Patents by Inventor Kohji Sakai

Kohji Sakai 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: 6366384
    Abstract: A multi-beam scanning method for scanning a scanning surface with a plurality of beams which are formed into a plurality of beam spots separated from each other in a sub scanning direction includes providing n number of semiconductor laser array units, each of the n number of semiconductor laser array units having m number of light emitting points, where n is not equal to 1 and m is not equal to 1, coupling light beams emitted from the light emitting points of the semiconductor laser arrays, synthesizing the coupled beams with a beam synthesizing device to obtain m×n number of beams and deflecting the m×n number of beams at substantially the same time such that the deflected beams are impinged on the scanning surface.
    Type: Grant
    Filed: June 15, 1999
    Date of Patent: April 2, 2002
    Assignee: Ricoh Company, Ltd.
    Inventors: Magane Aoki, Kohji Sakai
  • Patent number: 6348989
    Abstract: A scanning and image forming lens system in an optical scanning apparatus optical scans a surface to be scanned by deflecting a luminous flux emitted from a light source in a direction corresponding to a main scanning direction via an optical deflector at equiangular velocity. The scanning image forming lens system transmits the luminous flux deflected by the optical deflector so as to condense the luminous flux into an optical beam spot on the surface to be scanned and to scan the surface to be scanned with the optical beam spot. The scanning image forming lens system includes one or more image forming optical elements including at least one lens. At least one lens surface of the at least one lens of the scanning image forming lens system has a non-arc shape in a sub scanning cross section.
    Type: Grant
    Filed: May 29, 2001
    Date of Patent: February 19, 2002
    Assignee: Ricoh Company, Ltd.
    Inventors: Magane Aoki, Kohji Sakai
  • Patent number: 6348988
    Abstract: A scanning and image forming lens system in an optical scanning apparatus optical scans a surface to be scanned by deflecting a luminous flux emitted from a light source in a direction corresponding to a main scanning direction via an optical deflector at equiangular velocity. The scanning image forming lens system transmits the luminous flux deflected by the optical deflector so as to condense the luminous flux into an optical beam spot on the surface to be scanned and to scan the surface to be scanned with the optical beam spot. The scanning image forming lens system includes one or more image forming optical elements including at least one lens. At least one lens surface of the at least one lens of the scanning image forming lens system has a non-arc shape in a sub scanning cross section.
    Type: Grant
    Filed: May 29, 2001
    Date of Patent: February 19, 2002
    Assignee: Ricoh Company, Ltd.
    Inventors: Magane Aoki, Kohji Sakai
  • Patent number: 6347004
    Abstract: An optical scanning apparatus includes a light source for outputting light, a first lens system arranged to receive the light output from the light source and to transmit a light flux therefrom, an optical deflector arranged to receive the light flux from the first lens system and having a deflecting reflective plane to deflect the light flux from a surface therefrom and a second lens system arranged to receive the light flux deflected from the optical deflector and to condense the deflected luminous flux into an optical beam spot on a surface to be scanned so as to form images having image heights, the luminous flux condensed by the second lens system into the optical beam spot including an optical beam waist.
    Type: Grant
    Filed: August 6, 1999
    Date of Patent: February 12, 2002
    Assignee: Ricoh Company, Ltd.
    Inventors: Seizo Suzuki, Magane Aoki, Kohji Sakai
  • Publication number: 20010055140
    Abstract: An optical scanning apparatus reduces shading and variations in light intensity and significantly increases light usage during an optical scanning process using a simple construction in which a laser beam from a light source is deflected by a light deflector having a reflective surface and is focused to a spot upon a scanning surface by a scanning lens to thereby perform optical scanning. The light source is arranged to produce a laser beam which includes both P-polarized light and S-polarized light. A direction of polarization of the light source is inclined in a plane perpendicular to the optical axis with respect to both the deflecting direction (the Y-axis direction) and a direction perpendicular to the deflecting direction (Z-axis direction).
    Type: Application
    Filed: February 22, 2001
    Publication date: December 27, 2001
    Inventors: Kohji Sakai, Yoshinori Hayashi
  • Publication number: 20010053014
    Abstract: A scanning and image forming lens system in an optical scanning apparatus optical scans a surface to be scanned by deflecting a luminous flux emitted from a light source in a direction corresponding to a main scanning direction via an optical deflector at equiangular velocity. The scanning image forming lens system transmits the luminous flux deflected by the optical deflector so as to condense the luminous flux into an optical beam spot on the surface to be scanned and to scan the surface to be scanned with the optical beam spot. The scanning image forming lens system includes one or more image forming optical elements including at least one lens. At least one lens surface of the at least one lens of the scanning image forming lens system has a non-arc shape in a sub scanning cross section.
    Type: Application
    Filed: May 29, 2001
    Publication date: December 20, 2001
    Inventors: Magane Aoki, Kohji Sakai
  • Publication number: 20010048543
    Abstract: A scanning and image forming lens system in an optical scanning apparatus optical scans a surface to be scanned by deflecting a luminous flux emitted from a light source in a direction corresponding to a main scanning direction via an optical deflector at equiangular velocity. The scanning image forming lens system transmits the luminous flux deflected by the optical deflector so as to condense the luminous flux into an optical beam spot on the surface to be scanned and to scan the surface to be scanned with the optical beam spot. The scanning image forming lens system includes one or more image forming optical elements including at least one lens. At least one lens surface of the at least one lens of the scanning image forming lens system has a non-arc shape in a sub scanning cross section.
