Patents by Inventor Kengo Hayase

Kengo Hayase 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: 6002903
    Abstract: An apparatus unit includes a detachably mounted unit having a developing sleeve, a toner and a toner applicator, all of which are enclosed by an outer casing. The toner has a shape factor SF-1 of 100-150 and is formed of 100 parts binder, 1-20 parts of a non-magnetic color and 5-40 parts wax and has a specific storage modulus ratio (a) at 60.degree. C. and 80.degree. C. and (b) at 155.degree. C. and 190.degree. C., of at least 80 for (a) and of 0.95-5 for (b). Toner images are visualized by forming an electrostatic image, developing the electrostatic image with the toner, transferring the toner image to a transfer material and fixing the toner image by heat and pressure.
    Type: Grant
    Filed: January 14, 1998
    Date of Patent: December 14, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kengo Hayase, Tatsuya Nakamura, Tatsuhiko Chiba
  • Patent number: 5753396
    Abstract: An image forming method comprising;a charging step of electrostatically charging a photosensitive member;an exposure step of exposing the charged photosensitive member to form an electrostatic latent image;a developing step of bringing a toner carried on a developer carrying member, into contact with the surface of the photosensitive member to develop the electrostatic latent image to form a toner image on the photosensitive member;a transfer step of transferring the toner image formed on the photosensitive member, to a transfer medium; anda cleaning-at-development step of collecting the toner remaining on the photosensitive member after the transfer step, onto the developer carrying member;a wherein;the surface of said photosensitive member has a contact angle with water of 85.degree. or greater;said toner contains residual monomers in an amount not more than 1,000 ppm; andsaid toner has a shape factor SF-1 of from 100 to 180 and a shape factor SF-2 of from 100 to 140.
    Type: Grant
    Filed: November 28, 1995
    Date of Patent: May 19, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tatsuya Nakamura, Masayoshi Kato, Shuichi Aita, Koji Inaba, Kengo Hayase, Yuki Nishio
  • Patent number: 5753399
    Abstract: A toner for developing an electrostatic image includes: 100 wt. parts of a binder resin, 1-150 wt. parts of a colorant and a relatively large amount of 5-40 wt. parts of a low-softening point substance. The toner is further characterized by viscoelastic properties including: a storage modulus at 60.degree. C. (G'.sub.60) and a storage modulus at 80.degree. C. (G'.sub.80) providing a ratio (G'.sub.60 /G'.sub.80) of at least 80, and a storage modulus at 155.degree. C. (G'.sub.155) and a storage modulus at 190.degree. C. (G'.sub.190) providing a ratio (G'.sub.155 /G'.sub.190) of 0.95-5. As a result, the toner shows good low-temperature fixability and anti-offset characteristic, and also little temperature-dependence of gloss.
    Type: Grant
    Filed: May 15, 1996
    Date of Patent: May 19, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kengo Hayase, Tatsuya Nakamura, Tatsuhiko Chiba
  • Patent number: 5750303
    Abstract: A toner for developing an electrostatic image includes toner particles constituted by at least a binder resin, a colorant, a polar resin and a release agent. The polar resin has at least one terminal group which has been modified by a polycarbonate acid having at least three carboxyl groups. The polar resin has an acid value of 3-35 mgKOH/g. The polar resin may preferably be a polyester resin having an acid value of 4-35 mgKOH/g and having a number-average molecular weight (Mn) of 3,000-15,000, a weight-average molecular weight (Mw) of 6,000-50,000, and an Mw/Mn of 1.2-3.0 based on GPC. The polar resin (preferably polyester resin) having modified by a polycarboxylic acid having at least three carboxylic groups to provide a specific acid value is effective in improving resultant toner performances, such as low-temperature fixability, anti-offset characteristic at high temperatures, triboelectric chargeability, and flowability.
    Type: Grant
    Filed: April 30, 1997
    Date of Patent: May 12, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kohji Inaba, Kazunori Kato, Kengo Hayase
  • Patent number: 5712072
    Abstract: The present invention relates to a toner for developing an electrostatic image, comprising toner particles containing a binding resin composed of a styrene homopolymer or copolymer, a coloring agent, a polar resin, and a specified solid ester wax.
    Type: Grant
    Filed: February 22, 1996
    Date of Patent: January 27, 1998
    Assignee: Canon Kabusbiki Kaisha
    Inventors: Kohji Inaba, Tatsuya Nakamura, Tatsuhiko Chiba, Kengo Hayase
  • Patent number: 5635325
    Abstract: A toner for developing electrostatic images includes: at least a binder resin, a colorant and an ester wax. The ester wax is contained in 3-40 wt. parts per 100 wt. parts of the binder resin. The ester wax includes ester compounds represented by a formula ofR.sub.1 --COO--R.sub.2,wherein R.sub.1 an R.sub.2 independently denote a hydrocarbon group of 15-45 carbon atoms. The ester wax contains 50-95 wt. % thereof of ester compounds having an identical number of total carbon atoms. The toner is especially characterized by low-temperature fixability, wide non-offset temperature range, good color mixing characteristic and transparency.
    Type: Grant
    Filed: May 26, 1995
    Date of Patent: June 3, 1997
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kohji Inaba, Tatsuya Nakamura, Tatsuhiko Chiba, Takao Ishiyama, Kengo Hayase