Patents by Inventor Hideyuki Santo

Hideyuki Santo 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: 20150227071
    Abstract: A toner including at least a crystalline resin as a binder resin, wherein a tetrahydrofuran soluble content of the toner includes 5.0% or more as a peak area of a component having a molecular weight of 100,000 or greater in a molecular weight distribution measured by gel permeation chromatography, and the tetrahydrofuran soluble content of the toner has a weight-average molecular weight of 20,000 to 60,000.
    Type: Application
    Filed: April 23, 2015
    Publication date: August 13, 2015
    Inventors: Shingo SAKASHITA, Shinya NAKAYAMA, Masahide YAMADA, Atsushi YAMAMOTO, Hideyuki SANTO, Yukiko NAKAJIMA, Suzuka AMEMORI
  • Patent number: 9042802
    Abstract: An image forming apparatus includes: an image bearing member; a charger; an irradiator; a development device having an accommodation unit to accommodate toner to obtain a visible image; a transfer device; and a fixing device to fix the visible image transferred onto a recording medium. The fixing device having a fixing rotation member; and a pressure rotation member to form a nipping portion by contacting the fixing rotation member, wherein the surface pressure of the nipping portion is 1.5 kgf/cm2 or less, wherein the fixing rotation member has a Martens hardness of 1.0 N/mm2 or less at 23° C., wherein the ratio of the projected area of a single particle of the toner onto the recording medium at 120° C. to the projected area of a single particle of the toner onto the recording medium at 23° C. is 1.60 or less.
    Type: Grant
    Filed: February 26, 2014
    Date of Patent: May 26, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Takamasa Hase, Shinya Nakayama, Atsushi Yamamoto, Hideyuki Santo, Minoru Masuda, Yukiko Iwasaki, Tsuneyasu Nagatomo
  • Patent number: 9005859
    Abstract: A colorless transparent toner containing a crystalline resin having a urethane bond and/or a urea bond.
    Type: Grant
    Filed: February 4, 2013
    Date of Patent: April 14, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Akiyoshi Sabu, Shinya Nakayama, Atsushi Yamamoto, Yukiko Nakajima, Hideyuki Santo
  • Patent number: 8951705
    Abstract: A development agent containing toner that contains a binder resin having a crystalline resin that has a urethane and/or urea bond in its main chain, a coloring agent, and an organically modified inorganic laminate compound in which organic ions are at least partially substituted for ions present between layers of the organically modified inorganic laminate compound, and toner carrier that contains a core material whose surface is coated with a coating layer having a condensed compound of a melamine resin and/or a guanamine resin and an acrylic resin having a hydroxyl group.
    Type: Grant
    Filed: March 4, 2013
    Date of Patent: February 10, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinya Nakayama, Atsushi Yamamoto, Yukiko Nakajima, Masahide Yamada, Hideyuki Santo, Suzuka Amemori
  • Patent number: 8951707
    Abstract: A toner, including: a crystalline resin containing a urethane bond, a urea bond, or both thereof; and a compound represented by the following General Formula (1), wherein an amount of the compound represented by the General Formula (1) is 0.01% by mass to 0.25% by mass: CnH2n+1R??General Formula (1) where n is 8 to 22 and R is COOH, NH2 or OH.
    Type: Grant
    Filed: August 29, 2013
    Date of Patent: February 10, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Suzuka Amemori, Atsushi Yamamoto, Masahide Yamada, Yukiko Nakajima, Shinya Nakayama, Hideyuki Santo
  • Publication number: 20140363184
    Abstract: An image forming apparatus, including: electrostatic latent image bearing member; electrostatic latent image forming unit; developing unit configured to develop with toner to form visible image; transferring unit; fixing unit; and discharging unit, the toner containing binder resin, colorant, and releasing agent, the binder resin containing crystalline resin containing urethane or urea bond, or both, the toner satisfying: C/(C+A)?0.15, C being integrated intensity of part of spectrum derived from crystalline structure of the binder resin, A being integrated intensity of part of the spectrum derived from non-crystalline structure, the spectrum being diffraction spectrum of the toner as obtained by X-ray diffraction spectroscopy, storage elastic modulus G?(70) of the toner at 70° C. being 5.0×104 Pa?G?(70)?1.0×106 Pa, and storage elastic modulus G?(160) thereof at 160° C. being 1.0×103 Pa?G?(160)?1.
    Type: Application
    Filed: May 29, 2014
    Publication date: December 11, 2014
    Applicant: RICOH COMPANY, LTD.
    Inventors: Hideyuki Santo, Yukiko Iwasaki, Takamasa Hase
  • Patent number: 8877415
    Abstract: A toner including a resin particle (C) is provided. The resin particle (C) includes a resin particle (B) and; a resin particle (A) or covering layer (P) that is adhered to a surface of the resin particle (B). The resin particle (B) includes a resin (b) having a polyhydroxycarboxylic acid skeleton. The resin particle (A) or covering layer (P) includes a resin (a). The resin (a) is a polyester resin having a polybasic acid unit and a polyol unit and has a weight average molecular weight within a range from 9,500 to 100,000.
