Patents by Inventor Ryuuichi Shimizu
Ryuuichi Shimizu 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: 7459252Abstract: An electrophotographic toner for visualizing an electrostatic latent image formed by an electrophotographic process, an electrostatic printing process, an electrostatic recording process, etc., which is produced in consideration of the environment and safety. The electrophotographic toner includes a fixing resin and a colorant. The electrophotographic toner is a black toner using a titanium compound containing no carbon black as the colorant. The electrophotographic toner may be an electrophotographic two-component black toner using magnetic iron oxide containing no carbon black as the colorant.Type: GrantFiled: February 1, 2007Date of Patent: December 2, 2008Assignee: Ricoh Printing Systems, Ltd.Inventors: Shigenori Yaguchi, Ryuuichi Shimizu, Hiroshi Ueno
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Patent number: 7327974Abstract: An electrophotographic toner for visualizing an electrostatic latent image formed by an electrophotographic process, an electrostatic printing process, an electrostatic recording process, etc., which is produced in consideration of the environment and safety. The electrophotographic toner includes a fixing resin and a colorant. The electrophotographic toner is a black toner using a titanium compound containing no carbon black as the colorant. The electrophotographic toner may be an electrophotographic two-component black toner using magnetic iron oxide containing no carbon black as the colorant.Type: GrantFiled: September 11, 2003Date of Patent: February 5, 2008Assignee: Ricoh Printing Systems, Ltd.Inventors: Shigenori Yaguchi, Ryuuichi Shimizu, Hiroshi Ueno
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Publication number: 20070134580Abstract: An electrophotographic toner for visualizing an electrostatic latent image formed by an electrophotographic process, an electrostatic printing process, an electrostatic recording process, etc., which is produced in consideration of the environment and safety. The electrophotographic toner includes a fixing resin and a colorant. The electrophotographic toner is a black toner using a titanium compound containing no carbon black as the colorant. The electrophotographic toner may be an electrophotographic two-component black toner using magnetic iron oxide containing no carbon black as the colorant.Type: ApplicationFiled: February 1, 2007Publication date: June 14, 2007Applicant: RICOH PRINTING SYSTEMS, LTD.Inventors: Shigenori Yaguchi, Ryuuichi Shimizu, Hiroshi Ueno
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Patent number: 7144667Abstract: The invention provides an electrostatic charge image developing toner containing a fixing resin and a wax, characterized in that in a DSC curve measured by a differential scanning calorimeter for the wax, a maximum endothermic peak of endothermic peaks at temperature up is less than 70° C., on-set temperature attributable to the maximum endothermic peak is above 50° C., and lowest on-set temperature of on-set temperatures attributable to endothermic peaks except the maximum endothermic peak is in a range of from 30° C. to 40° C.Type: GrantFiled: March 1, 2004Date of Patent: December 5, 2006Assignee: Ricoh Printing Systems, Ltd.Inventors: Tsuneaki Kawanishi, Junji Kobayashi, Ryuuichi Shimizu, Shigenori Yaguchi, Hirobumi Ouchi
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Patent number: 7022448Abstract: An electrophotographic toner containing: a fixing resin, a colorant, and wax. The wax at least contains hydrocarbon wax having a number-average molecular weight of not higher than 600, and polyethylene wax having a number-average molecular weight of not higher than 600, a melting viscosity of lower than 15 mPa·s at 140° C. and a crystallinity of lower than 95%. A ratio of the hydrocarbon wax to the polyethylene wax is in a range of from 1:10 to 2:1. A maximum of absorption peaks in a heat-up time absorption calorie curve in a DSC curve of the toner measured by a differential scanning calorimeter is at a temperature not higher than 75° C. An onset temperature in absorption of heat is not higher than 65° C.Type: GrantFiled: September 2, 2003Date of Patent: April 4, 2006Assignee: Ricoh Printing Systems, Ltd.Inventors: Shigenori Yaguchi, Ryuuichi Shimizu, Junji Kobayashi, Tadahiro Kaneko, Nobuyoshi Hoshi, Tsuneaki Kawanishi
