Patents by Inventor Minoru Masuda

Minoru Masuda 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: 12147192
    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: Grant
    Filed: February 3, 2022
    Date of Patent: November 19, 2024
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroyuki Kishida, Kousuke Suzuki, Tohru Suganuma, Minoru Masuda, Masashi Nagayama, Kento Takeuchi, Kaede Masuko
  • Publication number: 20240302763
    Abstract: An image forming method is provided that includes: developing an electrostatic latent image formed on an image bearer, with use of a developer containing a carrier and toner, the carrier having a core material particle and a covering layer, the covering layer covering the core material particle and containing an antimony-containing particle; and supplying the carrier to the developer.
    Type: Application
    Filed: February 26, 2024
    Publication date: September 12, 2024
    Inventors: Minoru MASUDA, Masashi NAGAYAMA, Tohru SUGANUMA, Kento TAKEUCHI, Tomomi SUZUKI
  • 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: 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
  • Patent number: 11687013
    Abstract: A toner for electrostatic charge image development, wherein a spin-spin relaxation time of the toner at 90° C. is 0.30 msec or more but 1.50 msec or less, and a spin-spin relaxation time of the toner at 50° C. is 0.0185 msec or more but 0.0300 msec or less, the spin-spin relaxation time of the toner at 90° C. and the spin-spin relaxation time of the toner at 50° C. being obtained by Hahn echo method of pulse NMR analysis.
    Type: Grant
    Filed: October 22, 2020
    Date of Patent: June 27, 2023
    Assignee: Ricoh Company, Ltd.
    Inventors: Toshihiko Sugiyama, Minoru Masuda, Yuka Mizoguchi, Hideki Sugiura
  • 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
  • Patent number: 11635711
    Abstract: An image forming method is provided. The image forming method includes: forming an electrostatic latent image on an electrostatic latent image bearer; developing the electrostatic latent image on the electrostatic latent image bearer with a toner to form a toner image; transferring the toner image from the electrostatic latent image bearer onto a continuous resin film; fixing the toner image on the continuous resin film with a heat roller or a heat belt. The toner contains a maleic-acid-modified polyolefin having a polypropylene block in a main chain.
    Type: Grant
    Filed: March 19, 2021
    Date of Patent: April 25, 2023
    Assignee: Ricoh Company, Ltd.
    Inventors: Minoru Masuda, Kazumi Suzuki, Toyoshi Sawada, Akira Azami
  • 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: 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: 11155936
    Abstract: The present invention provides a highly functional polyethylene fiber exhibiting reduction of change in their physical properties in a wide range of temperatures for processing for products and in a wide range of temperatures for usage as products, thereby enabling improvement of dimensional stability. In addition, the present invention provides a highly functional polyethylene fiber exhibiting a high degree of dye exhaustion to be obtained in a simple dyeing operation, and excellent color fastness. The highly functional polyethylene fiber of the present invention is characterized in that an intrinsic viscosity [?] is higher than or equal to 0.8 dL/g, and not higher than 4.9 dL/g, ethylene is substantially contained as a repeating unit thereof, and a maximum thermal shrinkage stress is less than or equal to 0.4 cN/dtex in TMA (thermo-mechanical analysis), and a thermal shrinking percentage at 100° C. is less than or equal to 2.5%.
    Type: Grant
    Filed: September 14, 2011
    Date of Patent: October 26, 2021
    Assignee: TOYOBO CO., LTD.
    Inventors: Yasunori Fukushima, Shoji Oda, Akira Hamano, Minoru Masuda
  • Publication number: 20210311416
    Abstract: An image forming method is provided. The image forming method includes: forming an electrostatic latent image on an electrostatic latent image bearer; developing the electrostatic latent image on the electrostatic latent image bearer with a toner to form a toner image; transferring the toner image from the electrostatic latent image bearer onto a continuous resin film; fixing the toner image on the continuous resin film with a heat roller or a heat belt. The toner contains a maleic-acid-modified polyolefin having a polypropylene block in a main chain.
    Type: Application
    Filed: March 19, 2021
    Publication date: October 7, 2021
    Inventors: Minoru MASUDA, Kazumi SUZUKI, Toyoshi SAWADA, Akira AZAMI
  • Patent number: 11061343
    Abstract: A toner including: a plate-shaped pigment containing a metal as a main component; and a binder resin containing polyester resin (A) that is insoluble in THF, wherein: a weight average molecular weight (Mw) of a tetrahydrofuran (THF)-soluble component of the toner as determined by gel permeation chromatography (GPC) is 5,000 or higher but 14,000 or lower; and a glass transition temperature (Tg) of a THF-insoluble component of the toner as determined from a differential scanning colorimetry (DSC) curve at first heating in DSC is ?60° C. or higher but 10° C. or lower.
    Type: Grant
    Filed: February 18, 2020
    Date of Patent: July 13, 2021
    Assignee: Ricoh Company, Ltd.
    Inventors: Yuka Mizoguchi, Ryota Inoue, Hiroshi Yamashita, Minoru Masuda, Daichi Hisakuni, Tomomi Harashima
  • Publication number: 20210124281
    Abstract: A toner for electrostatic charge image development, wherein a spin-spin relaxation time of the toner at 90° C. is 0.30 msec or more but 1.50 msec or less, and a spin-spin relaxation time of the toner at 50° C. is 0.0185 msec or more but 0.0300 msec or less, the spin-spin relaxation time of the toner at 90° C. and the spin-spin relaxation time of the toner at 50° C. being obtained by Hahn echo method of pulse NMR analysis.
