Patents by Inventor Tomohiro Nakajima

Tomohiro Nakajima 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: 7706040
    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 beams 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 9, 2008
    Date of Patent: April 27, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Taku Amada, Seizo Suzuki, Satoru Itoh, Tomohiro Nakajima
  • Publication number: 20100091083
    Abstract: An optical scanning device includes an optical housing in which a polygon mirror that is rotated by a motor is accommodated and an air inlet that includes a filter. An airflow guiding member is arranged at a position opposite to a surface of the polygon mirror on the air inlet side. An air inducing path is provided, which includes a first flowing path and a second flowing path. The first flowing path includes a first end linked to the air inlet and a second end arranged close to a mirror surface of the polygon mirror. The second flowing path is formed with a surface of the airflow guiding member on an opposite side of the air inlet and a top surface of the polygon mirror.
    Type: Application
    Filed: October 7, 2009
    Publication date: April 15, 2010
    Inventors: Yukio Itami, Tomoya Ohsugi, Magane Aoki, Tomohiro Nakajima, Yoshinori Hayashi, Naoki Miyatake, Kensuke Masuda, Naoto Watanabe, Satoshi Tsuchiya
  • Patent number: 7697180
    Abstract: A light deflector is disclosed that includes a movable mirror serving as a deflector supported by a rotary shaft and configured to deflect a light beam emitted from a light source and scan an area to be scanned; a rotation part configured to cause the movable mirror to vibrate in a reciprocating manner by periodically applying a rotational torque to the movable mirror; a driving circuit configured to control the rotation part; a circuit board having the driving circuit provided thereon, the circuit board being configured to support the movable mirror as a unit; a contact plane contacting the circuit board in a plane perpendicular to the rotary shaft of the movable mirror; and a positioning part configured to determine the position of the rotary shaft in the contact plane.
    Type: Grant
    Filed: November 20, 2006
    Date of Patent: April 13, 2010
    Assignee: Ricoh Company, Ltd.
    Inventor: Tomohiro Nakajima
  • Publication number: 20100045766
    Abstract: In a beam-spot position compensation method for use in an optical scanning device which scans a surface of a photosensitive medium by a light beam emitted by a light source, a plurality of sections are defined by dividing a scanning region on the scanned surface. An emission timing of the light beam for every section is adjusted so that a spacing between beam-spot positions corresponding to pixels of start and end of each section is changed by a predetermined amount. The sparseness or denseness of beam-spot position spacings of the plurality of sections in the whole scanning region is compensated.
    Type: Application
    Filed: October 29, 2009
    Publication date: February 25, 2010
    Inventors: Shigeaki IMAI, Tomohiro Nakajima
  • Patent number: 7619797
    Abstract: An optical scanning apparatus includes a housing that positions and holds a plurality of light sources emitting light beams, a deflection mirror that deflects the light beams to perform main scanning, and at least one of optical image forming elements closest to the deflection mirror to form images on respective image carriers. A plurality of reflectors guide the light beams exiting the housing to the respective image carriers. A pair of support members face each other to support the housing in a main scanning direction. A support mechanism supports the reflectors by bridging the reflectors between the support members and also couples the support members to each other. Relative positions of the reflectors are arranged in a cross-sectional plane perpendicular to a main scanning direction between the support members.
    Type: Grant
    Filed: October 14, 2008
    Date of Patent: November 17, 2009
    Assignee: Ricoh Company, Ltd.
    Inventor: Tomohiro Nakajima
  • Patent number: 7599105
    Abstract: A disclosed optical scanning device includes an oscillating mirror supported by a torsion beam for deflecting light beams from a light source unit to scan an object surface backward and forward. A window member transmits light beams incident on and reflected from an oscillating mirror. A sealing member holds the window member and seals a space in which the oscillating mirror is mounted.
    Type: Grant
    Filed: December 11, 2006
    Date of Patent: October 6, 2009
    Assignee: Ricoh Company, Ltd.
    Inventor: Tomohiro Nakajima
  • Patent number: 7593029
    Abstract: An optical deflector of the present invention includes a movable mirror and torsion bars supporting the mirror and formed integrally with the mirror. The mirror reciprocatingly vibrates to reflect a light beam to thereby deflect it. The mirror is curved in the form of an arch in a section including at least the torsion bars. The mirror deforms little during vibration even if it is thin. Small power can cause such a thin mirror to vibrate with a large amplitude.
