Patents by Inventor Kazuoki Fuwa

Kazuoki Fuwa 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: 20160033924
    Abstract: An image forming apparatus is provided which includes an image bearer, a charger, an irradiator, a developing device to develop an electrostatic latent image on the image bearer with a toner to form a toner image, a transfer device to transfer the toner image onto a transfer medium, and a cleaner to remove toner particles remaining on the image bearer without being transferred. The toner includes a mother particle including a binder resin and a colorant and one or more external additives. At least one of the external additives includes primary particles having a number average particle diameter in the range of 0.05 to 0.30 ?m. The cleaner includes an elastic body blade having a contact part with the image bearer. The contact part has a surface elastic modulus in the range of 15 to 25 N/mm2 and a surface friction coefficient in the range of 0.5 to 0.7.
    Type: Application
    Filed: July 6, 2015
    Publication date: February 4, 2016
    Inventors: Tomohiro FUKAO, Tsuyoshi NOZAKI, Yoshihiro MIKURIYA, Yoshimichi ISHIKAWA, Atsushi YAMAMOTO, Kazuoki FUWA, Tomoharu MIKI, Naoki NAKATAKE, Takeshi YAMASHITA, Tetsushi SAKUMA
  • Patent number: 9182688
    Abstract: An image forming apparatus, including: an electrostatic latent image bearing member; an electrostatic latent image forming unit configured to form an electrostatic latent image on the electrostatic latent image bearing member; and a developing unit containing a toner and configured to develop the electrostatic latent image with the toner to thereby form a visible image, wherein the developing unit is a contact type one-component developing unit which includes a toner bearing member being in contact with the electrostatic latent image bearing member, wherein a contact pressure between the electrostatic latent image bearing member and the toner bearing member is 2.0×104 N/m2 to 7.5×104 N/m2, wherein the toner contains a binder resin and a releasing agent, and wherein an extracted amount of the releasing agent extracted with hexane from the toner is 10 mg/g to 25 mg/g.
    Type: Grant
    Filed: November 25, 2013
    Date of Patent: November 10, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Takuya Kadota, Yoshihiro Mikuriya, Tsuyoshi Nozaki, Yoshimichi Ishikawa, Kazuoki Fuwa, Tomohiro Fukao, Yuta Takeuchi, Tomoharu Miki, Takayuki Nakamura, Naoki Nakatake, Yasuhide Matsuno
  • Patent number: 9152066
    Abstract: A toner, including: a binder resin; releasing agent-encapsulating capsules; and a colorant, wherein the releasing agent-encapsulating capsules each include: a capsule formed of a resin (I) which is different from the binder resin; and a releasing agent (RA) which is encapsulated in the capsule, and the releasing agent-encapsulating capsules exist in the binder resin, and wherein 50% to 100% of the releasing agent-encapsulating capsules exist in a region from a surface of the toner to a depth of 0.10 times a volume-average particle diameter of the toner.
    Type: Grant
    Filed: March 11, 2013
    Date of Patent: October 6, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Ryota Inoue, Hiroaki Katoh, Masahiro Seki, Shun Saito, Yoshitaka Sekiguchi, Yoshihiro Mikuriya, Kazuoki Fuwa, Satoshi Ogawa, Tomohiro Fukao, Takayuki Nakamura
  • Publication number: 20140356774
    Abstract: A toner including: a core particle containing at least a binder resin, a colorant and a releasing agent; and a shell on a surface of the core particle, wherein the toner gives a supernatant having a transmittance of 50% to 95% with respect to light having a wavelength of 800 nm, where the supernatant is formed after 3 g of the toner is added to 40 g of ion-exchange water containing 0.5% by mass of sodium dodecyl sulfate, followed by stirring for 90 min and by irradiating with ultrasonic waves of 20 kHz and 80 W for 5 min, and a liquid containing the toner dispersed therein is centrifugated at 3,000 rpm for 5 min.
