Patents by Inventor Hiroto Higuchi

Hiroto Higuchi 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).

  • Patent number: 7587161
    Abstract: A fixer fixing a toner including a binder resin and a colorant on a recording medium upon application of at least one of heat and pressure, including: a fixing member fixing the toner on the recording medium; a pressurizing member pressurizing the toner thereon; and a cleaning member collecting the toner from the fixing member or the pressurizing member onto the cleaning member, wherein a storage modulus of the toner collected on the cleaning member is larger than a storage modulus thereof before fixed.
    Type: Grant
    Filed: August 2, 2005
    Date of Patent: September 8, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroshi Yamada, Junichi Awamura, Tomomi Suzuki, Hiroto Higuchi, Naohito Shimota, Masami Tomita, Fumihiro Sasaki, Toshiki Nanya
  • Patent number: 7531281
    Abstract: A toner for developing a latent electrostatic image including a base of toner particle which contains a binder resin and a coloring agent, and an external additive. Herein, a plurality of the base of toner particle has a volume average particle diameter (Dv) of 3 ?m to 7 ?m, a ratio (Dv/Dn) of the volume average particle diameter (Dv) to a number average particle diameter (Dn) is 1.01 to 1.25, a plurality of the base of toner particle contains 15% by number or less of the base of toner particle having a particle diameter of 0.6 ?m to 2.0 ?m, a plurality of the base of toner particle has a circularity of 0.930 to 0.990 on average, the binder resin contains a modified polyester resin, and the toner contains 0.3 parts by weight to 5.0 parts by weight of the external additive, relative to 100 parts by weight of the base of toner particle.
    Type: Grant
    Filed: October 31, 2007
    Date of Patent: May 12, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Masami Tomita, Tadao Takikawa, Tomoyuki Ichikawa, Fumihiro Sasaki, Toshiki Nanya, Hiroto Higuchi, Shigeru Emoto, Shinichiro Yagi, Naohito Shimota, Maiko Kondo
  • Patent number: 7521164
    Abstract: A toner which includes a toner material, wherein the toner satisfies the following formula: 0° C.??Tm?20° C. where ?Tm represents Tma (° C.)?Tmb (° C.), Tma (° C.) is ½ flown-out temperature of the toner by a capillary type flow tester, and Tmb (° C.) is ½ flown-out temperature of a melt kneaded mixture of the toner by the capillary type flow tester, and wherein Tma is from 130° C. to 200° C.
    Type: Grant
    Filed: March 31, 2008
    Date of Patent: April 21, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinya Nakayama, Satoshi Mochizuki, Yasuaki Iwamoto, Yasuo Asahina, Akihiro Kotsugai, Masayuki Ishii, Osamu Uchinokura, Hisashi Nakajima, Tomoyuki Ichikawa, Tomoko Utsumi, Koichi Sakata, Hideki Sugiura, Shigeru Emoto, Junichi Awamura, Masami Tomita, Takahiro Honda, Shinichiro Yagi, Tomomi Suzuki, Hiroshi Yamada, Toshiki Nanya, Hiroto Higuchi, Fumihiro Sasaki, Naohito Shimota
  • Publication number: 20090081304
    Abstract: Milling approaches provide for the efficient formation of composite particles having an inorganic nanoparticle core with an organic coating composition. The nanoparticles can additionally function as a milling media or distinct milling particles can be used and later separated from the product composite particles. In general, the milling is performed in the presence of a dispersing agent that facilitates dispersing of the composite particles in a carrier liquid. The processes described herein can be effectively used in the formation of composite particles comprising organic pigments. Similarly, the composite particles can be formed with other organic compounds, such as organic pharmaceutical compositions.
