Patents by Inventor Yoshinori Urata
Yoshinori Urata 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: 7601475Abstract: A two-component developing agent containing a carrier which can maintain a charge-imparting property to a toner at a high level for a long period of time, does not generate flying of the carrier and can correspond to an image forming apparatus of present day having a long operation life and can form a high-quality image having high image density and sharpness, is provided. In the two-component developing agent containing a carrier in which a resin coating layer is formed on a surface of a core material, and a toner, in which an X-ray intensity of an alumina particle by a fluorescent X-ray analysis, the amount of the alumina particle to be used to the resin coating layer is adjusted such that it comes to be smaller than the X-ray intensity by the fluorescent X-ray analysis of a metal contained in a largest amount in the core material.Type: GrantFiled: September 12, 2006Date of Patent: October 13, 2009Assignee: Sharp Kabushiki KaishaInventors: Takeshi Katoh, Toshihisa Ishida, Yoshinori Urata, Kazuya Korematu, Takeshi Takayama, Mitsuhiro Hasegawa
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Patent number: 7455945Abstract: A carrier excellent in durability and environmental stability and a two-component developing agent is provided. In the carrier, a core material is coated with a resin, and the coating resin is formed on the core material such that the coating resin comes to be in an amount of 5% by weight to 20% by weight on the basis of a weight of the core material, thereby enhancing durability. Further, the coating resin contains fine particles of titanium oxide, thereby enhancing environmental stability.Type: GrantFiled: June 6, 2005Date of Patent: November 25, 2008Assignee: Sharp Kabushiki KaishaInventors: Takeshi Katoh, Yoshinori Urata, Kazuya Korematu
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Patent number: 7393622Abstract: A durable two-component developing agent for electrophotography is provided that can not only suppress scattering of a toner into an inside of an apparatus but also obtain a high image density and can stably obtain a high-quality image even in use for a long period of time. The two-component developing agent for electrophotography includes a toner, and a carrier. The carrier contains a core material and a coating layer formed on a surface thereof. The coating layer is a silicone resin coating layer containing dendritic titanium oxide. Therefore, it is possible to not only suppress scattering of the toner but also obtain a sufficient image density and to form a high-quality image without reducing the image density even in use for a long period of time.Type: GrantFiled: June 2, 2005Date of Patent: July 1, 2008Assignee: Sharp Kabushiki KaishaInventors: Yoshinori Urata, Takeshi Katoh
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Publication number: 20070059629Abstract: A two-component developing agent containing a carrier which can maintain a charge-imparting property to a toner at a high level for a long period of time, does not generate flying of the carrier and can correspond to an image forming apparatus of present day having a long operation life and can form a high-quality image having high image density and sharpness, is provided. In the two-component developing agent containing a carrier in which a resin coating layer is formed on a surface of a core material, and a toner, in which an X-ray intensity of an alumina particle by a fluorescent X-ray analysis, the amount of the alumina particle to be used to the resin coating layer is adjusted such that it comes to be smaller than the X-ray intensity by the fluorescent X-ray analysis of a metal contained in a largest amount in the core material.Type: ApplicationFiled: September 12, 2006Publication date: March 15, 2007Applicant: SHARP KABUSHIKI KAISHAInventors: Takeshi Katoh, Toshihisa Ishida, Yoshinori Urata, Kazuya Korematu, Takeshi Takayama, Mitsuhiro Hasegawa
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Publication number: 20050277049Abstract: A carrier excellent in durability and environmental stability and a two-component developing agent is provided. In the carrier, a core material is coated with a resin, and the coating resin is formed on the core material such that the coating resin comes to be in an amount of 5% by weight to 20% by weight on the basis of a weight of the core material, thereby enhancing durability. Further, the coating resin contains fine particles of titanium oxide, thereby enhancing environmental stability.Type: ApplicationFiled: June 6, 2005Publication date: December 15, 2005Applicant: Sharp Kabushiki KaishaInventors: Takeshi Katoh, Yoshinori Urata, Kazuya Korematu
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Publication number: 20050271966Abstract: A durable two-component developing agent for electrophotography is provided that can not only suppress scattering of a toner into an inside of an apparatus but also obtain a high image density and can stably obtain a high-quality image even in use for a long period of time. The two-component developing agent for electrophotography includes a toner, and a carrier. The carrier contains a core material and a coating layer formed on a surface thereof. The coating layer is a silicone resin coating layer containing dendritic titanium oxide. Therefore, it is possible to not only suppress scattering of the toner but also obtain a sufficient image density and to form a high-quality image without reducing the image density even in use for a long period of time.Type: ApplicationFiled: June 2, 2005Publication date: December 8, 2005Applicant: Sharp Kabushiki KaishaInventors: Yoshinori Urata, Takeshi Katoh
