Patents by Inventor Hajime Miyatuka
Hajime Miyatuka 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: 4481253Abstract: A process for preparing a ferromagnetic metal powder and a magnetic recording medium utilizing that powder are disclosed. The ferromagnetic metal powder is prepared by heat-treating an acicular iron oxyhydroxide or an acicular iron oxide powder prepared from the acicular iron oxyhydroxide in a non-reducing gas at a temperature of from 300.degree. C. to 1000.degree. C. or in a reducing gas at a temperature of from 150.degree. C. to 500.degree. C. The heat-treated material is washed and then reduced under heating. The ferromagnetic metal powder prepared in this manner is dispersed in a binder and cated on a non-magnetic base to form a magnetic recording medium. By utilizing the washing step followed by heat-treating preparing the ferromagnetic metal powder a large amount of water soluble impurities are removed from the metal powder. The metal powder produced according to this disclosed process as excellent oxidation stability and ability to resist corrosion.Type: GrantFiled: December 10, 1982Date of Patent: November 6, 1984Assignee: Fuji Photo Film Co., Ltd.Inventors: Akihiro Matsufuji, Shizuo Umemura, Akira Kasuga, Hajime Miyatuka, Goro Akashi
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Patent number: 4465737Abstract: A magnetic recording medium is disclosed. The medium is comprised of a support having a magnetic layer coated thereon. The magnetic layer is comprised of a ferromagnetic metal powder and a binder. The ferromagnetic metal powder has a specific surface area of not less than 30 m.sup.2 /g. The magnetic layer is further comprised of a fatty acid and a fatty acid ester in a total amount of 2 to 10 wt % based on the weight of the ferromagnetic metal powder. The proportion of the fatty acid ester is 15 to 60 wt % based on the total weight of the fatty acid and the fatty acid ester. The surface roughness of the magnetic layer is not more than 0.03.mu..Type: GrantFiled: January 31, 1983Date of Patent: August 14, 1984Assignee: Fuji Photo Film Co., Ltd.Inventors: Hajime Miyatuka, Akira Kasuga, Akihiro Matsufuji, Tsutomu Sugisaki
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Patent number: 4455345Abstract: A magnetic recording medium is disclosed. The medium is comprised of a support having a magnetic layer coated thereon. The magnetic layer is comprised of ferromagnetic metal powder and a binder. The ferromagnetic metal powder has a specific surface area of 35 to 70 m.sup.2 /g, a saturation magnetization (.sigma..sub.s) of 120 to 160 emu/g and a metal content of 75 to 98 wt %. The magnetic recording medium has a high S/N ratio, particularly a high video S/N ratio and has stable magnetic properties.Type: GrantFiled: January 11, 1983Date of Patent: June 19, 1984Assignee: Fuji Photo Film Co., Ltd.Inventors: Hajime Miyatuka, Akira Kasuga
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Patent number: 4105448Abstract: An electrophotographic photosensitive layer comprising finely divided photoconductive powders and a resin binder comprising a mixture of an acrylic resin and an epoxy ester resin in a ratio by volume of the acrylic resin to the epoxy ester resin of about 10:90 to 70:30; and an electrophotographic marking method suitable for use on substrates subsequently machined comprising electrophotographically marking machining information on a coating film, forming on a support to be machined, of the electrophotographic photosensitive layer as defined above and hardening the coating film.Type: GrantFiled: August 25, 1975Date of Patent: August 8, 1978Assignee: Fuji Photo Film Co., Ltd.Inventors: Hajime Miyatuka, Takashi Saida, Satoru Honjo
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Patent number: 4072522Abstract: Electronic-photography light-sensitive material provided with a light-sensitive material layer suitable for rendering of continuous gradation of tones.Type: GrantFiled: November 15, 1976Date of Patent: February 7, 1978Assignee: Xerox CorporationInventor: Hajime Miyatuka
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Patent number: 4062789Abstract: A liquid developer for electrophotography is disclosed which comprises toner particles, a regulating agent composed of a copolymer of a half-alkylamide of maleic acid and .alpha.-diisobutylene and an electric insulating carrier liquid and, if desired, an organic acid.Type: GrantFiled: May 1, 1974Date of Patent: December 13, 1977Assignee: Fuji Photo Film Co., Ltd.Inventors: Tasuo Tamai, Sadao Osawa, Hajime Miyatuka, Masaya Yamamoto
