Patents by Inventor Tsuyoshi Nozaki

Tsuyoshi Nozaki 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: 20120237267
    Abstract: An electrostatic image developing toner including: toner particles each containing binder resin and colorant; and an external additive supported on the toner particles, wherein the toner particles each have protrusions on surface thereof, average of lengths of long sides of the protrusions is 0.10 ?m or more but less than 0.50 ?m, standard deviation of the lengths of the long sides of the protrusions is 0.20 or less, coverage rate of the protrusions on the surface of each toner particle is 30% to 90%, the external additive includes at least two different particles including external additive (A) and one or more external additives (B), external additive (A) has longest average primary particle diameter among the external additives and charged to have the opposite polarity to the toner particles, and at least one of the external additives (B) is charged to have the same polarity as the toner particles.
    Type: Application
    Filed: March 16, 2012
    Publication date: September 20, 2012
    Inventors: Tomohiro FUKAO, Takuya Kadota, Yoshihiro Mikuriya, Tsuyoshi Nozaki, Yoshimichi Ishikawa, Kazuoki Fuwa, Tomoharu Miki
  • Publication number: 20120237253
    Abstract: An electrostatic image developing toner including: toner particles; wherein the toner particles each contain: a core particle including a first resin and a colorant; and fine resin particles each formed of a second resin and existing in a surface of the core particle, wherein part of each fine resin particle is embedded in the core particle to form an embedded region, and the remaining part of the fine resin particle is exposed on the surface of the core particle to form an exposed region, and wherein each toner particle satisfies an expression of R1>R1? where, in a cross-section of the toner particle, R1? denotes an average diameter of openings of the first resin in which the second resin is embedded and R1 denotes an average diameter of the exposed regions.
    Type: Application
    Filed: March 12, 2012
    Publication date: September 20, 2012
    Inventors: Tomohiro FUKAO, Takuya Kadota, Yoshihiro Mikuriya, Tsuyoshi Nozaki, Yoshimichi Ishikawa, Kazuoki Fuwa, Tomoharu Miki
  • Patent number: 8268527
    Abstract: A toner is provided including a core particle comprising a binder resin, a colorant, and a release agent, and a shell layer comprising particles of a vinyl resin. The vinyl resin comprises 80% by weight or more of a unit of an aromatic compound having a vinyl-polymerizable functional group. A method of manufacturing the above toner is also provided, including steps of dissolving or dispersing the binder resin, the colorant, and the release agent in an organic solvent to prepare an oily liquid, dispersing the oily liquid in an aqueous medium to prepare the core particles, and adhering particles of a vinyl resin to the surfaces of the core particles to form shell layers.
    Type: Grant
    Filed: August 11, 2010
    Date of Patent: September 18, 2012
    Assignee: Ricoh Company, Limited
    Inventors: Takuya Kadota, Yoshihiro Mikuriya, Tsuyoshi Nozaki, Atsushi Yamamoto, Yoshimichi Ishikawa, Tomohiro Fukao, Tomoharu Miki
  • Publication number: 20120219321
    Abstract: A toner including a binder resin, a colorant and protruding portions on a surface of the toner, wherein the average length of long sides of the protruding portions is 0.1 ?m or greater, but less than 0.5 ?m, wherein the standard deviation of the lengths of the long sides of the protruding portions is 0.2 or less, and wherein the protruding portions have a coverage of 30% to 90%.
    Type: Application
    Filed: October 27, 2010
    Publication date: August 30, 2012
    Inventors: Tomohiro Fukao, Takuya Kadota, Yoshihiro Mikuriya, Tsuyoshi Nozaki, Yoshimichi Ishikawa, Atsushi Yamamoto, Tomoharu Miki, Kazuoki Fuwa
  • Patent number: 8216755
    Abstract: A toner manufactured by a method including the steps of dissolving or dispersing toner components comprising a binder resin, a colorant, and an encapsulated plasticizer to prepare an oily toner components liquid, and emulsifying or dispersing the oily toner components liquid in an aqueous medium to prepare the toner.
    Type: Grant
    Filed: June 1, 2009
    Date of Patent: July 10, 2012
    Assignee: Ricoh Company, Limited
    Inventors: Yoshimichi Ishikawa, Chiyoshi Nozaki, Tsuyoshi Nozaki, Takuya Kadota, Katsunori Kurose, Mitsuyo Matsumoto, Atsushi Yamamoto
  • Patent number: 8139984
    Abstract: An image forming apparatus, wherein a surface resistivity Rse[?] of a charger and a volume resistivity Rsw [?·cm] of the composition having a low softening point satisfy the following relationship: 0.8×10?1Rse<Rvw<1.5×10Rse is provided. The image forming apparatus contains a photoreceptor; a charger configured to charge the photoreceptor with a charger contacting thereto; an irradiator configured to irradiate the photoreceptor to form an electrostatic latent image thereon; an image developer configured to develop the electrostatic latent image with a toner to form a toner image on the photoreceptor; a transferer configured to transfer the toner image onto a recording material directly or through an intermediate transferer; and a fixer configured to fix the toner image on the recording material, wherein the toner comprises: a binder resin; a colorant; a composition having a low softening point; and an external additive.
