Patents by Inventor Tomonari Hokkyo
Tomonari Hokkyo 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: 7813674Abstract: A toner for electrophotography containing at least a fixing resin, a coloring agent and a wax is a toner containing rice wax and carnauba wax as the wax constitutional component thereof. A cleaning unit employs the blade cleaning mode; and for the purposes of keeping the performance of the cleaning unit and preventing the generation of printing failure. The toner has a relationship between a charge amount X (i.e., an absolute value of charge amount of the toner, ?C/g) and a deposition amount Y (mg/cm2) satisfied with the following expression (1) or (2): X?21 ??(1) X>21 and Y??0.0329X+1.Type: GrantFiled: December 30, 2004Date of Patent: October 12, 2010Assignee: Ricoh Company, Ltd.Inventors: Junji Kobayashi, Shigenori Yaguchi, Tomonari Hokkyo, Hirobumi Ouchi
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Patent number: 7689153Abstract: An image formation system is configured by connecting two or more image formation devices. The system includes a fixing device fixing an unfixed development image to a record medium and a charge elimination device eliminating a charge of the record medium in an inlet of the fixing device of the second or later image formation device.Type: GrantFiled: May 20, 2005Date of Patent: March 30, 2010Assignee: Ricoh Company, Ltd.Inventors: Tsutomu Nakagawa, Koji Kato, Tomonari Hokkyo, Kenji Nozawa
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Patent number: 7570904Abstract: In the image forming apparatus by: visualizing an electrostatic latent image formed on an electrostatic charge carrying member; transferring a toner image, which is thus visualized, to a recording medium, or to a recording medium through an intermediate transfer material; and fixing the toner image, which is thus transferred to the recording medium, to obtain a recorded image, the toner includes at least a fixing resin, a colorant, a releasing agent, and an external additive, the toner has an average particle diameter in a range of from 4 to 12 ?m and including no particle having a diameter of 45 ?m or more, a ratio of a toner adhesion amount in a character part to a toner adhesion amount in a solid image part upon printing is more than 0.5 and less than 4, and the toner adhesion amount in a character part is 1.6 mg/cm2 or less.Type: GrantFiled: May 26, 2005Date of Patent: August 4, 2009Assignee: Ricoh Printing Systems, Ltd.Inventors: Shigenori Yaguchi, Junji Kobayashi, Hirobumi Ouchi, Tomonari Hokkyo
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Publication number: 20090180810Abstract: In the image forming apparatus by: visualizing an electrostatic latent image formed on an electrostatic charge carrying member; transferring a toner image, which is thus visualized, to a recording medium, or to a recording medium through an intermediate transfer material; and fixing the toner image, which is thus transferred to the recording medium, to obtain a recorded image, the toner includes at least a fixing resin, a colorant, a releasing agent, and an external additive, the toner has an average particle diameter in a range of from 4 to 12 ?m and including no particle having a diameter of 45 ?m or more, a ratio of a toner adhesion amount in a character part to a toner adhesion amount in a solid image part upon printing is more than 0.5 and less than 4, and the toner adhesion amount in a character part is 1.6 mg/cm2 or less.Type: ApplicationFiled: February 17, 2009Publication date: July 16, 2009Applicant: RICOH COMPANY, LTD.Inventors: Shigenori Yaguchi, Junji Kobayashi, Hirobumi Ouchi, Tomonari Hokkyo
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Patent number: 7435519Abstract: An electrophotographic toner comprising at least a fixing resin, a coloring agent, a release agent and a charge control agent, wherein the release agent is carnauba wax, the charge control agent is a boron complex of a salicylic acid derivative, and the fixing resin contains two kinds of polyester resins in ratio represented by the following equation (1); A ? ( T 1 / 2 ) - A ? ( T fb ) B ? ( T 1 / 2 ) - B ? ( T fb ) ? A ? ( T 1 / 2 ) × C B ? ( T 1 / 2 ) × D ? B ? ( T 1 / 2 ) - B ? ( T fb ) A ? ( T 1 / 2 ) - A ? ( T fb ) , ( 1 ) wherein in the above equation, A(T1/2)?A(Tfb)<B(T1/2)?B(Tfb), A(T1/2) represents a softening point (° C.) of the polyester A, A(Tfb) a flow-out start point (° C.) of the polyester A, B(T1/2) a softening point (° C.) of the polyester B, B(Tfb) a flow-out start point (° C.Type: GrantFiled: January 10, 2005Date of Patent: October 14, 2008Assignee: Ricoh Printing Systems, Ltd.Inventors: Shigenori Yaguchi, Junji Kobayashi, Tomonari Hokkyo, Hirobumi Ouchi
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Publication number: 20050271428Abstract: In the image forming apparatus by: visualizing an electrostatic latent image formed on an electrostatic charge carrying member; transferring a toner image, which is thus visualized, to a recording medium, or to a recording medium through an intermediate transfer material; and fixing the toner image, which is thus transferred to the recording medium, to obtain a recorded image, the toner includes at least a fixing resin, a colorant, a releasing agent, and an external additive, the toner has an average particle diameter in a range of from 4 to 12 ?m and including no particle having a diameter of 45 ?m or more, a ratio of a toner adhesion amount in a character part to a toner adhesion amount in a solid image part upon printing is more than 0. 5 and less than 4, and the toner adhesion amount in a character part is 1.6 mg/cm2 or less.Type: ApplicationFiled: May 26, 2005Publication date: December 8, 2005Applicant: Ricoh Printing Systems, Ltd.Inventors: Shigenori Yaguchi, Junji Kobayashi, Hirobumi Ouchi, Tomonari Hokkyo
