Patents by Inventor Takehito Kawasumi

Takehito Kawasumi 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: 10073330
    Abstract: An illumination apparatus includes an illumination optical system, a first light source unit that includes a first solid-state light source, a second light source unit that includes a second solid-state light source with a characteristic different from that of the first wavelength conversion element, an optical path combining system that includes a first light guide surface, and a second light guide surface. The first light guide surface viewed from an optical axis direction of the illumination optical system does not overlap the second light guide surface and is provided at a position different from that of the second light guide surface. The optical path combining system includes a first condenser optical system, and a second condenser optical system. A predetermined condition is satisfied.
    Type: Grant
    Filed: April 24, 2017
    Date of Patent: September 11, 2018
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Takehito Kawasumi, Kazuhiro Inoko
  • Patent number: 10015455
    Abstract: The optical apparatus includes multiple reflective light modulators, an illumination optical system and multiple dichroic surfaces separating a light flux from the illumination optical system into multiple color lights to introduce them to the light modulators and combining the multiple color lights reflected by the light modulators. The optical system includes a condenser lens disposed between an area in which light source images are formed and the multiple reflective light modulators. The light modulators are arranged such that their long sides are parallel to a first section, and a condition of f/D1>f/D2 is satisfied where f represents a focal length of the condenser lens, D1 and D2 represent maximum effective widths of the areas in which the light source images are formed in the first section and in a second section parallel to an optical axis and orthogonal to the first section.
    Type: Grant
    Filed: November 16, 2015
    Date of Patent: July 3, 2018
    Assignee: CANON KABUSHIKI KAISHA
    Inventor: Takehito Kawasumi
  • Publication number: 20180149956
    Abstract: A light source optical system includes a micro lens array, a condenser lens unit, and a dichroic surface. In a direction orthogonal to an optical axis in a cross section parallel to a normal of the dichroic surface and the optical axis of the condenser lens unit, a width of the dichroic surface is narrower than a width of the condenser lens unit. A light source optical system satisfies a predetermined conditional expression.
    Type: Application
    Filed: January 29, 2018
    Publication date: May 31, 2018
    Inventor: Takehito Kawasumi
  • Patent number: 9921462
    Abstract: A light source optical system includes a micro lens array, a condenser lens unit, and a dichroic surface. In a direction orthogonal to an optical axis in a cross section parallel to a normal of the dichroic surface and the optical axis of the condenser lens unit, a width of the dichroic surface is narrower than a width of the condenser lens unit. A light source optical system satisfies a predetermined conditional expression.
    Type: Grant
    Filed: November 18, 2016
    Date of Patent: March 20, 2018
    Assignee: Canon Kabushiki Kaisha
    Inventor: Takehito Kawasumi
  • Patent number: 9851631
    Abstract: A light source optical system includes a first fly-eye lens including a plurality of first lens cells, and a second fly-eye lens including a plurality of second lens cells that guide a light flux from the first fly-eye lens to a fluorescent member. A light source image is formed between the first fly-eye lens and the fluorescent member. When a short side direction of the second lens cells is defined as a first direction and a long side direction of the second lens cells is defined as a second direction, the width of the light source image in the second direction is wider than the width of the light source image in the first direction.
    Type: Grant
    Filed: November 30, 2016
    Date of Patent: December 26, 2017
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kazuhiro Inoko, Takehito Kawasumi
  • Publication number: 20170307969
    Abstract: An illumination apparatus includes an illumination optical system, a first light source unit that includes a first solid-state light source, a second light source unit that includes a second solid-state light source with a characteristic different from that of the first wavelength conversion element, an optical path combining system that includes a first light guide surface, and a second light guide surface. The first light guide surface viewed from an optical axis direction of the illumination optical system does not overlap the second light guide surface and is provided at a position different from that of the second light guide surface. The optical path combining system includes a first condenser optical system, and a second condenser optical system. A predetermined condition is satisfied.
    Type: Application
    Filed: April 24, 2017
    Publication date: October 26, 2017
    Inventors: Takehito Kawasumi, Kazuhiro Inoko
  • Publication number: 20170299958
    Abstract: An illumination apparatus includes an illumination optical system configured to illuminate a light modulation element; a plurality of light source units each including a fluorescent member, at least one light source, and a light-guiding optical system; and an optical-path combining system. A predetermined region in an area where light source images are formed by the illumination optical system using light beams from the optical-path combining system is defined as an effective region, and the number of the light source units is denoted by N. In this case, the light source images and N subregions obtained by dividing the effective region by N along a first side direction of the effective region or a second side direction orthogonal to the first side direction satisfy a predetermined relation.
