Patents by Inventor Tomohiro Aruga

Tomohiro Aruga 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: 8126355
    Abstract: A developing device, includes: a housing that stores toner inside; a toner carrier roller that is shaped approximately like a cylinder, is mounted to the housing rotatably about a rotational axis, rotates while carrying the toner on a surface thereof to convey the toner to outside of the housing, and is provided, on the surface thereof, with a plurality of convex sections which are regularly arranged and a concave section which surrounds the convex sections, the convex sections including top surfaces that coincide with a part of a curved surface of single cylinder and have electrical conductivity; and a seal member that is arranged in abutting contact with the surface of the toner carrier roller moving from the outside the housing toward the inside the housing at a position downstream of the opposed position in a rotation direction of the toner carrier roller to prevent toner leakage from the housing, a contact surface of the seal member being made of a material located at a position to charge the toner with
    Type: Grant
    Filed: January 13, 2009
    Date of Patent: February 28, 2012
    Assignee: Seiko Epson Corporation
    Inventors: Tomohiro Aruga, Masahiro Maeda
  • Patent number: 8087170
    Abstract: A method for manufacturing a developing agent carrier of a hollow or solid cylindrical shape having an outer peripheral surface and an irregularity section formed on the outer peripheral surface to carry a developing agent is provided. The method comprises a step of preparing a base material of a hollow or solid cylindrical shape which is to become the developing agent carrier, the base material having an outer peripheral surface; and a step of forming the irregularity section by pressing dice for formation of the irregularity section against the outer peripheral surface of the base material.
    Type: Grant
    Filed: November 17, 2006
    Date of Patent: January 3, 2012
    Assignee: Seiko Epson Corporation
    Inventors: Noboru Sakurai, Yoichi Yamada, Junichi Nakahara, Masanao Kunugi, Tomohiro Aruga, Katsumi Okamoto
  • Patent number: 8086150
    Abstract: A developing device includes a toner particle-bearing roller that bears toner particles on its surface and develops a latent image borne by an image-bearing member with those toner particles, the toner particle-bearing roller has a projection portion disposed on its surface, the projection portion having a top surface having a flat portion, and a width of the top surface being equal to or more than a volume average particle diameter of the toner particles.
    Type: Grant
    Filed: November 2, 2006
    Date of Patent: December 27, 2011
    Assignee: Seiko Epson Corporation
    Inventors: Yoichi Yamada, Tomohiro Aruga, Noboru Sakurai
  • Publication number: 20110193920
    Abstract: A liquid ejecting apparatus includes a recording head that ejects an ink from a plurality of nozzles, a liquid supply passage and a reservoir that supply the ink from an upstream side toward a downstream side, a maintenance pump that is able to suck and discharge the ink from and to the liquid supply passage, a filter that clarify the ink in the reservoir, and a control unit that performs a recovery process of the nozzles by controlling an operation of the pump, wherein the control unit causes the maintenance pump to perform a sucking operation to suck the ink, and then causes the pump to perform a discharging operation to discharge the ink, thereby supplying the ink clarified by the filter to the nozzle side.
    Type: Application
    Filed: February 7, 2011
    Publication date: August 11, 2011
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Tomohiro Aruga, Masaru Kobashi
  • Publication number: 20110193918
    Abstract: A printer includes: a fluid ejecting head provided with multiple nozzles that eject ink; an ink supply tube that supplies the ink to the fluid ejecting head; and a pressure application mechanism that pressurizes the ink to swell from the nozzles by pressurizing the ink within the ink supply tube and then depressurizes the interior of the ink supply tube while the ink is swelling from the nozzles.
