Patents by Inventor Hideki Zemba

Hideki Zemba 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: 7734233
    Abstract: A disclosed development device includes: a latent image carrier; a conveying member disposed so as to face the latent image carrier, the conveying member having plural electrodes insulated from one another and arranged at predetermined intervals so as to generate an electric field for moving toner on the conveying member; a voltage application unit applying a voltage of n phases (n is a positive integer not less than one) to the electrodes so as to form a cloud of the toner and the toner is adhered to the latent image carrier so as to form a visualized toner image; a toner supply unit supplying the toner to the conveying member; and a height adjusting member adjusting a uniform height for a toner layer of the toner immediately before a development area on the conveying member in which development is performed.
    Type: Grant
    Filed: April 12, 2007
    Date of Patent: June 8, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Katsuhiro Aoki, Hideki Zemba, Tomoko Takahashi, Nobuaki Kondoh, Masanori Horike, Masaaki Yamada, Takeo Tsukamoto, Hideki Kosugi, Ichiro Kadota, Yoshinori Nakagawa, Yasuyuki Ishii
  • Publication number: 20100129113
    Abstract: An image forming apparatus includes an endless transfer member and a plurality of image forming units. The endless transfer member is arranged at a transverse position in the image forming apparatus, and has a circulatory rotating surface declining at a predetermined angle to a horizontal plane. Each of the plurality of image forming units includes a first surface facing the endless transfer member and a second surface opposite to the first surface and angled in a similar direction to the endless transfer member. The plurality of image forming units perform an image forming operation and are arranged next to one another facing the endless transfer member such that, in any two adjacent image forming units of the plurality of image forming units, one of the any two adjacent image forming units has a portion overhanging the other one of the any two adjacent image forming units.
    Type: Application
    Filed: January 7, 2010
    Publication date: May 27, 2010
    Inventors: Atsushi Sampe, Yoshiyuki Kimura, Hiroshi Hosokawa, Hiroyuki Nagashima, Nobuo Kuwabara, Wakako Murakami, Hideki Zemba
  • Patent number: 7672625
    Abstract: A developing device, process cartridge, and image forming apparatus that use ETH development, and are capable of forming good multi-color images with a simple construction, and are capable of preventing the dispersal of powder. The developing device is for developing latent images on a latent image carrying member by applying powder to the latent image carrying member, and comprises: a transport member disposed in opposition to the latent image carrying member and having a plurality of transport electrodes that generate a progressive wave electric field to move the powder; a voltage supply device for applying a multi-phase voltage to the transport electrodes; and a transport member surface potential determination device for determining the surface potential of the transport member.
    Type: Grant
    Filed: March 5, 2007
    Date of Patent: March 2, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomoko Takahashi, Katsuhiro Aoki, Hideki Zemba
  • Patent number: 7672605
    Abstract: A transfer device is provided for an image forming apparatus designed such that toner images formed on a plurality of image bearing members are transferred one over another on a transfer body disposed in contact with each of the image bearing members with predetermined pressure and thus a toner image in two or more colors is formed on the transfer body. The transfer device includes a pressure varying mechanism which is capable of separating the transfer body from at least some of the image bearing members, and capable of varying transfer pressure between the image bearing members and the transfer body in contact with said image bearing members.
    Type: Grant
    Filed: June 6, 2007
    Date of Patent: March 2, 2010
    Assignee: Ricoh Company, Limited
    Inventors: Shin Kayahara, Yoshiyuki Kimura, Eisaku Murakami, Masahiko Satoh, Masanori Kawasumi, Hideki Zemba, Takeshi Uchitani, Eiji Shimojo, Shunichi Hashimoto
  • Patent number: 7630659
    Abstract: A method and an apparatus of controlling a charge voltage including the steps of applying, charging, detecting, and determining. The applying step applies an application voltage having a direct-current voltage and an alternating-current voltage superimposed onto the direct-current voltage to a charge-applying member to charge a charge carrier. The changing step charges the alternating-current voltage of the application voltage. The detecting step detects an alternating current flowing through the charge carrier when the charge-applying member applies the application voltage to the charge carrier. The determining step determines a value of the alternating-current voltage of the application voltage based on at least two alternating currents detected by the alternating-current detector.
    Type: Grant
    Filed: May 9, 2006
    Date of Patent: December 8, 2009
    Assignee: Ricoh Co., Ltd.
