Patents by Inventor Yasumasa Tomita

Yasumasa Tomita 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: 20170373313
    Abstract: A positive electrode active material for a non-aqueous electrolyte secondary battery includes LiX, where X represents a halogen atom.
    Type: Application
    Filed: September 8, 2017
    Publication date: December 28, 2017
    Applicants: YAMAHA HATSUDOKI KABUSHIKI KAISHA, NATIONAL UNIVERSITY CORPORATION SHIZUOKA UNIVERSITY
    Inventors: Juichi ARAI, Yasumasa TOMITA
  • Patent number: 8384752
    Abstract: An optical scanning unit used in an image forming apparatus having a latent image carrier includes a light emitter, a rotary deflector, an inclination adjustment unit, and a controller. The light emitter emits a light beam. The rotary deflector deflects and scans the light beam onto a surface of the latent image carrier. The inclination adjustment unit adjusts an inclination of a scan line corresponding to the light beam relative to a reference scan line on the latent image carrier. The controller changes at least one of a linear velocity of the latent image carrier and a rotation speed of the rotary deflector so as to change a ratio between the linear velocity of the latent image carrier and a scan speed of the light beam, and controls the inclination adjustment unit based on the ratio to keep the scan line from inclining relative to the reference scan line.
    Type: Grant
    Filed: March 14, 2008
    Date of Patent: February 26, 2013
    Assignee: Ricoh Company, Ltd.
    Inventor: Yasumasa Tomita
  • Patent number: 7821678
    Abstract: An image forming apparatus includes an image carrier and an optical scanning device. The optical scanning device generates an optical scanning beam and includes an enclosure. The enclosure includes a pair of arch-like-shaped supporting members. Inside the enclosure there are provided a light source for emitting a light beam, a light deflector for deflecting the light beam emitted from the light source so as to convert the light beam into the optical scanning beam, and at least one reflecting mirror for reflecting the optical scanning beam deflected by the light deflector to scan the image carrying surface of the image carrier. At least one of the reflecting mirrors includes a specific reflecting mirror having a light reflecting surface and mounted on the pair of arch-like-shaped supporting members at a position to reflect the optical scanning beam with the light reflecting surface toward the image carrying surface of the image carrier.
    Type: Grant
    Filed: September 7, 2006
    Date of Patent: October 26, 2010
    Assignee: Ricoh Company, Ltd.
    Inventor: Yasumasa Tomita
  • Patent number: 7612928
    Abstract: An optical scanning apparatus includes a plurality of light sources for emitting light beams and a rotary deflector for deflecting the light beams. A revolution number (Rm) of the rotary deflector is reduced to Rdef×(V/Vmax) if V/Vmax is greater than a value; and the revolution number (Rm) thereof is reduced to Rdef×(V/Vmax)×m and the number of the light beams is reduced to Ndef/m if V/Vmax is not greater than the value. V is a process linear velocity of the image forming apparatus; Vmax is a maximum process linear velocity thereof; Ndef is the number of the light beams at the maximum process linear velocity Vmax; and Rdef is the revolution number of the rotary deflector thereat; and m is a positive integer, and Vmax is greater than V (Vmax>V).
    Type: Grant
    Filed: April 26, 2007
    Date of Patent: November 3, 2009
    Assignee: Ricoh Company, Ltd.
    Inventor: Yasumasa Tomita
  • Patent number: 7598972
    Abstract: A deflecting unit deflects a light beam emitted by each of a plurality of light-beam emitting units independently to scan surfaces of different bodies to be scanned. Each of a plurality of light-receiving units receives the deflected light beam at a predetermined position in a direction of the deflection. An incident angle of the deflected light beam with respect to a scanning line extending in a direction of scanning on a light-receiving surface of the light-receiving unit is set to be identical for all of the light-receiving units.