    Type: Application
    Filed: October 22, 2020
    Publication date: April 29, 2021
    Inventors: Toshihiko SUGIYAMA, Minoru MASUDA, Yuka MIZOGUCHI, Hideki SUGIURA
  • Patent number: 10895816
    Abstract: An image forming apparatus is provided that includes: first and second electrostatic latent image bearers; first and second electrostatic latent image forming devices; first and second developing devices configured to develop first and second electrostatic latent images with a colored toner and a special-color toner to form a colored toner image and a special-color toner image, respectively; a primary transfer device configured to transfer the colored toner image and the special-color toner image onto an intermediate image bearer in an overlapping manner to form a composite toner image; a secondary transfer device configured to transfer the composite toner image onto a recording medium; and a fixing device configured to fix the composite toner image thereon. The special-color toner comprises plate-like and/or film-like pigments. An absolute difference in volume resistivity between the special-color toner and the colored toner is 0.30 log ? cm or less.
    Type: Grant
    Filed: September 12, 2019
    Date of Patent: January 19, 2021
    Assignee: Ricoh Company, Ltd.
    Inventors: Minoru Masuda, Hiroshi Yamashita, Ryota Inoue, Yuka Mizoguchi, Daichi Hisakuni, Tomomi Harashima
  • Publication number: 20200301298
    Abstract: A toner for developing an electrostatic image is provided. The toner comprises a binder resin and a glitter pigment having an average surface roughness Ra of 100 nm or less.
    Type: Application
    Filed: March 18, 2020
    Publication date: September 24, 2020
    Inventors: Ryota INOUE, Hiroshi Yamashita, Minoru Masuda, Yuka Mizoguchi, Daichi Hisakuni
  • Publication number: 20200285167
    Abstract: A toner including: a plate-shaped pigment containing a metal as a main component; and a binder resin containing polyester resin (A) that is insoluble in THF, wherein: a weight average molecular weight (Mw) of a tetrahydrofuran (THF)-soluble component of the toner as determined by gel permeation chromatography (GPC) is 5,000 or higher but 14,000 or lower; and a glass transition temperature (Tg) of a THF-insoluble component of the toner as determined from a differential scanning colorimetry (DSC) curve at first heating in DSC is ?60° C. or higher but 10° C. or lower.
    Type: Application
    Filed: February 18, 2020
    Publication date: September 10, 2020
    Inventors: Yuka MIZOGUCHI, Ryota INOUE, Hiroshi YAMASHITA, Minoru MASUDA, Daichi HISAKUNI, Tomomi HARASHIMA
  • Patent number: 10712681
    Abstract: A toner is provided that contains a crystalline polyester resin comprising a polycondensed resin of a dicarboxylic acid represented by the following formula (1) with a diol represented by the following formula (2). A content of a cyclic ester represented by the following formula (3) in the toner, measured by a thermal extraction gas chromatographic mass spectrometry at a thermal extraction temperature of 160° C., is from 1 to 200 ppm in terms of toluene: where n represents an integer of from 2 to 12; where m represents an integer of from 2 to 12; and where n represents an integer of from 2 to 12, m represents an integer of from 2 to 12, and m+n?6 is satisfied.
    Type: Grant
    Filed: January 28, 2019
    Date of Patent: July 14, 2020
    Assignee: Ricoh Company, Ltd.
    Inventors: Minoru Masuda, Atsushi Yamamoto, Taichi Nemoto, Junichi Watanabe, Taro Araki, Takeshi Shibuya
  • Publication number: 20200089140
    Abstract: An image forming apparatus is provided that includes: first and second electrostatic latent image bearers; first and second electrostatic latent image forming devices; first and second developing devices configured to develop first and second electrostatic latent images with a colored toner and a special-color toner to form a colored toner image and a special-color toner image, respectively; a primary transfer device configured to transfer the colored toner image and the special-color toner image onto an intermediate image bearer in an overlapping manner to form a composite toner image; a secondary transfer device configured to transfer the composite toner image onto a recording medium; and a fixing device configured to fix the composite toner image thereon. The special-color toner comprises plate-like and/or film-like pigments. An absolute difference in volume resistivity between the special-color toner and the colored toner is 0.30 log ? cm or less.
    Type: Application
    Filed: September 12, 2019
    Publication date: March 19, 2020
    Inventors: Minoru MASUDA, Hiroshi YAMASHITA, Ryota INOUE, Yuka MIZOGUCHI, Daichi HISAKUNI, Tomomi HARASHIMA
  • Publication number: 20190235405
    Abstract: A toner is provided that contains a crystalline polyester resin comprising a polycondensed resin of a dicarboxylic acid represented by the following formula (1) with a diol represented by the following formula (2). A content of a cyclic ester represented by the following formula (3) in the toner, measured by a thermal extraction gas chromatographic mass spectrometry at a thermal extraction temperature of 160° C., is from 1 to 200 ppm in terms of toluene: where n represents an integer of from 2 to 12; where m represents an integer of from 2 to 12; and where n represents an integer of from 2 to 12, m represents an integer of from 2 to 12, and m+n?6 is satisfied.
    Type: Application
    Filed: January 28, 2019
    Publication date: August 1, 2019
    Inventors: Minoru MASUDA, Atsushi YAMAMOTO, Taichi NEMOTO, Junichi WATANABE, Taro ARAKI, Takeshi SHIBUYA