Patents by Inventor Akihisa Itabashi

Akihisa Itabashi 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: 8217978
    Abstract: An optical scanning apparatus, an image formation apparatus, and a phase modulation method are disclosed. The optical scanning apparatus includes a liquid crystal device for deflecting an optical beam irradiated by a semiconductor laser. The driving voltages for the liquid crystal device are controlled based on, e.g., the temperature of the liquid crystal device so that degradation of the diameter of a spot of the optical beam due to wavefront aberration is prevented.
    Type: Grant
    Filed: February 27, 2007
    Date of Patent: July 10, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Taku Amada, Tomohiro Nakajima, Akihisa Itabashi, Seizo Suzuki
  • Patent number: 7936494
    Abstract: An optical scanning device includes a light source, a deflector, and an optical system including an elongated optical element that focuses deflected luminous flux on a surface of a medium to be scanned. The optical element is supported by a first elastic member and reinforced by a reinforcing member arranged outside a beam effective range along a length of the optical element. The optical element is pressed by a pressing member in a pressing direction orthogonal to a deflection direction, and biased by a second elastic member in a direction opposite to the pressing direction. The pressing member and the second elastic member control a posture of the optical element at a substantially central part in a main scanning direction.
    Type: Grant
    Filed: September 24, 2010
    Date of Patent: May 3, 2011
    Assignee: Ricoh Company, Limited
    Inventor: Akihisa Itabashi
  • Patent number: 7903134
    Abstract: Each light detecting sensor, which is installed corresponding to each photoconductor drum, and to which the plurality of light beams passing through the scanning optical system are incident while moving in a main scanning direction includes a light-receiving device having a first light-receiving unit and a second light-receiving unit, which have different intervals from each other in the main scanning direction depending on a position of a sub-scanning direction, all the sizes of the first and the second light-receiving units being sizes covering an overall virtual area in a quadrangular shape surrounding a plurality of light spots in the light-receiving surface.
    Type: Grant
    Filed: February 27, 2008
    Date of Patent: March 8, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Akihisa Itabashi, Satoru Itoh, Mitsuo Suzuki
  • Patent number: 7826116
    Abstract: An optical scanning device includes a light source, a deflector, and an optical system including an elongated optical element that focuses deflected luminous flux on a surface of a medium to be scanned. The optical element is supported by a first elastic member and reinforced by a reinforcing member arranged outside a beam effective range along a length of the optical element. The optical element is pressed by a pressing member in a pressing direction orthogonal to a deflection direction, and biased by a second elastic member in a direction opposite to the pressing direction. The pressing member and the second elastic member control a posture of the optical element at a substantially central part in a main scanning direction.
    Type: Grant
    Filed: February 27, 2007
    Date of Patent: November 2, 2010
    Assignee: Ricoh Company, Ltd.
    Inventor: Akihisa Itabashi
  • Patent number: 7719737
    Abstract: An optical scanning device includes a laser-beam-phase-modulatable liquid crystal device. The liquid crystal device has stripe-like electrode patterns arranged in one direction, with a provision of a part for changing an effective value of a driving voltage separately for each of stripe-like electrode patterns.
    Type: Grant
    Filed: January 4, 2008
    Date of Patent: May 18, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Taku Amada, Seizo Suzuki, Akihisa Itabashi, Hiroyuki Suhara, Mitsuo Suzuki
  • Patent number: 7450274
    Abstract: An optical scanning apparatus includes M number of light sources that includes M number of semiconductor lasers and M number of coupling lenses, where M is a positive integer, a deflecting scanning unit that deflects laser beams from the light sources to a surface to be scanned, and a transmission-type prism that deflects optical path of the laser beam from at least one of the light sources by an infinitesimal amount of angle. The prism is disposed between the light sources and the deflecting scanning unit, has an incident surface and an output surface nonparallel to each other, and can rotate around an axis of rotation substantially parallel to the optical path of the laser beam.
    Type: Grant
    Filed: May 7, 2004
    Date of Patent: November 11, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Akihisa Itabashi, Taku Amada, Seizo Suzuki, Toshihiro Suzuki
  • Publication number: 20080204852
    Abstract: An optical scanning apparatus, an image formation apparatus, and a phase modulation method are disclosed. The optical scanning apparatus includes a liquid crystal device for deflecting an optical beam irradiated by a semiconductor laser. The driving voltages for the liquid crystal device are controlled based on, e.g., the temperature of the liquid crystal device so that degradation of the diameter of a spot of the optical beam due to wavefront aberration is prevented.