    Type: Application
    Filed: April 13, 2017
    Publication date: October 19, 2017
    Inventor: Takehito Kawasumi
  • Publication number: 20170168380
    Abstract: A light source optical system includes a first fly-eye lens including a plurality of first lens cells, and a second fly-eye lens including a plurality of second lens cells that guide a light flux from the first fly-eye lens to a fluorescent member. A light source image is formed between the first fly-eye lens and the fluorescent member. When a short side direction of the second lens cells is defined as a first direction and a long side direction of the second lens cells is defined as a second direction, the width of the light source image in the second direction is wider than the width of the light source image in the first direction.
    Type: Application
    Filed: November 30, 2016
    Publication date: June 15, 2017
    Inventors: Kazuhiro Inoko, Takehito Kawasumi
  • Publication number: 20170153538
    Abstract: A light source optical system includes a micro lens array, a condenser lens unit, and a dichroic surface. In a direction orthogonal to an optical axis in a cross section parallel to a normal of the dichroic surface and the optical axis of the condenser lens unit, a width of the dichroic surface is narrower than a width of the condenser lens unit. A light source optical system satisfies a predetermined conditional expression.
    Type: Application
    Filed: November 18, 2016
    Publication date: June 1, 2017
    Inventor: Takehito Kawasumi
  • Patent number: 9638992
    Abstract: The illumination optical system includes a first optical system configured to shape a light flux from a light source such that a light flux cross-sectional shape of the light flux becomes close to a rectangular shape of an illumination surface, a second optical system having an optical axis tilted with respect to a normal to the illumination surface and configured to introduce the light flux from the first optical system to the illumination surface, and a light-transmissive element having an entrance surface and an exit surface respectively forming mutually different angles with respect to the optical axis of the second optical system in a plane including the optical axis of the second optical system and the normal to the illumination surface. The light-transmissive element is disposed between the first optical system and the illumination surface.
    Type: Grant
    Filed: May 8, 2015
    Date of Patent: May 2, 2017
    Assignee: Canon Kabushiki Kaisha
    Inventor: Takehito Kawasumi
  • Patent number: 9436073
    Abstract: An illumination optical system is capable of changing a light beam diameter in one of first and second cross sections orthogonal to each other that include an optical axis, and includes a light source, a condenser lens that concentrates light from the light source, a first fly-eye lens including a first lens cell on which light concentrated by the condenser lens is incident, a second fly-eye lens including a second lens cell, a polarization conversion element that performs polarization conversion on light from the second fly-eye lens, and an image display element that displays an image based on light from the polarization conversion element, and widths of the image display element and a light emitting surface of the light source, widths of the first and second fly-eye lens, and change rates ? and ? of the light beam diameters are set within appropriate ranges.
    Type: Grant
    Filed: February 12, 2014
    Date of Patent: September 6, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventor: Takehito Kawasumi
  • Patent number: 9389427
    Abstract: An optical system is configured to introduce light modulated by a reflective light modulator to a projection lens configured to project the light onto a target plane. The optical system includes a polarization beam splitter configured to introduce each of first colored light as p-polarized light and second colored light as s-polarized light to a corresponding one of reflective optical modulators that are different from each other, and to synthesize light fluxes modulated by the reflective optical modulators with each other, a beam splitter arranged between the polarization beam splitter and the projection lens and configured to split the first colored light in accordance with a polarization direction of the first colored light and to transmit or reflect the second colored light irrespective of a polarization direction of the second colored light, and a half-wave plate arranged between the polarization beam splitter and the beam splitter.
    Type: Grant
    Filed: April 24, 2013
    Date of Patent: July 12, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Hiroyuki Kodama, Takehito Kawasumi
  • Publication number: 20160150202
    Abstract: The optical apparatus includes multiple reflective light modulators, an illumination optical system and multiple dichroic surfaces separating a light flux from the illumination optical system into multiple color lights to introduce them to the light modulators and combining the multiple color lights reflected by the light modulators. The optical system includes a condenser lens disposed between an area in which light source images are formed and the multiple reflective light modulators. The light modulators are arranged such that their long sides are parallel to a first section, and a condition of f/D1>f/D2 is satisfied where f represents a focal length of the condenser lens, D1 and D2 represent maximum effective widths of the areas in which the light source images are formed in the first section and in a second section parallel to an optical axis and orthogonal to the first section.
    Type: Application
    Filed: November 16, 2015
    Publication date: May 26, 2016
    Inventor: Takehito Kawasumi
  • Publication number: 20150338729
    Abstract: The illumination optical system includes a first optical system configured to shape a light flux from a light source such that a light flux cross-sectional shape of the light flux becomes close to a rectangular shape of an illumination surface, a second optical system having an optical axis tilted with respect to a normal to the illumination surface and configured to introduce the light flux from the first optical system to the illumination surface, and a light-transmissive element having an entrance surface and an exit surface respectively forming mutually different angles with respect to the optical axis of the second optical system in a plane including the optical axis of the second optical system and the normal to the illumination surface. The light-transmissive element is disposed between the first optical system and the illumination surface.
