Patents by Inventor Tsunemi Sugiyama

Tsunemi Sugiyama 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: 20030077536
    Abstract: A toner composition including toner particles including a binder resin; and a colorant, and a charge controlling agent which is at least located on a surface of the toner particles, wherein the toner composition has a spherical degree of from 0.96 to 0.99, and wherein the toner composition satisfies the relationship: 10≦M/T≦1,000 wherein M represents a quantity of an element on a surface of the toner particles in units of % by weight, wherein the element is included only in the charge controlling agent, and is one of elements of second to fifth periodical elements in the long form periodic table other than hydrogen, carbon, oxygen and rare gas elements; and T represents a quantity of the element in the toner composition in units of % by weight.
    Type: Application
    Filed: March 8, 2002
    Publication date: April 24, 2003
    Inventors: Hiroshi Yamashita, Kazuhito Watanabe, Chiaki Tanaka, Tsunemi Sugiyama, Shigeru Emoto, Masami Tomita
  • Patent number: 6544704
    Abstract: A two-component developer comprises a toner which contains at least a resin and a colorant and to which an external additive is added, and a carrier. The toner has a number average molecular weight (Mn) not greater than 3,000 and contains particles having a molecular weight not greater than 1,000 in an amount not less than 40 number %. The carrier satisfies the relation 3,000,000≦&sgr;1000×Dc3≦20,000,00  (1) where &sgr;1000 represents a magnetization (emu/g) of the carrier at 1,000 oersted, and Dc represents a volume average particle diameter (&mgr;m) of the carrier.
    Type: Grant
    Filed: August 30, 2002
    Date of Patent: April 8, 2003
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroaki Matsuda, Masanori Suzuki, Akemi Sugiyama, Hiroto Higuchi, Tsunemi Sugiyama, Fumihiro Sasaki, Yasuaki Iwamoto, Hiroshi Nakai, Kumi Hasegawa
  • Publication number: 20030055159
    Abstract: A dry toner for developing an electrostatic image, including a toner binder containing a urea-modified polyester. The toner has an average sphericity of 0.96 or more and contains no more than 30% by weight of particles having a sphericity of less than 0.95.
    Type: Application
    Filed: July 3, 2002
    Publication date: March 20, 2003
    Inventors: Hiroshi Yamashita, Tsunemi Sugiyama, Shigeru Emoto, Masami Tomita
  • Patent number: 6534232
    Abstract: An electrophotographic image formation method for developing a latent electrostatic image formed on a latent image bearing member with toner to a toner image, using a two-component developer including a carrier and a toner. The zoner is held on a developer bearing member, with a gap between the facing surfaces of the latent image bearing member and the developer bearing member being set in a range of 0.1 mm to 0.5 mm. The carrier includes carrier particles, each carrier particle including a core material and a coating material which is coated on the surface of the core material The coating material includes a polysiloxane resin including at least an oxygen atom (O) and a silicon atom as constituent elements therefor, with an atomic ratio of the constituent elements, O/Si, being in a range of 2.1 to 4.0, and the carrier having a specific resistivity of 109 to 1016 &OHgr;·cm.
    Type: Grant
    Filed: May 10, 2000
    Date of Patent: March 18, 2003
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroaki Matsuda, Masanori Suzuki, Akemi Sugiyama, Hiroto Higuchi, Tsunemi Sugiyama
  • Publication number: 20030027074
    Abstract: A method of fixing toner in a belt fixing unit having a fixing roller; a heating roller; an endless fixing belt binding the heating roller and the fixing roller under tension therebetween; a pressure roller disposed to face the fixing roller intervening the fixing belt; and a fixing heater disposed inside one of the pressure roller and the heating roller, the method of fixing includes: a step for fixing a toner image on an image fixing material by conveying the toner image on the image fixing material in between a portion of the fixing belt not touching the fixing roller and the pressure roller; featured by the toner particle being spherical having a roundness of 0.96 or more and contains a colorant and resin component containing a modified polyester resin.
