Patents by Inventor Mariko Takii

Mariko Takii 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: 10915035
    Abstract: A carrier for developing an electrostatic latent image includes a core material particle and a resin layer covering a surface of the core material particle. The resin layer includes a resin and at least one kind of a fine particle. At least one kind of the fine particles includes a chargeable fine particle. The chargeable fine particle has a long diameter of 400 to 900 nm. The chargeable fine particle has a shape factor SF-1 of 160 to 250.
    Type: Grant
    Filed: May 26, 2017
    Date of Patent: February 9, 2021
    Assignee: Ricoh Company, Ltd.
    Inventors: Haruki Murata, Hiroyuki Kishida, Toyoaki Tano, Kenichi Mashiko, Masato Taikoji, Mariko Takii, Yoshihiro Murasawa
  • Publication number: 20200183297
    Abstract: A carrier for developing an electrostatic latent image includes a core material particle and a resin layer covering a surface of the core material particle. The resin layer includes a resin and at least one kind of a fine particle. At least one kind of the fine particles includes a chargeable fine particle. The chargeable fine particle has a long diameter of 400 to 900 nm. The chargeable fine particle has a shape factor SF-1 of 160 to 250.
    Type: Application
    Filed: May 26, 2017
    Publication date: June 11, 2020
    Inventors: Haruki MURATA, Hiroyuki KISHIDA, Toyoaki TANO, Kenichi MASHIKO, Masato TAIKOJI, Mariko TAKII, Yoshihiro MURASAWA
  • Patent number: 10474051
    Abstract: Provided is a carrier for a developer of an electrostatic latent image, the carrier including a core particle, and a resin layer covering the core particle, where the resin layer includes metal compound particles, wherein the metal compound particles include magnesium compound particles or barium compound particles, and an exposed amount B (atomic %) of the magnesium or the barium on a surface of the carrier particle satisfies a relationship below: 10.0?B ?1.2.
    Type: Grant
    Filed: September 14, 2018
    Date of Patent: November 12, 2019
    Assignee: Ricoh Company, Ltd.
    Inventors: Mariko Takii, Koichi Sakata, Tohru Suganuma, Masahiro Seki, Masashi Nagayama, Shinya Nakagawa, Kei Niwayama
  • Patent number: 10444651
    Abstract: A carrier is provided including a core particle and a resin layer coating the surface of the core particle. The resin layer includes fine metal particles, and a detected metal element amount A obtained by X-ray photoelectron spectrometry of the surface of the carrier is in a range of 4.0 atomic %?A?20.0 atomic % and an average major-axis length B of the fine metal particle exposing from the resin layer is in a range of 100 nm?B?800 nm.
    Type: Grant
    Filed: March 5, 2018
    Date of Patent: October 15, 2019
    Assignee: Ricoh Company, Ltd.
    Inventors: Mariko Takii, Koichi Sakata, Tohru Suganuma, Masahiro Seki, Masashi Nagayama, Toyoaki Tano, Kohsuke Miyazaki
  • Patent number: 10197948
    Abstract: A developing device, including: a developer containing toner and carrier; and developer bearer configured to have surface thereof bear the developer and endlessly move, and to develop latent image over surface of latent image bearer by supplying toner in developer to latent image in developing region facing the latent image bearer, wherein carrier contains fine particles, value X in volume resistivity R (=10X) (?·cm) of carrier is 11.5-16.0, developer bearer includes: magnetic field generating unit including a plurality of magnetic poles; and developing sleeve having a cylindrical shape enclosing magnetic field generating unit, and configured to bear developer over outer circumferential surface of cylindrical shape by magnetic force of the magnetic field generating unit and perform surface moving by rotating relative to developing device body, and developing device includes developing sleeve voltage applying unit configured to apply AC component-containing voltage to developing sleeve.
    Type: Grant
    Filed: August 31, 2015
    Date of Patent: February 5, 2019
    Assignee: Ricoh Company, Ltd.
