Patents by Inventor Hiroshi Fukao

Hiroshi Fukao 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: 6051356
    Abstract: A toner is provided for electrostatic latent image developing which exhibits desirable smearing, offset and filming characteristics during copying, and which has excellent toner flow characteristics and chargeability properties. The toner of the present invention contains at least a binder resin containing polyethylene wax, and at least polypropylene wax, and colorant. The toner of the present invention is made by a process whereby polyethylene wax is added to a binder resin to form a mixture. The mixture is then added or mixed with a colorant and polypropylene wax.
    Type: Grant
    Filed: March 12, 1998
    Date of Patent: April 18, 2000
    Assignee: Minolta Co., Ltd.
    Inventors: Yoshikazu Nishihara, Ichiro Demizu, Yoshihiro Mikuriya, Hiroshi Fukao, Fumiko Hirano, Hiroyuki Fukuda
  • Patent number: 6029025
    Abstract: An image forming apparatus, such as a printer or photocopier, has a cleaning device for cleaning an image carrier. The efficiency with which the cleaning device cleans the image carrier is varied in dependence upon the image forming conditions, to thereby reduce wear on both the cleaning device and the image carrier. In one embodiment, cleaning efficiency is varied by changing the contact pressure between a cleaning blade and the image carrier. In a color apparatus with multiple image-forming units, the image forming conditions relate to whether the image to be formed is monochrome, composite color or simul-color.
    Type: Grant
    Filed: March 9, 1998
    Date of Patent: February 22, 2000
    Assignee: Minolta Co., Ltd.
    Inventors: Hiroshi Sakakibara, Hiroshi Fukao, Mineyuki Sako, Kuniya Matsuura, Shingo Hirota
  • Patent number: 6014540
    Abstract: An image forming apparatus includes a movable recording medium bearing member, an image forming device for forming an image on the image bearing member with a developer having an additive and a cleaning device having a cleaning member which makes a contact with the image bearing member for cleaning thereof at a cleaning station. The apparatus further includes a transferring device for transferring the image from the image bearing member to a recording medium. A processing device is mounted between the transfer station and the cleaning station for processing the additive that has not been transferred but still remains on the image bearing member such that one component of the additive remains on the image bearing member and another component of the additive is removed.
    Type: Grant
    Filed: July 8, 1998
    Date of Patent: January 11, 2000
    Assignee: Minolta Co., Ltd.
    Inventors: Mineyuki Sako, Kenzo Toya, Kazuhiro Sakamoto, Hiroshi Fukao
  • Patent number: 5824446
    Abstract: The present invention relates to toners for developing electrostatically charged images which contains polyethylene fine particles and polypropylene fine particles as wax, which have a specific particle size. By incorporating such polyethylene and polypropylene fine particles into toners the prevention of smear, offset, filming, and improvement of fluidity and chargeability of the toners can be achieved.
    Type: Grant
    Filed: April 22, 1997
    Date of Patent: October 20, 1998
    Assignee: Minolta Co., Ltd.
    Inventors: Yoshikazu Nishihara, Ichiro Demizu, Yoshihiro Mikuriya, Fumiko Nakazawa, Hiroshi Fukao
  • Patent number: 5807653
    Abstract: A toner for two-component developing agent is provided which can prevent smearing and offsetting during copying operation, and which is not liable to fluidity decrease and chargeability deterioration. The toner contains polyethylene and polypropylene as toner waxes and incorporates a magnetic powder having a certain BET specific surface area.
    Type: Grant
    Filed: April 22, 1997
    Date of Patent: September 15, 1998
    Assignee: Minolta Co., Ltd.
    Inventors: Yoshikazu Nishihara, Ichiro Demizu, Yoshihiro Mikuriya, Fumiko Nakazawa, Hiroshi Fukao
  • Patent number: 5272040
    Abstract: The present invention relates to a toner for developing electrostatic latent images which has silica and titania or alumina on the toner surface at specified ratio or in specified states, so that environmental stability in chargeability and stable copy images with fine texture can be obtained.
    Type: Grant
    Filed: March 27, 1992
    Date of Patent: December 21, 1993
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Shinobu Nakasawa, Hiroshi Fukao, Keiji Asakawa, Toshikazu Muramatsu, Ichiro Demizu
  • Patent number: 5219696
    Abstract: The present invention relates to a toner for developing electrostatic latent images, comprising titanium oxide or aluminum oxide having two peak values within the range between 10 and 20 m.mu.m and between 30 and 60 m.mu.m in primary particle size.
    Type: Grant
    Filed: November 26, 1991
    Date of Patent: June 15, 1993
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Ichiro Demizu, Mitsutoshi Nakamura, Hiroshi Fukao
  • Patent number: 5212039
    Abstract: This invention relates to a developing method for electrostatic latent images for developing the electrostatic latent images retained on an electrostatic latent image retaining member, comprisinga step of supplying a specified developer;a step of transferring the developer to a developing area; anda step of developing the electrostatic latent images formed on the electrostatic latent image retaining member in the development area under a specified development bias voltage.
    Type: Grant
    Filed: November 27, 1991
    Date of Patent: May 18, 1993
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Ichiro Demizu, Mitsutoshi Nakamura, Hiroshi Fukao, Yuji Shintani, Shinobu Nakasawa
  • Patent number: 4926218
    Abstract: An image forming apparatus provided with a transport device for discharging waste toner remained on a holding member of electrostatic latent image in an image forming section after transporting the toner onto a cleaning web arranged for cleaning fixing rollers of a fixing device. The waste toner transported and discharged by the transport device is absorbed into a wide area of the cleaning web and rolled therein since used portion of the cleaning web is rolled up. The transport device includes a mechanism for dispersing the discharged waste toner onto the cleaning web thereby collecting the waste toner in a wide area of the cleaning web.
    Type: Grant
    Filed: September 11, 1989
    Date of Patent: May 15, 1990
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventor: Hiroshi Fukao
  • Patent number: 4812873
    Abstract: A heat fixing unit in an electrophotographic copying apparatus is disclosed. The heat fixing unit comprises a heat fixing roller with a heater, a pressure roller with a plurality of fibers, and driven ring components disposed on the ends of the pressure roller for adjusting the contact amount between the heat fixing roller and the pressure roller. The heat fixing unit offers a less warming up time and a better paper delivery performance, and requires less material cost.The heat fixing unit in an electrophotographic copying apparatus may employ a fixed type or a rotary type curing unit for raising the plurality of fibers.
    Type: Grant
    Filed: September 4, 1987
    Date of Patent: March 14, 1989
    Assignee: Minolta Camera Kabushiki Kaisha
    Inventors: Sanji Inagaki, Hiroshi Fukao, Tetsuya Yamada, Etsuaki Urano, Yoshihiro Hattori