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Publication number: 20050271431Abstract: An image formation system is configured by connecting two or more image formation devices. The system includes a fixing device fixing an unfixed development image to a record medium and a charge elimination device eliminating a charge of the record medium in an inlet of the fixing device of the second or later image formation device.Type: ApplicationFiled: May 20, 2005Publication date: December 8, 2005Applicant: Ricoh Printing Systems, Ltd.Inventors: Tsutomu Nakagawa, Koji Kato, Tomonari Hokkyo, Kenji Nozawa
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Publication number: 20050164110Abstract: An electrophotographic toner comprising at least a fixing resin, a coloring agent, a release agent and a charge control agent, wherein the release agent is carnauba wax, the charge control agent is a boron complex of a salicyclic acid derivative, and the fixing resin contains two kinds of polyester resins in ratio represented by the following equation (1); A ? ( T 1 / 2 ) - A ? ( T fb ) B ? ( T 1 / 2 ) - B ? ( T fb ) ? A ? ( T 1 / 2 ) × C B ? ( T 1 / 2 ) × D ? B ? ( T 1 / 2 ) - B ? ( T fb ) A ? ( T 1 / 2 ) - A ? ( T fb ) , ( 1 ) wherein in the above equation, A(T1/2)?A(Tfb)<B(T1/2)?B(Tfb), A(T1/2) represents a softening point (° C.) of the polyester A, A(Tfb) a flow-out start point (° C.) of the polyester A, B(T1/2) a softening point (° C.) of the polyester B, B(Tfb) a flow-out start point (° C.Type: ApplicationFiled: January 10, 2005Publication date: July 28, 2005Inventors: Shigenori Yaguchi, Junji Kobayashi, Tomonari Hokkyo, Hirobumi Ouchi
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Publication number: 20050158645Abstract: A toner for electrophotography containing at least a fixing resin, a coloring agent and a wax is a toner containing rice wax and carnauba wax as the wax constitutional component thereof. A cleaning unit employs the blade cleaning mode; and for the purposes of keeping the performance of the cleaning unit and preventing the generation of printing failure. The toner has a relationship between a charge amount X (i.e., an absolute value of charge amount of the toner, ?C/g) and a deposition amount Y (mg/cm2) satisfied with the following expression (1) or (2): X?21 ??(1) X>21 and Y??0.0329X+1.Type: ApplicationFiled: December 30, 2004Publication date: July 21, 2005Applicant: Ricoh Printing Systems, Ltd.Inventors: Junji Kobayashi, Shigenori Yaguchi, Tomonari Hokkyo, Hirobumi Ouchi
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Patent number: 6157798Abstract: An electrostatic recording apparatus including: an image carrier including an organic photoconductive photoreceptor having an abrasion-resisting outermost periphery; an exposing unit which exposes the image carrier to form an electrostatic latent image thereon; a developing unit which contains a toner and develops the electrostatic latent image with the toner to form a toner image; a transferring unit which transfers the toner image thus formed onto a recording medium; and a fixing unit which fixes the transferred toner image on said recording medium, wherein the toner contained in said developing unit includes an electrically conductive fine powder attached to the surface thereof.Type: GrantFiled: April 5, 1999Date of Patent: December 5, 2000Assignee: Hitachi Koki Co., Ltd.Inventors: Tsuneaki Kawanishi, Tomonari Hokkyo, Katsuya Kawai, Koji Kato, Masayasu Anzai
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Patent number: 5923933Abstract: A uniform image is obtained by matching the sliding friction force, the moving speed and the developing agent in a developing region of two developing rollers and an electric characteristic of a photosensitive body used for image development. Two developing rollers rotating in directions opposite to each other are used, the moving direction of the first developing roller being opposite to the moving direction of the photosensitive body, and a circumferential speed ratio of a circumferential speed of the first developing roller to a circumferential speed of the photosensitive body is within a rage of 0.5 to 2.5; and the moving direction of the second developing roller is equal to the moving direction of the photosensitive body, and a circumferential speed ratio of a circumferential speed of the second developing roller to a circumferential speed of the photosensitive body is within a range of 1.5 to 3.5.Type: GrantFiled: February 13, 1998Date of Patent: July 13, 1999Assignee: Hitachi Koki Co., Ltd.Inventors: Masayasu Anzai, Tsuneaki Kawanishi, Yoshitaka Fujinuma, Hiroyoshi Matsumoto, Yasuo Takuma, Hisao Okada, Masayuki Ainoya, Takashi Suzuki, Yuichiro Suzuki, Tomonari Hokkyo, Koji Kato, Katsuya Kawai, Tsutomu Nakagawa