    Inventors: Takeshi Uchitani, Eisaku Murakami, Yoshiyuki Kimura, Masahiko Satoh, Masanori Kawasumi, Hideki Zemba, Eiji Shimojo, Shunichi Hashimoto, Shin Kayahara
  • Patent number: 7603062
    Abstract: A conductive member, including a long conductive supporting body, an electrical resistance adjusting layer, disposed on the outer circumferential surface of the conductive supporting body and having a reduced diameter section at either end, and a pair of gap maintaining members which are respectively fitted onto said reduced diameter sections of the electrical resistance adjusting layer. The outer circumferential surfaces of the gap maintaining members have a height differential with respect to the outer circumferential surface of the electrical resistance adjusting layer, in such a manner that when abutted against an image carrier, a prescribed gap is formed between the outer circumferential surface of the image carrier and the outer circumferential surface of the electrical resistance adjusting layer. An interval between the end faces of the electrical resistance adjusting layer and the faces of the gap maintaining members opposing the end faces satisfies a predetermined relationship.
    Type: Grant
    Filed: September 8, 2006
    Date of Patent: October 13, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Eiji Shimojo, Masanori Kawasumi, Yoshiyuki Kimura, Masahiko Satoh, Takeshi Uchitani, Hideki Zemba, Yutaka Narita, Shunichi Hashimoto, Eisaku Murakami, Shin Kayahara
  • Patent number: 7555243
    Abstract: A charging member, which can be provided in a process cartridge and/or in an image forming apparatus, includes a conductive supporting member, an electrical resistance control layer formed on an outer circumferential surface of the conductive supporting member, and a nonconductive gap retaining member configured to retain a gap between the conductive supporting member and an image carrying member closely disposed to each other to have a constant distance. At least a portion of the nonconductive gap retaining member is mounted on the electrical resistance control layer at both ends of the conductive supporting member, and a circumference of the nonconductive gap retaining member projects from the electrical resistance control layer. An amount of projection of the gap retaining member from the electrical resistance control layer decreases as the gap retaining member tapers in a direction toward a center of an image formation region.
    Type: Grant
    Filed: July 6, 2007
    Date of Patent: June 30, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Masahiko Satoh, Masanori Kawasumi, Yoshiyuki Kimura, Eisaku Murakami, Hideki Zemba, Takeshi Uchitani, Shin Kayahara, Shunichi Hashimoto, Eiji Shimojo
  • Patent number: 7548712
    Abstract: A latent image carrier includes a thin-walled cylinder with a chargeable photosensitive layer. The latent image carrier is configured to form an electrostatic latent image corresponding to an optically written image. A cylindrical damper including an elastic body disposed inside the latent image carrier. A first end of the cylindrical damper includes a wall extending inward toward an axis of the damper. A second end of the damper, opposite the first end along the axis of the damper, includes an opening, which is open in an axial direction. The wall includes a through-hole connecting an internal cavity and an outside of the damper. An outer diameter of an outermost part of the first end of the damper along the axis of the damper is smaller than an outer diameter of an outermost part of the second end of the damper along the axis of the damper.
    Type: Grant
    Filed: August 17, 2007
    Date of Patent: June 16, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Takatsugu Fujishiro, Takeo Suda, Hideki Zemba, Hisao Murayama
  • Patent number: 7466947
    Abstract: An image forming apparatus includes a container configured to contain two-component developer including toner particles and carrier beads. The image forming apparatus further includes a developer carrying member configured to carry thereon the two-component developer and having a magnetic field generating member and a plurality of grooves having a generally V-like shape satisfying h?50+R/2+{(R/2)/sin(?/2)}, in which h represents a depth of the grooves, ? represents an opening angle of the grooves, and R represents a volume-average diameter of the carrier beads.
    Type: Grant
    Filed: March 10, 2006
    Date of Patent: December 16, 2008
    Assignee: Ricoh Company, Ltd.
    Inventor: Hideki Zemba
  • Publication number: 20080226311
    Abstract: A novel development device includes a developer roller, a developer reservoir, a rotatable conveyor, and a replenisher unit. The developer roller is configured to supply toner particles to the electrostatic latent image. The developer reservoir is configured to hold the developer therewithin for application to the developer roller. The rotatable conveyor is configured to rotate within the developer reservoir to convey the developer toward the developer roller. The replenisher unit has a tubular member terminating at a port opening in the developer reservoir. The replenisher unit is configured to direct a particulate material through the tubular member into the developer reservoir via the port. The particulate material is toner particles, carrier particles, or a mixture of toner particles and a given amount of carrier particles. The port is submerged in the developer within the developer reservoir as the rotatable conveyor rotates.