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Publication number: 20040175640Abstract: The invention provides an electrostatic charge image developing toner containing a fixing resin and a wax, characterized in that in a DSC curve measured by a differential scanning calorimeter for the wax, a maximum endothermic peak of endothermic peaks at temperature up is less than 70° C., on-set temperature attributable to the maximum endothermic peak is above 50° C., and lowest on-set temperature of on-set temperatures attributable to endothermic peaks except the maximum endothermic peak is in a range of from 30° C. to 40° C.Type: ApplicationFiled: March 1, 2004Publication date: September 9, 2004Applicant: Hitachi Printing Solutions, Ltd.Inventors: Tsuneaki Kawanishi, Junji Kobayashi, Ryuuichi Shimizu, Shigenori Yaguchi, Hirobumi Ouchi
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Patent number: 6783909Abstract: Electrostatic image developing toner includes fixing resin; and wax. The wax is hydrocarbon-based wax. The wax is containing, as its constitutional components, first wax and second wax. The first wax is higher than 1.5 in ratio of weight average molecular weight (Mw) to number average molecular weight (Mn), lower than 10 mPa·s in melt viscosity at 140° C. and higher than 75% and not higher than 85% in degree of crystallinity. The second wax is not higher than 1.5 in ratio of weight average molecular weight (Mw) to number average molecular weight (Mn), lower than 10 mPa·s in melt viscosity at 140° C. and higher than 85% and not higher than 95% in degree of crystallinity.Type: GrantFiled: January 10, 2003Date of Patent: August 31, 2004Assignee: Hitachi Printing Solutions, Ltd.Inventors: Tsuneaki Kawanishi, Ryuuichi Shimizu, Shigenori Yaguchi, Junji Kobayashi, Tadahiro Kaneko, Nobuyoshi Hoshi
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Publication number: 20040058259Abstract: In an electrostatic charge image developing toner containing at least a fixing resin and a wax, assume that the wax is used as one type wax or a mixed system of K types (K is an integer in excess of 2) waxes, Tn (°C.) is an onset temperature of an absorbed heat quantity curve of a wax constitutive component N in a differential scanning calorimeter (DSC), and Wn (wt %) is a compound rate occupied in an overall wax, the toner that satisfies predetermined relationships among them is obtained.Type: ApplicationFiled: September 16, 2003Publication date: March 25, 2004Applicant: Hitachi Printing Solutions, Ltd.Inventors: Junji Kobayashi, Hirobumi Ouchi, Shigenori Yaguchi, Ryuuichi Shimizu, Tsuneaki Kawanishi
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Publication number: 20040058265Abstract: In an electrostatic charge image developing toner that contains a hydrocarbon wax whose crystallinity is less than 93%, an amount of maximum change in a quantity of charge of the toner is smaller than 20 &mgr;C/g and an amount of contamination of a carrier by the toner is less than 0.4 wt % when a developer which is formed by mixing the toner into the carrier is stirred for 24 hours at an atmospheric temperature that is lower than a glass transition point of the toner and is higher than 45 ° C.Type: ApplicationFiled: September 17, 2003Publication date: March 25, 2004Applicant: Hitachi Printing Solutions, Ltd.Inventors: Tsuneaki Kawanishi, Junji Kobayashi, Ryuuichi Shimizu, Shigenori Yaguchi
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Publication number: 20040053153Abstract: An electrophotographic toner for visualizing an electrostatic latent image formed by an electrophotographic process, an electrostatic printing process, an electrostatic recording process, etc., which is produced in consideration of the environment and safety. The electrophotographic toner includes a fixing resin and a colorant. The electrophotographic toner is a black toner using a titanium compound containing no carbon black as the colorant. The electrophotographic toner may be an electrophotographic two-component black toner using magnetic iron oxide containing no carbon black as the colorant.Type: ApplicationFiled: September 11, 2003Publication date: March 18, 2004Applicant: Hitachi Printing Solutions, Ltd.Inventors: Shigenori Yaguchi, Ryuuichi Shimizu, Hiroshi Ueno