    Inventors: Hitoshi Iwatsuki, Koichi Sakata, Hiroshi Tohmatsu, Toyoaki Tano, Kenichi Mashiko, Mariko Takii, Hiroyuki Kishida, Yoshihiro Murasawa, Keinosuke Kondoh, Toshio Koike, Yutaka Takahashi
  • Publication number: 20190018331
    Abstract: Provided is a carrier for a developer of an electrostatic latent image, the carrier including a core particle, and a resin layer covering the core particle, where the resin layer includes metal compound particles, wherein the metal compound particles include magnesium compound particles or barium compound particles, and an exposed amount B (atomic %) of the magnesium or the barium on a surface of the carrier particle satisfies a relationship below: 10.0?B?1.2.
    Type: Application
    Filed: September 14, 2018
    Publication date: January 17, 2019
    Inventors: Mariko Takii, Koichi Sakata, Tohru Suganuma, Masahiro Seki, Masashi Nagayama, Shinya Nakagawa, Kei Niwayama
  • Publication number: 20180267421
    Abstract: A carrier is provided including a core particle and a resin layer coating the surface of the core particle. The resin layer includes fine metal particles, and a detected metal element amount A obtained by X-ray photoelectron spectrometry of the surface of the carrier is in a range of 4.0 atomic %?A?20.0 atomic % and an average major-axis length B of the fine metal particle exposing from the resin layer is in a range of 100 nm?B?800 nm.
    Type: Application
    Filed: March 5, 2018
    Publication date: September 20, 2018
    Inventors: Mariko TAKII, Koichi SAKATA, Tohru SUGANUMA, Masahiro SEKI, Masashi NAGAYAMA, Toyoaki TANO, Kohsuke MIYAZAKI
  • Patent number: 10067438
    Abstract: Provided is an electrostatic latent image developing white toner, including: a white toner including at least a binder resin, a white pigment, and a release agent; and a magnetic carrier including at least a core material, and a coating layer coating the core material and made of a coating resin and conductive particles, wherein Ra of the magnetic carrier is in a range of from 0.50 ?m to 1.00 ?m, and a bulk density of the magnetic carrier is in a range of from 2.08 g/cm3 to 2.24 g/cm3.
    Type: Grant
    Filed: September 29, 2015
    Date of Patent: September 4, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshihiro Murasawa, Hiroshi Tohmatsu, Hitoshi Iwatsuki, Mariko Takii, Koichi Sakata, Hiroyuki Kishida, Toyoaki Tano, Kenichi Mashiko
  • Patent number: 10054868
    Abstract: A carrier includes a core and a covering layer covering the core and including at least carbon black and a filler. The maximum height Ry of the surface of the carrier is from 4.0 ?m to 5.0 ?m.
    Type: Grant
    Filed: October 21, 2016
    Date of Patent: August 21, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroyuki Kishida, Kenichi Mashiko, Mariko Takii, Yoshihiro Murasawa, Haruki Murata
  • Patent number: 10031434
    Abstract: A carrier includes a resin layer including Al and Sn and covering the surface of the carrier. A detectable amount of Al is from 1.0% to 12.1% by atom and a ratio (Al/Sn) of the detectable amount of Al to that of Sn is from 2.0 to 50.0 when the carrier is subjected to an X-ray photoelectron spectroscopic (XPS) analysis.
    Type: Grant
    Filed: May 20, 2016
    Date of Patent: July 24, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Mariko Takii, Yoshihiro Murasawa, Takahiro Nakamura, Kei Niwayama, Haruki Murata, Masato Taikoji, Koichi Sakata
  • Patent number: 10025214
    Abstract: Carrier for image forming includes a core material particle including a magnetic material and a coating layer disposed on the surface of the core material particle, the coating layer including a resin, carbon black, an inorganic particulate A, and an inorganic particulate B. The carbon black has a concentration gradient along a thickness direction of the coating layer with a concentration from high to low toward a surface of the coating layer while the inorganic particulate A has a concentration gradient along a thickness direction of the coating layer with a concentration from low to high toward the surface of the coating layer. The volume ratio of the carbon black is 0-30 percent at a depth range of 0.0-0.1 ?m from the surface of the coating layer. The inorganic particulate A is electroconductive with a powder specific resistance of 200 ?·cm or less.