    Type: Grant
    Filed: February 6, 2013
    Date of Patent: November 4, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Daiki Yamashita, Shinya Nakayama, Atsushi Yamamoto, Yukiko Nakajima, Akiyoshi Sabu, Yoshihiro Moriya, Hideyuki Santo
  • Patent number: 8865384
    Abstract: An electrophotographic toner, including: a binder resin; a colorant; and an organically-modified layered inorganic mineral, wherein the binder resin contains 50% by mass or more of a crystalline resin relative to the binder resin, and the crystalline resin contains a resin having a sulfonic acid group, and wherein an amount of the sulfonic acid group is 0.1% by mass to 2.0% by mass relative to the resin having the sulfonic acid group.
    Type: Grant
    Filed: March 8, 2013
    Date of Patent: October 21, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Masahide Yamada, Shinya Nakayama, Atsushi Yamamoto, Hideyuki Santo, Shingo Sakashita, Yukiko Nakajima, Suzuka Amemori, Akiyoshi Sabu
  • Patent number: 8859179
    Abstract: A developer, including a toner including a binder resin comprising a crystalline resin; and a colorant, and a resin carrier comprising a resin; a magnetic particulate material having a magnetic anisotropy, dispersed in the resin, and having a saturated magnetization of from 16 to 30 emu/g, a coercive force of from 15 to 40 kA/m and an average particle diameter not less than 15 ?m and less than 100 ?m.
    Type: Grant
    Filed: November 16, 2012
    Date of Patent: October 14, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Hideyuki Santo, Masahide Yamada, Kazumi Suzuki, Shinya Nakayama, Atsushi Yamamoto, Tatsuya Morita, Shingo Sakashita, Yukiko Nakajima, Keiji Makabe, Daiki Yamashita
  • Publication number: 20140301757
    Abstract: A toner including at least a crystalline resin as a binder resin, wherein a tetrahydrofuran soluble content of the toner includes 5.0% or more as a peak area of a component having a molecular weight of 100,000 or greater in a molecular weight distribution measured by gel permeation chromatography, and the tetrahydrofuran soluble content of the toner has a weight-average molecular weight of 20,000 to 60,000.
    Type: Application
    Filed: October 17, 2012
    Publication date: October 9, 2014
    Inventors: Shingo Sakashita, Shinya Nakayama, Masahide Yamada, Atsushi Yamamoto, Hideyuki Santo, Yukiko Nakajima, Suzuka Amemori
  • Patent number: 8852834
    Abstract: To provide a toner, including: a crystalline binder resin including a urethane bond or a urea bond, or both thereof; and a colorant, wherein the colorant has a number-average particle diameter of 0.5 ?m or less, and a ratio of particles having a particle diameter of 0.7 ?m or greater in a number-size distribution of the colorant is 5% by number or less.
    Type: Grant
    Filed: November 19, 2012
    Date of Patent: October 7, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Hideyuki Santo, Shinya Nakayama, Atsushi Yamamoto, Daiki Yamashita, Suzuka Amemori
  • Publication number: 20140270874
    Abstract: An image forming apparatus includes: an image bearing member; a charger; an irradiator; a development device having an accommodation unit to accommodate toner to obtain a visible image; a transfer device; and a fixing device to fix the visible image transferred onto a recording medium. The fixing device having a fixing rotation member; and a pressure rotation member to form a nipping portion by contacting the fixing rotation member, wherein the surface pressure of the nipping portion is 1.5 kgf/cm2 or less, wherein the fixing rotation member has a Martens hardness of 1.0 N/mm2 or less at 23° C., wherein the ratio of the projected area of a single particle of the toner onto the recording medium at 120° C. to the projected area of a single particle of the toner onto the recording medium at 23° C. is 1.60 or less.
    Type: Application
    Filed: February 26, 2014
    Publication date: September 18, 2014
    Inventors: Takamasa Hase, Shinya Nakayama, Atsushi Yamamoto, Hideyuki Santo, Minoru Masuda, Yukiko Iwasaki, Tsuneyasu Nagatomo
  • Publication number: 20140272696
    Abstract: Toner contains a mother toner particle that contains a crystalline resin; and wax; and a coloring agent, wherein the area of endothermic peak derived from the crystalline resin during a first temperature rising as measured by differential scanning calorimetry is at least 20 J/g, wherein the ratio of the area of endothermic peak derived from the wax during a second time temperature rising as measured by differential scanning calorimetry (DSC) to the area of endothermic peak derived from the wax during a first time temperature rising as measured by differential scanning calorimetry is at least 0.50, wherein the ratio of the area of endothermic peak derived from the wax during a first time temperature rising as measured by differential scanning calorimetry to the area of endothermic peak derived from the crystalline resin during a first temperature rising as measured by differential scanning calorimetry is at least 0.10.
