Patents by Inventor Harumi Ishiyama

Harumi Ishiyama 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: 7424232
    Abstract: A charging apparatus includes a charger for being supplied with an AC voltage and for electrically charging a member to be charged; a current measurer for measuring a current flowing between the charger and the member to be charged when the AC voltage is supplied to the charger; and a particular current extractor for extracting from the current a particular current having a particular frequency.
    Type: Grant
    Filed: June 28, 2006
    Date of Patent: September 9, 2008
    Assignee: Canon Kabushiki Kaisha
    Inventors: Norio Takahashi, Harumi Ishiyama, Jun Hirabayashi
  • Publication number: 20060245775
    Abstract: A charging apparatus includes charging means for being supplied with an AC voltage and for electrically charging a member to be charged; current measuring means for measuring a current flowing between the charging means and the member to be charged when the AC voltage is supplied the charging means; and particular current extraction means for extracting from the current a particular current having a particular frequency.
    Type: Application
    Filed: June 28, 2006
    Publication date: November 2, 2006
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Norio Takahashi, Harumi Ishiyama, Jun Hirabayashi
  • Patent number: 7116922
    Abstract: A charging apparatus includes a charging section supplied with an AC voltage and for electrically charging a member to be charged; a current measuring section for measuring a current flowing between the charging section and the member to be charged when the AC voltage is supplied to the charging section; and a particular current extraction section for extracting from the current a particular current having a particular frequency.
    Type: Grant
    Filed: May 3, 2004
    Date of Patent: October 3, 2006
    Assignee: Canon Kabushiki Kaisha
    Inventors: Norio Takahashi, Harumi Ishiyama, Jun Hirabayashi
  • Patent number: 6904253
    Abstract: A charging member for charging a member to be charged, includes an elastic foam member provided at a surface of the charging member. The elastic foam member includes a plurality of cell portions with wall portion defining the cell portions. The gaps connecting the cell portions have areas which are not less than 5% and not more than 50%, for respective cells.
    Type: Grant
    Filed: April 17, 2002
    Date of Patent: June 7, 2005
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takahiro Hosokawa, Harumi Ishiyama, Yasunori Chigono, Jun Hirabayashi
  • Publication number: 20050002681
    Abstract: A charging apparatus includes charging means for being supplied with an AC voltage and for electrically charging a member to be charged; current measuring means for measuring a current flowing between the charging means and the member to be charged when the AC voltage Is supplied the charging means; and particular current extraction means for extracting from the current a particular current in having a particular frequency.
    Type: Application
    Filed: May 3, 2004
    Publication date: January 6, 2005
    Applicant: Canon Kabushiki Kaisha
    Inventors: Norio Takahashi, Harumi Ishiyama, Jun Hirabayashi
  • Patent number: 6832062
    Abstract: A charging apparatus includes a charging member for charging a member to be charged while forming a nip with the member to be charged, and electroconductive particles disposed in the nip. The charging member is supplied with a voltage of a certain polarity, a surface of the member to be charged is triboelectrically charged by a surface of the charging member so as to have a polarity opposite from that of the voltage, and the electroconductive particles are triboelectrically charged in the nip so as to have a polarity opposite from that of the voltage.
    Type: Grant
    Filed: February 4, 2003
    Date of Patent: December 14, 2004
    Assignee: Canon Kabushiki Kaisha
    Inventors: Harumi Ishiyama, Yasunori Chigono, Jun Hirabayashi, Norio Takahashi
  • Patent number: 6788911
    Abstract: A charging device includes a charging member for electrically charging a member to be charged which is adapted to form a nip with a member to be charged which has a surface layer having a volume resistivity of 1×109-1×1014 &OHgr;cm, said charging member having an elastic member and movable with a peripheral speed difference relative to the member to be charged; and electroconductive particles carried on said charging member to the nip, wherein a peripheral speed Vd (mm/sec) of said member to be charged, a peripheral speed Vc (mm/sec) of said charging member, a width N (mm) of the nip measured in a moving direction of said charging member, and a coverage ratio Rc of said electroconductive particles on said charging member, satisfy: N·Rc·|Vc−Vd|/Vd≧1.
    Type: Grant
    Filed: May 9, 2002
    Date of Patent: September 7, 2004
    Assignee: Canon Kabushiki Kaisha
    Inventors: Harumi Ishiyama, Yasunori Chigono, Jun Hirabayashi
  • Publication number: 20030180073
    Abstract: A charging apparatus includes a charging member for charging a member to be charged while forming a nip with the member to be charged, and electroconductive particles disposed in the nip. The charging member is supplied with a voltage of a polarity, a surface of the member to be charged is triboelectrically charged by a surface of the charging member so as to have a polarity opposite from that of the voltage, and the electroconductive particles are triboelectrically charged in the nip so as to have a polarity opposite from that of the voltage.
