Patents by Inventor Toshiaki Tokita

Toshiaki Tokita 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: 20130076851
    Abstract: An optical scanning device scanning scan target surfaces in a first direction with light includes: a light source emitting first and second light beams corresponding to two of the scan target surfaces; an optical deflector including a reflection surface on which the emitted first and second light beams are obliquely incident while being separated from each other in a second direction perpendicular to the first direction, and deflecting the first and second light beams; a scanning lens disposed on respective optical paths of the deflected first and second light beams; and a branching optical element transmitting therethrough most of the first light beam transmitted through the scanning lens, and reflecting most of the second light beam transmitted through the scanning lens. The deflected first and second light beams intersect between the optical deflector and the branching optical element, when projected on a plane perpendicular to the first direction.
    Type: Application
    Filed: September 21, 2012
    Publication date: March 28, 2013
    Inventors: Naoto WATANABE, Toshiaki Tokita, Kohji Sakai, Nobuaki Kubo
  • Publication number: 20130070323
    Abstract: An optical scanning device separately scanning plural scan target surfaces in a first direction with light includes: a light source unit configured to emit first and second light beams mutually different in polarization state; an optical deflector configured to rotate around an axis parallel to a second direction perpendicular to the first direction, and deflect the emitted light beams; an imaging optical element provided on respective optical paths of the deflected light beams; a polarization adjustment element provided on the optical paths of the light beams transmitted through the imaging optical element, and configured to correct respective changes in polarization state of the light beams occurring during the transmission of the light beams through the imaging optical element; and a polarization separation element provided on the optical paths of the light beams emitted from the polarization adjustment element, and configured to separate the light beams from each other.
    Type: Application
    Filed: September 10, 2012
    Publication date: March 21, 2013
    Inventors: Toshiaki TOKITA, Nobuaki KUBO, Naoto WATANABE, Kohji SAKAI
  • Patent number: 8368736
    Abstract: An optical scanning device includes four light sources, a pre-deflector optical system, a polygon mirror, an optical scanning system, etc. The optical scanning system includes deflector-side scanning lenses made of glass, imaging-surface-side scanning lenses made of resin, polarized light splitters, and reflecting mirrors. The deflector-side scanning lenses, the imaging-surface-side scanning lenses, the polarized light splitters, and the reflecting mirrors are arranged in this order on an optical path of light going from the polygon mirror toward drum-shaped photosensitive elements.
    Type: Grant
    Filed: June 22, 2010
    Date of Patent: February 5, 2013
    Assignee: Ricoh Company, Limited
    Inventors: Kenichiro Saisho, Toshiaki Tokita, Nobuaki Kubo
  • Patent number: 8351118
    Abstract: A polarization splitting device includes a polarization beam splitter having a polarization splitting surface and allows P-polarized light to transmit therethrough and reflects S-polarized light. A subwavelength structure grating is formed on the polarization splitting surface with a grating pitch smaller than wavelength of incident light. The polarization splitting device also includes a polarizer that is arranged on an optical path of light reflected from the polarization beam splitter and has a transmission axis that is parallel to a polarization direction of the S-polarized light.
    Type: Grant
    Filed: October 22, 2009
    Date of Patent: January 8, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Toshiaki Tokita, Hideaki Hirai, Seizo Suzuki
  • Patent number: 8162485
    Abstract: An image projection device performing pixel shift in synchronization with sequential updating of image data is disclosed that is able to start and stop pixel shift operations within a period of updating the image frames while maintaining brightness of the image. The image projection device has an intermediate image formation optical system including a light valve able to update an image frame in a line-sequential manner, a pixel shift unit to shift the light path of a light beam from the light valve so as to shift a position of an image formed on the light valve, and an intermediate image formation unit arranged on the light path between the light valve and the pixel shift unit for forming an intermediate image of the image on the light valve at a position of the pixel shift unit.