    Type: Application
    Filed: September 21, 2007
    Publication date: March 26, 2009
    Inventors: Lye Han Valerie Choy, Shivkumar Chiruvolu, Nobuyuki Kambe, Vladimir K. Dioumaev, Hui Du, Shinichi Kuramoto, Hiroto Higuchi
  • Publication number: 20090017392
    Abstract: A toner composition including toner particles including at least a binder resin; and a colorant, wherein the toner composition satisfies at least one of the following relationships (1) and (2): B?14 when 155<A?180; and B?0.6A?79 when 145?A?155,??(1) wherein A represents a shape factor SF-1 of the toner composition and B represents a content of toner particles having a particle diameter not greater than 3 ?m; and B?14 when 0.920?A??0.950; and B?394?400A? when 0.950<A??0.965??(2) wherein A? represents an average circularity of the toner composition and B represents a content of toner particles having a particle diameter not greater than 3 ?m.
    Type: Application
    Filed: September 17, 2008
    Publication date: January 15, 2009
    Inventors: Hiroto HIGUCHI, Fumihiro SASAKI, Shinichiro YAGI, Shigeru EMOTO, Junichi AWAMURA, Naohito SHIMOTA, Masami TOMITA, Toshiki NANYA, Takahiro HONDA, Maiko KONDO
  • Publication number: 20090010687
    Abstract: An image forming apparatus including an image bearing member; a charger; a light irradiator; a developing device; a transfer device; an image bearing member's cleaner; and a fixing device, wherein the fixing device includes a fixing member configured to fix a toner image upon application of heat and pressure thereto; a pressing member configured to press the recording material toward the fixing member; and a cleaning member configured to clean a surface of the fixing member and/or the pressing member, wherein the cleaning member has an outermost layer including a reactive material which increases viscoelasticity of a binder resin of the toner by reacting with the binder resin.
    Type: Application
    Filed: September 4, 2008
    Publication date: January 8, 2009
    Inventors: Hiroshi YAMADA, Fumihiro Sasaki, Shigeru Emoto, Jun Okamoto, Shlnji Ohtani, Hiroto Higuchi, Naohito Shimota, Shinichiro Yagi, Junichi Awamura, Tomomi Suzuki, Masami Tomita, Toshiki Nanya, Yoshiki Yamaguchi
  • Patent number: 7473508
    Abstract: A toner composition including toner particles including at least a binder resin; and a colorant, wherein the toner composition satisfies at least one of the following relationships (1) and (2): B?14 when 155<A?180; and B?0.6A?79 when 145?A?155,??(1) wherein A represents a shape factor SF-1 of the toner composition and B represents a content of toner particles having a particle diameter not greater than 3 ?m; and B?14 when 0.920?A??0.950; and B?394?400A? when 0.950<A??0.965??(2) wherein A? represents an average circularity of the toner composition and B represents a content of toner particles having a particle diameter not greater than 3 ?m.
    Type: Grant
    Filed: March 5, 2004
    Date of Patent: January 6, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroto Higuchi, Fumihiro Sasaki, Shinichiro Yagi, Shigeru Emoto, Junichi Awamura, Naohito Shimota, Masami Tomita, Toshiki Nanya, Takahiro Honda, Maiko Kondo
  • Patent number: 7455942
    Abstract: It is an object of the present invention to provide a toner that can sustain favorable transferability and cleaning ability for prolonged periods; prevent photoconductor filming; exhibit no variation in image nonuniformity or external additive immersion induced by developer agitation at the time of use; excels in stability with flowability and charge stability over prolonged periods. Therefore, provided is the toner of which the quantity of aggregate of residual external additives found on the sieve of 635-mesh and 452 cm2 of mesh area, after 0.2 g of the toner on the sieve is blasted with air at a blow pressure of 0.2 MPa from 160 mm above the sieve while being air-suctioned at a suction force of 5 mmHg, and then air-suctioned at a suction force of 20 mmHg, is 4,500 or less and 5 or more.
    Type: Grant
    Filed: September 16, 2005
    Date of Patent: November 25, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Tsuneyasu Nagatomo, Akihiro Kotsugai, Hiroshi Yamashita, Masayuki Ishii, Hiroto Higuchi, Osamu Uchinokura, Satoshi Mochizuki, Fumihiro Sasaki, Hisashi Nakajima, Hideki Sugiura, Yasuo Asahina, Shinya Nakayama, Koichi Sakata, Tomoyuki Ichikawa, Takuya Saito, Sonoh Matsuoka
  • Publication number: 20080268366
    Abstract: A toner which includes a toner material, wherein the toner satisfies the following formula: 0° C.??Tm?20° C. where ?Tm represents Tma (° C.)?Tmb (° C.), Tma (° C.) is ½ flown-out temperature of the toner by a capillary type flow tester, and Tmb (° C.) is ½ flown-out temperature of a melt kneaded mixture of the toner by the capillary type flow tester, and wherein Tma is from 130° C. to 200° C.