    Type: Application
    Filed: September 12, 2012
    Publication date: December 4, 2014
    Inventors: Tomoharu Miki, Takuya Kadota, Yoshihiro Mikuriya, Tsuyoshi Nozaki, Yoshimichi Ishikawa, Kazuoki Fuwa, Tomohiro Fukao
  • Patent number: 8852836
    Abstract: A toner including: a base resin; and charge-controlling resin particles contained in the base resin, wherein the toner is in shape of particles, and the charge-controlling resin particles are present in a region of each toner particle which is 500 nm in depth from a surface of the toner particle and an average of amounts of the charge-controlling resin particles present in the regions of the toner particles is 20% by volume to 70% by volume, wherein an average of embedment rates of the charge-controlling resin particles in the toner particles is 90% or higher, where each embedment rate is an average of embedment rates of the charge-controlling resin particles in each toner particle, and wherein the charge-controlling resin particles have a charge amount of 60 ?C/m2 or more as measured by a blow-off method.
    Type: Grant
    Filed: June 18, 2012
    Date of Patent: October 7, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Masahiro Seki, Yoshitaka Sekiguchi, Ryota Inoue, Kazuoki Fuwa
  • Publication number: 20140147780
    Abstract: A toner is prepared by wet granulation methods, including a monoester wax having carbon atoms of from 36 to 46 on average as a release agent. The toner has a DSC endothermic energy amount (?H1) originating from the wax of from 10 to 12 mJ/mg and a DSC endothermic energy amount (?H2) originating from the wax of from 0.6 to 0.9 times as much as ?H1 after a part of the wax is separated by hexane extraction from the toner. The hexane extraction includes mixing 1 g of the toner in 7 ml of n-hexane to prepare a mixture; stirring the mixture at 120 rpm for 1 min by a pot mill to prepare a dispersion; and subjecting the dispersion to suction filtration.
    Type: Application
    Filed: October 23, 2013
    Publication date: May 29, 2014
    Inventors: Tsuyoshi NOZAKI, Takuya Kadota, Yoshihiro Mikuriya, Yoshimichi Ishikawa, Kazuoki Fuwa, Tomohiro Fukao, Tomoharu Miki
  • Publication number: 20140147784
    Abstract: An image forming apparatus, including: an electrostatic latent image bearing member; an electrostatic latent image forming unit configured to form an electrostatic latent image on the electrostatic latent image bearing member; and a developing unit containing a toner and configured to develop the electrostatic latent image with the toner to thereby form a visible image, wherein the developing unit is a contact type one-component developing unit which includes a toner bearing member being in contact with the electrostatic latent image bearing member, wherein a contact pressure between the electrostatic latent image bearing member and the toner bearing member is 2.0×104 N/m2 to 7.5×104 N/m2, wherein the toner contains a binder resin and a releasing agent, and wherein an extracted amount of the releasing agent extracted with hexane from the toner is 10 mg/g to 25 mg/g.
    Type: Application
    Filed: November 25, 2013
    Publication date: May 29, 2014
    Inventors: Takuya Kadota, Yoshihiro Mikuriya, Tsuyoshi Nozaki, Yoshimichi Ishikawa, Kazuoki Fuwa, Tomohiro Fukao, Yuta Takeuchi, Tomoharu Miki, Takayuki Nakamura, Naoki Nakatake, Yasuhide Matsuno
  • Publication number: 20140147779
    Abstract: A toner is provided. The toner includes a crystalline resin and a non-crystalline resin, and has a thermal property such that when the toner is heated after being firstly heated to 60° C. followed by cooling in differential scanning calorimetry (DSC), the toner has a clear peak specific to melting of the crystalline resin at a temperature T1, and when the toner is heated after being firstly heated to 80° C. followed by cooling in the differential scanning calorimetry (DSC), the toner does not have a clear peak specific to melting of the crystalline resin at a temperature not higher than the temperature T1.
    Type: Application
    Filed: October 1, 2013
    Publication date: May 29, 2014
    Inventors: Kazuoki FUWA, Takuya KADOTA, Yoshihiro MIKURIYA, Tsuyoshi NOZAKI, Yoshimichi ISHIKAWA, Yuta TAKEUCHI, Tomohiro FUKAO, Tomoharu MIKI, Takayuki NAKAMURA
  • Publication number: 20140050504
    Abstract: An electrostatic image developing toner including: toner base particles each including a binder resin and a colorant; and an external additive, wherein the toner base particles each have protrusions on a surface thereof, an average of lengths of long sides of the protrusions is 0.1 ?m or more but less than 0.5 ?m, a standard deviation of the lengths of the long sides of the protrusions is 0.2 or less, a coverage rate of the protrusions on the surface of each toner base particle is 10% to 90%, and the external additive includes an external additive (A) which is fine inorganic particles each containing silicone oil.
