Patents by Inventor Tatsuo Imafuku
Tatsuo Imafuku 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: 9040217Abstract: The present invention provides a carrier for a two-component electrophotographic developer, comprising a core particle and a thermoset silicone resin layer coated thereon, wherein said layer comprises a charge control agent and is formed by heat-treatment at a temperature below the melting point of said charge control agent.Type: GrantFiled: February 26, 2009Date of Patent: May 26, 2015Assignee: SHARP KABUSHIKI KAISHAInventors: Kazuki Takatsuka, Tatsuo Imafuku, Takahiro Bito, Takeshi Satoh, Masaki Ueji
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Publication number: 20120268349Abstract: A multidisplay device includes: a first flat display element and a second flat display element arranged such that sides thereof are coupled to face each other, and having a boundary portion at a portion where the sides are coupled to each other; and a lenticular lens provided to cover the boundary portion and to cover a row of pixels including a red pixel, a green pixel and a blue pixel arranged side by side adjacent to the boundary portion. Observers are even less likely to become aware of the fact that the plurality of flat display elements are coupled to one another.Type: ApplicationFiled: March 7, 2012Publication date: October 25, 2012Inventors: Rika Hayashi, Tatsuo Imafuku, Nobuyuki Yoshioka, Ayae Nagaoka, Masanobu Deguchi
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Patent number: 8043781Abstract: A toner comprising a small-particle diameter external additive having a number average particle diameter of 7 to 20 nm, a large-particle diameter external additive having a number average particle diameter of 40 to 80 nm and a toner particle having a volume average particle diameter of 4 to 7 ?m, wherein the large-particle diameter external additive is stuck to the surface of the toner particles in a semi-embedded state and has a rate of liberation of 0.1% by weight or less from the surface of the toner particle.Type: GrantFiled: August 1, 2008Date of Patent: October 25, 2011Assignee: Sharp Kabushiki KaishaInventors: Tatsuo Imafuku, Takahiro Bito, Takeshi Satoh
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Publication number: 20090226218Abstract: The present invention provides a carrier for a two-component electrophotographic developer, comprising a core particle and a thermoset silicone resin layer coated thereon, wherein said layer comprises a charge control agent and is formed by heat-treatment at a temperature below the melting point of said charge control agent.Type: ApplicationFiled: February 26, 2009Publication date: September 10, 2009Inventors: Kazuki Takatsuka, Tatsuo Imafuku, Takahiro Bito, Takeshi Satoh, Masaki Ueji
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Developing toner for electrostatic latent images, imaging forming method and image forming apparatus
Patent number: 7514193Abstract: Provided is a developing toner for electrostatic latent images capable of coping with the size reduction of an image forming apparatus and decrease of the consumption amount, not shortening the working life of a photoreceptor, less causing paper jam, background fogging, etc., excellent in various characteristics required for the toner, and capable of forming images of good picture quality. The developing toner being used when images are formed to a recording material in an image forming apparatus comprising an image forming station, a recording material feeding station, an image fixing station and a controlling station, the developing toner for electrostatic latent images containing hydrophobic fluidizing particles deposited to the surface of coloring resin particles comprising a binder resin containing a polyester resin, a polyalkylene, a polyolefin dispersant and a non-oxidized polyethylene resin, and an inorganic pigment, and having time constant ? of from 100 to 350 msec.Type: GrantFiled: March 28, 2005Date of Patent: April 7, 2009Assignee: Sharp Kabushiki KaishaInventors: Hitoshi Nagahama, Tatsuo Imafuku, Takahiro Bito, Tenjiku Eiji, Takeshi Satoh, Ohkawa Takeshi -
Publication number: 20090035683Abstract: A toner comprising a small-particle diameter external additive having a number average particle diameter of 7 to 20 nm, a large-particle diameter external additive having a number average particle diameter of 40 to 80 nm and a toner particle having a volume average particle diameter of 4 to 7 ?m, wherein the large-particle diameter external additive is stuck to the surface of the toner particles in a semi-embedded state and has a rate of liberation of 0.1% by weight or less from the surface of the toner particle.Type: ApplicationFiled: August 1, 2008Publication date: February 5, 2009Inventors: Tatsuo IMAFUKU, Takahiro Bito, Takeshi Satoh
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Patent number: 7449274Abstract: A toner for electrostatic image development, which contains toner particles in which not more than 13 percent by number of the toner particles have a particle diameter of smaller than 4 ?m, not less than 20 percent by number of the toner particles have a particle diameter of 4 ?m to 6 ?m, and not more than 2.0 percent by volume of the toner particles have a particle diameter of 16 ?m or greater. The toner particles have a volume average diameter of 4 ?m to 9 ?m, and at least an external additive is added to the toner particles.Type: GrantFiled: November 1, 2005Date of Patent: November 11, 2008Assignee: Sharp Kabushiki KaishaInventors: Tatsuo Imafuku, Takahiro Bito, Eiji Tenjiku, Takeshi Satoh, Takeshi Ohkawa, Akiko Tsujimoto