    Type: Application
    Filed: February 3, 2011
    Publication date: August 11, 2011
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Masaru Kobashi, Yoichi Yamada, Daisuke Matsumoto, Tomohiro Aruga, Kiyoteru Katsuki
  • Publication number: 20110193900
    Abstract: The liquid ejecting apparatus includes nozzles which eject ink, an ink flow path which supplies ink from the upstream side toward the downstream side, a maintenance pump capable of suctioning and discharging ink from the ink flow path, a one-way valve which is opened in accordance with decompression on the downstream side, thereby allowing passage of ink from the upstream side to the downstream side, and a control unit which controls the driving of the maintenance pump, thereby performing a cleaning process, wherein the control unit makes the maintenance pump suction ink from a pressure-changing position in the ink flow path by performing the suction driving of the maintenance pump after making the maintenance pump discharge ink from the pressure-changing position in the ink flow path into the ink flow path by performing the discharge driving of the maintenance pump.
    Type: Application
    Filed: February 7, 2011
    Publication date: August 11, 2011
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Tomohiro Aruga, Masaru Kobashi
  • Patent number: 7991319
    Abstract: In an image forming apparatus, a toner carrier roller rotatably mounted to a housing that stores toner rotates to convey toner to an opposed position facing a latent image carrier outside the housing. A plurality of convex sections are regularly arranged on a surface of the roller in an axial direction parallel to the rotational axis and in a circumferential direction orthogonal to the axial direction and parallel to a circumferential surface of the roller and a concave section surrounds the convex sections. A seal member abuts the surface of the roller moving from the outside toward the inside of the housing at a position downstream of the opposed position in a rotation direction of the roller to prevent toner leakage from inside the housing. The roller moves relative to the seal member in the axial direction.
    Type: Grant
    Filed: January 5, 2009
    Date of Patent: August 2, 2011
    Assignee: Seiko Epson Corporation
    Inventors: Tomohiro Aruga, Masahiro Maeda
  • Patent number: 7945194
    Abstract: An image formation apparatus includes an image carrier and a toner carrier having a concave portion arrayed in a regular pattern on its surface. A latent image that is carried on the image carrier is developed by toner carried in the concave portion by applying a development voltage to the toner carrier. After the toner carrier has developed the latent image, at least one layer of toner remains in the concave portion.
    Type: Grant
    Filed: May 15, 2008
    Date of Patent: May 17, 2011
    Assignee: Seiko Epson Corporation
    Inventors: Yoichi Yamada, Hiroshi Kato, Tomohiro Aruga, Takatomo Fukumoto
  • Patent number: 7925195
    Abstract: A method of manufacturing a toner carrier roller that is shaped like a cylinder on an outer circumferential surface of which concave and convex sections for carrying toner are provided, includes: preparing a roller base member which is shaped like a cylinder; forming helix-like first grooves on the outer circumferential surface of the roller base member; and forming helix-like second grooves, which cross the first grooves, on the outer circumferential surface of the roller base member, wherein a pitch ratio of the first grooves and the second grooves is a non-integer ratio.
    Type: Grant
    Filed: January 15, 2009
    Date of Patent: April 12, 2011
    Assignee: Seiko Epson Corporation
    Inventors: Tomohiro Aruga, Masahiro Maeda
  • Publication number: 20100261109
    Abstract: A toner includes toner base particles containing at least a binder resin, a coloring agent, and a release agent; and alumina fine particles whose phase angle (?) is |80°| or less at an alternating current frequency of 1 to 10 kHz in an alternating current impedance method.
    Type: Application
    Filed: April 9, 2010
    Publication date: October 14, 2010
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Hideki OKADA, Tomotaka MORI, Tomohiro ARUGA
  • Publication number: 20100261113
    Abstract: A toner includes toner base particles containing at least a binder resin, a coloring agent, and a release agent and having a volume-average particle size of 2 to 6 ?m; a small particle size silica having an average particle size of 7 to 15 nm; a large particle size silica having an average particle size of 50 to 400 nm; and a small particle size transition alumina obtained by a dawsonite method and having an average particle size of 7 to 20 nm.