    Type: Application
    Filed: March 17, 2008
    Publication date: September 18, 2008
    Inventors: Tetsuya Senoh, Eisaku Murakami, Masahiko Satoh, Masanori Kawasumi, Hideki Zemba, Takeshi Uchitani, Kenichi Taguma, Shunichi Hashimoto
  • Patent number: 7366449
    Abstract: A developing unit includes a developer container that includes an opening and holds a developer; a first screw that stirs and conveys the developer, and that supplies the developer to a developing roller; a second screw that stirs the first developer, and that conveys the developer to a direction opposite to a direction to which the first screw conveys the developer; and a partition wall that partitions between the first screw and the second screw. The partition wall includes a guiding member that guides, to a position within a range in which rotation of the first conveying unit reaches, a part of the developer that is supplied to the developing roller and is returned after being used for development from the developing roller, and at least a part of the guiding member is an adhesion surface to which a sealing member for sealing the opening is adhered.
    Type: Grant
    Filed: May 11, 2005
    Date of Patent: April 29, 2008
    Assignee: Ricoh Company, Ltd.
    Inventor: Hideki Zemba
  • Patent number: 7321742
    Abstract: An image forming apparatus includes a photoreceptor belt formed by either a belt or a thin-walled cylinder. A charging unit that sets bias characteristics of the photoreceptor belt has an arrangement to approach towards the photoreceptor belt. A damper is provided on a side of the photoreceptor belt opposite to the side facing the charging unit. The damper absorbs vibrations in the photoreceptor belt through a supporting plate.
    Type: Grant
    Filed: January 10, 2006
    Date of Patent: January 22, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Takatsugu Fujishiro, Takeo Suda, Hideki Zemba, Hisao Murayama
  • Publication number: 20080008499
    Abstract: A charging member, which can be provided in a process cartridge and/or in an image forming apparatus, includes a conductive supporting member, an electrical resistance control layer formed on an outer circumferential surface of the conductive supporting member, and a nonconductive gap retaining member configured to retain a gap between the conductive supporting member and an image carrying member closely disposed to each other to have a constant distance. At least a portion of the nonconductive gap retaining member is mounted on the electrical resistance control layer at both ends of the conductive supporting member, and a circumference of the nonconductive gap retaining member projects from the electrical resistance control layer. An amount of projection of the gap retaining member from the electrical resistance control layer decreases as the gap retaining member tapers in a direction toward a center of an image formation region.
    Type: Application
    Filed: July 6, 2007
    Publication date: January 10, 2008
    Inventors: Masahiko Satoh, Masanori Kawasumi, Yoshiyuki Kimura, Eisaku Murakami, Hideki Zemba, Takeshi Uchitani, Shin Kayahara, Shunichi Hashimoto, Eiji Shimojo
  • Publication number: 20080003017
    Abstract: A latent image carrier includes a thin-walled cylinder with a chargeable photosensitive layer. The latent image carrier is configured to form an electrostatic latent image corresponding to an optically written image. A cylindrical damper including an elastic body disposed inside the latent image carrier. A first end of the cylindrical damper includes a wall extending inward toward an axis of the damper. A second end of the damper, opposite the first end along the axis of the damper, includes an opening, which is open in an axial direction. The wall includes a through-hole connecting an internal cavity and an outside of the damper. An outer diameter of an outermost part of the first end of the damper along the axis of the damper is smaller than an outer diameter of an outermost part of the second end of the damper along the axis of the damper.
    Type: Application
    Filed: August 17, 2007
    Publication date: January 3, 2008
    Inventors: Takatsugu FUJISHIRO, Takeo SUDA, Hideki ZEMBA, Hisao MURAYAMA
  • Publication number: 20070286628
    Abstract: A transfer device is provided for an image forming apparatus designed such that toner images formed on a plurality of image bearing members are transferred one over another on a transfer body disposed in contact with each of the image bearing members with predetermined pressure and thus a toner image in two or more colors is formed on the transfer body. The transfer device includes a pressure varying mechanism which is capable of separating the transfer body from at least some of the image bearing members, and capable of varying transfer pressure between the image bearing members and the transfer body in contact with said image bearing members.