    Type: Application
    Filed: March 31, 2008
    Publication date: October 30, 2008
    Inventors: Shinya Nakayama, Satoshi Mochizuki, Yasuaki Iwamoto, Yasuo Asahina, Akihiro Kotsugai, Masayuki Ishii, Osamu Uchinokura, Hisashi Nakajima, Tomoyuki Ichikawa, Tomoko Utsumi, Koichi Sakata, Hideki Sugiura, Shigeru Emoto, Junichi Awamura, Masami Tomita, Takahiro Honda, Shinichiro Yagi, Tomomi Suzuki, Hiroshi Yamada, Toshiki Nanya, Hiroto Higuchi, Fumihiro Sasaki, Naohito Shimota
  • Patent number: 7437111
    Abstract: An image forming apparatus including an image bearing member; a charger; a light irradiator; a developing device; a transfer device; an imagebearingmember's cleaner; and a fixing device, wherein the fixing device includes a fixing member configured to fix a toner image upon application of heat and pressure thereto; a pressing member configured to press the recording material toward the fixing member; and a cleaning member configured to clean a surface of the fixing member and/or the pressing member, wherein the cleaning member has an outermost layer including a reactive material which increases viscoelasticity of a binder resin of the toner by reacting with the binder resin.
    Type: Grant
    Filed: February 16, 2005
    Date of Patent: October 14, 2008
    Assignee: Ricoh Company Limited
    Inventors: Hiroshi Yamada, Fumihiro Sasaki, Shigeru Emoto, Jun Okamoto, Shinji Ohtani, Hiroto Higuchi, Naohito Shimota, Shinichiro Yagi, Junichi Awamura, Tomomi Suzuki, Masami Tomita, Toshiki Nanya, Yoshiki Yamaguchi
  • Patent number: 7429442
    Abstract: A toner is provided that contains a binder resin; a colorant; a release agent; and an external additive, wherein the toner has an average circularity of from 0.940 to 0.965 and a crater having a depth of from 0.02 to 0.1 ?m, and wherein the crater has an amount of the external additive larger than an average amount thereof on the toner, along with a two-component developer containing the toner and an image forming apparatus using the toner.
    Type: Grant
    Filed: February 22, 2005
    Date of Patent: September 30, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Takahiro Honda, Masami Tomita, Toshiki Nanya, Fumihiro Sasaki, Shigeru Emoto, Hiroto Higuchi, Hiroshi Yamada, Shinichiro Yagi, Tomomi Suzuki, Junichi Awamura, Naohito Shimota
  • Publication number: 20080138735
    Abstract: A toner for developing a latent electrostatic image including a base of toner particle which contains a binder resin and a coloring agent, and an external additive. Herein, a plurality of the base of toner particle has a volume average particle diameter (Dv) of 3 ?m to 7 ?m, a ratio (Dv/Dn) of the volume average particle diameter (Dv) to a number average particle diameter (Dn) is 1.01 to 1.25, a plurality of the base of toner particle contains 15% by number or less of the base of toner particle having a particle diameter of 0.6 ?m to 2.0 ?m, a plurality of the base of toner particle has a circularity of 0.930 to 0.990 on average, the binder resin contains a modified polyester resin, and the toner contains 0.3 parts by weight to 5.0 parts by weight of the external additive, relative to 100 parts by weight of the base of toner particle.
