Patents by Inventor Kazunori Bannai

Kazunori Bannai 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: 7907869
    Abstract: A charging brush unit includes a brush and a conductive holder. The brush includes a plurality of flexible conductive fibers. The plurality of flexible conductive fibers is supplied with a charging bias to generate electrical discharge between a top of the plurality of conductive fibers and a latent image carrier across a gap formed between the top of the plurality of conductive fibers and the latent image carrier. The gap is provided with an electrode. The electrode includes a plurality of openings opposing the top of the plurality of conductive fibers and is supplied with a bias different from the charging bias applied to the plurality of conductive fibers. The conductive holder holds the brush.
    Type: Grant
    Filed: March 12, 2008
    Date of Patent: March 15, 2011
    Assignee: Ricoh Company Limited
    Inventors: Kohta Takenaka, Kazunori Bannai, Hidehiko Fujiwara, Yu Wakabayashi
  • Publication number: 20110052227
    Abstract: An image forming apparatus includes an image forming device to form an image on a sheet and a sheet feeding unit to feed the sheet to the image forming device. The sheet feeding unit includes an endless, dielectric belt disposed facing an upper surface of a sheet stack to contact and attract an uppermost sheet to the surface thereof and feed the sheet in the sheet feeding direction, and an electric potential pattern forming unit to form an electric potential pattern on the surface of the dielectric belt. The electric potential pattern has multiple potential holding sections of identical absolute values and opposite polarities disposed adjacent to each other at a uniform pitch. The electric potential pattern forming unit forms the electric potential pattern to have equal numbers of positive potential holding sections and negative potential holding sections.
    Type: Application
    Filed: August 30, 2010
    Publication date: March 3, 2011
    Inventors: Tsugunao Toyooka, Manabu Nonaka, Kazunori Bannai
  • Publication number: 20110026961
    Abstract: A fixing device for fixing an unfixed toner image on a recording medium includes a rotatable fixing member heated by a heater to contact the recording medium bearing the unfixed toner image while rotating, with the heater disposed inside a hollow of the fixing member and turned on and off intermittently at a start of a fixing process to heat the fixing member intermittently, a first pressing member disposed opposite the fixing member to press against and rotate the fixing member to define a fixing nip through which the recording medium passes to fix the unfixed toner image with heat and pressure, and a temperature detector to detect a change in the temperature of the fixing member when the heater turns on and off intermittently. When the temperature detector detects the change in the temperature of the fixing device, the heater is turned on continuously.
    Type: Application
    Filed: July 16, 2010
    Publication date: February 3, 2011
    Inventors: Yoshihide OHTA, Kazunori Bannai, Kohta Takenaka, Hidehiko Fujiwara
  • Patent number: 7880760
    Abstract: A first beam separation device is arranged either to allow the light beams to enter and pass or to reflect the light beams in accordance with a direction of entrance of the light beams. A second beam separation device is provided either to allow or to reflect the light beams having passed through the first beam separation device in accordance a wavelength thereof. The light beam passing through the second beam separation device scans one of plural scan objectives and the light beam reflected by the second beam separation device is further reflected by the first beam separation device and then scans the other one of the plural scan objectives. A first imaging device is provided to correct a f-theta (f?) performance and a curvature of an imaging plane to enable the light beams to scan the plural scan objectives at a constant speed. The first imaging device is integral with the first beam separation device.
    Type: Grant
    Filed: March 2, 2009
    Date of Patent: February 1, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Kazunori Bannai, Daisuke Imaki
  • Publication number: 20110020018
    Abstract: A fixing device includes a fixing member including a recording medium passing area inside thereof through which the recording medium passes, a first heater disposed in the fixing member to heat the fixing member, a first pressing member disposed opposite the fixing member to press against and rotate the fixing member to fix the unfixed toner image on the recording medium, a second heater disposed outside the recording medium passing area and inside the fixing member to heat the fixing member cyclically in a given cycle of heating, a temperature detector to detect a change in the temperature of the fixing member when the fixing member is cyclically heated by the second heater, and a determination unit to evaluate a condition of rotation of the fixing member based on the cycle of heating by the second heater and the cycle of change in the temperature detected by the temperature detector.
