Patents by Inventor Masashi Nagayama

Masashi Nagayama 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: 11934145
    Abstract: A developing apparatus includes an electrostatic latent image bearer, a developing sleeve, a case, and an air filter. The case accommodates a two-component developer and the developing sleeve. The air filter is attached to the case. The air filter has a thickness of 2 to 20 mm and has a density gradient with a pressure loss of 2 to 40 Pa at a wind speed of 10 cm/s. The air filter forms an airflow sucked into the case from a gap between the developing sleeve and the case and forms an airflow discharged from the case through the air filter. The two-component developer accommodated in the case contains a magnetic particle a surface of which is coated with a resin layer. The resin layer contains at least one type of chargeable particle.
    Type: Grant
    Filed: November 7, 2022
    Date of Patent: March 19, 2024
    Assignee: Ricoh Company, Ltd.
    Inventors: Minoru Masuda, Tohru Suganuma, Masashi Nagayama, Hiroyuki Kishida, Kento Takeuchi, Kaede Masuko, Tomomi Suzuki, Takuya Suganuma, Kazuki Yogosawa
  • Publication number: 20230393491
    Abstract: A carrier for forming an electrophotographic image contains a core particle and a coating layer coating the core particle, wherein the coating layer contains a particle containing antimony and an anionic dispersant and the particle containing antimony includes a substrate particle containing a first inorganic fine particle.
    Type: Application
    Filed: May 31, 2023
    Publication date: December 7, 2023
    Applicant: Ricoh Company, Ltd.
    Inventors: Kento TAKEUCHI, Masashi Nagayama, Tohru Suganuma, Tomomi Suzuki
  • Publication number: 20230305439
    Abstract: A carrier for electrophotographic image formation includes carrier particles. Each of the carrier particles includes a core particle and a coating layer covering the core particle. The coating layer includes diantimony pentoxide-containing particles.
    Type: Application
    Filed: March 1, 2023
    Publication date: September 28, 2023
    Inventors: Masashi NAGAYAMA, Tomomi SUZUKI, Kento TAKEUCHI, Tohru SUGANUMA
  • Publication number: 20230205108
    Abstract: A carrier is provided that includes a core particle and a coating layer coating the core particle. The coating layer includes a resin and chargeable inorganic fine particles, and has voids. The resin has an average film thickness of 0.10 ?m or larger and smaller than 0.45 ?m. The coating layer has a porosity of 0.1% or higher and lower than 2.8%, when the porosity expressed by the following equation: Porosity [%]=S1/S2×100 where, on a cross section of the coating layer, S1 represents a cross sectional area of the voids and S2 represents a cross sectional area of the resin.
    Type: Application
    Filed: December 14, 2022
    Publication date: June 29, 2023
    Applicant: Ricoh Company ,Ltd.
    Inventors: Kaede MASUKO, Tohru Suganuma, Minoru Masuda, Masashi Nagayama, Hiroyuki Kishida, Tomomi Suzuki, Kento Takeuchi
  • Publication number: 20230195004
    Abstract: A developing apparatus includes an electrostatic latent image bearer, a developing sleeve, a case, and an air filter. The case accommodates a two-component developer and the developing sleeve. The air filter is attached to the case. The air filter has a thickness of 2 to 20 mm and has a density gradient with a pressure loss of 2 to 40 Pa at a wind speed of 10 cm/s. The air filter forms an airflow sucked into the case from a gap between the developing sleeve and the case and forms an airflow discharged from the case through the air filter. The two-component developer accommodated in the case contains a magnetic particle a surface of which is coated with a resin layer. The resin layer contains at least one type of chargeable particle.
    Type: Application
    Filed: November 7, 2022
    Publication date: June 22, 2023
    Applicant: Ricoh Company, Ltd.
    Inventors: Minoru Masuda, Tohru Suganuma, Masashi Nagayama, Hiroyuki Kishida, Kento Takeuchi, Kaede Masuko, Tomomi Suzuki, Takuya Suganuma, Kazuki Yogosawa
  • Publication number: 20220291603
    Abstract: A carrier for developing an electrostatic latent image is provided. The carrier comprises a core particle having an internal void ratio of from 0.0% to 2.0% and a coating layer coating the core particle. The coating layer contains flat chargeable particles satisfying Formula 1 blow: 1.0?R1/R2?3.0??Formula 1 where R1 [nm] and R2 [nm] represent a major axis and a thickness, respectively, of each of the flat chargeable particles. The carrier has an apparent density of from 2.0 to 2.5 g/cm3.
    Type: Application
    Filed: February 3, 2022
    Publication date: September 15, 2022
    Applicant: Ricoh Company, Ltd.
    Inventors: Hiroyuki KISHIDA, Kousuke Suzuki, Tohru Suganuma, Minoru Masuda, Masashi Nagayama, Kento Takeuchi, Kaede Masuko
  • Publication number: 20220291604
    Abstract: A carrier for forming an electrophotographic image is provided. The carrier comprises a core particle and a coating layer coating the core particle. The coating layer contains a conductive component comprising an element A, and a coating resin comprising an element B. The element A is undetected in the coating resin by an energy dispersive X-ray spectrometer, and the element B is undetected in the conductive component by the energy dispersive X-ray spectrometer. A standard deviation of a value A/B is 0.4 or less, where the value A/B is a ratio of the element A to the element B in intensity measured by the energy dispersive X-ray spectrometer.
    Type: Application
    Filed: February 25, 2022
    Publication date: September 15, 2022
    Applicant: Ricoh Company, Ltd.