    Type: Application
    Filed: October 31, 2007
    Publication date: June 12, 2008
    Inventors: Masami Tomita, Tadao Takikawa, Tomoyuki Ichikawa, Fumihiro Sasaki, Toshiki Nanya, Hiroto Higuchi, Shigeru Emoto, Shinichiro Yagi, Naohito Shimota, Maiko Kondo
  • Patent number: 7384720
    Abstract: A toner for developing a latent electrostatic image including a base of toner particle which contains a binder resin and a coloring agent, and an external additive. Herein, a plurality of the base of toner particle has a volume average particle diameter (Dv) of 3 ?m to 7 ?m, a ratio (Dv/Dn) of the volume average particle diameter (Dv) to a number average particle diameter (Dn) is 1.01 to 1.25, a plurality of the base of toner particle contains 15% by number or less of the base of toner particle having a particle diameter of 0.6 ?m to 2.0 ?m, a plurality of the base of toner particle has a circularity of 0.930 to 0.990 on average, the binder resin contains a modified polyester resin, and the toner contains 0.3 parts by weight to 5.0 parts by weight of the external additive, relative to 100 parts by weight of the base of toner particle.
    Type: Grant
    Filed: December 12, 2005
    Date of Patent: June 10, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Masami Tomita, Tadao Takikawa, Tomoyuki Ichikawa, Fumihiro Sasaki, Toshiki Nanya, Hiroto Higuchi, Shigeru Emoto, Shinichiro Yagi, Naohito Shimota, Maiko Kondo
  • Patent number: 7374851
    Abstract: A toner which includes a toner material, wherein the toner satisfies the following formula: 0° C.??Tm?20° C. where ?Tm represents Tma (° C.)?Tmb (° C.), Tma (° C.) is ½ flown-out temperature of the toner by a capillary type flow tester, and Tmb (° C.) is ½ flown-out temperature of a melt kneaded mixture of the toner by the capillary type flow tester, and wherein Tma is from 130° C. to 200° C.
    Type: Grant
    Filed: March 20, 2006
    Date of Patent: May 20, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinya Nakayama, Satoshi Mochizuki, Yasuaki Iwamoto, Yasuo Asahina, Akihiro Kotsugai, Masayuki Ishii, Osamu Uchinokura, Hisashi Nakajima, Tomoyuki Ichikawa, Tomoko Utsumi, Koichi Sakata, Hideki Sugiura, Shigeru Emoto, Junichi Awamura, Masami Tomita, Takahiro Honda, Shinichiro Yagi, Tomomi Suzuki, Hiroshi Yamada, Toshiki Nanya, Hiroto Higuchi, Fumihiro Sasaki, Naohito Shimota
  • Patent number: 7323281
    Abstract: A toner comprising toner particles comprising a first binder resin; a second binder resin different from said first binder resin and having a glass transition temperature of from 40 to 55° C.; a colorant; and a release agent, and a particulate resin material which is located on surface of the toner particles with a coverage of from 50 to 100%, and which has a glass transition temperature of from 50 to 90° C., wherein a weight ratio (W2/W1) between the second binder resin (W2) and the first binder resin (W1) is from 5/95 to 40/60, and wherein a ratio (G?80/G?180) between a storage modulus of the toner at 80° C. (G?80) and a storage modulus at 180° C. (G?180) is from 100 to 1,000.
    Type: Grant
    Filed: September 29, 2006
    Date of Patent: January 29, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Shigeru Emoto, Shinichiro Yagi, Naohito Shimota, Maiko Kondo, Fumihiro Sasaki, Toshiki Nanya, Hiroto Higuchi, Masami Tomita, Tomoyuki Ichikawa
  • Publication number: 20070020546
    Abstract: A toner comprising toner particles comprising a first binder resin; a second binder resin different from said first binder resin and having a glass transition temperature of from 40 to 55 ° C.; a colorant; and a release agent, and a particulate resin material which is located on surface of the toner particles with a coverage of from 50 to 100%, and which has a glass transition temperature of from 50 to 90 ° C., wherein a weight ratio (W2/W1) between the second binder resin (W2) and the first binder resin (W1) is from 5/95 to 40/60, and wherein a ratio (G?80/G?180) between a storage modulus of the toner at 80 ° C. (G?80) and a storage modulus at 180 ° C. (G?180) is from 100 to 1,000.