    Type: Grant
    Filed: October 26, 2010
    Date of Patent: March 20, 2012
    Assignee: Ricoh Company, Limited
    Inventors: Hiroyuki Murakami, Masahide Inoue, Chiyoshi Nozaki, Tsuyoshi Nozaki, Atsushi Yamamoto, Takuya Kadota, Mitsuyo Matsumoto, Katsunori Kurose, Yoshimichi Ishikawa
  • Patent number: 8110330
    Abstract: To provide a toner that contains at least a binder resin, a colorant, a releasing agent and zeolite, the toner being manufactured through O/W type wet granulation and having an average circularity of 0.970 or greater, and a developer and image forming method using the toner.
    Type: Grant
    Filed: September 18, 2007
    Date of Patent: February 7, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshimichi Ishikawa, Chiyoshi Nozaki, Tsuyoshi Nozaki, Takuya Kadota, Katsunori Kurose, Mitsuyo Matsumoto, Atsushi Yamamoto, Masahide Inoue
  • Publication number: 20110287356
    Abstract: An electrostatic image developing toner including toner core particles each containing at least a first resin and a colorant, and fine resin particles formed of a second resin, wherein part of each of the fine resin particles is embedded in each of the toner core particles, and the remaining part of the fine resin particle is exposed on a surface of the toner core particle to form a protrusion, and wherein when a rate of the part of the fine resin particle to the fine resin particle is indicated by an embedment rate, an average of the embedment rates in the fine resin particles is 40% to 80%.
    Type: Application
    Filed: May 23, 2011
    Publication date: November 24, 2011
    Inventors: Tomohiro Fukao, Takuya Kadota, Chieko Yamazaki, Yoshihiro Mikuriya, Tsuyoshi Nozaki, Yoshimichi Ishikawa, Atsushi Yamamoto, Kazuoki Fuwa, Tomoharu Miki
  • Patent number: 8062821
    Abstract: A toner containing a binder resin including a unit of a polyester resin I having an amino group and another unit of a polyester resin II having an anion functional group and a coloring agent, wherein the toner is manufactured by dissolving or dispersing the polyester resin I, the polyester resin II and the coloring agent in an organic solvent to obtain an oil phase, dispersing the oil phase in an aqueous medium and removing the organic solvent followed by drying.
    Type: Grant
    Filed: March 5, 2009
    Date of Patent: November 22, 2011
    Assignee: Ricoh Company, Limited
    Inventors: Atsushi Yamamoto, Chiyoshi Nozaki, Tsuyoshi Nozaki
  • Patent number: 8039185
    Abstract: To provide a toner for developing a latent electrostatic image comprising at least a colorant, a wax, and a binder resin, wherein Iwax (s) is a value measured by FTIR-ATR Spectroscopy before heating a mirror-surfaced pellet formed by compressing and molding the toner, and Iwax (t) is a value measured by FTIR-ATR Spectroscopy after heating the pellet at a surface temperature thereof of 130° C. for 1 minute satisfy Formulae (1), (2), (3), and (4), Iwax (t)?0.2*100/[T½(° C.)]??Formula (1) Iwax (s)?0.26??Formula (2) Iwax (t)?0.50??Formula (3) Iwax (t)>Iwax (s)??Formula (4) wherein both Iwax(s) and Iwax(t) are obtained by a formula: absorbance derived from the wax (2850 cm?1)/absorbance derived from the binder resin (828 cm?1).
    Type: Grant
    Filed: March 16, 2007
    Date of Patent: October 18, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Mitsuyo Matsumoto, Chiyoshi Nozaki, Tsuyoshi Nozaki, Minoru Nakamura, Atsushi Yamamoto
  • Publication number: 20110250533
    Abstract: To provide a toner for an electrostatic image developer, including: a core particle obtained by dispersing, in an aqueous medium, an oil phase prepared by dissolving or dispersing at least a binder resin, a colorant and a release agent in an organic solvent; and a shell layer formed of vinyl resin fine particles present on a surface of the core particle, wherein the shell layer has protruding portions formed of the vinyl resin fine particles, and wherein the vinyl resin fine particles contain 80% by mass or more of an aromatic compound which has a vinyl-polymerizable functional group, and a vinyl resin which forms the vinyl resin fine particles has a weight average molecular weight of 8,000 to 16,000.