    Type: Grant
    Filed: August 1, 2006
    Date of Patent: October 6, 2009
    Assignee: Ricoh Company, Limited
    Inventor: Yasumasa Tomita
  • Patent number: 7593149
    Abstract: An optical scanning unit includes: a light source configured to emit a light beam; a lens arranged so that the light beam emitted from the light source passes therethrough; a rotatable deflector configured to deflect the light beam coming from the lens, the deflected light beam being guided to a light receiving member; a movable lens holder configured to hold the lens, the lens holder being provided in a space between the light source and the deflector; a support member having a first face located on a first side thereof, the first face facing toward a vertically-downward direction and extending in a direction substantially parallel to a reference-axis defined between the light source and the deflector, there also being a second face located on a second side, the second face being arranged opposite to the first face; and a force-transferring member configured to transfer a force to the lens holder for moving the lens holder along the first face of the support member, the force being applied to the force-trans
    Type: Grant
    Filed: January 11, 2007
    Date of Patent: September 22, 2009
    Assignee: Ricoh Company, Ltd.
    Inventor: Yasumasa Tomita
  • Patent number: 7538924
    Abstract: An optical scanner includes more than two light sources, a rotatable deflecting unit that commonly deflects the light beams emitted by the light sources. An optical unit guides a corresponding one of deflected light beams to a corresponding surface to be scanned. The optical system units are disposed symmetrically around a center of rotation of the deflecting unit. A housing unit that houses the light source units, the deflecting unit, and the optical system units. A light shielding unit disposed in the housing unit so as to prevent the reflection and scattering of the deflected light beams by the optical system units, the light shielding unit being disposed between light beams that fall on the deflecting unit and light beams that are deflected from the deflecting unit.
    Type: Grant
    Filed: December 14, 2005
    Date of Patent: May 26, 2009
    Assignee: Ricoh Company, Ltd.
    Inventor: Yasumasa Tomita
  • Publication number: 20080225365
    Abstract: An optical scanning device for scanning surfaces of an even number of photoconductors simultaneously includes a rotating deflecting device arranged substantially at a center in a housing to deflect optical beams, and a plurality of scanning optical systems corresponding to the even number of photoconductors, arranged to be substantially symmetrical with the rotating deflecting device as a symmetry center. The plurality of scanning optical systems include a plurality of folding-back mirrors and at least one long lens having power in a sub-scanning direction, respectively, and the pluralities of folding-back mirrors and the at least one long lenses of the symmetrically arranged scanning optical systems are arranged to be symmetrical to each other with the rotating deflecting device as the symmetry center, respectively.
    Type: Application
    Filed: May 15, 2008
    Publication date: September 18, 2008
    Inventor: Yasumasa TOMITA
  • Publication number: 20080225102
    Abstract: An optical scanning unit used in an image forming apparatus having a latent image carrier includes a light emitter, a rotary deflector, an inclination adjustment unit, and a controller. The light emitter emits a light beam. The rotary deflector deflects and scans the light beam onto a surface of the latent image carrier. The inclination adjustment unit adjusts an inclination of a scan line corresponding to the light beam relative to a reference scan line on the latent image carrier. The controller changes at least one of a linear velocity of the latent image carrier and a rotation speed of the rotary deflector so as to change a ratio between the linear velocity of the latent image carrier and a scan speed of the light beam, and controls the inclination adjustment unit based on the ratio to keep the scan line from inclining relative to the reference scan line.
    Type: Application
    Filed: March 14, 2008
    Publication date: September 18, 2008
    Inventor: Yasumasa Tomita
  • Patent number: 7397589
    Abstract: An optical scanning device for scanning surfaces of an even number of photoconductors simultaneously includes a rotating deflecting device arranged substantially at a center in a housing to deflect optical beams, and a plurality of scanning optical systems corresponding to the even number of photoconductors, arranged to be substantially symmetrical with the rotating deflecting device as a symmetry center. The plurality of scanning optical systems include a plurality of folding-back mirrors and at least one long lens having power in a sub-scanning direction, respectively, and the pluralities of folding-back mirrors and the at least one long lenses of the symmetrically arranged scanning optical systems are arranged to be symmetrical to each other with the rotating deflecting device as the symmetry center, respectively.
