic powder and a binder; a nonmagnetic support; and a back coat layer, in this order, wherein the nonmagnetic support contains polyester having an intrinsic viscosity of from 0.40 to 0.60 dl/g and a number average molecular weight of from 12,000 to 24,000, a surface of the magnetic layer on a side not having the nonmagnetic support has a surface roughness Ra of from 1 to 5 nm, and a surface of the back coat layer on a side not having the nonmagnetic support has a surface roughness Ra of from 6 to 20 nm.Type: ApplicationFiled: January 26, 2005Publication date: August 4, 2005Inventors: Mikio Ohno, Tatsuo Ishikawa, Tomohiro Ichikawa
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Publication number: 20040219393Abstract: In one aspect, the magnetic recording medium comprises a magnetic layer comprising a ferromagnetic powder and a binder and said binder comprises polyurethane resin having a glass transition temperature of 100 to 200° C. 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 and at least the binder comprised in said magnetic layer comprises polyurethane resin having a glass transition temperature of 100 to 200° C. In both aspects, said magnetic layer has a thickness equal to or less than 0.15 &mgr;m, said ferromagnetic powder has a mean major axis length or a mean plate diameter of 60 nm or less, and said magnetic layer has a coercivity of 159 to 239 kA/m in a longitudinal or in-plane direction.Type: ApplicationFiled: March 29, 2004Publication date: November 4, 2004Applicant: FUJI PHOTO FILM CO., LTD.Inventors: Mikio Ohno, Tatsuo Ishikawa
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Patent number: 6811855Abstract: A magnetic recording medium is provided which includes a non-magnetic support and a magnetic layer formed on or above the support. The magnetic layer includes a ferromagnetic powder, a binder resin, an abrasive, and a fatty acid ester. The fatty acid ester is a fatty acid alkyl ester compound having an acid hydrolysis rate of 0.030 (1/hr) or less. The abrasive present on the surface of the magnetic layer satisfies the relational expression 0.01≦H15/H10≦0.20 where H10 denotes the number of particles per unit area having a height less than 10 nm (particles/&mgr;m2) and H15 denotes the number of particles per unit area having a height equal to or greater than 15 nm (particles/&mgr;m2).Type: GrantFiled: May 7, 2003Date of Patent: November 2, 2004Assignee: Fuji Photo Film Co., Ltd.Inventor: Mikio Ohno
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Publication number: 20040191528Abstract: A magnetic recording medium comprising: a nonmagnetic support; an undercoat layer containing a compound polymerizable by radiation exposure; and a magnetic layer containing ferromagnetic powder and a binder, in this order wherein the undercoat layer has a thickness of from 0.1 to 1 &mgr;m, the binder contains a polyurethane resin having a glass transition temperature of from 100 to 200° C., the magnetic layer has a thickness of from 20 to 150 nm, and an average particle size of the ferromagnetic powder is from 20 to 60 nm.Type: ApplicationFiled: March 19, 2004Publication date: September 30, 2004Applicant: FUJI PHOTO FILM CO., LTD.Inventors: Tatsuo Ishikawa, Mikio Ohno
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Patent number: 6692849Abstract: A magnetic recording medium is provided comprising a non-magnetic support and at least one magnetic layer comprising ferromagnetic metal particles principally containing iron, having a spindle shape and having an average major axis length of 0.15 &mgr;m or less, and a binder resin, and optionally further comprising, between the support and the magnetic layer, at least one adhesive layer or at least one non-magnetic layer principally containing a non-magnetic inorganic powder and a binder, and wherein center line average surface roughness Ra of the magnetic layer surface being 2 to 6 nm, said recording medium having the following properties; steel ball wear at 23° C. and 70% RH being 2×10−5 to 4×10−5 mm3, surface C/Fe ratio measured by Auger electron spectroscopy being 50 to 100, and coefficient of friction between the magnetic layer surface and an SUS rod having a roughness of 8 to 10 nm being 0.2 to 0.3.Type: GrantFiled: September 20, 2001Date of Patent: February 17, 2004Assignee: Fuji Photo Film Co., Ltd.Inventors: Hiroaki Araki, Mikio Ohno, Toshichika Aoki
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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