    Type: Application
    Filed: April 25, 2012
    Publication date: February 20, 2014
    Inventors: Tomohiro Fukao, Takuya Kadota, Yoshihiro Mikuriya, Tsuyoshi Nozaki, Yoshimichi Ishikawa, Kazuoki Fuwa, Tomoharu Miki
  • Patent number: 8647803
    Abstract: A method for producing colored resin particles including: dissolving or dispersing at least binder resin and colorant in organic solvent to prepare oil phase; dissolving resin A and basic compound in aqueous medium to prepare aqueous phase, the resin A having solubility <2.0 g/100 g water having temperature 25° C. and pH 3.0 and solubility ?2.0 g/100 g water having temperature 25° C. and pH 10.0; dispersing the oil phase in the aqueous phase to prepare core particle dispersion liquid; dispersing resin particles in aqueous medium to prepare resin particle dispersion liquid, and adding the resin particle dispersion liquid to the core particle dispersion liquid so that the resin particles are attached onto the core particles, to prepare dispersion liquid containing particles each having the core particle and the resin particles attached thereonto; removing the organic solvent from the dispersion liquid; washing the particles; and drying the particles.
    Type: Grant
    Filed: February 1, 2012
    Date of Patent: February 11, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Atsushi Yamamoto, Takuya Kadota, Yoshihiro Mikuriya, Tsuyoshi Nozaki, Yoshimichi Ishikawa, Kazuoki Fuwa, Tomohiro Fukao, Tomoharu Miki
  • Publication number: 20140038095
    Abstract: A toner including: toner particles each including a toner base particle and an external additive attached thereon, where the toner base particle includes a binder resin and a colorant, wherein the toner base particles each have protrusions on a surface thereof, an average of lengths of long sides of the protrusions is 0.10 ?m or more but less than 0.50 ?m, a standard deviation of the lengths of the long sides of the protrusions is 0.2 or less, a coverage rate of the protrusions on the surface of the toner base particle is 10% to 90%, and the external additive includes fine inorganic particles whose surfaces have been treated with an amino group-containing silane coupling agent.
    Type: Application
    Filed: April 25, 2012
    Publication date: February 6, 2014
    Inventors: Yoshimichi Ishikawa, Takuya Kadota, Yoshihiro Mikuriya, Tsuyoshi Nozaki, Kazuoki Fuwa, Tomohiro Fukao, Tomoharu Miki
  • Patent number: 8642238
    Abstract: A toner including: a core particle; and fine resin particles, the core particle containing at least a binder resin, a releasing agent and a colorant, wherein the toner is in shape of particles, and each toner particle has a sea-island structure having the core particle and island portions, which are convex portions formed from the fine resin particles on surface of the core particle, wherein the binder resin contains first and second resins, and the fine resin particles are made of third resin, wherein the first resin is crystalline resin, and the second and third resins are non-crystalline resin, wherein the second resin has glass transition temperature (Tg2) and the crystalline resin has melting point (Tc1) where Tg2 is higher than Tc1, and wherein the third resin has glass transition temperature (Tg3) and the toner has glass transition temperature (Tgt) wherein Tg3 is higher than Tgt.
    Type: Grant
    Filed: July 25, 2012
    Date of Patent: February 4, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Tsuyoshi Nozaki, Tomoharu Miki, Tomohiro Fukao, Kazuoki Fuwa, Yoshimichi Ishikawa, Yoshihiro Mikuriya, Takuya Kadota
  • Patent number: 8623581
    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: Grant
    Filed: March 16, 2012
    Date of Patent: January 7, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomohiro Fukao, Takuya Kadota, Yoshihiro Mikuriya, Tsuyoshi Nozaki, Yoshimichi Ishikawa, Kazuoki Fuwa, Tomoharu Miki
  • Publication number: 20130344427
    Abstract: To provide a toner, which contains a binder resin, a colorant, and a silicone oil-treated external additive, wherein the silicone oil-treated external additive contains free silicone oil, and a total amount of the free silicone oil is 0.2% by mass to 0.5% by mass relative to the toner, and wherein the toner has the average circularity of 0.96 to 1.