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Patent number: 7070897Abstract: In the two-component developer for use in electrophotography containing a toner and a carrier, said toner contains a magnetic powder as an external additive, said carrier is a resin coated magnetic carrier of 6.0 to 8.0 in true specific gravity, and the coating resin is a silicone based resin containing a crosslinking agent having phenyl groups and an aminosilane coupling agent. The crossliking agent in the coating resin for the carrier has phenyl groups in a content ratio of 0.2 to 15% by number.Type: GrantFiled: October 29, 2002Date of Patent: July 4, 2006Assignee: Sharp Kabushiki KaishaInventors: Tatsuo Imafuku, Junichi Saito, Takahiro Bito
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Publication number: 20060093947Abstract: A toner for electrostatic image development, which contains toner particles in which not more than 13 percent by number of the toner particles have a particle diameter of smaller than 4 ?m, not less than 20 percent by number of the toner particles have a particle diameter of 4 ?m to 6 ?m, and not more than 2.0 percent by volume of the toner particles have a particle diameter of 16 ?m or greater. The toner particles have a volume average diameter of 4 ?m to 9 ?m, and at least an external additive is added to the toner particles.Type: ApplicationFiled: November 1, 2005Publication date: May 4, 2006Applicant: SHARP KABUSHIKI KAISHAInventors: Tatsuo Imafuku, Takahiro Bito, Eiji Tenjiku, Takeshi Satoh, Takeshi Ohkawa, Akiko Tsujimoto
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Developing toner for electrostatic latent images, imaging forming method and image forming apparatus
Publication number: 20050221214Abstract: Provided is a developing toner for electrostatic latent images capable of coping with the size reduction of an image forming apparatus and decrease of the consumption amount, not shortening the working life of a photoreceptor, less causing paper jam, background fogging, etc., excellent in various characteristics required for the toner, and capable of forming images of good picture quality. The developing toner being used when images are formed to a recording material in an image forming apparatus comprising an image forming station, a recording material feeding station, an image fixing station and a controlling station, the developing toner for electrostatic latent images containing hydrophobic fluidizing particles deposited to the surface of coloring resin particles comprising a binder resin containing a polyester resin, a polyalkylene, a polyolefin dispersant and a non-oxidized polyethylene resin, and an inorganic pigment, and having time constant ? of from 100 to 350 msec.Type: ApplicationFiled: March 28, 2005Publication date: October 6, 2005Applicant: SHARP KABUSHIKI KAISHAInventors: Hitoshi Nagahama, Tatsuo Imafuku, Takahiro Bito, Tenjiku Eiji, Takeshi Satoh, Ohkawa Takeshi -
Patent number: 6864031Abstract: The present invention provides an electrophotographic developer which reduces toner contamination on the surface of a developer carrier even when a development effective range is narrowed and which is stabilized in an image quality in every environmental situation and has a long life and a low cost and an image-forming method using the same. In the present invention, used for the electrostatically charged-image holder described above having a radius of curvature of 18 mm or less in a development effective range is the electrophotographic developer which is a two-component developer comprising a toner comprising at least a binder and a colorant and a carrier which is coated with a resin and has a weight average particle diameter of 40 to 100 ?m, wherein the above toner has a volume average particle diameter of 8 to 11.5 ?m, and the toner particles having a diameter of 6.35 ?m or less account for 20 number % or less.Type: GrantFiled: January 5, 2004Date of Patent: March 8, 2005Assignee: Sharp Kabushiki KaishaInventors: Toshihisa Ishida, Tatsuo Imafuku, Junichi Saito, Takahiro Bito
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Publication number: 20040142267Abstract: The present invention provides an electrophotographic developer which reduces toner contamination on the surface of a developer carrier even when a development effective range is narrowed and which is stabilized in an image quality in every environmental situation and has a long life and a low cost and an image-forming method using the same.Type: ApplicationFiled: January 5, 2004Publication date: July 22, 2004Applicant: Sharp Kabushika KaishaInventors: Toshihisa Ishida, Tatsuo Imafuku, Junichi Saito, Takahiro Bito