    Type: Grant
    Filed: January 30, 2006
    Date of Patent: April 24, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Atsushi Takaura, Takanobu Osaka, Yasuyuki Takiguchi, Toshiaki Tokita, Kazuhiro Fujita, Kazuya Miyagaki, Hiroyuki Sugimoto
  • Patent number: 8158020
    Abstract: A liquid crystal element comprising a pair of transparent substrates, a liquid crystal layer which fills in between the pair of substrates and can form a chiral smectic C phase in homeotropic orientation, and an electrode which generates, at least, an electric field (parallel electric field) in directions parallel to a principal face of the substrate for the liquid crystal layer is provided, wherein the liquid crystal layer comprises, at least, a chiral compound of the following general formula (1-I) or a chiral compound of the following general formula (2-I) and a chiral compound of the following general formula (2 -II) in a base liquid crystal material which can provide a phase sequence of an isotropic liquid phase, a nematic phase, a smectic A phase and a smectic C phase from a higher temperature side, wherein R1, A2, Z1, Z2, m and 1 in formula (1-I), X, R1, R2, and * in formula (2-I), and X, R3, R4, R5, and * in formula (2-II) are defined in the specification.
    Type: Grant
    Filed: March 1, 2007
    Date of Patent: April 17, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Yohei Takano, Hiroyuki Sugimoto, Toshiaki Tokita, Koh Fujimura, Yasuyuki Takiguchi, Yumi Matsuki, Haruki Amagawa, Toshiaki Nonaka
  • Publication number: 20110316959
    Abstract: An optical scanning device, arranged on one side of at least two to-be-scanned members in a second direction, and the two to-be-scanned members being arranged in a first direction perpendicular to the second, includes: an illuminating system that emits beams including a first beam and a second beam whose polarization directions are different from each other; an optical deflector that deflects the beams; and a scanning optical system that includes a polarization separation element that transmits one of the first and second beams and reflects the other; a first mirror group including reflecting mirrors for guiding the first beam to a to-be-scanned member; and a second mirror group including reflecting mirrors for guiding the second beam to a to-be-scanned member. Last-stage reflecting mirrors in the first and second mirror groups are arranged on one side of the beams deflected by the optical deflector in the second direction.
    Type: Application
    Filed: June 27, 2011
    Publication date: December 29, 2011
    Inventors: Kenichiroh SAISHO, Toshiaki Tokita, Nobuaki Kubo, Seizo Suzuki
  • Publication number: 20110235132
    Abstract: An optical scanning device includes a light source that emits first and second light beams, and an optical splitter to which the first and second light beams deflected by an optical deflector are incident. Principal rays of the first and second light beams incident to the optical splitter are nonparallel to each other in a plane orthogonal to a main-scanning direction. Transmitted light from the optical splitter out of the first light beam and reflected light from the optical splitter out of the second light beam are guided to corresponding scanning target surfaces, and transmitted light from the optical splitter out of the second light beam and reflected light from the optical splitter out of the first light beam reach none of the scanning target surfaces.
    Type: Application
    Filed: March 22, 2011
    Publication date: September 29, 2011
    Inventors: Kenichiroh Saisho, Toshiaki Tokita, Nobuaki Kubo
  • Publication number: 20110216386
    Abstract: A light scanning device scanning a plurality of scanned faces by a light beam, includes a light source unit emitting a plurality of light beams including a first light beam and a second light beam having different polarization directions to each other; a beam splitter splitting each of the first light beam and the second light beam emitted from the light source unit; an incident optical system allowing each of split first light beams to be incident with an a angular difference to each other, and allowing each of split second light beams to be incident with an angular difference to each other; a deflector respectively deflecting each of the split first light beams and each of the split second light beams entered from the incident optical system; and a scanning optical system, including a polarization splitting device for splitting a plurality of the light beams deflected by the deflector based on a difference in a polarization direction, individually focusing each of the plurality of the light beams split by t
    Type: Application
    Filed: March 7, 2011
    Publication date: September 8, 2011
    Inventors: Naoto WATANABE, Toshiaki TOKITA
  • Patent number: 7929071
    Abstract: A disclosed electric field generating device includes an electric field generating unit including a substrate, line electrodes, and an electric field generating resistor and configured to generate an electric field. In the disclosed electric field generating device, the line electrodes are formed on at least one side of the substrate in parallel with each other so as to divide the side of the substrate into multiple sections; the electric field generating resistor is shaped like a strip and positioned so as to touch a part of each of the line electrodes; and some of the line electrodes have connectors for electric connection.
