Patents by Inventor Hideo Maehata

Hideo Maehata 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: 6416918
    Abstract: A toner for developing an electrostatic image, a developer for developing an electrostatic image, a process for producing them, and a process for forming an image that provide excellent developing and transferring performance and also provide excellent performance stability, as well as high image quality and reliability are provided. The problem can be solved by a toner for developing an electrostatic image having a particle size distribution index on a small particle side GSDpS in number distribution of a particle diameter of about 1.27 or less, GSDpS is D50p/D16p, D50p represents a particle diameter providing, a particle diameter accumulation in number distribution of 50%, and D16p represents a particle diameter providing a particle diameter accumulation in number distribution of 16% from a small diameter side.
    Type: Grant
    Filed: March 6, 2001
    Date of Patent: July 9, 2002
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Yasuo Matsumura, Hisae Yoshizawa, Hideo Maehata, Masaaki Suwabe, Yasuo Kadokura
  • Patent number: 6391510
    Abstract: The invention relates to a toner for developing an electrostatic latent image, a process for producing the same, a developer for an electrostatic latent image, and a process for forming an image, and the toner contains a binder resin and a coloring agent and has a molecular weight between crosslinking points Mc obtained by a measurement of temperature dispersion on dynamic viscoelasticity of from 3.6×106 to 7.5×108, and the molecular weight between crosslinking points Mc and a crosslinking density Me satisfying the relationship 14.0≦Log10(Mc/Me)≦16.5.
    Type: Grant
    Filed: August 18, 2000
    Date of Patent: May 21, 2002
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Takao Ishiyama, Manabu Serizawa, Takeshi Shoji, Yasuo Matsumura, Hideo Maehata
  • Publication number: 20020058190
    Abstract: Provided are a toner and its production, a developer, an image forming method and an image forming apparatus. The toner has excellent fixation characteristics of good releasability, hot offset resistance, folding resistance, surface glossiness, and OHP transparency. The toner contains a binder resin, a colorant, a release agent and an inorganic particles. The inorganic particles therein contain inorganic particles (A) having the mean primary particle size not less than approximately 5 nm and less than approximately 30 nm and inorganic particles (B) having the mean primary particle size not less than approximately 30 nm and less than approximately 200 nm.
    Type: Application
    Filed: September 6, 2001
    Publication date: May 16, 2002
    Applicant: FUJI XEROX CO., LTD
    Inventors: Takao Ishiyama, Hiroshi Takano, Yasuo Kadokura, Yasuo Matsumura, Hideo Maehata, Masaaki Suwabe, Shuji Sato
  • Patent number: 6340549
    Abstract: The foregoing problem is solved with a toner for the development of an electrostatic image obtained by externally adding agglomerated particles to toner particles containing a binder resin and a colorant, characterized in that the agglomerated particles are made of (i) a particulate resin alone, (ii) a particulate lubricant alone or (iii) at least two particulate materials selected from the group consisting of particulate resin, particulate lubricant and inorganic particulate material and have a shape factor of 130 or more and a volume-average particle diameter of from 0.5 &mgr;m to 10 &mgr;m.
    Type: Grant
    Filed: September 15, 2000
    Date of Patent: January 22, 2002
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Hideo Maehata, Yasuo Matsumura, Hisae Yoshizawa, Masaaki Suwabe
  • Publication number: 20010053492
    Abstract: A toner for developing a static image having excellent charging characteristics and transferring characteristics, a process for producing the toner, a developer for a static image using the toner, and a process for producing an image are provided. A toner for developing a static image including at least a binder resin and a coloring agent, having an external additive adhered on a surface thereof, the toner having an average volume particle diameter D50 of about from 3.0 to 8.0 &mgr;m, an average volume particle diameter distribution index GSDv of about 1.26 or less, and a surface property index expressed by the following equations of about 6.
    Type: Application
    Filed: February 29, 2000
    Publication date: December 20, 2001
    Inventors: MASAAKI SUWABE, SHUJI SATO, YASUO KADOKURA, HISAE YOSHIZAWA, HIDEO MAEHATA
  • Publication number: 20010033984
    Abstract: A toner for developing an electrostatic image, a developer for developing an electrostatic image, a process for producing them, and a process for forming an image that provide excellent developing and transferring performance and also provide excellent performance stability, as well as high image quality and reliability are provided. The problem can be solved by a toner for developing an electrostatic image having a particle size distribution index on a small particle side GSDpS in number distribution of a particle diameter of about 1.27 or less, GSDpS is D50p/D16p, D50p represents a particle diameter providing, a particle diameter accumulation in number distribution of 50%, and D16p represents a particle diameter providing a particle diameter accumulation in number distribution of 16% from a small diameter side.
    Type: Application
    Filed: March 6, 2001
    Publication date: October 25, 2001
    Inventors: Yasuo Matsumura, Hisae Yoshizawa, Hideo Maehata, Masaaki Suwabe, Yasuo Kadokura
  • Patent number: 6294302
    Abstract: It is to easily form a fixed image, especially a full color image, that exhibits a small difference in gloss depending on the fixing conditions of the toner, is excellent in smoothness, exhibits small unevenness of gloss, and has high image quality and high reliability. A toner for developing a static image to be fixed by heat on a fixing substrate, wherein a fixed image has a gloss Gm of about 20% or more, and a maximum value of a degree of change Gs of the gloss per 1° C. of a difference of a surface temperature within a range of about from 140 to 170° C. of a fixing member as a heating and fixing unit is 1.8% or less per 1° C.; and a developer for a static image and a process for producing an image using the toner are provided.
    Type: Grant
    Filed: February 29, 2000
    Date of Patent: September 25, 2001
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Manabu Serizawa, Takao Ishiyama, Takeshi Shoji, Yukiko Watanabe, Hideo Maehata
  • Patent number: 6153346
    Abstract: Disclosed is an electrostatic image developing toner comprising a binder resin and a coloring agent, which exhibits a volume-average particle distribution GSDv of not more than 1.26 and an acid value of from 1.0 to 20 mgKOH/g and contains a surface active agent in an amount of not more than 3% by weight in the particulate toner and an inorganic metal salt having an electric charge having a valence of two or more in an amount of from not less than 10 ppm to not more than 1% by weight.
    Type: Grant
    Filed: February 24, 1999
    Date of Patent: November 28, 2000
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Hideo Maehata, Shuji Sato, Yasuo Kadokura, Masaaki Suwabe, Hisae Yoshizawa, Yasuo Matsumura, Takao Ishiyama