Patents by Inventor Masanori Fujii

Masanori Fujii 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: 4416964
    Abstract: Disclosed is a dry magnetic developer consisting essentially of a particulate shaped article of a composition comprising a binder resin medium and a powdery magnetic material dispersed in the binder resin medium, wherein said composition is composed of a non-pulverizing agglomerate of cubic particles, and particles having a number average particle size of 1 to 10 microns, as measured by an electron microscope, are incorporated as the powdery magnetic material.This magnetic developer is excellent in the image sharpness, the resolving power and the half tone-reproducing property, and is especially effective for developing a positively charged latent image which is formed on a p-type photosensitive plate such as a selenium photosensitive plate or a photosensitive plate comprising an organic photoconductor layer.
    Type: Grant
    Filed: August 26, 1981
    Date of Patent: November 22, 1983
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Nobuhiro Miyakawa, Takashi Teshima, Haruo Koyama, Kouji Maekawa, Masanori Fujii
  • Patent number: 4414321
    Abstract: Disclosed is a dry composite magnetic developer consisting essentially of a particulate shaped article of a composition comprising a binder resin medium and a powdery magnetic material dispersed in the binder resin medium, wherein said developer is formed by dry blending (A) a first particulate shaped article comprising a non-pulverizing agglomerate of cubic particles of magnetite having a number average particle size of 1 to 10 .mu.m as measured by an electron microscope with (B) a second particulate shaped article comprising magnetite particles having a particle size of 0.2 to 1 .mu.m at an (A)/(B) weight ratio of from 95/5 to 10/90, especially from 95/5 to 30/70.
    Type: Grant
    Filed: November 24, 1981
    Date of Patent: November 8, 1983
    Assignee: Mita Industrial Co. Ltd.
    Inventors: Nobuhiro Miyakawa, Masanori Fujii, Kouzi Maekawa
  • Patent number: 4414322
    Abstract: Disclosed is a two-component type magnetic developer comprising a magnetic carrier consisting of a non-pulverizing agglomerate of cubic particles of magnetite having a particle size of 1 to 14 microns as measured by an electron microscope and a magnetic toner having a high electric resistance and consisting of particles having a particle size of 3 to 30 microns and comprising a binder resin medium and magnetite having a particle size smaller than 1 micron, which is dispersed in the binder resin medium, the magnetic carrier/magnetic toner mixing weight ratio being in the range of from 5/100 to 40/100.
    Type: Grant
    Filed: January 22, 1982
    Date of Patent: November 8, 1983
    Assignee: Mita Industrial Co. Ltd.
    Inventors: Nobuhiro Miyakawa, Masanori Fujii, Kouzi Maekawa
  • Patent number: 4407923
    Abstract: Disclosed is a dry magnetic developer consisting essentially of a particulate shaped article of a composition comprising a binder resin medium and a powdery magnetic material dispersed in the binder resin medium, wherein said composition comprises as the powdery magnetic material a non-pulverizing agglomerate having a secondary particle size of 1 to 10 microns, which is formed by granulating and sintering fine cubic particles of magnetite or other ferrite having a primary particle size of 0.1 to 1 micron.
    Type: Grant
    Filed: June 24, 1982
    Date of Patent: October 4, 1983
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Nobuhiro Miyakawa, Masanori Fujii, Kouzi Maekawa, Haruo Koyama, Takashi Teshima
  • Patent number: 4404269
    Abstract: A two-component dry-type composite developer which is a mixture of 100 parts of (A) magnetic toner particles of a binder resin and 40 to 70% by weight of magnetite having a bulk density of at least 0.45 g/ml, a number average maximum size of at least 0.5 .mu.m and a maximum size/minimum size ratio of from 1.0 to 5.5 and 1 to 30 parts of (B) non-magnetic toner particles of binder resin, pigment and negative charge controlling agent. The magnetic toner particles have an electrostatic capacitance of 7 to 8.5 picofarad, a dielectric constant of 3.59 to 4.36, and a volume resistivity of 1.2 to 8.6.times.10.sup.14 .OMEGA.-cm, and the nonmagnetic toner particles have an electrostatic capacitance of 6.0 to 8.0 picofarad and a dielectric constant of 3.08 to 4.10. The toner particles (A) and (B) have friction chargeability characteristics of the same polarity and are consumed at the same rate during development such that the mixing ratio remains constant and the development characteristics are not changed during use.
    Type: Grant
    Filed: November 13, 1981
    Date of Patent: September 13, 1983
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Nobuhiro Miyakawa, Kouzi Maekawa, Masanori Fujii