    Type: Application
    Filed: July 26, 2010
    Publication date: January 27, 2011
    Inventors: Kohta TAKENAKA, Kazunori Bannai, Hidehiko Fujiwara
  • Patent number: 7860442
    Abstract: An image fixing device for use in an image forming apparatus. The fixing device includes a fixing member which fixes a toner image on a recording medium at a nip area, a pressurizing member which pressures the recording medium toward the fixing member at the nip area, a carbon lamp which emits infrared rays, and a reflecting member which reflects the infrared rays to the nip area.
    Type: Grant
    Filed: July 3, 2007
    Date of Patent: December 28, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Tetsuji Nishikawa, Takayuki Niihara, Kazuki Suzuki, Kazunori Bannai, Makoto Kikura, Yasuhiro Maehata
  • Publication number: 20100232822
    Abstract: In a fixing device, a first reflection plate covers a part of an outer circumferential surface of an infrared heater in a circumferential direction of the infrared heater along an axial direction of the infrared heater substantially perpendicular to the circumferential direction of the infrared heater. The first reflection plate reflects light emitted by the infrared heater toward a fixing member. At least one light control mirror is provided in at least one end of the first reflection plate in an axial direction of the first reflection plate. At least one second reflection plate opposes the infrared heater via the at least one light control mirror to reflect the light emitted by the infrared heater and passing through the at least one light control mirror toward a center portion of the fixing member in an axial direction of the fixing member.
    Type: Application
    Filed: March 9, 2010
    Publication date: September 16, 2010
    Inventors: Kohta Takenaka, Kazunori Bannai, Hidehiko Fujiwara, Toshihiro Shimada
  • Patent number: 7705872
    Abstract: An optical writing device includes a dichroic mirror and a deflection beam splitter. The dichroic mirror causes a light beam to pass therethrough or reflect depending on the wavelengths of the light beam. The deflection beam splitter causes a light beam to pass therethrough or reflect depending on a direction from which the light beam is received.
    Type: Grant
    Filed: August 29, 2008
    Date of Patent: April 27, 2010
    Assignee: Ricoh Company, Limited
    Inventors: Hideto Higaki, Kazunori Bannai, Noboru Kusunose, Yoshinobu Sakaue
  • Patent number: 7697184
    Abstract: An optical scanning device includes a polygon mirror, a beam detector, a correcting unit, and a controller. The polygon mirror deflects and scans a light beam in a main scanning direction on a surface of an image carrier. The beam detector detects a beam position of the deflected light beam in a sub-scanning direction. The correcting unit calculates a correction amount of out-of-color registration based on the beam position, and corrects out-of-color registration in the sub-scanning direction based on the correction amount. The controller controls, during correction of out-of-color registration, a deflection speed of the deflector to be less than a deflection speed for writing a latent image on the surface of the image carrier.
    Type: Grant
    Filed: July 10, 2007
    Date of Patent: April 13, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshinobu Sakaue, Kazunori Bannai, Iwao Matsumae, Noboru Kusunose
  • Publication number: 20100034563
    Abstract: P-polarized light beam passing through an f? lens passes through a polarization beam splitter, is converted into S-polarized light beam by a quarter-wave plate and a reflecting mirror, re-enters the polarization beam splitter, and is reflected at the polarization beam splitter in the ?Z direction. An optical path of a light beam between a polygon mirror and the f? lens, between the f? lens and the polarization beam splitter, between the polarization beam splitter and the quarter-wave plate, between the quarter-wave plate and a reflecting mirror, between the reflecting mirror and the quarter-wave plate, and between the quarter-wave plate and the polarization beam splitter are in the same plane.