    Type: Application
    Filed: June 6, 2007
    Publication date: December 13, 2007
    Inventors: Shin KAYAHARA, Yoshiyuki Kimura, Eisaku Murakami, Masahiko Satoh, Masanori Kawasumi, Hideki Zemba, Takeshi Uchitani, Eiji Shimojo, Shunichi Hashimoto
  • Patent number: 7305203
    Abstract: An image forming apparatus includes at least one process cartridge removably mounted on an apparatus body and including at least an image carrier on which a toner image is to be formed and a cleaning device configured to remove toner left after image transfer with a cleaning blade. A hole for passing a light beam emitted from an optical writing unit toward the image carrier therethrough is formed in part of a case bottom wall of the process cartridge higher in level than part of the case bottom wall below the cleaning blade.
    Type: Grant
    Filed: April 15, 2005
    Date of Patent: December 4, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Atsushi Sampe, Hiroyuki Nagashima, Yoshiyuki Kimura, Nobuo Kuwabara, Hiroshi Hosokawa, Hideki Zemba, Wakako Murakami
  • Patent number: 7295796
    Abstract: A cleaningless image forming apparatus of the present invention uses spherical toner grains on surfaces of which a charge control agent and/or organic fine grains are present, thereby enhancing efficient image transfer. A brush roller collects, among toner grains left on a photoconductive drum after image transfer, toner grains of polarity opposite to preselected polarity and then releases them to the drum at preselected timing. The toner grains of opposite polarity are then transferred to an intermediate image transfer belt. When the toner grains of opposite polarity pass a charging zone assigned to a charge roller, a bias to the charge roller is interrupted or the charge roller is released from the drum.
    Type: Grant
    Filed: September 2, 2003
    Date of Patent: November 13, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Eisaku Murakami, Hideo Yoshizawa, Hiroyuki Nagashima, Yoshiyuki Kimura, Hideki Zemba, Eiji Kurimoto, Takeshi Uchitani, Toshio Koike, Masato Yanagida, Masami Tomita, Atsushi Sampe, Naohiro Kumagai, Takeshi Shintani, Masanori Kawasumi
  • Patent number: 7292817
    Abstract: An image forming apparatus includes a frame body, a frame cover supported by the frame body so as to be capable of opening and closing, an image forming unit that forms a toner image on an image carrier, a cleaning unit that removes and collects residual toner from the image carrier, and a toner container for accumulating the toner collected by the cleaning unit. The toner container is supported by the frame cover.
    Type: Grant
    Filed: December 13, 2006
    Date of Patent: November 6, 2007
    Assignee: Ricoh Company, Limited
    Inventors: Eisaku Murakami, Hideo Yoshizawa, Hiroyuki Nagashima, Yoshiyuki Kimura, Hideki Zemba, Eiji Kurimoto, Ishii Hiroshi, Yuji Arai
  • Publication number: 20070242985
    Abstract: A disclosed development device includes: a latent image carrier; a conveying member disposed so as to face the latent image carrier, the conveying member having plural electrodes insulated from one another and arranged at predetermined intervals so as to generate an electric field for moving toner on the conveying member; a voltage application unit applying a voltage of n phases (n is a positive integer not less than one) to the electrodes so as to form a cloud of the toner and the toner is adhered to the latent image carrier so as to form a visualized toner image; a toner supply unit supplying the toner to the conveying member; and a height adjusting member adjusting a uniform height for a toner layer of the toner immediately before a development area on the conveying member in which development is performed.
    Type: Application
    Filed: April 12, 2007
    Publication date: October 18, 2007
    Inventors: Katsuhiro AOKI, Hideki Zemba, Tomoko Takahashi, Nobuaki Kondoh, Masanori Horike, Masaaki Yamada, Takeo Tsukamoto, Hideki Kosugi, Ichiro Kadota, Yoshinori Nakagawa, Yasuyuki Ishii
  • Publication number: 20070212121
    Abstract: A developing device, process cartridge, and image forming apparatus that use ETH development, and are capable of forming good multi-color images with a simple construction, and are capable of preventing the dispersal of powder. The developing device is for developing latent images on a latent image carrying member by applying powder to the latent image carrying member, and comprises: a transport member disposed in opposition to the latent image carrying member and having a plurality of transport electrodes that generate a progressive wave electric field to move the powder; a voltage supply device for applying a multi-phase voltage to the transport electrodes; and a transport member surface potential determination device for determining the surface potential of the transport member.
    Type: Application
    Filed: March 5, 2007
    Publication date: September 13, 2007
    Inventors: Tomoko TAKAHASHI, Katsuhiro AOKI, Hideki ZEMBA