    Inventors: Namie Suzuki, Kousuke Suzuki, Tohru Suganuma, Masashi Nagayama, Minoru Masuda, Hiroyuki Kishida, Kento Takeuchi, Kaede Masuko
  • Publication number: 20220283523
    Abstract: A carrier can be used for forming an electrophotographic image. The carrier contains a core particle and a coating layer coating the core particle. The coating layer contains a chargeable particle. The carder has an internal void ratio of 0.0% or greater but less than 2.0%, and an apparent density of 2.0 g/cm3 or greater but less than 2.5 g/cm3.
    Type: Application
    Filed: November 12, 2020
    Publication date: September 8, 2022
    Applicant: Ricoh Company, Ltd.
    Inventors: Masashi NAGAYAMA, Kousuke Suzuki, Masahiro Seki, Hiroyuki Kishida, Namie Suzuki
  • Publication number: 20220187729
    Abstract: A carrier for forming an electrophotographic image is provided. The carrier comprises a core particle and a coating layer coating the core particle. The coating layer contains chargeable particles and a dispersant. The carrier has an apparent density of from 2.0 g/cm3 or greater but less than 2.5 g/cm3.
    Type: Application
    Filed: December 6, 2021
    Publication date: June 16, 2022
    Applicant: Ricoh Company, Ltd.
    Inventors: Masashi Nagayama, Kousuke Suzuki, Hiroyuki Kishida, Tohru Suganuma, Minoru Masuda, Kento Takeuchi, Kaede Masuko
  • Patent number: 11106150
    Abstract: A carrier for forming an electrophotographic image is provided. The carrier includes a core particle comprising a manganese-based ferrite particle having an apparent density of from 2.0 to 2.2 g/cm3 and a magnetization of from 44 to 52 emu/g in a magnetic field of 500 Oe; and a coating layer coating a surface of the core particle. The coating layer contains a carbon black, an inorganic particle A, and an inorganic particle B. The inorganic particle A and the carbon black each have a concentration gradient in a thickness direction of the coating layer. A concentration of the inorganic particle A increases toward a surface of the coating layer, and a concentration of the carbon black decreases toward the surface of the coating layer.
    Type: Grant
    Filed: November 14, 2019
    Date of Patent: August 31, 2021
    Assignee: RICOH COMPANY, LTD.
    Inventors: Masashi Nagayama, Hiroyuki Kishida, Masahiro Seki, Yoshimichi Ishikawa, Saori Yamada
  • Publication number: 20200166867
    Abstract: A carrier for forming an electrophotographic image is provided. The carrier includes a core particle comprising a manganese-based ferrite particle having an apparent density of from 2.0 to 2.2 g/cm3 and a magnetization of from 44 to 52 emu/g in a magnetic field of 500 Oe; and a coating layer coating a surface of the core particle. The coating layer contains a carbon black, an inorganic particle A, and an inorganic particle B. The inorganic particle A and the carbon black each have a concentration gradient in a thickness direction of the coating layer. A concentration of the inorganic particle A increases toward a surface of the coating layer, and a concentration of the carbon black decreases toward the surface of the coating layer.
    Type: Application
    Filed: November 14, 2019
    Publication date: May 28, 2020
    Inventors: Masashi NAGAYAMA, Hiroyuki KISHIDA, Masahiro SEKI, Yoshimichi ISHIKAWA, Saori YAMADA
  • 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: 10274856
    Abstract: A toner for electrophotography, which contains a binder resin, and a release agent, wherein a maximum value of loss tangent of the toner at 95° C. to 115° C. is 8 or greater, as a viscoelasticity of the toner is measured, where the loss tangent is represented by the following formula: Loss tangent (tan ?)=loss elastic modulus (G?)/storage elastic modulus (G?).
    Type: Grant
    Filed: January 6, 2015
    Date of Patent: April 30, 2019
    Assignee: Ricoh Company, Ltd.
    Inventors: Hisashi Nakajima, Kazumi Suzuki, Masashi Nagayama, Saori Yamada, Yoshitaka Yamauchi, Yu Naito, Yoshitaka Sekiguchi
  • Patent number: 10203620
    Abstract: Toner contains a binder resin, a releasing agent, and a tri- or higher metal salt, wherein the toner has a weight average molecular weight (Mw) of from 7,000 to 10,000, a ratio of the weight average molecular weight (Mw) to a number average molecular weight (Mn) of 5 or less, and an acid value of from 6 mgKOH/g to 12 mgKOH/g, wherein the binder resin is a polyester resin, wherein the releasing agent is a monoester wax.
    Type: Grant
    Filed: July 17, 2014
    Date of Patent: February 12, 2019
    Assignee: Ricoh Company, Ltd.
    Inventors: Yu Naito, Kazumi Suzuki, Yoshitaka Yamauchi, Masashi Nagayama, Hisashi Nakajima, Saori Yamada
  • 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: 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: 9946177
    Abstract: A carrier 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 resin, a conductive particle including tungsten tin oxide, and a chargeable filler.
    Type: Grant
    Filed: January 3, 2017
    Date of Patent: April 17, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshihiro Murasawa, Koichi Sakata, Masashi Nagayama, Toyoaki Tano, Hiroyuki Kishida
  • Patent number: 9765731
    Abstract: A canister arrangement structure for a saddle-ride type vehicle in which a canister for adsorbing evaporated fuel in a fuel tank is disposed below a step floor on which an occupant's foot is placed, the step floors are configured as a left and right pair and are supported from below by left and right step frames that extend back and forth at a position on the side of the main frame of the vehicle. The canister is supported by the one step frame.
    Type: Grant
    Filed: March 13, 2013
    Date of Patent: September 19, 2017
    Assignee: HONDA MOTOR CO., LTD.
    Inventors: Katsuyuki Okubo, Masanori Nakamura, Masashi Nagayama, Tetsunori Iwamoto, Takasumi Yamanaka, Matake Sugeno