    Type: Grant
    Filed: November 22, 2004
    Date of Patent: July 8, 2008
    Assignee: Ricoh Company, Ltd.
    Inventor: Yasumasa Tomita
  • Patent number: 7355617
    Abstract: An optical scanner for writing an electrostatic latent image on an image carrier includes a scanning optical system that forms an optical scanning path, a pair of optical detecting units arranged at two positions on the optical scanning path for detecting a write-start position and a write-end position to measure a time for scanning from the write-start position to the write-end position, and an optical housing that houses at least the scanning optical system and the optical detecting units. The optical detecting units are mounted on the optical housing via an intermediate member having a thermal expansion coefficient smaller than that of the optical housing.
    Type: Grant
    Filed: June 29, 2007
    Date of Patent: April 8, 2008
    Assignee: Ricoh Company, Limited
    Inventors: Keiichi Serizawa, Yasumasa Tomita
  • Patent number: 7319475
    Abstract: An image forming apparatus includes an image bearing member having a photosensitive surface and an optical writing apparatus generating a laser beam modulated according to image data. The optical writing apparatus includes a housing, an optical deflector, an f-theta lens and a separator. The optical deflector is configured to rotate to deflect the laser beam. The f-theta lens is configured to correct the laser beam deflected by the optical deflector and to transmit a corrected laser beam towards the image bearing member. The separator is configured to separate an inside space of the housing into at least two sections including a first section in which the optical deflector is mounted and a second section in which the f-theta lens is mounted. The separator includes a heat resistant transparent plate disposed at a position of crossing passage of the laser beam between the optical deflector and the f-theta lens.
    Type: Grant
    Filed: June 1, 2004
    Date of Patent: January 15, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Yasumasa Tomita, Hiroshi Yoshizawa, Tetsuya Kimura, Masato Yokoyama, Keiji Okamoto, Keiichi Serizawa
  • Publication number: 20070253049
    Abstract: An optical scanning apparatus includes a plurality of light sources for emitting light beams and a rotary deflector for deflecting the light beams. A revolution number (Rm) of the rotary deflector is reduced to Rdef×(V/Vmax) if V/Vmax is greater than a value; and the revolution number (Rm) thereof is reduced to Rdef×(V/Vmax)×m and the number of the light beams is reduced to Ndef/m if V/Vmax is not greater than the value. V is a process linear velocity of the image forming apparatus; Vmax is a maximum process linear velocity thereof; Ndef is the number of the light beams at the maximum process linear velocity Vmax; and Rdef is the revolution number of the rotary deflector thereat; and m is a positive integer, and Vmax is greater than V (Vmax>V).
    Type: Application
    Filed: April 26, 2007
    Publication date: November 1, 2007
    Inventor: Yasumasa Tomita
  • Publication number: 20070247510
    Abstract: An optical scanner for writing an electrostatic latent image on an image carrier includes a scanning optical system that forms an optical scanning path, a pair of optical detecting units arranged at two positions on the optical scanning path for detecting a write-start position and a write-end position to measure a time for scanning from the write-start position to the write-end position, and an optical housing that houses at least the scanning optical system and the optical detecting units. The optical detecting units are mounted on the optical housing via an intermediate member having a thermal expansion coefficient smaller than that of the optical housing.
    Type: Application
    Filed: June 29, 2007
    Publication date: October 25, 2007
    Inventors: Keiichi SERIZAWA, Yasumasa Tomita
  • Patent number: 7256813
    Abstract: An optical scanner for writing an electrostatic latent image on an image carrier includes a scanning optical system that forms an optical scanning path, a pair of optical detecting units arranged at two positions on the optical scanning path for detecting a write-start position and a write-end position to measure a time for scanning from the write-start position to the write-end position, and an optical housing that houses at least the scanning optical system and the optical detecting units. The optical detecting units are mounted on the optical housing via an intermediate member having a thermal expansion coefficient smaller than that of the optical housing.