    Type: Application
    Filed: April 11, 2011
    Publication date: October 13, 2011
    Inventors: Takuya Kadota, Yoshihiro Mikuriya, Tsuyoshi Nozaki, Atsushi Yamamoto, Yoshimichi Ishikawa, Kazuoki Fuwa, Tomohiro Fukao, Tomoharu Miki
  • Publication number: 20110217644
    Abstract: A method for preparing a toner including toner particles is provided. The toner preparation method includes preparing a toner component liquid including at least a binder resin, a colorant and an organic solvent; mixing a resin A having a solubility of less than 2.0 g/100 g in water having a pH of 3.0 at 25° C. while having a solubility of not less than 2.0 g/100 g, a basic material, and water to prepare an aqueous phase liquid, in which the resin A is dissolved; forming droplets of the toner component liquid in the aqueous phase liquid; and removing the organic solvent from the droplets of the toner component liquid to prepare the toner particles.
    Type: Application
    Filed: March 3, 2011
    Publication date: September 8, 2011
    Inventors: Atsushi Yamamoto, Tsuyoshi Nozaki, Chiyoshi Nozaki
  • Patent number: 8012658
    Abstract: A toner including a binder resin including a polyester resin and a vinyl resin; a wax; and a colorant, wherein the vinyl resin includes a unit obtained from a radically polymerizable monomer having an alkyloxysilyl group. An image forming apparatus including an image bearing member configured to bear an electrostatic image thereon; a developing device configured to develop the electrostatic image with a developer including the toner to form a toner image on the image bearing member; and a transfer device configured to transfer the toner image onto a receiving material. A process cartridge including an image bearing member; and a developing device configured to develop an electrostatic image on the image bearing member with a developer including the toner, wherein the process cartridge is detachably attached to an image forming apparatus as a unit.
    Type: Grant
    Filed: February 5, 2008
    Date of Patent: September 6, 2011
    Assignee: Ricoh Company Limited
    Inventors: Chiyoshi Nozaki, Takuya Kadota, Katsunori Kurose, Mitsuyo Matsumoto, Tsuyoshi Nozaki, Yoshimichi Ishikawa, Atsushi Yamamoto, Hiroyuki Murakami
  • Publication number: 20110164901
    Abstract: A toner containing core particles each containing at least a resin A having a polyester skeleton and a colorant; and vinyl resin fine particles each of which encapsulates a resin B having at least a polyester skeleton and an endothermic peak measured by differential scanning calorimeter (DSC) at 40° C. to 110° C., wherein the vinyl resin fine particles are attached onto each of the core particles.
    Type: Application
    Filed: December 6, 2010
    Publication date: July 7, 2011
    Inventors: Atsushi YAMAMOTO, Takuya Kadota, Yoshihiro Mikuriya, Tsuyoshi Nozaki, Yoshimichi Ishikawa, Kazuoki Fuwa, Tomohiro Fukao, Tomoharu Miki, Masayuki Hagi
  • Patent number: 7903998
    Abstract: An image forming apparatus having at least a latent electrostatic image bearing member, and a recharging unit configured to recharge a residual toner remaining on the latent electrostatic image bearing member, wherein after transfer, the residual toner is passed through the recharging unit and is then recovered in a developing device; a charging component of the recharging unit that comes into contact with the latent electrostatic image bearing member is a polymer sheet having a surface roughness (Ra) of 0.12 ?m to 0.51 ?m; the toner contains at least a pigment, a binder resin, and a releasing agent, and contains inorganic fine particles as an external additive, and the amount of the inorganic fine particles and the amount of the releasing agent satisfy three specific Expressions.
    Type: Grant
    Filed: March 12, 2008
    Date of Patent: March 8, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Mitsuyo Matsumoto, Chiyoshi Nozaki, Takuya Kadota, Katsunori Kurose, Tsuyoshi Nozaki, Atsushi Yamamoto, Yoshimichi Ishikawa
  • Publication number: 20110053071
    Abstract: To provide a toner comprising: a binder resin, a colorant, and a releasing agent, wherein the toner has a core shell structure, and wherein the core contains at least one resin selected from the group consisting of a hybrid resin and a polyester resin, where the hybrid resin is a resin in which a polyester resin and a vinyl resin are chemically bonded to each other, and the shell contains a resin prepared by polymerizing at least a styrene monomer and an ester monomer represented by the following General Formula (1): where, ‘n’ is 2 or 3, ‘X’ is any of 0 to 9, R1 is a hydrogen atom, or an alkyl group, and R2 is a hydrogen atom, an alkyl group, or a phenyl group.
