Patents by Inventor Yuta Kawashima

Yuta Kawashima 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).

  • Publication number: 20160195830
    Abstract: In an image forming apparatus, an electric charging member, spaced apart from an image bearer across an electric charge gap, electrically charges the image bearer uniformly across the electric charge gap. A voltage applying device applies a voltage to the electric charging member. A cleaner collects residual toner remaining on the image bearer therefrom after a transfer device transfers a toner image onto a recording medium. An electric charge gap maintaining device forms and keeps constant the electric charge gap between the electric charging member and the image bearer. A calculating device calculates a value of discharge current to be generated by the electric charging member. A processor controls the voltage applying device to vary a voltage applied to the electric charging device to render the value of discharge current calculated by the calculating device substantially constant.
    Type: Application
    Filed: January 4, 2016
    Publication date: July 7, 2016
    Applicant: Ricoh Company, Ltd.
    Inventors: Hideyasu Seki, Satoshi Hatori, Takeshi Fukao, Yuta Kawashima
  • Publication number: 20160179027
    Abstract: An electric charging-diselectrifying device includes an electric charging member that contacts an image bearer to form an electric charging nip between the electric charging member and the image bear. The electric charging member electrically charges multiple electric charge regions in the image bearer located both upstream and downstream of the electric charging nip in a direction of rotation of the image bearer. An electric charge removing device is provided to remove electric charge borne on the image bearer by irradiating the multiple electric charging regions of the image bearer with light. The electric charging member is made of a material that allows the light emitted from the electric charge removing device to penetrate the electric charging member.
    Type: Application
    Filed: December 22, 2015
    Publication date: June 23, 2016
    Applicant: Ricoh Company, Ltd.
    Inventors: Hideyasu Seki, Satoshi Hatori, Takeshi Fukao, Yuta Kawashima
  • Patent number: 9367022
    Abstract: A toner conveyance device includes a conveyance channel through which toner is transported, communicating with a conveyance origin and a destination container disposed inside an image forming apparatus, a conveyor disposed in the conveyance channel to rotate in the conveyance channel, a driving source to drive the conveyor; and a slide-assist sheet attached to an inner face of the conveyance channel positioned facing the conveyor.
    Type: Grant
    Filed: April 7, 2015
    Date of Patent: June 14, 2016
    Assignee: RICOH COMPANY, LTD.
    Inventors: Yuta Kawashima, Satoshi Hatori, Takeshi Fukao, Hideyasu Seki
  • Patent number: 9366985
    Abstract: An electric charging-diselectrifying device includes an electric charging member that contacts an image bearer to form an electric charging nip between the electric charging member and the image bear. The electric charging member electrically charges multiple electric charge regions in the image bearer located both upstream and downstream of the electric charging nip in a direction of rotation of the image bearer. An electric charge removing device is provided to remove electric charge borne on the image bearer by irradiating the multiple electric charging regions of the image bearer with light. The electric charging member is made of a material that allows the light emitted from the electric charge removing device to penetrate the electric charging member.
    Type: Grant
    Filed: December 22, 2015
    Date of Patent: June 14, 2016
    Assignee: Ricoh Company, Ltd.
    Inventors: Hideyasu Seki, Satoshi Hatori, Takeshi Fukao, Yuta Kawashima
  • Patent number: 9354538
    Abstract: A charging device includes a charger and a power supply circuit. The charger is disposed opposing a latent image bearer. The power supply circuit applies to the charger an alternating voltage obtained by superimposing a pulsating voltage on a direct-current voltage. The alternating voltage generates normal discharge from the charger to a surface of the latent image bearer and reverse discharge from the surface of the latent image bearer to the charger. A pulse ON time of a voltage component toward a reverse discharge side relative to a desired surface potential Vde of the latent image bearer is shorter than a pulse ON time of a voltage component toward a normal discharge side relative to the desired surface potential Vde of the latent image bearer.
    Type: Grant
    Filed: February 19, 2015
    Date of Patent: May 31, 2016
    Assignee: Ricoh Company, Ltd.
    Inventors: Hideyasu Seki, Satoshi Hatori, Takeshi Fukao, Yuta Kawashima
  • Patent number: 9310707
    Abstract: An image forming apparatus includes a latent image bearer, an electric charging member to electrically charge the latent image bearer uniformly while forming an electric charging nip therebetween by contacting the latent image bearer. A value obtained by dividing a moment of inertia of area of the latent image bearer by the cube of length thereof ranges from about 0.000058 [mm] or more to about 0.000145 [mm] or less. A width of the electric charging nip in a direction of rotation at longitudinal ends of the latent image bearer is larger than that at a longitudinal center thereof. A difference between the width of the electric charging nip in the direction of rotation at the longitudinal ends of the latent image bearer and that at the longitudinal center thereof is larger than an amount of deformation of the latent image bearer generated during rotation at the longitudinal center thereof.
    Type: Grant
    Filed: December 4, 2014
    Date of Patent: April 12, 2016
    Assignee: Ricoh Company, Ltd.
    Inventors: Hideyasu Seki, Satoshi Hatori, Takeshi Fukao, Yuta Kawashima
  • Publication number: 20150301496
    Abstract: A toner conveyance device includes a conveyance channel through which toner is transported, communicating with a conveyance origin and a destination container disposed inside an image forming apparatus, a conveyor disposed in the conveyance channel to rotate in the conveyance channel, a driving source to drive the conveyor; and a slide-assist sheet attached to an inner face of the conveyance channel positioned facing the conveyor.
    Type: Application
    Filed: April 7, 2015
    Publication date: October 22, 2015
    Applicant: RICOH COMPANY, LTD.
    Inventors: Yuta KAWASHIMA, Satoshi HATORI, Takeshi FUKAO, Hideyasu SEKI
  • Publication number: 20150248075
    Abstract: A charging device includes a charger and a power supply circuit. The charger is disposed opposing a latent image bearer. The power supply circuit applies to the charger an alternating voltage obtained by superimposing a pulsating voltage on a direct-current voltage. The alternating voltage generates normal discharge from the charger to a surface of the latent image bearer and reverse discharge from the surface of the latent image bearer to the charger. A pulse ON time of a voltage component toward a reverse discharge side relative to a desired surface potential Vde of the latent image bearer is shorter than a pulse ON time of a voltage component toward a normal discharge side relative to the desired surface potential Vde of the latent image bearer.
    Type: Application
    Filed: February 19, 2015
    Publication date: September 3, 2015
    Applicant: RICOH COMPANY, LTD.
    Inventors: Hideyasu SEKI, Satoshi HATORI, Takeshi FUKAO, Yuta KAWASHIMA
  • Publication number: 20150160587
    Abstract: An image forming apparatus includes a latent image bearer, an electric charging member to electrically charge the latent image bearer uniformly while forming an electric charging nip therebetween by contacting the latent image bearer. A value obtained by dividing a moment of inertia of area of the latent image bearer by the cube of length thereof ranges from about 0.000058 [mm] or more to about 0.000145 [mm] or less. A width of the electric charging nip in a direction of rotation at longitudinal ends of the latent image bearer is larger than that at a longitudinal center thereof. A difference between the width of the electric charging nip in the direction of rotation at the longitudinal ends of the latent image bearer and that at the longitudinal center thereof is larger than an amount of deformation of the latent image bearer generated during rotation at the longitudinal center thereof.
    Type: Application
    Filed: December 4, 2014
    Publication date: June 11, 2015
    Applicant: RICOH COMPANY, LTD.
    Inventors: Hideyasu Seki, Satoshi Hatori, Takeshi Fukao, Yuta Kawashima