    Type: Grant
    Filed: December 28, 2016
    Date of Patent: July 17, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Masashi Nagayama, Mariko Takii, Yoshihiro Murasawa, Haruki Murata, Kei Niwayama, Tohru Suganuma, Koichi Sakata, Saori Yamada, Shinya Nakagawa, Kohsuke Miyazaki
  • Patent number: 9989874
    Abstract: A carrier for developing electrostatic latent images is provided. The carrier includes a magnetic core particle and a resin layer coating a surface of the magnetic core particle. The resin layer includes a particulate material A having a volume average particle diameter (a) and a particulate material B having a volume average particle diameter (b). The volume average particle diameter (a) of the particulate material A is the largest among volume average particle diameters of all particulate materials included in the resin layer, and an inequation 100?(a)/(b)?5 is satisfied. The particulate material A is barium sulfate.
    Type: Grant
    Filed: March 3, 2017
    Date of Patent: June 5, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshihiro Murasawa, Toyoaki Tano, Hiroyuki Kishida, Masato Taikoji, Kenichi Mashiko, Mariko Takii, Haruki Murata
  • Publication number: 20170329247
    Abstract: Provided is an electrostatic latent image developing white toner, including: a white toner including at least a binder resin, a white pigment, and a release agent; and a magnetic carrier including at least a core material, and a coating layer coating the core material and made of a coating resin and conductive particles, wherein Ra of the magnetic carrier is in a range of from 0.50 ?m to 1.00 ?m, and a bulk density of the magnetic carrier is in a range of from 2.08 g/cm3 to 2.24 g/cm3.
    Type: Application
    Filed: September 29, 2015
    Publication date: November 16, 2017
    Inventors: Yoshihiro MURASAWA, Hiroshi TOHMATSU, Hitoshi IWATSUKI, Mariko TAKII, Koichi SAKATA, Hiroyuki KISHIDA, Toyoaki TANO, Kenichi MASHIKO
  • Publication number: 20170269497
    Abstract: A carrier for developing electrostatic latent images is provided. The carrier includes a magnetic core particle and a resin layer coating a surface of the magnetic core particle. The resin layer includes a particulate material A having a volume average particle diameter (a) and a particulate material B having a volume average particle diameter (b). The volume average particle diameter (a) of the particulate material A is the largest among volume average particle diameters of all particulate materials included in the resin layer, and an inequation 100?(a)/(b)?5 is satisfied. The particulate material A is barium sulfate.
    Type: Application
    Filed: March 3, 2017
    Publication date: September 21, 2017
    Inventors: Yoshihiro MURASAWA, Toyoaki TANO, Hiroyuki KISHIDA, Masato TAIKOJI, Kenichi MASHIKO, Mariko TAKII, Haruki MURATA
  • Publication number: 20170248871
    Abstract: A developing device, including: a developer containing toner and carrier; and developer bearer configured to have surface thereof bear the developer and endlessly move, and to develop latent image over surface of latent image bearer by supplying toner in developer to latent image in developing region facing the latent image bearer, wherein carrier contains fine particles, value X in volume resistivity R (=10X) (?·cm) of carrier is 11.5-16.0, developer bearer includes: magnetic field generating unit including a plurality of magnetic poles; and developing sleeve having a cylindrical shape enclosing magnetic field generating unit, and configured to bear developer over outer circumferential surface of cylindrical shape by magnetic force of the magnetic field generating unit and perform surface moving by rotating relative to developing device body, and developing device includes developing sleeve voltage applying unit configured to apply AC component-containing voltage to developing sleeve.
    Type: Application
    Filed: August 31, 2015
    Publication date: August 31, 2017
    Inventors: Hitoshi IWATSUKI, Koichi SAKATA, Hiroshi TOHMATSU, Toyoaki TANO, Kenichi MASHIKO, Mariko TAKII, Hiroyuki KISHIDA, Yoshihiro MURASAWA, Keinosuke KONDOH, Toshio KOIKE, Yutaka TAKAHASHI
  • Publication number: 20160363880
    Abstract: A carrier includes a resin layer including Al and Sn and covering the surface of the carrier. A detectable amount of Al is from 1.0% to 12.1% by atom and a ratio (Al/Sn) of the detectable amount of Al to that of Sn is from 2.0 to 50.0 when the carrier is subjected to an X-ray photoelectron spectroscopic (XPS) analysis.