    Type: Application
    Filed: April 14, 2010
    Publication date: October 14, 2010
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Tomohiro ARUGA, Hideki OKADA, Yoichi YAMADA, Daisuke MATSUMOTO
  • Publication number: 20100261111
    Abstract: A toner includes at least a binder resin, a colorant, and a release agent. The toner contains base toner particles having an average volume particle size of 2 ?m to 6 ?m, small particle silica having an average volume particle size of 7 nm to 15 nm, large particle silica having an average volume particle size of 50 nm to 400 nm, small particle transition alumina having an average volume particle size of 7 nm to 20 nm, and large particle ?-type alumina having an average volume particle size of 50 nm to 400 nm or large particle cerium oxide having an average volume particle size of 50 nm to 400 nm.
    Type: Application
    Filed: April 13, 2010
    Publication date: October 14, 2010
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Tomohiro ARUGA, Hideki OKADA, Yoichi YAMADA, Daisuke MATSUMOTO
  • Publication number: 20100261112
    Abstract: A toner includes toner base particles containing at least a binder resin, a coloring agent, and a release agent and having a volume-average particle size of 2 to 6 ?m; at least two types of silica each having a different average particle size; at least one type of electron-conductive oxide semiconductor fine particles selected from titania, transition alumina, zinc oxide, and tin oxide; and at least one type of ion-conductive oxide semiconductor fine particles selected from cerium oxide and stabilized zirconia.
    Type: Application
    Filed: April 13, 2010
    Publication date: October 14, 2010
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Tomohiro ARUGA, Yoichi YAMADA, Daisuke MATSUMOTO
  • Publication number: 20100247187
    Abstract: An image forming apparatus includes: a latent image carrier which circumferentially rotates in a predetermined rotational direction; a lubricant applying unit which applies a lubricant on a surface of the latent image carrier in a predetermined application position; a developing unit which adheres a toner including an additive having an abrasion effect onto the surface of the latent image carrier on which the lubricant is coated to form a toner image, in a development position located on a downstream side of the application position in the rotational direction; and a conductive blade which cleans and removes the toner on the surface of the latent image carrier in contact with the surface of the latent image carrier, and charges the surface of the latent image carrier, in a cleaning and charging position located on an upstream side of the development position in the rotational direction.
    Type: Application
    Filed: March 19, 2010
    Publication date: September 30, 2010
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Masahiro MAEDA, Yoichi YAMADA, Masaru KOBASHI, Tomohiro ARUGA, Takatomo FUKUMOTO, Atsunori KITAZAWA
  • Publication number: 20100248131
    Abstract: Provided is an image forming apparatus including: a latent image carrier; a lubricant applying unit configured to bring a conductive contact member into contact with a surface of the latent image carrier; a development unit configured to attach toner to the surface of the latent image carrier; and a conductive blade brought into contact with the surface of the latent image carrier at a cleaning position, wherein a bias is applied to at least one of the conductive contact member and the conductive blade such that the surface of the latent image carrier is electrified, and wherein, as the durability of the conductive blade is prolonged, a ratio of the electrification of the surface of the latent image carrier by the conductive blade and the electrification of the surface of the latent image carrier by the conductive contact member is changed.
    Type: Application
    Filed: March 19, 2010
    Publication date: September 30, 2010
    Applicant: Seiko Epson Corporation
    Inventors: Masahiro MAEDA, Yoichi YAMADA, Masaru KOBASHI, Tomohiro ARUGA, Takatomo FUKUMOTO, Atsunori KITAZAWA
  • Publication number: 20100248129
    Abstract: An image forming apparatus includes: a latent image carrier which circumferentially rotates in a predetermined rotational direction; a conductive blade which cleans a surface of the latent image carrier by being in contact with the surface of the latent image carrier, and charges the surface of the latent image carrier at a first electric potential having the same polarity as normal charged polarity of a toner according to application of direct current voltage having the same polarity as the normal charged polarity of the toner, in a predetermined cleaning and charging position; and a charger which provides electric charge having reverse polarity to the normal charged polarity and adjusts an electric potential of the surface of the latent image carrier to a second electric potential, in a secondary charging position located on a downstream side of the cleaning and charging position in the rotational direction.