    Type: Application
    Filed: September 29, 2006
    Publication date: January 25, 2007
    Inventors: Shigeru Emoto, Shinichiro Yagi, Naohito Shimota, Maiko Kondo, Fumihiro Sasaki, Toshiki Nanya, Hiroto Higuchi, Masami Tomita, Tomoyuki Ichikawa
  • Publication number: 20070015077
    Abstract: A toner is provided manufactured by a method having the steps: dispersing toner constituents including a resin, in an aqueous medium containing a particulate resin, wherein the resin has a polyester skeleton formed by a ring-opening addition reaction of a cyclic ester with a first compound having an active hydrogen group; and a developer and an image forming method using the toner, and a toner container containing the toner.
    Type: Application
    Filed: July 17, 2006
    Publication date: January 18, 2007
    Inventors: Hiroshi Yamashita, Tsuyoshi Sugimoto, Hiroto Higuchi, Yohichiroh Watanabe, Yasuhiro Shindo
  • Patent number: 7157201
    Abstract: A toner for developing a latent electrostatic image including a base of toner particle which contains a binder resin and a coloring agent, and an external additive. Herein, a plurality of the base of toner particle has a volume average particle diameter (Dv) of 3 ?m to 7 ?m, a ratio (Dv/Dn) of the volume average particle diameter (Dv) to a number average particle diameter (Dn) is 1.01 to 1.25, a plurality of the base of toner particle contains 15% by number or less of the base of toner particle having a particle diameter of 0.6 ?m to 2.0 ?m, a plurality of the base of toner particle has a circularity of 0.930 to 0.990 on average, the binder resin contains a modified polyester resin, and the toner contains 0.3 parts by weight to 5.0 parts by weight of the external additive, relative to 100 parts by weight of the base of toner particle.
    Type: Grant
    Filed: June 27, 2003
    Date of Patent: January 2, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Masami Tomita, Tadao Takikawa, Tomoyuki Ichikawa, Fumihiro Sasaki, Toshiki Nanya, Hiroto Higuchi, Shigeru Emoto, Shinichiro Yagi, Naohito Shimota, Maiko Kondo
  • Patent number: 7157199
    Abstract: A toner comprising toner particles comprising a first binder resin; a second binder resin different from said first binder resin and having a glass transition temperature of from 40 to 55° C.; a colorant; and a release agent, and a particulate resin material which is located on surface of the toner particles with a coverage of from 50 to 100%, and which has a glass transition temperature of from 50 to 90° C., wherein a weight ratio (W2/W1) between the second binder resin (W2) and the first binder resin (W1) is from 5/95 to 40/60, and wherein a ratio (G?80/G?180) between a storage modulus of the toner at 80° C. (G?80) and a storage modulus at 180° C. (G?180) is from 100 to 1,000.
    Type: Grant
    Filed: December 1, 2003
    Date of Patent: January 2, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Shigeru Emoto, Shinichiro Yagi, Naohito Shimota, Maiko Kondo, Fumihiro Sasaki, Toshiki Nanya, Hiroto Higuchi, Masami Tomita, Tomoyuki Ichikawa
  • Patent number: 7129013
    Abstract: A toner for developing latent electrostatic images is in the form of particles prepared by dissolving or dispersing each component of a composition in an organic solvent to form a solution or dispersion, the composition containing at least a resin reactive with a compound having an active hydrogen group, a compound having an active hydrogen group, a coloring agent, a releasing agent, and a graft polymer C of a polyolefin resin A on which a vinyl resin B has been at least partially grafted; dispersing the solution or dispersion in an aqueous medium; reacting the reactive resin with the compound having an active hydrogen group; removing the organic solvent during or after the step of reacting; and washing and drying particles formed by removing the organic solvent.
    Type: Grant
    Filed: January 21, 2004
    Date of Patent: October 31, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroto Higuchi, Masami Tomita, Fumihiro Sasaki, Shigeru Emoto, Naohito Shimota, Maiko Kondo, Takahiro Honda, Junichi Awamura, Shinichiro Yagi, Toshiki Nanya, Tadao Takikawa