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Publication number: 20040043317Abstract: An electrophotographic toner containing: a fixing resin, a colorant, and wax. The wax at least contains hydrocarbon wax having a number-average molecular weight of not higher than 600, and polyethylene wax having a number-average molecular weight of not higher than 600, a melting viscosity of lower than 15 mPa·s at 140° C. and a crystallinity of lower than 95%. A ratio of the hydrocarbon wax to the polyethylene wax is in a range of from 1:10 to 2:1. A maximum of absorption peaks in a heat-up time absorption calorie curve in a DSC curve of the toner measured by a differential scanning calorimeter is at a temperature not higher than 75° C. An onset temperature in absorption of heat is not higher than 65° C.Type: ApplicationFiled: September 2, 2003Publication date: March 4, 2004Applicant: Hitachi Printing Solutions, Ltd.Inventors: Shigenori Yaguchi, Ryuuichi Shimizu, Junji Kobayashi, Tadahiro Kaneko, Nobuyoshi Hoshi, Tsuneaki Kawanishi
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Patent number: 6696210Abstract: Electrostatic charge developing toner contains at least fixing resin, a coloring agent and wax. Wax having number average molecular weight of not higher than 600 is contained as a component of the wax. A volume average particle size of the toner is in a range of from 5 &mgr;m to 10 &mgr;m. Toner particles each having a particle size of not larger than 4 &mgr;m are contained by 10% or lower by number of the total number of toner particles.Type: GrantFiled: March 8, 2002Date of Patent: February 24, 2004Assignee: Hitachi Printing Solutions, Ltd.Inventors: Shigenori Yaguchi, Ryuuichi Shimizu, Junji Kobayashi, Tsuneaki Kawanishi, Nobuyoshi Hoshi
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Publication number: 20030134216Abstract: Electrostatic image developing toner includes fixing resin; and wax. The wax is hydrocarbon-based wax. The wax is containing, as its constitutional components, first wax and second wax. The first wax is higher than 1.5 in ratio of weight average molecular weight (Mw) to number average molecular weight (Mn), lower than 10 mPa·s in melt viscosity at 140° C. and higher than 75% and not higher than 85% in degree of crystallinity. The second wax is not higher than 1.5 in ratio of weight average molecular weight (Mw) to number average molecular weight (Mn), lower than 10 mPa·s in melt viscosity at 140° C. and higher than 85% and not higher than 95% in degree of crystallinity.Type: ApplicationFiled: January 10, 2003Publication date: July 17, 2003Applicant: HITACHI PRINTING SOLUTIONS, LTD.Inventors: Tsuneaki Kawanishi, Ryuuichi Shimizu, Shigenori Yaguchi, Junji Kobayashi, Tadahiro Kaneko, Nobuyoshi Hoshi
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Publication number: 20020160291Abstract: Electrostatic charge developing toner contains at least fixing resin, a coloring agent and wax. Wax having number average molecular weight of not higher than 600 is contained as a component of the wax. A volume average particle size of the toner is in a range of from 5 &mgr;m to 10 &mgr;m. Toner particles each having a particle size of not larger than 4 &mgr;m are contained by 10% or lower by number of the total number of toner particles.Type: ApplicationFiled: March 8, 2002Publication date: October 31, 2002Inventors: Shigenori Yaguchi, Ryuuichi Shimizu, Junji Kobayashi, Tsuneaki Kawanishi, Nobuyoshi Hoshi
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Publication number: 20020022189Abstract: Toner for developing an electrostatic charge image comprises: polyethylene wax having a value (Mw/Mn) of weight average molecular weight/number average molecular weight which is larger than 1.5, melt viscosity lower than 10 mPa•s at 140° C., and degree of crystallinity lower than 90%.Type: ApplicationFiled: September 4, 2001Publication date: February 21, 2002Applicant: HITACHI KOKI CO., LTD.Inventors: Tsuneaki Kawanishi, Ryuuichi Shimizu, Shigenori Yaguchi, Katsuya Kawai, Nobuyoshi Hoshi, Akira Hosoya
