Patents by Inventor Yoshitaka Itoh

Yoshitaka Itoh 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: 8496335
    Abstract: A projector includes an illumination optical system, a light modulation element, and a projection optical system. The illumination optical system includes a first light source section, a plurality of second light source sections, and an optical axis conversion element. The optical axis conversion element emits the light beam, which is input from the first light source section, so that an exit optical axis of the light beam approximately matches with an illumination optical axis, and emits the light beams, which are respectively input from the plurality of second light source sections, so that exit optical axes of the light beams intersect the exit optical axis of the light beam from the first light source section between the optical axis conversion element and the light modulation element.
    Type: Grant
    Filed: April 14, 2009
    Date of Patent: July 30, 2013
    Assignee: Seiko Epson Corporation
    Inventor: Yoshitaka Itoh
  • Patent number: 8414134
    Abstract: An illumination apparatus includes first and second light source units. An optical axis converting element has a first surface that reflects a luminous flux emitted from the first light source unit and a second surface that reflects a luminous flux emitted from the second light source unit and is configured to reflect respective luminous fluxes emitted from the respective light source units in substantially one direction. Each of the luminous fluxes entering the optical axis converting element has different dimensions in two directions orthogonal to each other in a plane orthogonal to an emission axis of the each light source unit. The optical axis converting element is arranged such that a cross-sectional shape of the luminous flux entering each optical axis converting element taken along the surface has a short side direction in the same direction as the direction of arrangement of the first and second surfaces.
    Type: Grant
    Filed: December 22, 2009
    Date of Patent: April 9, 2013
    Assignee: Seiko Epson Corporation
    Inventor: Yoshitaka Itoh
  • Patent number: 8308307
    Abstract: An illuminator includes: a first light source and a second light source that are disposed substantially symmetrically with respect to an illumination optical axis, wherein each of the first and second light sources includes an arc tube, a first reflector disposed to surround part of the entire space around the optical axis of the arc tube, the first reflector reflecting the light emitted from the arc tube toward an object to be illuminated, and a second reflector disposed on the opposite side of the optical axis of the arc tube to the first reflector, the second reflector reflecting the light emitted from the arc tube toward the first reflector.
    Type: Grant
    Filed: August 18, 2009
    Date of Patent: November 13, 2012
    Assignee: Seiko Epson Corporation
    Inventor: Yoshitaka Itoh
  • Publication number: 20120229775
    Abstract: An illumination device includes a light source including plural light emitting devices arranged in a pattern and that generate and guide light, the light emitting devices having tilted gain regions wherein guiding directions of the light are tilted with respect to a perpendicular of output surfaces of the light source, an optical axis conversion device that bends optical axes of the light output from the light source, and a light distribution control device that controls a light distribution angle of the light output from the optical axis conversion device, wherein the light emitting devices are super luminescent diodes, and the light output from the light distribution control device diverge.
    Type: Application
    Filed: February 29, 2012
    Publication date: September 13, 2012
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Yoshitaka ITOH, Hiroyasu KASEYA, Fumika SUMIYAMA, Junichi OKAMOTO
  • Publication number: 20110304827
    Abstract: A projector includes a liquid crystal light valve to which the image data is written in a line sequential manner, a polarization switching element for switching between the first and second polarization states throughout the switching areas in a line sequential manner, and a birefringent optical element for changing the light path of the incident light in accordance with the polarization state thereof. The boundary position between the switching areas of the first and second polarization states moves in sync with the boundary position between the first and second image data writing areas corresponding to the first and second sub-frame.
    Type: Application
    Filed: June 13, 2011
    Publication date: December 15, 2011
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Yoshitaka Itoh
  • Publication number: 20110242490
    Abstract: A projector includes a liquid crystal light valve to which first image data and second image data are alternately written and a polarization switching device that has a plurality of switching areas and switches a polarization state between a first polarization state and a second polarization state for each of the switching areas. A boundary position between a switching area that provides the first polarization state and a switching area that provides the second polarization state moves in synchronization with a boundary position between an area where the first image data is written and an area where the second image data is written.