    Type: Application
    Filed: August 27, 2010
    Publication date: March 3, 2011
    Inventors: Tomoharu Miki, Takuya Kadota, Yoshihiro Mikuriya, Tsuyoshi Nozaki, Atsushi Yamamoto, Yoshimichi Ishikawa, Tomohiro Fukao
  • Publication number: 20110053077
    Abstract: The present invention provides a method for producing a colored resin particle, the method including: preparing an oil phase in which at least a resin and a colorant are dissolved or dispersed in an organic solvent; preparing an aqueous phase containing at least a surfactant in an aqueous medium; dispersing the oil phase in the aqueous phase to prepare a colored particle dispersion liquid so as to form core particles; causing resin fine particles to adhere to surfaces of the core particles by adding at least the resin fine particles to the colored particle dispersion liquid, in which the core particles have been formed; removing the solvent from the colored particle dispersion liquid to obtain colored resin particles, washing the colored resin particles, and drying the colored resin particles, wherein an inorganic base is dissolved in the colored particle dispersion liquid.
    Type: Application
    Filed: August 27, 2010
    Publication date: March 3, 2011
    Inventors: Yoshihiro MIKURIYA, Tomoharu Miki, Tomohiro Fukao, Kazuoki Fuwa, Takuya Kadota, Yoshimichi Ishikawa, Atsushi Yamamoto, Tsuyoshi Nozaki
  • Publication number: 20110053063
    Abstract: A toner is provided including a core particle comprising a binder resin, a colorant, and a release agent, and a shell layer comprising particles of a vinyl resin. The vinyl resin comprises 80% by weight or more of a unit of an aromatic compound having a vinyl-polymerizable functional group. A method of manufacturing the above toner is also provided, including steps of dissolving or dispersing the binder resin, the colorant, and the release agent in an organic solvent to prepare an oily liquid, dispersing the oily liquid in an aqueous medium to prepare the core particles, and adhering particles of a vinyl resin to the surfaces of the core particles to form shell layers.
    Type: Application
    Filed: August 11, 2010
    Publication date: March 3, 2011
    Inventors: Takuya KADOTA, Yoshihiro MIKURIYA, Tsuyoshi NOZAKI, Atsushi YAMAMOTO, Yoshimichi ISHIKAWA, Tomohiro FUKAO, Tomoharu MIKI
  • Publication number: 20110045401
    Abstract: An image forming apparatus, wherein a surface resistivity Rse[?] of a charger and a volume resistivity Rsw [?·cm] of the composition having a low softening point satisfy the following relationship: 0.8×10?1Rse<Rvw<1.5×10Rse is provided. The image forming apparatus contains a photoreceptor; a charger configured to charge the photoreceptor with a charger contacting thereto; an irradiator configured to irradiate the photoreceptor to form an electrostatic latent image thereon; an image developer configured to develop the electrostatic latent image with a toner to form a toner image on the photoreceptor; a transferer configured to transfer the toner image onto a recording material directly or through an intermediate transferer; and a fixer configured to fix the toner image on the recording material, wherein the toner comprises: a binder resin; a colorant; a composition having a low softening point; and an external additive.
    Type: Application
    Filed: October 26, 2010
    Publication date: February 24, 2011
    Inventors: Hiroyuki MURAKAMI, Masahide Inoue, Chiyoshi Nozaki, Tsuyoshi Nozaki, Atsushi Yamamoto, Takuya Kadota, Mitsuyo Matsumoto, Katsunori Kurose, Yoshimichi Ishikawa
  • Patent number: 7867685
    Abstract: An image forming method, including charging a photoreceptor with a charger contacting thereto; irradiating the photoreceptor to form an electrostatic latent image thereon; developing the electrostatic latent image with a toner to form a toner image on the photoreceptor; transferring the toner image onto a recording material directly or through an intermediate transferer; and fixing the toner image on the recording material, wherein the toner includes a binder resin; a colorant; a composition having a low softening point; and an external additive, and wherein a surface resistivity Rse [?] of the charger and a volume resistivity Rsw [?·cm] of the composition having a low softening point satisfy the following relationship: 0.8×10?1Rse<Rvw<1.5×10Rse.
    Type: Grant
    Filed: September 7, 2007
    Date of Patent: January 11, 2011
    Assignee: Ricoh Company, Limited
    Inventors: Hiroyuki Murakami, Masahide Inoue, Chiyoshi Nozaki, Tsuyoshi Nozaki, Atsushi Yamamoto, Takuya Kadota, Mitsuyo Matsumoto, Katsunori Kurose, Yoshimichi Ishikawa