    Type: Application
    Filed: February 27, 2007
    Publication date: August 28, 2008
    Inventors: Taku Amada, Tomohiro Nakajima, Akihisa Itabashi, Seizo Suzuki
  • Publication number: 20080204846
    Abstract: Each light detecting sensor, which is installed corresponding to each photoconductor drum, and to which the plurality of light beams passing through the scanning optical system are incident while moving in a main scanning direction includes a light-receiving device having a first light-receiving unit and a second light-receiving unit, which have different intervals from each other in the main scanning direction depending on a position of a sub-scanning direction, all the sizes of the first and the second light-receiving units being sizes covering an overall virtual area in a quadrangular shape surrounding a plurality of light spots in the light-receiving surface.
    Type: Application
    Filed: February 27, 2008
    Publication date: August 28, 2008
    Inventors: Akihisa ITABASHI, Satoru Itoh, Mitsuo Suzuki
  • Publication number: 20080170282
    Abstract: An optical scanning device includes a laser-beam-phase-modulatable liquid crystal device. The liquid crystal device has stripe-like electrode patterns arranged in one direction, with a provision of a part for changing an effective value of a driving voltage separately for each of stripe-like electrode patterns.
    Type: Application
    Filed: January 4, 2008
    Publication date: July 17, 2008
    Inventors: Taku AMADA, Seizo Suzuki, Akihisa Itabashi, Hiroyuki Suhara, Mitsuo Suzuki
  • Publication number: 20070206256
    Abstract: An optical scanning device includes a light source, a deflector, and an optical system including an elongated optical element that focuses deflected luminous flux on a surface of a medium to be scanned. The optical element is supported by a first elastic member and reinforced by a reinforcing member arranged outside a beam effective range along a length of the optical element. The optical element is pressed by a pressing member in a pressing direction orthogonal to a deflection direction, and biased by a second elastic member in a direction opposite to the pressing direction. The pressing member and the second elastic member control a posture of the optical element at a substantially central part in a main scanning direction.
    Type: Application
    Filed: February 27, 2007
    Publication date: September 6, 2007
    Inventor: Akihisa Itabashi
  • Publication number: 20070019269
    Abstract: An optical deflector deflects an optical beam output from a light source. An imaging optical system condenses the optical beam deflected by the optical deflector onto a surface to be scanned. The light source, the optical deflector, and the imaging optical system are accommodated in a housing. The housing includes a plurality of optical-deflector supporting units that supports the optical deflector; and an imaging-optical-system supporting unit that supports the imaging optical system. Distances from each of the optical-deflector supporting units to the imaging-optical-system supporting unit are substantially the same.
    Type: Application
    Filed: June 16, 2006
    Publication date: January 25, 2007
    Inventor: Akihisa Itabashi
  • Patent number: 7075563
    Abstract: There is provided a multi-beam laser scanning device able to efficiently suppress and prevent density fluctuation and achieve higher image quality. The multi-beam laser scanning device comprises a light emitting source generating a plurality of laser beams, a rotating deflector that has a plurality of deflecting surfaces. On a scanning surface, an interval between a scanning line X generated by deflection of a first deflecting surface of the deflector and a scanning line Y generated by deflection of a second deflecting surface of the deflector and adjacent to the scanning ling X satisfies at least one of the following two equations: ?P?<0.8·Ps ?P?<0.6·Ws where ?P? represents the difference between a maximum interval and a minimum interval between the scanning line X and the scanning line Y, Ps represents an object value of two neighboring scanning lines, and Ws represents the size of a light spot in the sub-scan direction.
    Type: Grant
    Filed: May 30, 2003
    Date of Patent: July 11, 2006
    Assignee: Ricoh Company, Ltd.
    Inventor: Akihisa Itabashi
  • Publication number: 20060132880
    Abstract: An optical-element holding device includes an elastic member that presses an optical element with an elastic force in a direction orthogonal to an optical axis of the optical element and orthogonal to a longitudinal direction of the optical element, and a support member that forms a pair with the elastic member and supports the optical element against a pressing force of the elastic member. At least three pairs of the elastic member and the support member are provided.
    Type: Application
    Filed: November 28, 2005
    Publication date: June 22, 2006
    Inventors: Taku Amada, Tomohiro Nakajima, Akihisa Itabashi
  • Patent number: 7050080
    Abstract: In an image forming apparatus which uses a semiconductor laser as a light source, a semiconductor laser is controlled by adjustment of an image write-in clock, and a highly accurate scanning position alignment is performed with a simple structure. An optical unit scans a rotational photo conductor by a laser light output by a semiconductor laser. A photodetector detects the laser light output by the semiconductor laser at a predetermined position. An electrostatic latent image is formed by scanning the rotational photo conductor based on the laser light detected by the photodetector. By dividing a clock output from a high-frequency clock generation circuit, an image clock which synchronized with the output of the photodetector is generated, and the phase of the image clock is changed.