    Type: Grant
    Filed: March 12, 2007
    Date of Patent: April 19, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Yukiko Hirano, Toshiaki Tokita, Koh Fujimura, Yumi Matsuki, Toshimichi Hagiya, Takanobu Osaka, Masanori Kobayashi, Yohei Takano
  • Patent number: 7889224
    Abstract: A disclosed optical path switching device includes a polarization bistable VCSEL that emits a beam having a rising polarization plane, a laser light source configured to emit a beam having a polarization plane orthogonal to the rising polarization plane, and an optical path switching unit configured to switch an optical path of the beam emitted from the polarization bistable VCSEL by switching the angle of the rising polarization plane of the beam emitted from the polarization bistable VCSEL. The beam emitted from the polarization bistable VCSEL is incident on an entrance window of the optical path switching unit, and the beam emitted from the laser light source is incident on an exit window of the polarization bistable VCSEL.
    Type: Grant
    Filed: September 4, 2008
    Date of Patent: February 15, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Toshimichi Hagiya, Kazuya Miyagaki, Atsushi Takaura, Toshiaki Tokita
  • Publication number: 20110002025
    Abstract: A polarization-separation device includes: a beam splitter that includes a beam-separating surface, on which a light beam that contains a first light beam and a second light beam impinges, wherein polarization direction of the first light beam and polarization direction of the second light beam are perpendicular to each other, and incident angle of the first light beam and incident angle of the second beam vary independently while incident into the beam-separating surface; a first polarizer arranged in an optical path of light beams having transmitted through the beam splitter, and allows the first light beam to transmit therethrough; and a second polarizer arranged in an optical path of light beams reflected from the beam splitter, and allows the second light beam to transmit therethrough.
    Type: Application
    Filed: June 29, 2010
    Publication date: January 6, 2011
    Inventors: Toshiaki Tokita, Nobuaki Kubo, Kenichiro Saisho
  • Publication number: 20100328417
    Abstract: An optical scanning device includes four light sources, a pre-deflector optical system, a polygon mirror, an optical scanning system, etc. The optical scanning system includes deflector-side scanning lenses made of glass, imaging-surface-side scanning lenses made of resin, polarized light splitters, and reflecting mirrors. The deflector-side scanning lenses, the imaging-surface-side scanning lenses, the polarized light splitters, and the reflecting mirrors are arranged in this order on an optical path of light going from the polygon mirror toward drum-shaped photosensitive elements.
    Type: Application
    Filed: June 22, 2010
    Publication date: December 30, 2010
    Inventors: Kenichiro Saisho, Toshiaki Tokita, Nobuaki Kubo
  • Patent number: 7857458
    Abstract: An image display device is disclosed that has a simplified structure and is able to display a high quality image of high resolution at low cost. The image display device includes a light separation unit configured to extract a light beam having a predetermined wavelength band from light emitted from a light source; a light valve that controls a light beam incident thereon to form a plurality of sub frames of a target image; and a light path shift unit operable to shift a light path of an output light beam from the light valve having the predetermined wavelength band according to a frame period of the target image to locate one or more sub frame of the target image at different positions from other sub frames of the target image formed by the light valve.
    Type: Grant
    Filed: November 2, 2005
    Date of Patent: December 28, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Kazuhiro Fujita, Atsushi Takaura, Yasuyuki Takiguchi, Toshiaki Tokita, Toshiharu Murai, Hiroyuki Sugimoto, Kazuya Miyagaki, Takanobu Osaka
  • Patent number: 7787001
    Abstract: An image processing apparatus that performs resolution conversion on image data to output to a display unit includes a resolution converting unit configured to perform resolution conversion on the image data to generate pixel data having a resolution ? times as high as a resolution of the display unit, where ?>1; an image processing unit configured to perform an image processing on the pixel data; and a decimation unit configured to decimate the pixel data on which the image processing has been performed, to have a resolution equal to or lower than the resolution of the display unit, and to output decimated data to the display unit.