    Type: Application
    Filed: August 4, 2009
    Publication date: February 11, 2010
    Inventors: Hiroyoshi Funato, Kazunori Bannai, Daisuke Imaki, Yoshinori Hayashi, Makoto Hirakawa
  • Patent number: 7619643
    Abstract: An image forming apparatus includes a first support member, an image carrying member configured to carry a toner image thereon, and an optical writing apparatus connected to the first support member and configured to form an electrostatic latent image on the image carrying member. The optical writing apparatus includes an optical system having at least one optical element, a first casing configured to support the optical system, and a second casing configured to encase the first casing and to prevent intrusion of dust to the optical system.
    Type: Grant
    Filed: February 28, 2007
    Date of Patent: November 17, 2009
    Assignee: Ricoh Co., Ltd.
    Inventors: Yoshinobu Sakaue, Kazunori Bannai, Kozo Yamazaki
  • Patent number: 7589756
    Abstract: A beam detecting unit detects at least one of a position of an optical beam in a sub scanning direction and a position of the optical beam in a main scanning direction. A color-misalignment correcting unit changes an optical-beam irradiating position on a photosensitive element based on a result of detection by the beam detecting unit. The beam detecting unit is arranged between an optical element that is closest to a corresponding photosensitive element and the corresponding photosensitive element.
    Type: Grant
    Filed: September 15, 2006
    Date of Patent: September 15, 2009
    Assignee: Ricoh Company, Limited
    Inventors: Iwao Matsumae, Yoshinobu Sakaue, Kazunori Bannai
  • Publication number: 20090220276
    Abstract: A first beam separation device is arranged either to allow the light beams to enter and pass or to reflect the light beams in accordance with a direction of entrance of the light beams. A second beam separation device is provided either to allow or to reflect the light beams having passed through the first beam separation device in accordance a wavelength thereof. The light beam passing through the second beam separation device scans one of plural scan objectives and the light beam reflected by the second beam separation device is further reflected by the first beam separation device and then scans the other one of the plural scan objectives. A first imaging device is provided to correct a f-theta (f?) performance and a curvature of an imaging plane to enable the light beams to scan the plural scan objectives at a constant speed. The first imaging device is integral with the first beam separation device.
    Type: Application
    Filed: March 2, 2009
    Publication date: September 3, 2009
    Inventors: Kazunori Bannai, Daisuke Imaki
  • Publication number: 20090208264
    Abstract: A fixing device includes a fixing member, a pressure member, a contact member, and a heater. The fixing member is provided in a width direction of a recording medium and to heat and fuse a toner image on the recording medium. The pressure member is to press against the fixing member. The contact member is provided inside the fixing member and to contact the pressure member through the fixing member to form a nip portion between the pressure member and the fixing member. The heater includes a heating element and is to heat the contact member. The heating element of the heater is a mold member of a relatively thin plate extending in a width direction of the fixing member and includes a flat surface that faces the contact member. An image forming apparatus for forming an image includes the fixing device.
    Type: Application
    Filed: February 17, 2009
    Publication date: August 20, 2009
    Inventors: Hidehiko Fujiwara, Kazunori Bannai
  • Publication number: 20090148207
    Abstract: A fixing device includes a flexible fixing member that heats a toner image to fuse, a contact member fixedly disposed internal to the fixing member and comes into contact with a pressure member via the fixing member to form a nip part, a plurality of heating devices that heats the contact member, wherein the contact member always maintains the contact state with the pressure member via the fixing member, the plurality of heating devices generally remain disposed in the fixing device under an operational state for heating and are freely removable for replacement under a non-operational state for heating.