    Type: Grant
    Filed: June 5, 2001
    Date of Patent: May 23, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Hidetoshi Ema, Akihisa Itabashi
  • Patent number: 7019766
    Abstract: An optical scanning device directs a light beam emitted from a light source to a mirror of a mechanical deflector through a first optical system, deflects the light beam in a main scanning direction by causing the light beam to be reflected by a mirror surface of the mirror, the angle of the mirror surface changing due to rotation of the mirror, and directs the deflected light beam through a second optical system to a surface to be scanned moving in a sub-scanning direction, the light source, first optical system and mechanical deflector being contained in a housing. The mechanical deflector is held in the housing through a holding member, and, also, material of the housing is different in heat conductivity from the holding member.
    Type: Grant
    Filed: July 18, 2003
    Date of Patent: March 28, 2006
    Assignee: Ricoh Company, Ltd.
    Inventor: Akihisa Itabashi
  • Patent number: 7006271
    Abstract: A coupling lens couples a beam emitted from a light source. A light deflector deflects the beam from the coupling lens at a uniform angular velocity. A line-image imaging optical system is disposed between the coupling lens and light deflector, and causes the beam to image a line image long along main scanning directions on or in the vicinity of a deflection reflective surface of the light deflector. A scanning and imaging optical system causes the beam deflected by the light deflector to image a beam spot on a medium to be scanned. In an optical housing, the light source, coupling lens, light deflector, line-image imaging optical system and scanning and imaging optical system are disposed, and contained. A plurality of holding and fixing locations are provided for holding and fixing a light-source part including the light source and coupling lens is provided in at least one of the light-source part and optical housing.
    Type: Grant
    Filed: April 6, 2001
    Date of Patent: February 28, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Nobuaki Ono, Akihisa Itabashi
  • Patent number: 6937371
    Abstract: An optical system includes three optical systems. The first has a coupling lens. The second includes a lens having a positive power in a vertical scanning direction and forms the light flux into a line image extending in the horizontal scanning direction on a deflector. The third includes a first lens having a positive power in the horizontal scanning direction, and a second lens having a positive power in the vertical scanning direction. Lateral magnification in the horizontal scanning direction is set larger than that in the vertical scanning direction. Temperature near the first lens is maintained higher than that near the second lens.
    Type: Grant
    Filed: June 15, 2004
    Date of Patent: August 30, 2005
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshinori Hayashi, Seizo Suzuki, Atsushi Kawamura, Hiromichi Atsuumi, Kohji Sakai, Akihisa Itabashi
  • Patent number: 6932271
    Abstract: An optical scanning apparatus scans a surface to be scanned in a main scanning direction by simultaneously using a plurality of optical spots formed of a plurality of optical beans emitted from an illuminant, comprising: a light path deflecting part deflecting a light path of at least one of the optical beams, wherein the light path deflecting part is provided in light paths of the optical beams wherein the light path deflecting part may use a liquid crystal deflecting element formed of a liquid crystal element being controllable by an electronic signal to deflect the light path of the one of the optical beams.
    Type: Grant
    Filed: January 26, 2001
    Date of Patent: August 23, 2005
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomohiro Nakajima, Akihisa Itabashi
  • Publication number: 20050179971
    Abstract: An optical scanning device includes: a light source; a deflector deflecting light beam from the light source; a coupling lens carrying out coupling of the light beam from the light source; a first optical system leading the light beam from the coupling lens to the deflector; a scanning optical system leading the light beam deflected by the deflector to a to-be-scanned surface; and a phase-modulatable liquid crystal device disposed on a light path lying from the light source through the to-be-scanned surface and driven by an electric signal, wherein: the first optical system at least comprises an optical device having: a surface having power positive in a sub-scanning direction; and a surface having power positive in a main scanning direction.
    Type: Application
    Filed: January 11, 2005
    Publication date: August 18, 2005
    Inventors: Taku Amada, Seizo Suzuki, Akihisa Itabashi, Hiroyuki Suhara, Mitsuo Suzuki
  • Publication number: 20050105156
    Abstract: An optical scanning apparatus includes light sources, an aperture having, and coupling lenses. Numbers of the light sources and the coupling lenses are equal to each other and the apparatus satisfies an inequality 12.7<(D×?0×m0×dpi)/(2×NA)<38.1 and an equation ?0=(?+???)/(n?1), wherein D represents a width of the slit of the aperture, ?0 represents a beam open angle, mo represents a total lateral magnification ratio, dpi represents a number of dots per inch, NA represents a numerical aperture, ?+ represents a positive open angle, ?? represents a negative open angle, and n represents the number. Further, an image forming apparatus using this optical scanning apparatus and an image forming method are provided.
    Type: Application
    Filed: December 21, 2004
    Publication date: May 19, 2005
    Inventors: Nobuaki Ono, Tomohiro Nakajima, Akihisa Itabashi, Kenichi Takanashi, Tomoya Ohsugi