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Patent number: 6131000Abstract: An electrophotographic printing apparatus using electric potential dividing development processing without the occurrence of primary fringe and fringe caused by auxiliary exposure has reverse electric fields causing primary fringe and fringe caused by auxiliary exposure adjusted to be nearly equal to each other. The auxiliary exposure is applied to an area surrounding one image, and an electric potential of an intermediate electric potential zone is brought close to a bias electric potential of another image which is not subjected to auxiliary exposure.Type: GrantFiled: December 10, 1998Date of Patent: October 10, 2000Assignees: Hitachi, Ltd., Hitachi Koki Co., Ltd.Inventors: Shinichi Akatsu, Teruaki Mitsuya, Kenichi Ito, Nobuyoshi Hoshi, Ryuuichi Shimizu, Hisao Okada, Hiroyuki Mabuchi, Masayoshi Ishii, Seiji Maruo
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Patent number: 6094558Abstract: A transfer belt for use in an electrophotographic apparatus for transporting an image support onto which a toner image formed on a surface of a photoconductor containing a photoconductive layer is transferred, and the transfer belt includes a surface layer formed from a coating liquid containing: a solvent; at least one kind of inorganic or organic fine particles dispersible in the solvent; and at least one kind of organic compound dissolved in the solvent. Also disclosed is an electrophotographic apparatus using the transfer belt.Type: GrantFiled: November 30, 1998Date of Patent: July 25, 2000Assignee: Hitachi Koki Co., Ltd.Inventors: Ryuuichi Shimizu, Takashi Nishimura, Kenichi Kugai, Masato Miwa, Masafumi Shimizu
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Patent number: 5649273Abstract: Image fixing device for use in electrophotographic apparatus, capable of suppressing gloss of fixed toner image, thus stably producing images of high quality and high level of fixing intensity over a long period of time. The fixing device is composed of a belt-type heating member and a pressing roller which are contacted with each other and rotate to form therebetween a nip through which a paper supporting unfixed toner image is passed to have the toner image fixed to the paper. The belt-type heating member comprises a metallic endless belt having fine irregularities formed on its surface and a surface layer made of a resin. The surface roughness of the fine irregularities ranges between 10 and 45 .mu.m, when measured by a ten-point averaging method.Type: GrantFiled: March 6, 1996Date of Patent: July 15, 1997Assignees: Hitachi, Ltd., Hitachi Koki Co., Ltd.Inventors: Ryuuichi Shimizu, Tsuneaki Kawanishi, Toshiya Satoh, Teruaki Mitsuya, Takashi Suzuki
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Patent number: 5519479Abstract: Image fixing device for use in electrophotographic apparatus, capable of suppressing gloss of fixed toner image, thus stably producing images of high quality and high level of fixing intensity over a long period of time. The fixing device has a fixing roller and a pressing roller which are contacted with each other and rotate to form therebetween a nip through which a paper supporting unfixed toner image is passed to have the toner image fixed to the paper. The fixing roller has a cylindrical core having fine irregularities formed on its surface and a surface layer made of a resin. The surface of the cylindrical core has a greater elastic modulus than that of the surface layer.Type: GrantFiled: August 22, 1995Date of Patent: May 21, 1996Assignees: Hitachi, Ltd., Hitachi Koki Co., Ltd.Inventors: Ryuuichi Shimizu, Tsuneaki Kawanishi, Toshiya Satoh, Teruaki Mitsuya, Takashi Suzuki
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Patent number: 5508138Abstract: Image fixing device for use in electrophotographic apparatus, capable of suppressing gloss of fixed toner image, thus stably producing images of high quality and high level of fixing intensity over a long period of time. The fixing device has a fixing roller and a pressing roller which are contacted with each other and rotate to form therebetween a nip through which a paper supporting unfixed toner image is passed to have the toner image fixed to the paper. The fixing roller has a cylindrical core having fine irregularities formed on its surface and a surface layer made of a resin. The surface of the cylindrical core has a greater elastic modulus than that of the surface layer.Type: GrantFiled: September 28, 1994Date of Patent: April 16, 1996Assignees: Hitachi, Ltd., Hitachi Koki Co., Ltd.Inventors: Ryuuichi Shimizu, Tsuneaki Kawanishi, Toshiya Satoh, Teruaki Mitsuya, Takashi Suzuki