    Type: Application
    Filed: December 10, 2008
    Publication date: June 11, 2009
    Inventors: Shintaroh Yamada, Hidehiko Fujiwara, Kazunori Bannai, Manabu Nonaka
  • Publication number: 20090066780
    Abstract: An image forming apparatus includes a plurality of image carriers and an optical writing device including light sources that emit light beams of different wavelengths, a deflector that deflects the light beams emitted from the light sources and synthesized on an identical axis in a sub-scanning direction, a first beam separator, a second beam separator, a first imaging device, and a second imaging device. The first beam separator and the second beam separator are located between the first imaging device and the second imaging device and transmit or reflect the light beams according to travel directions or wavelengths thereof. One of the targets is scanned with the light beam transmitted through the second beam separator. Another target is scanned with the light beam reflected by the second and first beam separators. The first and second imaging devices narrow the beams in the main scanning direction and the sub-scanning direction, respectively.
    Type: Application
    Filed: September 9, 2008
    Publication date: March 12, 2009
    Inventors: Kazunori Bannai, Hideto Higaki, Daisuke Imaki, Noboru Kusunose, Yoshinobu Sakaue
  • Publication number: 20090058981
    Abstract: An optical writing device includes a dichroic mirror and a deflection beam splitter. The dichroic mirror causes a light beam to pass therethrough or reflect depending on the wavelengths of the light beam. The deflection beam splitter causes a light beam to pass therethrough or reflect depending on a direction from which the light beam is received.
    Type: Application
    Filed: August 29, 2008
    Publication date: March 5, 2009
    Inventors: Hideto Higaki, Kazunori Bannai, Noboru Kusunose, Yoshinobu Sakaue
  • Publication number: 20090016792
    Abstract: An image forming apparatus includes an image forming mechanism for forming a toner image on a recording medium, and a fixing device for fixing the toner image on the recording medium. The fixing device including a fixing film, a pressure member, a contact member, a heating device, a holding member, and at least one of a low friction member and a thermal conductivity improving member provided between the fixing film and the contact member. The fixing film heated by the heating device via the contact member comes into contact with the recording medium. The pressure member comes into pressure contact with the fixing film. The contact member comes into pressure contact with the pressure member via the fixing film to form, between the fixing film and the pressure member, a nip portion through which the recording medium is passed. The holding member holds the contact member and the heating device.
    Type: Application
    Filed: July 8, 2008
    Publication date: January 15, 2009
    Inventors: Shintaroh Yamada, Hidehiko Fujiwara, Kazunori Bannai, Manabu Nonaka
  • Publication number: 20080304866
    Abstract: A charging brush unit includes a brush and a conductive holder. The brush includes a plurality of flexible conductive fibers. The plurality of flexible conductive fibers is supplied with a charging bias to generate electrical discharge between a top of the plurality of conductive fibers and a latent image carrier across a gap formed between the top of the plurality of conductive fibers and the latent image carrier. The gap is provided with an electrode. The electrode includes a plurality of openings opposing the top of the plurality of conductive fibers and is supplied with a bias different from the charging bias applied to the plurality of conductive fibers. The conductive holder holds the brush.
    Type: Application
    Filed: March 12, 2008
    Publication date: December 11, 2008
    Inventors: Kohta TAKENAKA, Kazunori Bannai, Hidehiko Fujiwara, Yu Wakabayashi
  • Patent number: 7450146
    Abstract: An optical scanning device includes a plurality of light sources, a deflector, optical systems, and a plurality of light shielding units to shield flare light from an opposite optical system. Two light shielding units are arranged not to satisfy ?=n(360/x) degrees, where ? is an angle formed by a line from a portion of one light shielding unit nearest the deflector to a rotation axis of the deflector and a line from a portion of the other light shielding unit nearest the deflector to the rotation axis of the deflector with the rotation axis of the deflector being an apex angle, x is the number of mirror faces of the deflector, and n is an integer not more than x.
    Type: Grant
    Filed: August 15, 2006
    Date of Patent: November 11, 2008
    Assignee: Ricoh Company Limited
    Inventors: Yoshinobu Sakaue, Kazunori Bannai