Patents by Inventor Toshiki Nanya

Toshiki Nanya 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).

  • Publication number: 20040126147
    Abstract: A method for developing an electrostatic latent image, including forming a magnet brush of a developer including a toner and a carrier on a developing sleeve including a main magnet and auxiliary magnets; and developing the electrostatic latent image with the magnet brush to form a toner image at a rubbing region, wherein the magnetic flux density in a normal line direction, half width, and attenuation ratio of the main magnet and the angle between the main magnet and auxiliary magnets are specified, and the magnetic sleeve has specific grooves thereon, and wherein the toner has a volume average particle diameter of from 4.0 to 7.0 &mgr;m, and includes fine particles having a circle equivalent diameter not greater than 2 &mgr;m in an amount not greater than 20% by number.
    Type: Application
    Filed: September 22, 2003
    Publication date: July 1, 2004
    Inventors: Maiko Kondo, Fumihiro Sasaki, Toshiki Nanya, Shinichiro Yagi, Masami Tomita, Shigeru Emoto, Naohito Shimota, Hiroto Higuchi, Tomoyuki Ichikawa
  • Patent number: 6733939
    Abstract: The electrophotographic toner according to the present invention comprises a binder resin, a colorant, and a negative charge control agent. The binder resin is polyester and/or polyol. The negative charge control agent comprises components which are (1) sulfonic-acid containing monomers, (2) aromatic monomers having electron-withdrawing groups, and (3) acrylate monomers and/or methacrylate monomers. In particular, substituted phenyl maleimides and substituted phenyl itaconimides are prefereably used as the aromatic monomers. Moreover, n-butyl (meth)acrylates and 2-ethylhexyl (meth)acrylates are prefereably used as the acrylate monomers and/or methacrylate monomers.
    Type: Grant
    Filed: September 28, 2001
    Date of Patent: May 11, 2004
    Assignee: Ricoh Company, Ltd.
    Inventors: Toshiki Nanya, Hiroyuki Fushimi, Osamu Uchinokura, Shinichiro Yagi, Kohki Katoh
  • Publication number: 20040053154
    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 &mgr;m to 7 &mgr;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 &mgr;m to 2.0 &mgr;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: June 27, 2003
    Publication date: March 18, 2004
    Inventors: Masami Tomita, Tadao Takikawa, Tomoyuki Ichikawa, Fumihiro Sasaki, Toshiki Nanya, Hiroto Higuchi, Shigeru Emoto, Shinichiro Yagi, Naohito Shimota, Maiko Kondo
  • Publication number: 20030180644
    Abstract: A toner for developing an electrostatic image, including a colorant, a binder resin comprising a modified polyester, and fine resin particles having a weight average particle diameter of 50 to 300 nm and being present on an outer surface of the toner, wherein the toner has a BET specific surface area of 1.5 to 4.0 m2/g.
    Type: Application
    Filed: March 24, 2003
    Publication date: September 25, 2003
    Inventors: Toshiki Nanya, Masami Tomita, Shigeru Emoto, Hiroshi Yamada, Shinichiro Yagi, Naohiro Watanabe, Tadao Takigawa
  • Publication number: 20030162112
    Abstract: A toner for developing an electrostatic image, comprising toner particles each containing at least a colorant and a resin, and an external additive present on each of the toner particles, wherein the water wettability of said toner particles without the external additive is W0, wherein the water wettability of the toner is W100, and wherein (W100−W0)/W100 is not greater than 0.3.