    Type: Application
    Filed: April 1, 2011
    Publication date: October 6, 2011
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Yoshitaka ITOH
  • Publication number: 20110188005
    Abstract: A projector includes: a housing; an optical element accommodated in the housing; and an air supply unit configured to generate a flow of cooling air for cooling a cooling target element including the optical element, a dustproof area into which the cooling air can be introduced from the outside of the housing via a dustproof filter is formed inside the housing, the optical element is accommodated in the dustproof area of the housing, and the air supply unit includes a first air supply unit configured to introduce the cooling air from the outside of the housing to the dustproof area via the dustproof filter, and a second air supply unit accommodated in the dustproof area and configured to supply the cooling air introduced to the dustproof area by the first air supply unit toward the optical element.
    Type: Application
    Filed: January 25, 2011
    Publication date: August 4, 2011
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Yasunaga MIYAZAWA, Yoshitaka ITOH, Toshihiko SAKAI, Katsuhiro MATSUYAMA, Yasuteru MIYAOKA
  • Publication number: 20100157252
    Abstract: An illumination apparatus includes first and second light source units. An optical axis converting element has a first surface that reflects a luminous flux emitted from the first light source unit and a second surface that reflects a luminous flux emitted from the second light source unit and is configured to reflect respective luminous fluxes emitted from the respective light source units in substantially one direction. Each of the luminous fluxes entering the optical axis converting element has different dimensions in two directions orthogonal to each other in a plane orthogonal to an emission axis of the each light source unit. The optical axis converting element is arranged such that a cross-sectional shape of the luminous flux entering each optical axis converting element taken along the surface has a short side direction in the same direction as the direction of arrangement of the first and second surfaces.
    Type: Application
    Filed: December 22, 2009
    Publication date: June 24, 2010
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Yoshitaka ITOH
  • Publication number: 20100053564
    Abstract: An illuminator includes: a first light source and a second light source that are disposed substantially symmetrically with respect to an illumination optical axis, wherein each of the first and second light sources includes an arc tube, a first reflector disposed to surround part of the entire space around the optical axis of the arc tube, the first reflector reflecting the light emitted from the arc tube toward an object to be illuminated, and a second reflector disposed on the opposite side of the optical axis of the arc tube to the first reflector, the second reflector reflecting the light emitted from the arc tube toward the first reflector.
    Type: Application
    Filed: August 18, 2009
    Publication date: March 4, 2010
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Yoshitaka ITOH
  • Publication number: 20090273760
    Abstract: A projector includes an illumination optical system, a light modulation element, and a projection optical system. The illumination optical system includes a first light source section, a plurality of second light source sections, and an optical axis conversion element. The optical axis conversion element emits the light beam, which is input from the first light source section, so that an exit optical axis of the light beam approximately matches with an illumination optical axis, and emits the light beams, which are respectively input from the plurality of second light source sections, so that exit optical axes of the light beams intersect the exit optical axis of the light beam from the first light source section between the optical axis conversion element and the light modulation element.
    Type: Application
    Filed: April 14, 2009
    Publication date: November 5, 2009
    Applicant: Seiko Epson Corporation
    Inventor: Yoshitaka ITOH
  • Publication number: 20090237618
    Abstract: An illumination apparatus includes: a first light source section; a plurality of second light source sections; and an optical axis conversion element which allows a light incident from the first light source section to emit in such a way that an exiting optical axis of the light approximately coincides with an illumination optical axis, and allows lights incident from the plurality of second light source sections to emit in such a way that exiting optical axes of the lights become approximately parallel to the illumination optical axis in positions close to the illumination optical axis.