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Patent number: 6177224Abstract: A method of manufacturing electrophotographic toner according to the present invention includes the step of mixing at least toner particles and an additive for a predetermined mixing time to produce the toner, with the predetermined mixing time being set within a range from a first mixing time, at which chargeability of the toner (which changes according to the duration of mixing of the toner particles and the additive) shows a singular point, through a second mixing time, at which preservation of the toner (which also changes according to the duration of mixing) shows a singular point. By this method, a mixing time which maximizes the effects of the additive can be easily set. Accordingly, using a method simpler than conventional methods, a toner can be obtained which has good characteristics with regard to both chargeability and preservation.Type: GrantFiled: January 21, 1998Date of Patent: January 23, 2001Assignee: Sharp Kabushiki KaishaInventors: Tatuo Imafuku, Tadashi Nakamura, Hitoshi Nagahama, Yoshinori Urata, Yasuharu Morinishi, Satoshi Ogawa
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Patent number: 6110635Abstract: A binder resin as the main component of the toner has a low molecular weight polypropylene as a separating agent, encapsulated therein. Using this binder a toner with the wax having a diameter of 0.3 .mu.m or less dispersed therein is produced. The wax is included 0.5 part to 5 parts by weight for 100 parts by weight of the binder resin. This limitation of the toner prevents the setoff phenomenon during the fixing process and at the same time prevents the filming phenomenon over the photoreceptor and achieves an improved fixing performance.Type: GrantFiled: September 10, 1998Date of Patent: August 29, 2000Assignee: Sharp Kabushiki KaishaInventors: Yoshinori Urata, Tatsuo Imafuku, Toshihisa Ishida, Takahiro Bito, Tadashi Nakamura, Yoshiaki Akazawa, Yasuharu Morinishi, Nobuyasu Honda
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Patent number: 6066423Abstract: A toner for electrophotography includes a binder resin as the main component and a coloring agent, wherein the binder resin contains a low molecular weight polypropylene as a separating agent, encapsulated therein; the acid value of the binder resin is adjusted equal to 1.0 (mgKOH/g) or below; and the coloring agent has a surface which is not oxidation treated and presents a pH of 7.0 or higher. Limiting the added amount and the diameter of encapsulated and dispersed polypropylene wax provides prevention against both the setoff and filming phenomena.Type: GrantFiled: March 11, 1999Date of Patent: May 23, 2000Assignee: Sharp Kabushiki KaishaInventors: Tatsuo Imafuku, Toshihisa Ishida, Yoshinori Urata, Takahiro Bito, Nobuyasu Honda
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Patent number: 6004713Abstract: A process for preparing a toner includes forming a melt-kneaded mixture by mixing a raw material mixture containing a quaternary ammonium salt compound at a temperature ranging from (M-7).degree. C. to (M+7).degree. C., where M is a melting point of the quaternary ammonium salt compound, with a kneading device having a discharge port whose temperature is set lower than a temperature at which a melt viscosity of the melt-kneaded mixture at the discharge port is not higher than 10,000 Pa.a, removing the melt-kneaded mixture from the kneading device, rolling out the melt-kneaded mixture to a thickness ranging from 1.2 mm to 3.0 mm, and cooling down the melt-kneaded mixture. With the use of the toner produced by this process, the amount of charge during copying is retained in an appropriate range irrespectively of the working atmosphere and conditions of use, thereby maintaining a good image density.Type: GrantFiled: March 26, 1998Date of Patent: December 21, 1999Assignee: Sharp Kabushiki KaishaInventors: Yoshinori Urata, Hitoshi Nagahama, Yasuharu Morinishi, Satoshi Ogawa, Toshihisa Ishida, Tadashi Nakamura, Takahiro Bito
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Patent number: 5799881Abstract: A toner producing system which can efficiently produce toner having a sharp particle size distribution by suppressing the occurrence of microscopic powders and improve energy efficiency in pulverization. The system is furnished with a second pulverizing apparatus having a second colliding plate inclined at an angle in a range between 45.degree. and 90.degree. inclusive with respect to a direction in which a raw material subject to pulverization is introduced into a second pulverizing chamber through a second nozzle, and a third pulverizing apparatus having a third colliding plate with a conical member being placed thereon, so that the raw material introduced into a third pulverizing chamber through a third nozzle collides with an inner surface thereof following the collision with the third colliding plate.Type: GrantFiled: January 31, 1997Date of Patent: September 1, 1998Assignee: Sharp Kabushiki KaishaInventors: Yoshinori Urata, Takao Yoneda, Yoshiaki Akazawa, Yasuharu Morinishi, Nobuhiko Nakano, Tadashi Nakamura, Takeaki Ouchi, Satoshi Ogawa
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Patent number: 5358819Abstract: The object of the invention is to provide a developer for electrophotography which may present stable charging properties and image density after a prolonged period of copying operations as well as have a long life. The object can be achieved by providing a developer for electrophotography, compounded of: a toner component; and a carrier component prepared from a ferrite powder mixture in total of 100 parts, consisting of 10 to 90 parts by weight of a ferrite powder having a specific surface range of 200 to 230 cm.sup.2 /g, and 10 to 90 parts by weight of a ferrite powder having a specific surface range of more than 230 to 300 cm.sup.2 /g.Type: GrantFiled: April 13, 1993Date of Patent: October 25, 1994Assignee: Sharp Kabushiki KaishiInventors: Yoshinori Urata, Toshihisa Ishida, Norio Tateishi, Shigeaki Tasaka, Naotaka Funayama