    Type: Application
    Filed: February 4, 2003
    Publication date: September 25, 2003
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Harumi Ishiyama, Yasunori Chigono, Jun Hirabayashi, Norio Takahashi
  • Patent number: 6615010
    Abstract: An electrifier for electrifying a member to be charged includes a charge rotary member that forms a first nip with the member to be charged, to charge the member to be charged, and that holds and carries charge particles to the first nip, and a nip forming member that forms a second nip with the charge rotary member, the nip forming member having a bias charge having the same polarity as the developer.
    Type: Grant
    Filed: September 28, 2001
    Date of Patent: September 2, 2003
    Assignee: Canon Kabushiki Kaisha
    Inventors: Jun Hirabayashi, Harumi Ishiyama, Yasunori Chigono
  • Patent number: 6580889
    Abstract: A charging apparatus includes a charging member, to which a voltage is applicable, for charging a member to be charged; the charging member including: a flexible member for forming a nip with the member to be charged, wherein the flexible member is moved with a peripheral speed difference between surfaces of the flexible member and the member to be charged at the nip; and electroconductive particles in the nip.
    Type: Grant
    Filed: August 7, 2000
    Date of Patent: June 17, 2003
    Assignee: Canon Kabushiki Kaisha
    Inventors: Harumi Ishiyama, Yukio Nagase, Yasunori Chigono, Jun Hirabayashi
  • Patent number: 6553199
    Abstract: A charging device, suitable for use in an electrophotographic image forming apparatus, is formed of an object to be charged, and a roller-shaped charging member disposed in contact with the object via electroconductive particles and supplied with a voltage to charge the objects. The charging member has a surface layer including an elastic foam and is moved with a surface speed difference relative to the object. The charging member has surface cavities having an average diameter of 5 to 150 &mgr;m and occupying an area percentage of 50 to 90%. An image forming apparatus and a process cartridge therefor including the charging device are also provided.
    Type: Grant
    Filed: October 19, 2001
    Date of Patent: April 22, 2003
    Assignee: Canon Kabushiki Kaisha
    Inventors: Harumi Ishiyama, Yasunori Chigono, Jun Hirabayashi
  • Patent number: 6549742
    Abstract: A charging device for electrically charging a member to be charged includes charging particles including electroconductive particles having particles diameters in the range of 10 nm-10 &mgr;m; and a charging particles carrying member, which has a nip with the member to be charged forming a nip with said member to be charged, for carrying the charging particle to the nip; wherein said charging particles have resistances in the range of 10−1-1012 &OHgr;cm; wherein (an amount, per unit area, of said charging particles carried by said charging particles carrying member)/(an average roughness Ra of a surface of said charging particles carrying member) is in the range of 0.005-1 mg/cm2/&mgr;m.
    Type: Grant
    Filed: October 25, 2001
    Date of Patent: April 15, 2003
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yasunori Chigono, Harumi Ishiyama, Jun Hirabayashi, Norio Takahashi
  • Patent number: 6519433
    Abstract: An image forming apparatus includes an image bearing member; charging means for electrically charging the image bearing member, the charging means carrying electroconductive particles and having a charging member elastially press-contacted to the image bearing member; image forming means for forming an electrostatic image by selectively dissipating electric charge on the image bearing member charged by the charging means; developing means for developing the electrostatic image on the image bearing member with toner and for supplying the electroconductive particles to the image bearing member, wherein the electroconductive particles supplied by the developing means is carried to a press-contact portion of the charging member to contribution for electric charging of the image bearing member; and changing means for changing a relation between the charging member and a supply position of the electroconductive particles of the developing means.
    Type: Grant
    Filed: October 4, 2000
    Date of Patent: February 11, 2003
    Assignee: Canon Kabushiki Kaisha
    Inventors: Jun Hirabayashi, Harumi Ishiyama, Yasunori Chigono
  • Publication number: 20030002888
    Abstract: A charging device includes a charging member for electrically charging a member to be charged which is adapted to form a nip with a member to be charged which has a surface layer having a volume resistivity of 1×109-1×1014 &OHgr;cm, said charging member having an elastic member and movable with a peripheral speed difference relative to the member to be charged; and electroconductive particles carried on said charging member to the nip, wherein a peripheral speed Vd (mm/sec) of said member to be charged, a peripheral speed Vc (mm/sec) of said charging member, a width N (mm) of the nip measured in a moving direction of said charging member, and a coverage ratio Rc of said electroconductive particles on said charging member, satisfy: N·Rc·|Vc−Vd|/Vd≧1.