    Type: Grant
    Filed: March 16, 2006
    Date of Patent: August 31, 2010
    Assignee: Ricoh Company, Limited
    Inventors: Kenji Namie, Toshiharu Murai, Toshiaki Tokita, Yasuyuki Takiguchi, Kazuhiro Fujita, Hiroyuki Sugimoto
  • Patent number: 7753531
    Abstract: An image display apparatus acquires a high-quality image by suppressing positional fluctuation of projected dots due to a positional offset of an optical path deflecting element. A spatial light modulation element (1) displays an image by projecting a light from an illumination light source. A projection optical system (3) enlarges and projects the image formed on the spatial light modulation element (1). An optical path deflecting element (2) is provided between the spatial light modulation element (1) and the image formed on a screen (4) so as to deflect an optical path in accordance with a screen frame period. The optical path deflecting element (2) shifts the optical path for the image projected on the screen (4) at a high rate so as to apparently increase a number of picture elements. The optical path deflecting element (2) is located within the projection optical system.
    Type: Grant
    Filed: May 11, 2005
    Date of Patent: July 13, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Kazuhiro Fujita, Takanobu Osaka, Kazuya Miyagaki, Atsushi Takaura, Masanori Kobayashi, Hiroyuki Sugimoto, Kenji Namie, Yumi Matsuki, Toshiaki Tokita
  • Patent number: 7733317
    Abstract: A reliable image display apparatus is provided that is capable of preventing a direct current from being applied to liquid crystal of a spatial light modulating element so that damage such as burns in the liquid crystal and screen flicker may be prevented and a high resolution image with high image quality may be displayed. The image display apparatus is configured to divide a frame into 2i sub frames (i corresponding to a natural number) and sequentially display the sub frames using the liquid crystal spatial light modulating element. The image display apparatus includes a polarity switching unit configured to reverse the polarity of a drive voltage for a pixel of the spatial light modulating element for every j sub frame(s) (j corresponding to a natural number that is less than 2i) and for every n frame(s)(n corresponding to a natural number).
    Type: Grant
    Filed: January 27, 2005
    Date of Patent: June 8, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Toshiharu Murai, Kazuhiro Fujita, Kenji Kameyama, Toshiaki Tokita, Yasuyuki Takiguchi
  • Publication number: 20100118366
    Abstract: A polarization splitting device includes a polarization beam splitter having a polarization splitting surface and allows P-polarized light to transmit therethrough and reflects S-polarized light. A subwavelength structure grating is formed on the polarization splitting surface with a grating pitch smaller than wavelength of incident light. The polarization splitting device also includes a polarizer that is arranged on an optical path of light reflected from the polarization beam splitter and has a transmission axis that is parallel to a polarization direction of the S-polarized light.
    Type: Application
    Filed: October 22, 2009
    Publication date: May 13, 2010
    Inventors: Toshiaki TOKITA, Hideaki HIRAI, Seizo SUZUKI
  • Patent number: 7564508
    Abstract: A light path shift device is disclosed that is able to divide an effective region of a light path and drive the divided regions independently. The light path shift device includes a liquid crystal layer held between at least two opposite transparent substrates, the liquid crystal layer being homeotropically aligned and being able to form a chiral smectic C phase; and plural electrodes for applying an electric field in the liquid crystal layer in a horizontal direction. An effective region of the liquid crystal layer through which a light path passes is divided into plural sub-regions, plural light path shift elements with the electrodes formed thereon are stacked only at positions corresponding to the sub-regions, and are arranged so that boundary lines of the sub-regions are in agreement when being viewed along the direction of light propagation.
    Type: Grant
    Filed: March 14, 2006
    Date of Patent: July 21, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroyuki Sugimoto, Toshiaki Tokita, Kazuhiro Fujita, Toshiharu Murai, Yasuyuki Takiguchi, Atsushi Takaura, Kazuya Miyagaki, Takanobu Osaka
  • Publication number: 20090080907
    Abstract: A disclosed optical path switching device includes a polarization bistable VCSEL that emits a beam having a rising polarization plane, a laser light source configured to emit a beam having a polarization plane orthogonal to the rising polarization plane, and an optical path switching unit configured to switch an optical path of the beam emitted from the polarization bistable VCSEL by switching the angle of the rising polarization plane of the beam emitted from the polarization bistable VCSEL. The beam emitted from the polarization bistable VCSEL is incident on an entrance window of the optical path switching unit, and the beam emitted from the laser light source is incident on an exit window of the polarization bistable VCSEL.
    Type: Application
    Filed: September 4, 2008
    Publication date: March 26, 2009
    Inventors: Toshimichi Hagiya, Kazuya Miyagaki, Atsushi Takaura, Toshiaki Tokita