    Type: Grant
    Filed: August 20, 2002
    Date of Patent: September 22, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Yukito Satoh, Mitsumi Fujii, Tomohiro Nakajima, Yoshinori Hayashi, Eiji Mochizuki
  • Publication number: 20090225383
    Abstract: An optical scanning device is disclosed that includes a light source unit, a light source drive unit, a deflection unit, a scanning image optical system, and a light beam detection unit. In the optical scanning device, the light source drive unit controls an amount of light emission of the light source unit, and a light emission amount control period in which the light source unit is forcibly turned OFF is set to the light source drive unit during a period from when the deflection unit deflects to an edge of a scanning angle for scanning the main scanning area to when the deflection unit deflects to a maximum deflection angle of the deflection unit within a non-image forming period.
    Type: Application
    Filed: March 3, 2009
    Publication date: September 10, 2009
    Inventors: Masahiro Soeda, Tomohiro Nakajima
  • Publication number: 20090225148
    Abstract: An optical writing head includes light-emitting element array chips; a circuit board on which the light-emitting element array chips are mounted; and an imaging element array that focuses light beams emitted from the light-emitting element array chips to form optical spots. The following inequality is satisfied: L 1 < 25.4 × N ? where L1 is an arrangement pitch [mm] between any adjacent light-emitting element array chips at normal temperature, ? is resolution [dpi] in a main scanning direction, and N is the number of light-emitting points of each of the light-emitting element array chips.
    Type: Application
    Filed: February 4, 2009
    Publication date: September 10, 2009
    Inventors: Yukio Itami, Tomohiro Nakajima
  • Patent number: 7561318
    Abstract: A disclosed optical scanning apparatus for scanning a scanning surface using a light beam, the optical scanning apparatus comprises: a light source having a plurality of luminous sources; a deflection unit collectively deflecting a plurality of light beams emitted from the plural luminous sources; a light guiding unit guiding at least a portion of each of the plural light beams to a predetermined direction without using the deflection unit; and a photo-detection system receiving the plural guided light beams and the plural deflected light beams and outputting a signal based on the received light beams.
    Type: Grant
    Filed: August 2, 2006
    Date of Patent: July 14, 2009
    Assignee: Ricoh Company, Ltd.
    Inventor: Tomohiro Nakajima
  • Publication number: 20090153933
    Abstract: A disclosed optical scanning device includes a light source unit configured to emit a laser beam; an oscillating mirror configured to deflect the laser beam from the light source unit; a scanning/imaging optical system configured to focus the deflected laser beam on a target surface; and plural light-receiving elements configured to receive the laser beam in a scanning area of the laser beam, the position of the oscillating mirror being adjusted such that time intervals between output pulses in output signals of the respective light-receiving elements become substantially the same between the light-receiving elements and/or widths of the output pulses become substantially the same between the light-receiving elements.
    Type: Application
    Filed: December 12, 2008
    Publication date: June 18, 2009
    Inventors: Satoshi Tsuchiya, Tomohiro Nakajima, Mitsuo Suzuki
  • Patent number: 7532227
    Abstract: An optical scanner is capable of effectively correcting a difference with respect to the sub-scanning direction between the positions of optical spots for scanning photoconductor drums of a tandem type color image forming apparatus. The optical scanner includes an optical axis adjusting part. The optical axis adjusting part uses a deflecting mirror or a wedge-shaped prism to deflect the optical axis of an optical beam with respect to the sub-scanning direction. As a result, it is possible to accurately correct a resist difference among individual image forming stations and form a high-quality color image without any color displacement.
    Type: Grant
    Filed: July 1, 2003
    Date of Patent: May 12, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomohiro Nakajima, Akira Kojima, Ikuko Yamashiro, Seizo Suzuki, Taku Amada, Yoshinori Hayashi, Kazuyuki Shimada
  • Publication number: 20090115834
    Abstract: An optical scanning apparatus includes a housing that positions and holds a plurality of light sources emitting light beams, a deflection mirror that deflects the light beams to perform main scanning, and at least one of optical image forming elements closest to the deflection mirror to form images on respective image carriers. A plurality of reflectors guide the light beams exiting the housing to the respective image carriers. A pair of support members face each other to support the housing in a main scanning direction. A support mechanism supports the reflectors by bridging the reflectors between the support members and also couples the support members to each other. Relative positions of the reflectors are arranged in a cross-sectional plane perpendicular to a main scanning direction between the support members.