    Type: Application
    Filed: November 4, 2002
    Publication date: August 28, 2003
    Inventors: Hiroshi Yamashita, Tsunemi Sugiyama, Shinichiro Yagi, Hiroshi Yamada, Masami Tomita, Toshiki Nanya, Shigeru Emoto, Naohiro Watanabe, Tadao Takigawa
  • Publication number: 20030162115
    Abstract: A toner for developing an electrostatic latent image, containing a colorant and a binder resin composed of two different resins (A) and (B), wherein resin (A) is substantially free of tetrahydrofuran insolubles, is selected from polyester resins and polyol resins and has such a molecular weight distribution according to gel permeation chromatography that (a) a main peak is present in a molecular weight of 3000 to 9,000 and (b) that portion of resin (A) having a molecular weight of 500 or less accounts for 4% or less based on a total weight of resin (A), wherein resin (B) is substantially free of tetrahydrofuran insolubles and is a polyester resin containing a diol component represented by the formula (1): 1
    Type: Application
    Filed: November 27, 2002
    Publication date: August 28, 2003
    Inventors: Osamu Uchinokura, Hiroyuki Fushimi, Kohki Katoh, Shinichiro Yagi, Toshiki Nanya
  • Publication number: 20030152859
    Abstract: A toner comprising:
    Type: Application
    Filed: November 4, 2002
    Publication date: August 14, 2003
    Applicant: RICOH COMPANY, LTD.
    Inventors: Shigeru Emoto, Tsunemi Sugiyama, Hiroshi Yamashita, Shinichiro Yagi, Masami Tomita, Hiroshi Yamada, Naohiro Watanabe, Toshiki Nanya
  • Publication number: 20030138717
    Abstract: Toner particles including a binder resin; a colorant; and a particulate resin which is present at least on a surface of the toner particles and which has a glass transition temperature of form 50 to 90° C., wherein a ratio (Dv/Dn) of a volume average particle diameter (Dv) of the toner particles to a number average particle diameter (Dn) thereof is from 1.00 to 1.40 and the surface of the toner particles is covered with the particulate resin at a covering ratio of from 1 to 90 %. A method for manufacturing the toner particles is provided. A developer including a toner including the toner particles is provided. A developing method using a toner including the toner particles is provided. A toner container containing the toner particles is provided.
    Type: Application
    Filed: October 31, 2002
    Publication date: July 24, 2003
    Applicant: RICOH COMPANY LIMITED
    Inventors: Shinichiro Yagi, Masami Tomita, Toshiki Nanya, Shigeru Emoto, Hiroshi Yamada, Hiroshi Yamashita, Naohiro Watanabe, Tsunemi Sugiyama, Tadao Takigawa
  • Publication number: 20030022080
    Abstract: A toner including at least a binder resin; a colorant; and a charge controlling agent, in which the binder resin includes at least a polyester resin having a molecular weight distribution such that components having a molecular weight not greater than 500 are included in an amount of 4% by weight and at least a peak is present in a range of from 3,000 to 9,000 when measured by Gel Permeation Chromatography. In addition, the binder resin does not include a tetrahydrofuran-insoluble compound and the charge controlling agent is a resin charge controlling agent including at least units obtained from a monomer including a sulfonate group; an aromatic monomer including an electron absorption group; and an acrylic ester and/or a methacrylic ester monomer.
    Type: Application
    Filed: April 3, 2002
    Publication date: January 30, 2003
    Inventors: Hiroyuki Fushimi, Toshiki Nanya, Osamu Uchinokura, Shinichiro Yagi, Kohki Katoh
  • Publication number: 20020064723
    Abstract: The electrophotographic toner according to the present invention comprises a binder resin, a colorant, and a negative charge control agent. The binder resin is polyester and/or polyol. The negative charge control agent comprises components which are (1) sulfonic-acid containing monomers, (2) aromatic monomers having electron-withdrawing groups, and (3) acrylate monomers and/or methacrylate monomers. In particular, substituted phenyl maleimides and substituted phenyl itaconimides are prefereably used as the aromatic monomers. Moreover, n-butyl (meth)acrylates and 2-ethylhexyl (meth)acrylates are prefereably used as the acrylate monomers and/or methacrylate monomers.