    Type: Application
    Filed: May 29, 2001
    Publication date: December 6, 2001
    Inventors: Magane Aoki, Kohji Sakai
  • Publication number: 20010022343
    Abstract: In a multi-beam scanning device and method of the present invention, a semiconductor laser array having a plurality of light emitting parts emitting multiple laser beams is provided. A rotary deflector deflects the laser beams emitted by the light emitting parts of the semiconductor laser array. The deflected laser beams from the rotary deflector is focused onto a scanned surface to form a plurality of beam spots that are separated on the scanned surface in a sub-scanning direction, the scanned surface being scanned simultaneously with the plurality of beam spots in a main scanning direction by a rotation of the rotary deflector.
    Type: Application
    Filed: February 21, 2001
    Publication date: September 20, 2001
    Applicant: RICOH COMPANY LTD.
    Inventors: Kohji Sakai, Seizo Suzuki, Hiromichi Atsuumi, Akhisa Itabashi
  • Patent number: 6288819
    Abstract: A scanning and image forming lens system in an optical scanning apparatus optical scans a surface to be scanned by deflecting a luminous flux emitted from a light source in a direction corresponding to a main scanning direction via an optical deflector at equiangular velocity. The scanning image forming lens system transmits the luminous flux deflected by the optical deflector so as to condense the luminous flux into an optical beam spot on the surface to be scanned and to scan the surface to be scanned with the optical beam spot. The scanning image forming lens system includes one or more image forming optical elements including at least one lens. At least one lens surface of the at least one lens of the scanning image forming lens system has a non-arc shape in a sub scanning cross section.
    Type: Grant
    Filed: May 11, 2000
    Date of Patent: September 11, 2001
    Assignee: Ricoh Company, Ltd.
    Inventors: Maga Aoki, Kohji Sakai
  • Patent number: 6256133
    Abstract: An optical scanning apparatus is constructed such that a light beam from a light source is formed into a linear image extending in a main scanning direction and is caused to be deflected at a constant velocity by virtue of a light deflecting system having a deflective reflecting surface which is located in a vicinity of an image formation position of the linear image. The deflected light beam is allowed to transmit through a scanning image formation lens so as to be converged into a beam spot on a surface to be scanned, thus causing the beam spot to scan the surface to be scanned at a constant speed.
    Type: Grant
    Filed: June 25, 1999
    Date of Patent: July 3, 2001
    Assignee: Ricoh Co., Ltd.
    Inventors: Seizo Suzuki, Magane Aoki, Kohji Sakai
  • Patent number: 6229638
    Abstract: An optical scanning apparatus reduces shading and variations in light intensity and significantly increases light usage during an optical scanning process using a simple construction in which a laser beam from a light source is deflected by a light deflector having a reflective surface and is focused to a spot upon a scanning surface by a scanning lens to thereby perform optical scanning. The light source is arranged to produce a laser beam which includes both P-polarized light and S-polarized light. A direction of polarization of the light source is inclined in a plane perpendicular to the optical axis with respect to both the deflecting direction (the Y-axis direction) and a direction perpendicular to the deflecting direction (Z-axis direction).
    Type: Grant
    Filed: June 1, 1999
    Date of Patent: May 8, 2001
    Assignee: Ricoh Company, Ltd.
    Inventors: Kohji Sakai, Yoshinori Hayashi
  • Patent number: 6166842
    Abstract: A scanning and image forming lens system in an optical scanning apparatus optical scans a surface to be scanned by deflecting a luminous flux emitted from a light source in a direction corresponding to a main scanning direction via an optical deflector at equiangular velocity. The scanning image forming lens system transmits the luminous flux deflected by the optical deflector so as to condense the luminous flux into an optical beam spot on the surface to be scanned and to scan the surface to be scanned with the optical beam spot. The scanning image forming lens system includes one or more image forming optical elements including at least one lens. At least one lens surface of the at least one lens of the scanning image forming lens system has a non-arc shape in a sub scanning cross section.
    Type: Grant
    Filed: January 20, 1999
    Date of Patent: December 26, 2000
    Assignee: Ricoh Company, Ltd.
    Inventors: Magane Aoki, Kohji Sakai
  • Patent number: 5999345
    Abstract: A multi-beam light source unit includes a light source section having a plurality of semiconductor lasers, a plurality of collimating lenses for collimating light beams emitted from the semiconductor lasers, and a supporting member for supporting the plurality of semiconductor lasers and the plurality of collimating lenses arranged in a main scanning direction. There is a relation expressed by D/d.noteq.1 relating to a distance D between adjacent ones of the semiconductor lasers and a distance d of adjacent ones of the collimating lenses, and the light source section is supported so that it can be angularly adjusted so as to change a rotational position of the light source section including the semiconductor lasers and the collimating lenses.
    Type: Grant
    Filed: June 30, 1998
    Date of Patent: December 7, 1999
    Assignee: Ricoh Company, Ltd.
    Inventors: Tomohiro Nakajima, Kohji Sakai
  • Patent number: 5831758
    Abstract: A multi-beam optical scanner, in which a lateral magnification .beta. in a composite system of an optical system between the light source for a multi-beam and the scanned surface satisfies the condition: 2<.beta..ltoreq.8.5, and a plurality of light spots on the scanned surface execute optical scanning of the scanning lines adjacent to each other.
    Type: Grant
    Filed: June 4, 1997
    Date of Patent: November 3, 1998
    Assignee: Ricoh Company, Ltd.
    Inventors: Kohji Sakai, Magane Aoki