    Type: Application
    Filed: March 9, 2012
    Publication date: December 26, 2013
    Inventors: Takuya Kadota, Yoshihiro Mikuriya, Tsuyoshi Nozaki, Yoshimichi Ishikawa, Kazuoki Fuwa, Tomohiro Fukao, Tomoharu Miki, Masayuki Hagi, Hidekazu Shono, Manabu Hamada, Tetsushi Sakuma
  • Patent number: 8614040
    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: Grant
    Filed: March 12, 2012
    Date of Patent: December 24, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomohiro Fukao, Takuya Kadota, Yoshihiro Mikuriya, Tsuyoshi Nozaki, Yoshimichi Ishikawa, Kazuoki Fuwa, Tomoharu Miki
  • Publication number: 20130244157
    Abstract: A toner, including: a binder resin; releasing agent-encapsulating capsules; and a colorant, wherein the releasing agent-encapsulating capsules each include: a capsule formed of a resin (I) which is different from the binder resin; and a releasing agent (RA) which is encapsulated in the capsule, and the releasing agent-encapsulating capsules exist in the binder resin, and wherein 50% to 100% of the releasing agent-encapsulating capsules exist in a region from a surface of the toner to a depth of 0.10 times a volume-average particle diameter of the toner.
    Type: Application
    Filed: March 11, 2013
    Publication date: September 19, 2013
    Inventors: Ryota INOUE, Hiroaki Katoh, Masahiro Seki, Shun Saito, Yoshitaka Sekiguchi, Yoshihiro Mikuriya, Kazuoki Fuwa, Satoshi Ogawa, Tomohiro Fukao, Takayuki Nakamura
  • Patent number: 8518625
    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: Grant
    Filed: May 23, 2011
    Date of Patent: August 27, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomohiro Fukao, Takuya Kadota, Chieko Yamazaki, Yoshihiro Mikuriya, Tsuyoshi Nozaki, Yoshimichi Ishikawa, Atsushi Yamamoto, Kazuoki Fuwa, Tomoharu Miki
  • Patent number: 8440380
    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: Grant
    Filed: December 6, 2010
    Date of Patent: May 14, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Atsushi Yamamoto, Takuya Kadota, Yoshihiro Mikuriya, Tsuyoshi Nozaki, Yoshimichi Ishikawa, Kazuoki Fuwa, Tomohiro Fukao, Tomoharu Miki, Masayuki Hagi
  • Patent number: 8431314
    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: Grant
    Filed: August 27, 2010
    Date of Patent: April 30, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshihiro Mikuriya, Tomoharu Miki, Tomohiro Fukao, Kazuoki Fuwa, Takuya Kadota, Yoshimichi Ishikawa, Atsushi Yamamoto, Tsuyoshi Nozaki
  • Publication number: 20130029260
    Abstract: A toner including: a core particle; and fine resin particles, the core particle containing at least a binder resin, a releasing agent and a colorant, wherein the toner is in shape of particles, and each toner particle has a sea-island structure having the core particle and island portions, which are convex portions formed from the fine resin particles on surface of the core particle, wherein the binder resin contains first and second resins, and the fine resin particles are made of third resin, wherein the first resin is crystalline resin, and the second and third resins are non-crystalline resin, wherein the second resin has glass transition temperature (Tg2) and the crystalline resin has melting point (Tc1) where Tg2 is higher than Tc1, and wherein the third resin has glass transition temperature (Tg3) and the toner has glass transition temperature (Tgt) wherein Tg3 is higher than Tgt.
    Type: Application
    Filed: July 25, 2012
    Publication date: January 31, 2013
    Inventors: Tsuyoshi NOZAKI, Tomoharu Miki, Tomohiro Fukao, Kazuoki Fuwa, Yoshimichi Ishikawa, Yoshihiro Mikuriya, Takuya Kadota