Patents by Inventor Yoshihiro Mikuriya

Yoshihiro Mikuriya 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: 20170248896
    Abstract: Image forming apparatus, including: image bearer; charging unit for electrically charging image bearer surface; developing unit for developing with toner, electrostatic latent image formed over image bearer by exposure unit for performing light exposure; transfer unit for transferring developed toner to receiving member; and cleaning unit for cleaning toner remaining over image bearer without being transferred, wherein the toner contains: external additives; and base particles made of at least binder resin and colorant, external additive content of the toner is from 4 to 7 parts by mass relative to 100 parts by mass of base particles, primary particles of at least one external additive have a number average particle diameter of 0.01 to 0.05 ?m, cleaning unit includes an elastic-body blade having surface elastic modulus of from 15 to 25 N/mm2 and surface friction coefficient of from 0.5 to 0.7 at an abutment part thereof abutting on image bearer.
    Type: Application
    Filed: July 17, 2015
    Publication date: August 31, 2017
    Inventors: Naoki NAKATAKE, Takeshi YAMASHITA, Tetsushi SAKUMA, Mitsutoshi KICHISE, Tsuyoshi NOZAKI, Yoshihiro MIKURIYA, Yoshimichi ISHIKAWA, Atsushi YAMAMOTO, Kazuoki FUWA, Tomohiro FUKAO, Tomoharu MIKI
  • Patent number: 9709912
    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: Grant
    Filed: October 1, 2013
    Date of Patent: July 18, 2017
    Assignee: Ricoh Company, Ltd.
    Inventors: Kazuoki Fuwa, Takuya Kadota, Yoshihiro Mikuriya, Tsuyoshi Nozaki, Yoshimichi Ishikawa, Yuta Takeuchi, Tomohiro Fukao, Tomoharu Miki, Takayuki Nakamura
  • Patent number: 9563140
    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: Grant
    Filed: October 23, 2013
    Date of Patent: February 7, 2017
    Assignee: Ricoh Company, Ltd.
    Inventors: Tsuyoshi Nozaki, Takuya Kadota, Yoshihiro Mikuriya, Yoshimichi Ishikawa, Kazuoki Fuwa, Tomohiro Fukao, Tomoharu Miki
  • Patent number: 9417541
    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: Grant
    Filed: April 25, 2012
    Date of Patent: August 16, 2016
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshimichi Ishikawa, Takuya Kadota, Yoshihiro Mikuriya, Tsuyoshi Nozaki, Kazuoki Fuwa, Tomohiro Fukao, Tomoharu Miki
  • Patent number: 9360824
    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: Grant
    Filed: July 6, 2015
    Date of Patent: June 7, 2016
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomohiro Fukao, Tsuyoshi Nozaki, Yoshihiro Mikuriya, Yoshimichi Ishikawa, Atsushi Yamamoto, Kazuoki Fuwa, Tomoharu Miki, Naoki Nakatake, Takeshi Yamashita, Tetsushi Sakuma
  • Patent number: 9285695
    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: Grant
    Filed: September 12, 2012
    Date of Patent: March 15, 2016
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomoharu Miki, Takuya Kadota, Yoshihiro Mikuriya, Tsuyoshi Nozaki, Yoshimichi Ishikawa, Kazuoki Fuwa, Tomohiro Fukao
  • Patent number: 9268244
    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: Grant
    Filed: April 25, 2012
    Date of Patent: February 23, 2016
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomohiro Fukao, Takuya Kadota, Yoshihiro Mikuriya, Tsuyoshi Nozaki, Yoshimichi Ishikawa, Kazuoki Fuwa, Tomoharu Miki
  • 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: 8871417
    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: Grant
    Filed: August 27, 2010
    Date of Patent: October 28, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomoharu Miki, Takuya Kadota, Yoshihiro Mikuriya, Tsuyoshi Nozaki, Atsushi Yamamoto, Yoshimichi Ishikawa, Tomohiro Fukao
  • 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