    Type: Application
    Filed: March 19, 2010
    Publication date: September 30, 2010
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Masahiro MAEDA, Yoichi YAMADA, Masaru KOBASHI, Tomohiro ARUGA, Takatomo FUKUMOTO, Atsunori KITAZAWA
  • Publication number: 20100239326
    Abstract: A developing device, an image forming apparatus and an image forming method are disclosed. The developing device includes a housing that stores toner therein; a toner carrying roller that has a plurality of convex portions and concave portions surrounding the convex portions are formed on the surface of the toner carrying roller; and a conductive regulation blade having a free end comes in contact with the surface of the toner carrying roller. The toner includes a conductive external additive as an external additive. The toner carrying roller carries both contact toner which is in direct contact with the surface of the toner carrying roller and non-contact toner which is not in direct contact with the surface of the toner carrying roller, on the concave portion. The regulation blade is applied with a regulation bias voltage of the same polarity as a normal charge polarity of the toner.
    Type: Application
    Filed: March 16, 2010
    Publication date: September 23, 2010
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Yoichi Yamada, Tomohiro Aruga, Daisuke Matsumoto, Atsunori Kitazawa, Masaru Kobashi
  • Publication number: 20100239328
    Abstract: A developing apparatus includes: a housing which contains toner; a toner supporting roller; and a regulating blade, wherein bias voltage is applied to the regulating blade, the toner includes, an insulating external additive and an electrically-conductive external additive, satisfies any of the following first to third conditions, the first condition: a volume average grain diameter of the electrically-conductive external additive is larger than a volume average grain diameter of the insulating external additive, the second condition: a volume average grain diameter of the electrically-conductive external additive is larger than a volume average grain diameter of the insulating external additive in which coverage in the toner is higher than that of the electrically-conductive external additive, and the third condition: coverage of the electrically-conductive external additive in the toner is higher than coverage of the insulating external additive that is larger in volume average grain diameter than the elect
    Type: Application
    Filed: March 11, 2010
    Publication date: September 23, 2010
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Yoichi YAMADA, Tomohiro ARUGA, Daisuke MATSUMOTO, Yoshio NAKAZAWA
  • Publication number: 20100239327
    Abstract: A development device includes a housing having toner housed therein; a toner carrying roller that has a plurality of convex portions and concave portions surrounding the convex portions, formed on a surface thereof; and a conductive restriction blade in which a free end or an adjoining region adjacent to the free end abuts the surface of the toner carrying roller, thereby restricting the amount of the toner carried on surface of the toner carrying roller, wherein the toner has an external additive including a metal oxide, the restriction blade is applied with a restriction bias voltage of the same polarity as the regular electrification polarity of the toner, and a gap between the front end of the free end and the convex portion of the toner carrying roller is smaller than a volume average particle diameter of the toner.
    Type: Application
    Filed: March 16, 2010
    Publication date: September 23, 2010
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Yoichi YAMADA, Tomohiro ARUGA, Daisuke MATSUMOTO, Atsunori KITAZAWA, Masaru KOBASHI
  • Publication number: 20090297231
    Abstract: An image forming apparatus includes an image carrier that carries an electrostatic latent image on a surface thereof, a toner carrying roller that is disposed to face the image carrier and rotates in a predetermined rotation direction with charged toner carried on a surface thereof so as to transport the toner in an opposing position for facing the image carrier, and a bias applying unit that develops the electrostatic latent image with the toner by applying an AC voltage as a developing bias to the toner carrying roller. In addition, periodical concavo-convexes that are formed of a plurality of convex portions arranged at a constant pitch in a circumferential direction and concave portions that surround the plurality of convex portions are formed on the surface of the toner carrying roller.
    Type: Application
    Filed: May 22, 2009
    Publication date: December 3, 2009
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Tomohiro Aruga, Masahiro Maeda