    Type: Application
    Filed: September 28, 2001
    Publication date: May 30, 2002
    Inventors: Toshiki Nanya, Hiroyuki Fushimi, Osamu Uchinokura, Shinichiro Yagi, Kohki Katoh
  • Patent number: 5759733
    Abstract: A liquid developer for use in electrophotography is disclosed, which comprises (i) a toner comprising as the main toner components a colorant, a resin, and a polyolefin resin having an acid value of from 5 to 50 and a melt viscosity at 200.degree. C. of from 100 to 15,000 cps, and (ii) a carrier liquid in which the toner is dispersed. The polyolefin resin and the colorant in the liquid developer may constitute an integral flushing colorant which is prepared by subjecting the resin and the colorant to flushing processing.
    Type: Grant
    Filed: January 13, 1992
    Date of Patent: June 2, 1998
    Assignee: Ricoh Company, Ltd.
    Inventors: Kazuo Tsubuko, Shinichi Kuramoto, Toshiki Nanya, Kazuhiko Umemura, Kayoko Nagai
  • Patent number: 5597673
    Abstract: A toner comprising a binder resin, a colorant, and a charge controlling agent comprising (a) a specific iron-containing azo dye and (b) a copolymer of a styrene monomer and/or an acrylic monomer with a sulfonic acid group-containing acrylamide, wherein the amount of the azo dye present on the surface of the toner is 7.times.10.sup.-3 to 20.times.10.sup.-3 g per 1 g of said toner. The toner is suitably used in conjunction with carrier particles, each having a surface layer containing a silicone resin, electroconductive particles and a silane coupling agent.
    Type: Grant
    Filed: September 1, 1995
    Date of Patent: January 28, 1997
    Assignee: Ricoh Company, Ltd.
    Inventors: Kazuhito Watanabe, Toshiki Nanya
  • Patent number: 5514511
    Abstract: A toner for developing latent electrostatic images including a coloring agent, and a binder resin composition having resin particles, each resin particle having a matrix and domain particles with an average particle diameter of 0.5 to 2.0 .mu.m dispersed in the matrix; with the toner having such rheological characteristics that the storage elastic modulus (G') thereof at 80.degree. to 100.degree. C. under a frequency of 100 Hz is in the range of 5.times.10.sup.6 to 5.times.10.sup.7 dyne/cm.sup.2, and the loss elastic modulus (G") thereof at 200.degree. to 220.degree. C. under a frequency of 100 Hz is in the range of 1.times.10.sup.3 to 1.times.10.sup.5 dyne/cm.sup.2.
    Type: Grant
    Filed: July 12, 1994
    Date of Patent: May 7, 1996
    Assignee: Ricoh Company, Ltd.
    Inventors: Yasuaki Iwamoto, Toshiki Nanya
  • Patent number: 5314777
    Abstract: A negatively chargeable toner for developing latent electrostatic images is composed of a coloring agent; releasing agent; a binder resin including a polyester and a styrene - acryl-based polymer component with a weight-average molecular weight of 50,000 to 150,000, a number-average molecular weight of 2,000 to 12,000, and a glass transition temperature of 55.degree. to 70.degree. C. at a mixing ratio by weight in the range of (95:5) to (50:50); and a charge controlling agent including at least one phthalic ester which is mixed with the styrene - acryl-based polymer component, and at least one fluorine-containing quaternary ammonium salt.
    Type: Grant
    Filed: June 14, 1993
    Date of Patent: May 24, 1994
    Assignee: Ricoh Company, Ltd.
    Inventors: Kazuhito Watanabe, Toshiki Nanya, Yasuaki Iwamoto
  • Patent number: 5225303
    Abstract: A dry-type toner for electrophotography composed of a binder resin, a coloring agent, and a release agent which contains as the main components a carnauba wax substantially free of free aliphatic acids and/or a montan ester wax, and an oxidized rice wax with an acid value of 10 to 30.