    Type: Application
    Filed: July 5, 2002
    Publication date: February 6, 2003
    Inventors: Shigeru Emoto, Chiaki Tanaka, Naohiro Watanabe, Hiroshi Yamada, Tsunemi Sugiyama, Hiroshi Yamashita, Kazuhito Watanabe, Masami Tomita
  • Publication number: 20030027066
    Abstract: A toner composition including toner particles, wherein the toner particles are prepared by a method in which toner constituents including at least a binder resin and a colorant are kneaded upon application of heat to prepare a toner constituent mixture; the toner constituent mixture is dissolved or swelled in an organic solvent capable of dissolving or swelling at least the binder resin to prepare an oil phase liquid; the oil phase liquid is emulsified in an aqueous liquid to prepare an emulsion; the emulsion is coagulated; and then the coagulated emulsion is dried to prepare the toner particles.
    Type: Application
    Filed: April 2, 2002
    Publication date: February 6, 2003
    Inventors: Hiroshi Yamashita, Masami Tomita, Shigeru Emoto, Tsunemi Sugiyama
  • Publication number: 20030022084
    Abstract: A dry toner including at least a modified polyester as a toner binder, wherein the modified polyester has a main peak in a molecular weight region of 1000 to 30000 in a molecular weight distribution as measured by GPC, contains 1 to 10% of a component having a molecular weight of at least 30000, and has an Mw/Mn ratio of not greater than 15.
    Type: Application
    Filed: March 18, 2002
    Publication date: January 30, 2003
    Inventors: Tsunemi Sugiyama, Shigeru Emoto, Hiroshi Yamasita, Masami Tomita, Kazuhito Watanabe, Chiaki Tanaka
  • Patent number: 6468706
    Abstract: A two-component developer consists of a toner, which contains at least a resin and a colorant and to which an external additive is added, and a carrier. This two-component developer has the toner that has a number average molecular weight (Mn) of 3,000 or less and contains particles having a molecular weight of 1,000 or less at 40 number % or more, and also has the carrier that satisfies general formula (1) as follows: 3,000,000≦&sgr;1000×Dc3≦20,000,000  (1) where &sgr;1000 represents a magnetization (emu/g) of a carrier at 1,000 oersted, and Dc represents volume average particle diameter (&mgr;m) of the carrier.
    Type: Grant
    Filed: May 23, 2001
    Date of Patent: October 22, 2002
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroaki Matsuda, Masanori Suzuki, Akemi Sugiyama, Hiroto Higuchi, Tsunemi Sugiyama, Fumihiro Sasaki, Yasuaki Iwamoto, Hiroshi Nakai, Kumi Hasegawa
  • Publication number: 20020081510
    Abstract: A toner for dry developing, containing a colorant, a binder including a modified polyester, and wax particles dispersed in the binder, wherein that portion of the wax particles having a dispersion diameter of 0.1-3 &mgr;m accounts for at least 70% by number of the wax particles.
    Type: Application
    Filed: November 7, 2001
    Publication date: June 27, 2002
    Inventors: Tsunemi Sugiyama, Masami Tomita, Shigeru Emoto, Hiroshi Yamashita
  • Publication number: 20020006567
    Abstract: A two-component developer consists of a toner, which contains at least a resin and a colorant and to which an external additive is added, and a carrier.
    Type: Application
    Filed: May 23, 2001
    Publication date: January 17, 2002
    Applicant: RICOH COMPANY, LIMITED
    Inventors: Hiroaki Matsuda, Masanori Suzuki, Akemi Sugiyama, Hiroto Higuchi, Tsunemi Sugiyama, Fumihiro Sasaki, Yasuaki Iwamoto, Hiroshi Nakai, Kumi Hasegawa
  • Patent number: 6335137
    Abstract: An electrophotographic toner including at least a binder resin, a colorant, and a releasing agent, wherein the binder resin includes one or more components soluble in tetrahydrofuran, and wherein the one or more components has a molecular weight distribution such that at least one peak is present between 1,000 and 10,000, and the peak has a half width not greater than 15,000 when the molecular weight is measured by a gel permeation chromatography (GPC) method.
    Type: Grant
    Filed: June 19, 2000
    Date of Patent: January 1, 2002
    Assignee: Ricoh Company Limited
    Inventors: Masanori Suzuki, Hiroaki Matsuda, Akemi Sugiyama, Hiroto Higuchi, Tsunemi Sugiyama