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Publication number: 20030082471Abstract: In the two-component developer for use in electrophotography containing a toner and a carrier, said toner contains a magnetic powder as an external additive, said carrier is a resin coated magnetic carrier of 6.0 to 8.0 in true specific gravity, and the coating resin is a silicone based resin containing a crosslinking agent having phenyl groups and an aminosilane coupling agent. The crossliking agent in the coating resin for the carrier has phenyl groups in a content ratio of 0.2 to 15% by number.Type: ApplicationFiled: October 29, 2002Publication date: May 1, 2003Applicant: Sharp Kabushiki KaishaInventors: Tatsuo Imafuku, Junichi Saito, Takahiro Bito
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Publication number: 20020119387Abstract: The present invention provides an electrophotographic developer which reduces toner contamination on the surface of a developer carrier even when a development effective range is narrowed and which is stabilized in an image quality in every environmental situation and has a long life and a low cost and an image-forming method using the same.Type: ApplicationFiled: December 26, 2001Publication date: August 29, 2002Applicant: Sharp Kabushiki KaishaInventors: Toshihisa Ishida, Tatsuo Imafuku, Junichi Saito, Takahiro Bito
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Patent number: 6420079Abstract: An electrophotographic toner constituting a dual component is composed of toner base particles and fine inorganic particles having a volume mean diameter of 250 to 600 nm with a specific surface area of 0.25 to 0.5 m2/g for serving as an abrasive, and is characterized in that 1.5 to 2 parts by weight of the abrasive is externally added to 100 parts by weight of the toner base particles and made to be deposited over the toner base particle surface. Also, the above electrophotographic toner is used for an electrophotographic apparatus which includes a photoreceptor cleaning device located above the level that passes through the center of the photoreceptor drum.Type: GrantFiled: January 9, 2001Date of Patent: July 16, 2002Assignee: Sharp Kabushiki KaishaInventors: Yasuharu Morinishi, Tatsuo Imafuku, Junichi Saito, Yoshiaki Akazawa, Yuichiro Takesue
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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: 6103439Abstract: In toner 1 containing a binder resin 2, wax particles 3 and a coloring agent, the wax particles 3 are designed so that the ratio of major axis/minor axis is set in the range of 1.4 to 4.0 and so that the major axis L is not more than 6.0 .mu.m. Moreover, the melt index of the binder resin ranges from 5.0 to 11.0, and the dielectric loss tangent (tan .delta.) is not more than 5.0. This arrangement prevents the wax particles 3 inside the toner 1 or at the toner 1 surface layer from exposing to or sticking out of the toner 1 surface, thereby making it possible to provide a superior offset-reducing property during the fixing process and electrophotographing toner that can reduce wax contamination on the surface of the toner-bearing body.Type: GrantFiled: April 15, 1998Date of Patent: August 15, 2000Assignee: Sharp Kabushiki KaishaInventors: Satoshi Ogawa, Hitoshi Nagahama, Yasuharu Morinishi, Tatsuo Imafuku, Takeaki Ohuchi, Toshihisa Ishida, Tadashi Nakamura
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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: 5364728Abstract: Spheroidal toner for developing electrostatic images is composed of a binding resin as its main component in which at least carbon black and a dispersion stabilizer for the carbon black are contained, the conductivity of the toner being in the range of 5.times.10.sup.-11 to 5.times.10.sup.-9 S/cm. The conductivity of the toner is preferably within the range of 4.times.10.sup.-10 to 5.times.10.sup.-9 S/cm. It is also desirable that the dispersion stabilizer be composed of at least one selected from the group consisting of oil-soluble dyes, coupling agents, and surfactants, and that according to Wadel's practical spheroidicity, the toner be within the range of 0.95 to 1.0.Type: GrantFiled: December 21, 1992Date of Patent: November 15, 1994Assignee: Mita Industrial Co., Ltd.Inventors: Hideki Ohta, Tatsuo Imafuku, Masami Tsujihiro, Toshiro Tokuno, Hiroshi Shimoyama, Nobuhiro Hirano
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Patent number: 5364719Abstract: Toner for developing electrostatic images contains at least a colorant and a charge control dye in a binding resin which is the main component thereof, the toner having a surface dye density of less than 5.times.10.sup.-3 g/g and containing a monomer having a charge control polar group within the range of 0.01 to 5 weight percent based on the weight of the toner. The binding resin is preferably formed from at least one kind of monomer selected from a group consisting of vinyl aromatic monomers, acrylic type monomers, vinyl ester type monomers, vinyl ether type monomers, diolefin type monomers and monoolefin type monomers, and further preferably from at least one kind of monomer selected from a group consisting of styrene, ester acrylate and ester methacrylate. Also, the binding resin may be formed from at least one kind of monomer selected from a group consisting of polyester, phenol and epoxy resins. It is desirable that the colorant be used in 0.Type: GrantFiled: February 24, 1993Date of Patent: November 15, 1994Assignee: Mita Industrial Co., Ltd.Inventors: Hideki Ohta, Tatsuo Imafuku, Masami Tsujihiro, Toshiro Tokuno, Hiroshi Shimoyama, Nobuhiro Hirano