    Type: Grant
    Filed: October 3, 1991
    Date of Patent: July 6, 1993
    Assignee: Ricoh Company, Ltd.
    Inventors: Masami Tomita, Toshiki Nanya, Yasuaki Iwamoto
  • Patent number: 5168028
    Abstract: A negatively chargeable toner for developing latent electrostatic images comprising a binder resin, a coloring agent and a charge controlling agent which comprises a fluorine-containing quaternary ammonium salt of formula (I): ##STR1## wherein X represents --SO.sub.2 or --CO; R.sub.1, R.sub.2, R.sub.3 and R.sub.4 independently represent hydrogen, an alkyl group having 1 to 10 carbon atoms or an aryl group; m is an integer of 1 to 5; and n is an integer of 1 to 10.
    Type: Grant
    Filed: October 31, 1990
    Date of Patent: December 1, 1992
    Assignee: Ricoh Company, Ltd.
    Inventors: Toshiki Nanya, Masanori Suzuki
  • Patent number: 5102766
    Abstract: A toner for developing latent electronstatic images comprises a coloring agent, a binder resin component and a negative charge controlling agent in an effective amount which is selected from the group consisting of:(i) an aromatic fluoride having formule (I); ##STR1## (ii) an aromatic fluoride having formula (II); ##STR2## (iii) an aromatic fluoride having formula (III); ##STR3## (iv) an aromatic fluoride having formula (IV); and ##STR4## (v) an aromatic fluoride having formula (V). ##STR5## wherein R.sup.1 to R.sup.8, R.sup.f1 and R.sup.f2, n, X and Y are the same as previously defined in the specification.
    Type: Grant
    Filed: March 20, 1990
    Date of Patent: April 7, 1992
    Assignee: Ricoh Company, Ltd.
    Inventors: Toshiki Nanya, Kimitoshi Yamaguchi, Hiromitsu Kawase, Makoto Ookawara
  • Patent number: 5085965
    Abstract: A negatively chargeable toner for developing latent electrostatic images comprising a coloring agent, a resin component which comprises a homopolymer of a first monomer having formula (I) or a copolymer of the aforementioned first monomer and a second monomer: ##STR1## wherein R.sup.1 represents --H or --CH.sub.3 ; R.sup.2 and R.sup.3 each represent --CN, --COOH or --NO.sub.2 ; R.sup.4 represents --F, --Cl or --Br; and n is an integer of 1 to 10.
    Type: Grant
    Filed: March 20, 1990
    Date of Patent: February 4, 1992
    Assignee: Ricoh Company, Ltd.
    Inventors: Toshiki Nanya, Kimitoshi Yamaguchi, Kazuo Tsubuko, Toshihiko Takahashi, Hiromitsu Kawase, Makoto Ookawara
  • Patent number: 5079123
    Abstract: A dry-type toner for electrophotography comprising a binder resin, a coloring agent, and, as a lubricant, a carnauba wax substantially free of free aliphatic acids. The toner may further comprise a magnetic material, and the resulting toner mixture can be used as a magnetic toner.
    Type: Grant
    Filed: May 30, 1990
    Date of Patent: January 7, 1992
    Assignee: Ricoh Company, Ltd.
    Inventors: Toshiki Nanya, Kimitoshi Yamaguchi, Hiromitsu Kawase
  • Patent number: 4990425
    Abstract: A dry-type toner is disclosed, which comprises as the main components a resin, a coloring agent and a negative charge controlling agent selected from the group consisting of (1) metallic salts of indolecarboxylic acid having the general formula (I); ##STR1## (2) metallic salts of quinolinecarboxylic acid having the general formula (II); ##STR2## and (3) metallic salts of benzothiazole derivatives having the general formula (III): ##STR3##
    Type: Grant
    Filed: April 5, 1989
    Date of Patent: February 5, 1991
    Assignee: Ricoh Company, Ltd.
    Inventors: Toshiki Nanya, Kimitoshi Yamaguchi