    Type: Application
    Filed: March 18, 2009
    Publication date: September 24, 2009
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Yoshitaka ITOH
  • Patent number: 7580603
    Abstract: Aspects of the invention can provide an illumination device capable of preventing or reducing a reduction in efficiency of utilization of lights emitted from the light source, and also suitable to display high-quality moving images, and a display device and a projection type display device using this illumination device.
    Type: Grant
    Filed: January 26, 2005
    Date of Patent: August 25, 2009
    Assignee: Seiko Epson Corporation
    Inventor: Yoshitaka Itoh
  • Patent number: 7445345
    Abstract: A projection-type display device 1 including a light source 10, an optical integrator 20, dichroic mirrors 30 and 35, a reflecting mirror 36, a relay optical system 40, parallelizing lenses 50B, 50G and 50R, liquid crystal light valves 60B, 60G and 60R, incident side lenses 70B, 70G and 70R, a light-synthesizing cross dichroic prism 80, a relay lens 90, an emergent side lens 95, a liquid crystal light valve 100 and a projection lens 110, and liquid crystal light valve 100 is provided in the rear stage of liquid crystal light valves 60B, 60G and 60R.
    Type: Grant
    Filed: December 17, 2004
    Date of Patent: November 4, 2008
    Assignee: Seiko Epson Corporation
    Inventors: Yoshitaka Itoh, Shohei Yoshida, Shoichi Uchiyama, Junichi Nakamura, Takashi Nitta, Tsunemori Asahi
  • Publication number: 20080218697
    Abstract: A polarization luminaire is disclosed having a light source, a system of the optical integrator, a polarized light splitting device for splitting a light emitted from the light source into two kinds of polarized lights whose polarization directions are perpendicular to each other and whose traveling directions are apart from each other by an angle of less than 90 degrees, and a polarization conversion device for causing the two kinds of polarized lights to have the same polarization direction. The polarized light splitting device is placed on one of the entrance side and the outputting side of the first lens plate of the system of the optical integrator or is placed within the second lens plate. A prism beam splitter having a polarized light splitting film constituted by a thermally stable dielectric multi-layer film is suitable for the polarized light splitting device. Most of the polarized lights can be utilized by causing the polarized lights to have the same polarization direction.
    Type: Application
    Filed: June 13, 2007
    Publication date: September 11, 2008
    Applicant: Seiko Epson Corporation
    Inventors: Yoshitaka Itoh, Kunio Yoneno
  • Patent number: 7364305
    Abstract: A projector which is small in size and excellent in light utilization efficiency while keeping the advantage of a spatially-pixel-arrangement type is provided. The luminous flux emitted from a light source is separated by a color separation system into a plurality of kinds of colors of light different in exit direction. These separated colors of light are modulated by a light valve, to form first optical images. The light valve has a plurality of sub-pixels provided corresponding to the colors of light and micro-lenses to focus the colors of light corresponding to the sub-pixels. The sub-pixels are structured in a size nearly equal to a size of a color of light to be focused on the relevant sub-pixel by micro-lenses. Accordingly, the first optical image is in a form non-analogous with the actual projection image. The first optical images are converted into second optical images having a desired aspect ratio by an anamorphic projection system, and then projected.
    Type: Grant
    Filed: May 6, 2005
    Date of Patent: April 29, 2008
    Assignee: Seiko Epson Corporation
    Inventor: Yoshitaka Itoh
  • Patent number: 7234822
    Abstract: A projection-type display device 100 including a light source 10, a luminance modulation light valve having a plurality of pixels capable of independently controlling a transmission factor T1, dichroic mirrors 44a and 44b that divided the light from the luminance modulation light valve into the three primary colors of red, green and blue, a plurality of color modulation light valves into which light divided with dichroic mirrors 44a and 44b respectively enters and have a plurality of pixels capable of independently controlling a transmission factor T2, and a dichroic prism 48 that synthesizes light from each of the color modulation light valves, and is provided with a relay optical system 16 on the light path of a luminance modulation section 14 and a color modulation section 18 that forms an optical image of the luminance modulation light valve on the pixel surfaces of each of the color modulation light valves.