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Patent number: 4025338Abstract: A process for machining metal work comprising forming a marked-off image from an image-forming material on a surface of a metal work or on a recording layer provided on the surface of the metal work and subsequently machining the metal work by machine cutting and/or oil immersion electrospark machining on the basis of the marked-off image, and including applying a protective resin layer on the image-bearing surface of the metal work prior to any metal machining, the resin layer comprising a mixture of nitrocellulose and a methacrylic polymer in a weight ratio ranging from about 80:20 to 40:60 of the nitrocellulose to the methacrylic polymer and not hindering the viewing of the image, and the methacrylic polymer mainly comprising methyl methacrylate and having a glass transition temperature of higher than about 85.degree. C.Type: GrantFiled: September 2, 1975Date of Patent: May 24, 1977Assignee: Fuji Photo Film Co., Ltd.Inventors: Hajime Miyatuka, Satoru Honjo
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Patent number: 3986968Abstract: A liquid developer composition is given whereby a mixture of pigment and resin is milled and washed prior to being dispersed in the carrier liquid.Type: GrantFiled: February 1, 1974Date of Patent: October 19, 1976Assignee: Rank Xerox Ltd.Inventors: Yasuo Tamai, Hajime Miyatuka
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Patent number: 3982938Abstract: Improved toner particles each comprising an intimate mixture of a photoconductive pigment and an insulating binder capable of transporting charge carriers when the charge carriers are injected therein from the pigment, the proportion of the total volume of the pigment in the toner particle being 2 to 30 volume percent of the toner particle and the insulating binder being substantially transparent to the light in the region of the spectrum to which the pigment is sensitive. The toner particle may have therein a core or cores of a material which is substantially transparent to the light in the spectral-sensitive region of the pigment. The toner particles have improved surface durability and can be used repeatedly.Type: GrantFiled: February 12, 1974Date of Patent: September 28, 1976Assignee: Fuji Photo Film Co., Ltd.Inventors: Satoru Honjo, Hajime Miyatuka, Seiji Matsumoto
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Patent number: 3969113Abstract: A photoconductive binder layer comprising a particulate mixture of photosensitive titanium dioxide and photosensitive cadmium pigment dispersed in an insulating resin binder.Type: GrantFiled: July 23, 1973Date of Patent: July 13, 1976Assignee: Rank Xerox Ltd.Inventor: Hajime Miyatuka
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Patent number: 3968044Abstract: A liquid developer composition is given whereby a dispersion comprising a milled mixture of graft pigment and alkyd resin is dispersed in an insulating liquid.Type: GrantFiled: February 1, 1974Date of Patent: July 6, 1976Assignee: Rank Xerox Ltd.Inventors: Yasuo Tamai, Hajime Miyatuka
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Patent number: 3963486Abstract: A liquid electrophotographic developer and processes for employing same are disclosed. The developer is composed of a liquid carrier, pigment, and a resin which results in a developed image that is abrasion resistant. The developer contains from 5 to 70% of the resin component which comprises an epoxy-ester.Type: GrantFiled: March 26, 1975Date of Patent: June 15, 1976Assignee: Rank Xerox Ltd.Inventors: Yasuo Tamai, Hajime Miyatuka, Satoru Honjo
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Patent number: 3941594Abstract: A photosensitive member for electrophotographic use having a photosensitive binder layer comprising zinc oxide and titanium dioxide photoconductive particles blended in a ratio of about 50:50 to 80:20 by weight and homogeneously dispersed into a film forming insulating resin binder, the particles having an average size of about 0.05 micron to 1.0 micron and the zinc oxide and titanium dioxide particles diffusing in light sensitivity by a factor of more than about 1.2 based on a gray filtered mean daylight source.Type: GrantFiled: July 25, 1973Date of Patent: March 2, 1976Assignee: Rank Xerox Ltd.Inventors: Satoru Honjo, Hajime Miyatuka