    Type: Grant
    Filed: December 12, 2003
    Date of Patent: August 14, 2007
    Assignee: Ricoh Company, Limited
    Inventors: Keiichi Serizawa, Yasumasa Tomita
  • Publication number: 20070159674
    Abstract: An optical scanning unit includes: a light source configured to emit a light beam; a lens arranged so that the light beam emitted from the light source passes therethrough; a rotatable deflector configured to deflect the light beam coming from the lens, the deflected light beam being guided to a light receiving member; a movable lens holder configured to hold the lens, the lens holder being provided in a space between the light source and the deflector; a support member having a first face located on a first side thereof, the first face facing toward a vertically-downward direction and extending in a direction substantially parallel to a reference-axis defined between the light source and the deflector, there also being a second face located on a second side, the second face being arranged opposite to the first face; and a force-transferring member configured to transfer a force to the lens holder for moving the lens holder along the first face of the support member, the force being applied to the force-trans
    Type: Application
    Filed: January 11, 2007
    Publication date: July 12, 2007
    Inventor: Yasumasa Tomita
  • Publication number: 20070052957
    Abstract: An image forming apparatus includes an image carrier and an optical scanning device. The optical scanning device generates an optical scanning beam and includes an enclosure. The enclosure includes a pair of arch-like-shaped supporting members. Inside the enclosure there are provided a light source for emitting a light beam, a light deflector for deflecting the light beam emitted from the light source so as to convert the light beam into the optical scanning beam, and at least one reflecting mirror for reflecting the optical scanning beam deflected by the light deflector to scan the image carrying surface of the image carrier. At least one of the reflecting mirrors includes a specific reflecting mirror having a light reflecting surface and mounted on the pair of arch-like-shaped supporting members at a position to reflect the optical scanning beam with the light reflecting surface toward the image carrying surface of the image carrier.
    Type: Application
    Filed: September 7, 2006
    Publication date: March 8, 2007
    Inventor: Yasumasa Tomita
  • Publication number: 20070030333
    Abstract: A deflecting unit deflects a light beam emitted by each of a plurality of light-beam emitting units independently to scan surfaces of different bodies to be scanned. Each of a plurality of light-receiving units receives the deflected light beam at a predetermined position in a direction of the deflection. An incident angle of the deflected light beam with respect to a scanning line extending in a direction of scanning on a light-receiving surface of the light-receiving unit is set to be identical for all of the light-receiving units.
    Type: Application
    Filed: August 1, 2006
    Publication date: February 8, 2007
    Inventor: Yasumasa Tomita
  • Publication number: 20060139440
    Abstract: An optical scanner includes more than two light sources, a rotatable deflecting unit that commonly deflects the light beams emitted by the light sources. An optical unit guides a corresponding one of deflected light beams to a corresponding surface to be scanned. The optical system units are disposed symmetrically around a center of rotation of the deflecting unit. A housing unit that houses the light source units, the deflecting unit, and the optical system units. A light shielding unit disposed in the housing unit so as to prevent the reflection and scattering of the deflected light beams by the optical system units, the light shielding unit being disposed between light beams that fall on the deflecting unit and light beams that are deflected from the deflecting unit.
    Type: Application
    Filed: December 14, 2005
    Publication date: June 29, 2006
    Inventor: Yasumasa Tomita
  • Patent number: 7038194
    Abstract: A multiple-beam scanning device of the present invention includes a light source unit provided with a plurality of light sources. A deflector deflects, in the main scanning direction, light beams issuing from the light sources. Optics condenses the light beams deflected by the deflector with optical devices having power in the subscanning direction main scanning direction, respectively, in such a manner as to establish a preselected beam spot diameter, and returns an optical path with at least one mirror for thereby scanning a subject surface. An adjusting device provides, in a plane formed by scanning lines deflected by the deflector, one of the optical devices with ? eccentricity about the center of an optical axis in the direction of the optical axis.
    Type: Grant
    Filed: August 21, 2003
    Date of Patent: May 2, 2006
    Assignee: Ricoh Company, Ltd.
    Inventor: Yasumasa Tomita