    Type: Grant
    Filed: December 20, 2004
    Date of Patent: June 26, 2007
    Assignee: Seiko Epson Corporation
    Inventors: Shoichi Uchiyama, Yoshitaka Itoh, Junichi Nakamura, Takashi Nitta, Tsunemori Asahi
  • Publication number: 20070024974
    Abstract: A polarization luminaire is disclosed having a light source, a system of the optical integrator, a polarized light splitting device for splitting a light emitted from the light source into two kinds of polarized lights whose polarization directions are perpendicular to each other and whose traveling directions are apart from each other by an angle of less than 90 degrees, and a polarization conversion device for causing the two kinds of polarized lights to have the same polarization direction. The polarized light splitting device is placed on one of the entrance side and the outputting side of the first lens plate of the system of the optical integrator or is placed within the second lens plate. A prism beam splitter having a polarized light splitting film constituted by a thermally stable dielectric multi-layer film is suitable for the polarized light splitting device. Most of the polarized lights can be utilized by causing the polarized lights to have the same polarization direction.
    Type: Application
    Filed: September 5, 2006
    Publication date: February 1, 2007
    Applicant: Seiko Epson Corporation
    Inventors: Yoshitaka Itoh, Kunio Yoneno, Junichi Nakamura
  • Patent number: 7126736
    Abstract: A projector capable of displaying a moving picture image in good quality with a clear outline and few blurs includes a light source, a pseudo rectangular light flux generating device to generate a band-shaped illumination light flux from a light flux emitted from the light source, and an optically scanning device to scan with the illumination light flux emitted from the pseudo rectangular light flux generating device on an optically modulating apparatus. The projector further includes an illumination light flux shaping device to shape the illumination light flux into a desired shape of illumination light flux, the illumination light flux shaping device being in an optical path of the illumination light flux emitted from the pseudo rectangular light flux generating device.
    Type: Grant
    Filed: May 18, 2005
    Date of Patent: October 24, 2006
    Assignee: Seiko Epson Corporation
    Inventors: Yoshitaka Itoh, Hideki Kojima
  • Patent number: 7119957
    Abstract: A polarization luminaire is disclosed having a light source that emits light having random polarization directions, a first lens plate and a second lens plate. The first lens plate has a plurality of condenser lenses, the condenser lenses being decentered lenses. The second lens plate is a composite layered element having a condenser lens array, a polarization beam splitting prism array, and a half-wave plate placed on an exit side of the polarization beam splitting prism array. The polarization beam splitting prism array splits each light emitted from both the plurality of condenser lenses and the condenser lens array into a p-polarized light and an s-polarized light. The polarization beam splitting prism array includes a plurality of polarizing beam splitters and a plurality of reflecting mirrors alternately arranged.
    Type: Grant
    Filed: September 1, 2004
    Date of Patent: October 10, 2006
    Assignee: Seiko Epson Corporation
    Inventors: Yoshitaka Itoh, Kunio Yoneno
  • Patent number: RE39951
    Abstract: A polarizing conversion device in accordance with the invention includes a first optical element for condensing an incident beam and forming a plurality of intermediate beams spatially separated from one another, and a second optical element for spatially separating each intermediate beam into two polarized beams and aligning the polarization directions of the polarized beams, thereby obtaining the same type of polarized beams. In the second optical element, a shading plate is placed to prevent light from directly entering a section corresponding to a reflecting plane of a polarizing separation unit array. Since the ability of separating the intermediate beam into two polarized beams is thereby enhanced, it is possible to perform conversion into the same type of polarized beams polarized in the same direction, with high efficiency.
    Type: Grant
    Filed: June 25, 1997
    Date of Patent: December 25, 2007
    Assignee: Seiko Epson Corporation
    Inventors: Yoshitaka Itoh, Toshiaki Hashizume