Patents by Inventor Minoru Yoshifuku

Minoru Yoshifuku 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: 9541853
    Abstract: A magnetic carrier includes resin-filled magnetic core particles including porous magnetic particles whose pores are filled with a resin, and resin coating layers on the surfaces of the resin-filled magnetic core particles. The porous magnetic particles have specific electrical properties.
    Type: Grant
    Filed: May 29, 2014
    Date of Patent: January 10, 2017
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hironori Minagawa, Wakashi Iida, Nobuyoshi Sugahara, Minoru Yoshifuku, Yuto Onozaki
  • Patent number: 9513571
    Abstract: A magnetic carrier contains a resin-filled magnetic core particle and a resin covering layer provided on a surface of the resin-filled magnetic core particle. The resin-filled magnetic core particle is a porous magnetic particle containing a resin in pores thereof. The magnetic carrier has a 50% particle diameter (D50) of 30.0 ?m or more and 80.0 ?m or less on a volume basis. An electric current flowing through the magnetic carrier at a voltage of 500 V ranges from 8.0 to 50.0 ?A. A proportion JR1 of a composition that is made up of the resin in a magnetic carrier portion of a region R1 and a proportion JR2 of the composition in a magnetic carrier portion of a region R2 satisfy the following relationship. The region R1 and the region R2 are illustrated in FIG. 1. 1.20?JR2/JR1?2.00.
    Type: Grant
    Filed: May 29, 2014
    Date of Patent: December 6, 2016
    Assignee: Canon Kabushiki Kaisha
    Inventors: Nobuyoshi Sugahara, Hironori Minagawa, Yuto Onozaki, Minoru Yoshifuku, Wakashi Iida
  • Patent number: 9500975
    Abstract: Provided is a magnetic carrier, including magnetic carrier particles each including: a magnetic carrier core including a magnetic material and a resin; and a resin coating layer formed on a surface of the magnetic carrier core, in which: the resin included in the magnetic carrier core has a hydroxy group; a surface portion of the magnetic carrier core includes a specific compound; and the magnetic carrier has an adsorbed moisture amount of 0.40 mass % or less when the magnetic carrier is left to stand in an environment of a temperature of 30° C. and a humidity of 80% RH for 72 hours.
    Type: Grant
    Filed: February 25, 2015
    Date of Patent: November 22, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Nobuyoshi Sugahara, Hironori Minagawa, Yuto Onozaki, Minoru Yoshifuku, Wakashi Iida
  • Patent number: 9341973
    Abstract: There is provided a magnetic carrier having a resin coating layer formed on the surface of each of particles prepared by putting resin in the pores of porous magnetic particles, wherein (i) the surface roughness Ra of the porous magnetic particles ranges from 0.180 ?m to 0.250 ?m, (ii) the pore size ranges from 0.40 ?m to 1.00 ?m, (iii) the amount of the resin held in the pores ranges from 3.0 parts by mass to 5.5 parts by mass relative to 100 parts by mass of the porous magnetic particles, (iv) the amount of resin used for forming the coating resin layer ranges from 1.0 parts by mass to 3.0 parts by mass relative to 100 parts by mass of the porous magnetic particles, and (v) the surface roughness Ra of the magnetic carrier ranges from 0.160 ?m to 0.220 ?m.
    Type: Grant
    Filed: May 29, 2014
    Date of Patent: May 17, 2016
    Assignee: Canon Kabushiki Kaisha
    Inventors: Minoru Yoshifuku, Wakashi Iida, Hironori Minagawa, Nobuyoshi Sugahara, Yuto Onozaki
  • Publication number: 20150241807
    Abstract: Provided is a magnetic carrier, including magnetic carrier particles each including: a magnetic carrier core including a magnetic material and a resin; and a resin coating layer formed on a surface of the magnetic carrier core, in which: the resin included in the magnetic carrier core has a hydroxy group; a surface portion of the magnetic carrier core includes a specific compound; and the magnetic carrier has an adsorbed moisture amount of 0.40 mass % or less when the magnetic carrier is left to stand in an environment of a temperature of 30° C. and a humidity of 80% RH for 72 hours.
    Type: Application
    Filed: February 25, 2015
    Publication date: August 27, 2015
    Inventors: Nobuyoshi Sugahara, Hironori Minagawa, Yuto Onozaki, Minoru Yoshifuku, Wakashi Iida
  • Publication number: 20140356782
    Abstract: A magnetic carrier contains a resin-filled magnetic core particle and a resin covering layer provided on a surface of the resin-filled magnetic core particle. The resin-filled magnetic core particle is a porous magnetic particle containing a resin in pores thereof. The magnetic carrier has a 50% particle diameter (D50) of 30.0 ?m or more and 80.0 ?m or less on a volume basis. An electric current flowing through the magnetic carrier at a voltage of 500 V ranges from 8.0 to 50.0 ?A. A proportion JR1 of a composition that is made up of the resin in a magnetic carrier portion of a region R1 and a proportion JR2 of the composition in a magnetic carrier portion of a region R2 satisfy the following relationship. The region R1 and the region R2 are illustrated in FIG. 1. 1.20?JR2/JR1?2.
    Type: Application
    Filed: May 29, 2014
    Publication date: December 4, 2014
    Inventors: Nobuyoshi Sugahara, Hironori Minagawa, Yuto Onozaki, Minoru Yoshifuku, Wakashi Iida
  • Publication number: 20140356783
    Abstract: There is provided a magnetic carrier having a resin coating layer formed on the surface of each of particles prepared by putting resin in the pores of porous magnetic particles, wherein (i) the surface roughness Ra of the porous magnetic particles ranges from 0.180 ?m to 0.250 ?m, (ii) the pore size ranges from 0.40 ?m to 1.00 ?m, (iii) the amount of the resin held in the pores ranges from 3.0 parts by mass to 5.5 parts by mass relative to 100 parts by mass of the porous magnetic particles, (iv) the amount of resin used for forming the coating resin layer ranges from 1.0 parts by mass to 3.0 parts by mass relative to 100 parts by mass of the porous magnetic particles, and (v) the surface roughness Ra of the magnetic carrier ranges from 0.160 ?m to 0.220 ?m.
    Type: Application
    Filed: May 29, 2014
    Publication date: December 4, 2014
    Inventors: Minoru Yoshifuku, Wakashi Iida, Hironori Minagawa, Nobuyoshi Sugahara, Yuto Onozaki
  • Publication number: 20140356781
    Abstract: A magnetic carrier includes resin-filled magnetic core particles including porous magnetic particles whose pores are filled with a resin, and resin coating layers on the surfaces of the resin-filled magnetic core particles. The porous magnetic particles have specific electrical properties.
    Type: Application
    Filed: May 29, 2014
    Publication date: December 4, 2014
    Inventors: Hironori Minagawa, Wakashi Iida, Nobuyoshi Sugahara, Minoru Yoshifuku, Yuto Onozaki