    Type: Application
    Filed: May 9, 2002
    Publication date: January 2, 2003
    Applicant: Canon Kabushiki Kaisha
    Inventors: Harumi Ishiyama, Yasunori Chigono, Jun Hirabayashi
  • Publication number: 20020197082
    Abstract: A charging member for charging a member to be charged, includes an elastic foam member provided at a surface of the charging member, the elastic with wall portion defining the cell portions, wherein gaps connecting said cell portions have areas which are not less than 5% and not more than 50%, for respective cells.
    Type: Application
    Filed: April 17, 2002
    Publication date: December 26, 2002
    Applicant: Canon Kabushiki Kaisha
    Inventors: Takahiro Hosokawa, Harumi Ishiyama, Yasunori Chigono, Jun Hirabayashi
  • Patent number: 6473582
    Abstract: A charging apparatus includes a charging member for being supplied with a voltage to charge a member to be charged, the charging member including an elastic member for forming a nip with the member to be charged, and said elastic member having a surface provided with a plurality of projections; wherein a speed A of a surface of said charging member (mm/sec) and a speed B of a surface of the member to be charged (mm/sec) satisfy: when B−A>0, said projections are inclined toward upstream with respect to a movement direction of the surface of the member to be charged in said nip, and when B−A<0, the projections are inclined toward downstream with respect to a movement direction of the surface of the member to be charged in said nip.
    Type: Grant
    Filed: September 14, 1998
    Date of Patent: October 29, 2002
    Assignee: Canon Kabushiki Kaisha
    Inventors: Harumi Ishiyama, Yasunori Chigono, Jun Hirabayashi
  • Patent number: 6466758
    Abstract: A developing apparatus prevents a reduction in image density due to paper powder by providing a developing apparatus that has a developing container, a toner carrying member, and a toner container, wherein the toner container has a space portion, which is disposed below the toner carrying member and which is not substantially replenished with the toner.
    Type: Grant
    Filed: February 27, 2001
    Date of Patent: October 15, 2002
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yasunori Chigono, Harumi Ishiyama, Jun Hirabayashi
  • Publication number: 20020141783
    Abstract: An image-forming apparatus and an image-forming method using a cleanerless system are disclosed in which a non-contact developing assembly develops an electrostatic latent image with a magnetic one-component developer to form a magnetic-toner image and collects a magnetic toner having remained on the charging object member, a member to be charged is charged by means of a charging assembly having a charging member the surface of which is movable with a velocity differential in the opposite direction with respect to the surface of the charging object member, and conductive particles are present at least at the contact surfaces between the charging member and the charging object member.
    Type: Application
    Filed: January 18, 2002
    Publication date: October 3, 2002
    Applicant: Canon Kabushiki Kaishi
    Inventors: Harumi Ishiyama, Yasunori Chigono, Jun Hirabayashi, Norio Takahashi
  • Patent number: 6442362
    Abstract: An image forming apparatus includes an image bearing member for bearing an electrostatic image. A developing device develops the electrostatic image on the image bearing member by toners charged with a predetermined polarity. A transfer device transfers a toner image on the image bearing member to a transferring material. An electrifying device inject-charges the image bearing member having transfer residual toners. An electrical conductive member provided and spaced apart from the image bearing member in a moving direction of the image bearing member downstream farther than the transfer means and upstream farther than the electrifying device. An electrical field forming device for forming an alternative electrical field between the electrical conductive member and the image bearing member.
    Type: Grant
    Filed: December 29, 2000
    Date of Patent: August 27, 2002
    Assignee: Canon Kabushiki Kaisha
    Inventors: Jun Hirabayashi, Harumi Ishiyama, Yasunori Chigono
  • Publication number: 20020106216
    Abstract: A charging device, suitable for use in an electrophotographic image forming apparatus, is formed of an object to be charged, and a roller-shaped charging member disposed in contact with the object via electroconductive particles and supplied with a voltage to charge the objects. The charging member has a surface layer comprising an elastic foam and moved with a surface speed difference relative to the object. The charging member has surface cavities having an average diameter of 5 to 150 &mgr;m and occupying an areal percentage of 50 to 90%. An image forming apparatus and a process-cartridge therefor including the charging device are also provided.
    Type: Application
    Filed: October 19, 2001
    Publication date: August 8, 2002
    Inventors: Harumi Ishiyama, Yasunori Chigono, Jun Hirabayashi