    Type: Application
    Filed: February 4, 2014
    Publication date: September 18, 2014
    Inventors: Hiroshi YAMASHITA, Toyoshi Sawada, Hideyuki Santo
  • Patent number: 8828635
    Abstract: A toner including a resin particle (C) is provided. The resin particle (C) includes a resin particle (B) and a resin particle (A). The resin particle (B) includes a resin (b). The resin particle (A) or covering layer (P) includes a resin (a). The resin particle (A) or covering layer (P) is adhered to a surface of the resin particle (B). The resin (a) is a polyester resin. The resin (a) has a total acid value of 15 to 36 mgKOH/g. The resin particle (A) or covering layer (P) has a surface acid value of 10 to 27 mgKOH/g.
    Type: Grant
    Filed: August 2, 2012
    Date of Patent: September 9, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshihiro Moriya, Shinya Nakayama, Atsushi Yamamoto, Hideyuki Santo, Akiyoshi Sabu, Yukiko Nakajima, Daiki Yamashita
  • Patent number: 8822118
    Abstract: Toner containing a binder resin that contains at least one kind of resin having a crystalline polyester unit as its main component and a releasing agent containing a straight-chain mono ester having 48 or more carbon atoms accounting for 40% by weight or more of the releasing agent.
    Type: Grant
    Filed: March 4, 2013
    Date of Patent: September 2, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Atsushi Yamamoto, Shinya Nakayama, Hideyuki Santo, Suzuka Amemori, Shingo Sakashita, Masahide Yamada
  • Patent number: 8808955
    Abstract: A toner includes a coloring agent, a binder resin comprising a crystalline resin having a urethane skeleton and/or urea skeleton, and a releasing agent (a microcrystalline wax). A development agent, a process cartridge, and an image forming apparatus employ the toner to form images on recording media electrophotographically.
    Type: Grant
    Filed: September 10, 2012
    Date of Patent: August 19, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinya Nakayama, Atsushi Yamamoto, Hideyuki Santo, Daiki Yamashita, Suzuka Amemori, Masahide Yamada
  • Patent number: 8795939
    Abstract: A toner, including a lactone compound having not less than 14-membered rings; and a resin including a crystalline polyester unit.
    Type: Grant
    Filed: October 1, 2012
    Date of Patent: August 5, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Atsushi Yamamoto, Shinya Nakayama, Masahide Yamada, Hideyuki Santo, Suzuka Amemori
  • Publication number: 20140065534
    Abstract: A toner, including: a crystalline resin containing a urethane bond, a urea bond, or both thereof; and a compound represented by the following General Formula (1), wherein an amount of the compound represented by the General Formula (1) is 0.01% by mass to 0.25% by mass: CnH2n+1R??General Formula (1) where n is 8 to 22 and R is COOH, NH2 or OH.
    Type: Application
    Filed: August 29, 2013
    Publication date: March 6, 2014
    Inventors: Suzuka AMEMORI, Atsushi Yamamoto, Masahide Yamada, Yukiko Nakajima, Shinya Nakayama, Hideyuki Santo
  • Patent number: 8603715
    Abstract: A toner including a core particle and projections at a surface of the core particle is provided. The core particle includes a binder resin and a colorant. The binder resin includes a crystalline resin as a major component. Each of the projections consists of a fine resin particle. An average length of long sides of the projections is not less than 0.15 ?m and less than 0.5 ?m. A standard deviation of lengths of the long sides of the projections is 0.2 or less. A surface coverage of the toner with the projections is within a range of 30 to 90%.
    Type: Grant
    Filed: October 19, 2012
    Date of Patent: December 10, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Suzuka Amemori, Atsushi Yamamoto, Masahide Yamada, Shinya Nakayama, Hideyuki Santo, Daiki Yamashita
  • Publication number: 20130252158
    Abstract: An electrophotographic toner, including: a binder resin; a colorant; and an organically-modified layered inorganic mineral, wherein the binder resin contains 50% by mass or more of a crystalline resin relative to the binder resin, and the crystalline resin contains a resin having a sulfonic acid group, and wherein an amount of the sulfonic acid group is 0.1% by mass to 2.0% by mass relative to the resin having the sulfonic acid group.
    Type: Application
    Filed: March 8, 2013
    Publication date: September 26, 2013
    Inventors: Masahide YAMADA, Shinya NAKAYAMA, Atsushi YAMAMOTO, Hideyuki SANTO, Shingo SAKASHITA, Yukiko NAKAJIMA, Suzuka AMEMORI, Akiyoshi SABU