    Type: Application
    Filed: October 14, 2008
    Publication date: May 7, 2009
    Inventor: Tomohiro Nakajima
  • Patent number: 7525561
    Abstract: An optical scanner is capable of effectively correcting a difference with respect to the sub-scanning direction between the positions of optical spots for scanning photoconductor drums of a tandem type color image forming apparatus. The optical scanner includes an optical axis adjusting part. The optical axis adjusting part uses a deflecting mirror or a wedge-shaped prism to deflect the optical axis of an optical beam with respect to the sub-scanning direction. As a result, it is possible to accurately correct a resist difference among individual image forming stations and form a high-quality color image without any color displacement.
    Type: Grant
    Filed: June 13, 2006
    Date of Patent: April 28, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomohiro Nakajima, Akira Kojima, Ikuko Yamashiro, Seizo Suzuki, Taku Amada, Yoshinori Hayashi, Kazuyuki Shimada
  • Patent number: 7511868
    Abstract: A multi-beam luminous source apparatus, an optical scanning apparatus, and an image formation apparatus are provided. The multi-beam luminous source includes a first member for supporting a coupling lens and a second member for supporting a control substrate that supports a Vertical Cavity Surface Emitting Laser (VCSEL). The first member and the second member are joined with a screw at a reference plane that perpendicularly intersects an optical axis of the coupling lens. The second member includes a base member that supports the control substrate and a base member that includes a branch mirror, a convergent lens, and an optical detection sensor.
    Type: Grant
    Filed: September 14, 2006
    Date of Patent: March 31, 2009
    Assignee: Ricoh Company, Ltd.
    Inventor: Tomohiro Nakajima
  • Publication number: 20090073524
    Abstract: A module configured to deflect light in an image forming apparatus. A torsion bar supports a mirror and defines a rotational axis of the mirror. A controller is configured to apply electronic pulses to at least one driving device to oscillate the mirror in the module around the rotational axis at a scanning frequency different than a resonance frequency of the mirror.
    Type: Application
    Filed: November 5, 2008
    Publication date: March 19, 2009
    Inventor: Tomohiro NAKAJIMA
  • Publication number: 20090060569
    Abstract: An image forming apparatus including a plurality of image forming cartridges removably mounted to an apparatus body one above the other is disclosed. Structural members each partition off a space between nearby image forming cartridges mounted to the apparatus body. The apparatus is capable of obviating banding ascribable to the vibration of the cartridges.
    Type: Application
    Filed: October 23, 2008
    Publication date: March 5, 2009
    Inventors: Yasushi NAKAZATO, Kazuyuki Shimada, Tomohiro Nakajima
  • Publication number: 20090060583
    Abstract: A light source unit is provided which includes a light source with a plurality of light emission portions two-dimensionally arranged; a substrate on which the light source is mounted; a first support portion supporting the substrate; a bias member biasing the substrate towards the first support portion; a coupling element coupling a light beam emitted from the light source; a second support portion supporting the coupling element; and a holding member holding a position of the substrate relative to the first support portion.
    Type: Application
    Filed: August 26, 2008
    Publication date: March 5, 2009
    Inventors: Taku Amada, Tomohiro Nakajima, Yoshinori Hayashi, Nobuaki Kubo
  • Publication number: 20090052944
    Abstract: A light source unit is provided, which includes a light source with a plurality of light emission portions two-dimensionally arranged; a substrate on which the light source is mounted; a first support portion supporting the substrate; a bias member biasing the substrate towards the first support portion; a coupling element coupling a light beam emitted from the light source; a second support portion supporting the coupling element; a holding member holding a position of the substrate relative to the first support portion, a fitting portion provided in each of the first and second support portions to rotatably fit the first and second support portions into each other around an optical axis of the light source; and a fastening member integrally fastening the first and second support portions.
    Type: Application
    Filed: August 19, 2008
    Publication date: February 26, 2009
    Inventors: Nobuaki Kubo, Tomohiro Nakajima, Taku Amada, Yoshinori Hayashi
  • Patent number: 7495813
    Abstract: A vibration mirror used in an optical scanning device has two reflection surfaces on opposite sides. A pair of light beams corresponding to a pair of different colors are irradiated on one reflection surface and another pair of light beams corresponding to another pair of different colors are irradiated on other reflection surface. If there are fluctuations in dimensions or a change in temperature, because the vibration mirror is one, all the colors are subjected to the same influences.
    Type: Grant
    Filed: April 5, 2006
    Date of Patent: February 24, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroshi Akiyama, Yoshinori Hayashi, Tomohiro Nakajima