    Type: Application
    Filed: May 20, 2016
    Publication date: December 15, 2016
    Inventors: Mariko TAKII, Yoshihiro MURASAWA, Takahiro NAKAMURA, Kei NIWAYAMA, Haruki MURATA, Masato TAIKOJI, Koichi SAKATA
  • Patent number: 9348259
    Abstract: A toner housing container includes a container body housing a toner; a conveying portion conveying the toner from one end of the container body, in a longer direction of the container body, to its other end at which a container opening portion is provided; a pipe receiving port receiving a conveying pipe fixed to a toner conveying device; and an uplifting portion moving the toner toward a toner receiving port of conveying pipe. Such toner has a molecular weight distribution having a peak in a range of 103 to 104, and has C/R of from 0.03 to 0.55 between peak height C attributed to crystalline polyester resin and R attributed to non-crystalline resin when measured by FT-IR after stored at 45° C. for 12 hours.
    Type: Grant
    Filed: May 15, 2014
    Date of Patent: May 24, 2016
    Assignee: RICOH COMPANY, LTD.
    Inventors: Masashi Nagayama, Hisashi Nakajima, Yoshitaka Sekiguchi, Saori Yamada, Shinya Hanatani, Mariko Takii, Hiroshi Hosokawa, Shunji Katoh, Shinji Tamaki, Hiroshi Ikeguchi, Kenji Kikuchi, Michiharu Suzuki
  • Patent number: 9304427
    Abstract: A carrier for developing an electrostatic latent image of the present invention includes a core material and a coating layer which coats the core material, wherein the coating layer includes a resin and fine particles, wherein the coating layer has an average layer thickness difference of 0.02 ?m to 3.0 ?m, and wherein the carrier for developing an electrostatic latent image has an arithmetic mean surface roughness Ra1 of 0.5 ?m to 0.9 ?m.
    Type: Grant
    Filed: June 26, 2013
    Date of Patent: April 5, 2016
    Assignee: Ricoh Company, Ltd.
    Inventors: Hitoshi Iwatsuki, Shigenori Yaguchi, Toyoaki Tano, Mariko Takii, Koichi Sakata, Hiroyuki Kishida, Hiroshi Tohmatsu
  • Patent number: 9182694
    Abstract: A toner, including: a binder resin; and a colorant, wherein the binder resin contains: a crystalline polyester resin (A); a non-crystalline resin (B); and a composite resin (C), where the composite resin (C) contains a condensation polymerization resin unit and an addition polymerization resin unit, wherein the toner contains chloroform insoluble matter in an amount of 1% by mass to 30% by mass, wherein the toner has a molecular weight distribution having a main peak in a range of 1,000 to 10,000 and a half width of 15,000 or less, where the molecular weight distribution is obtained through gel permeation chromatography (GPC) of tetrahydrofuran soluble matter of the toner, and wherein the toner has an endothermic peak in a range of 90° C. to 130° C. in measurement through differential scanning calorimetry (DSC).
    Type: Grant
    Filed: March 14, 2013
    Date of Patent: November 10, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Saori Yamada, Hisashi Nakajima, Masashi Nagayama, Shinya Hanatani, Mariko Takii, Yoshitaka Sekiguchi
  • Patent number: 9128398
    Abstract: A toner for forming an electrophotographic image is provided, wherein the toner includes at least four types of binder resins, wherein the binder resins includes at least: a crystalline polyester resin (A); a non-crystalline resin (B); a non-crystalline resin (C); and a composite resin (D) which includes a condensation polymerization resin unit and an addition polymerization resin unit, wherein the non-crystalline resin (B) includes a chloroform insoluble matter, wherein the non-crystalline resin (C) has a softening temperature (T½) lower than that of the non-crystalline resin (B) by 25° C. or more, and wherein the toner has a main peak between 1,000 to 10,000 in a molecular weight distribution obtained by GPC from a tetrahydrofuran soluble matter, and the toner has a half-value width of the molecular weight distribution of 15,000 or less.
    Type: Grant
    Filed: September 14, 2012
    Date of Patent: September 8, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Masashi Nagayama, Mitsuo Aoki, Hisashi Nakajima, Saori Yamada, Mariko Takii