    Type: Application
    Filed: May 8, 2015
    Publication date: November 26, 2015
    Inventor: Takehito Kawasumi
  • Patent number: 8955977
    Abstract: A projection-type image display apparatus includes a color separation element including a color separation surface, a light modulation element configured to receive the light divided by the color separation element, a polarizing beam splitter disposed between the color separation element and a projection optical system to separate a light path of a light modulated by the light modulation element according to a polarization direction and guide the resulting light to the projection optical system, and a phase difference plate disposed between the color separation element and the light modulation element. An optic axis of the phase difference plate and the normal of the color separation surface are substantially parallel or perpendicular to each other, in a cross section parallel to a normal of the color separation surface and a normal of the light modulation element.
    Type: Grant
    Filed: September 7, 2012
    Date of Patent: February 17, 2015
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yutaka Yamaguchi, Takehito Kawasumi
  • Patent number: 8857996
    Abstract: An illumination optical system include a first lens array including multiple lens cells that split a light beam emitted from a light source into multiple light beams, a second lens array including lens cells that the light beams split by the lens cells of the first lens array are incident thereon, and an optical element configured to illuminate an image display element by superposing light beams emerging from the second lens array on the image display element. At least one of the first lens array and the second lens array includes at least two lens cells each having a curved surface that is formed so as to be continuous with a curved surface of an adjacent lens cell, the at least two lens cells being decentered, and at least two lens cells of the first lens array have different radii of curvature.
    Type: Grant
    Filed: April 4, 2012
    Date of Patent: October 14, 2014
    Assignee: Canon Kabushiki Kaisha
    Inventor: Takehito Kawasumi
  • Publication number: 20140226132
    Abstract: An illumination optical system is capable of changing a light beam diameter in one of first and second cross sections orthogonal to each other that include an optical axis, and includes a light source, a condenser lens that concentrates light from the light source, a first fly-eye lens including a first lens cell on which light concentrated by the condenser lens is incident, a second fly-eye lens including a second lens cell, a polarization conversion element that performs polarization conversion on light from the second fly-eye lens, and an image display element that displays an image based on light from the polarization conversion element, and widths of the image display element and a light emitting surface of the light source, widths of the first and second fly-eye lens, and change rates ? and ? of the light beam diameters are set within appropriate ranges.
    Type: Application
    Filed: February 12, 2014
    Publication date: August 14, 2014
    Applicant: CANON KABUSHIKI KAISHA
    Inventor: Takehito KAWASUMI
  • Patent number: 8702240
    Abstract: An image display apparatus includes an image display element configured to display an image by controlling a polarization state of a polarized light beam. An illumination optical system guides the polarized light beam to the image display element. A polarizing beam splitter disposed between the illumination optical system and the image display element selectively splits polarization of incident light. A projection optical system projects the image displayed by the image display element onto a projection plane. The positional relationship between the polarizing beam splitter and an optical axis of the projection optical system is properly set.
    Type: Grant
    Filed: December 20, 2010
    Date of Patent: April 22, 2014
    Assignee: Canon Kabushiki Kaisha
    Inventor: Takehito Kawasumi
  • Publication number: 20130286357
    Abstract: An optical system is configured to introduce light modulated by a reflective light modulator to a projection lens configured to project the light onto a target plane. The optical system includes a polarization beam splitter configured to introduce each of first colored light as p-polarized light and second colored light as s-polarized light to a corresponding one of reflective optical modulators that are different from each other, and to synthesize light fluxes modulated by the reflective optical modulators with each other, a beam splitter arranged between the polarization beam splitter and the projection lens and configured to split the first colored light in accordance with a polarization direction of the first colored light and to transmit or reflect the second colored light irrespective of a polarization direction of the second colored light, and a half-wave plate arranged between the polarization beam splitter and the beam splitter.
    Type: Application
    Filed: April 24, 2013
    Publication date: October 31, 2013
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Hiroyuki Kodama, Takehito Kawasumi
  • Publication number: 20130063700
    Abstract: A projection-type image display apparatus includes a color separation element including a color separation surface, a light modulation element configured to receive the light divided by the color separation element, a polarizing beam splitter disposed between the color separation element and a projection optical system to separate a light path of a light modulated by the light modulation element according to a polarization direction and guide the resulting light to the projection optical system, and a phase difference plate disposed between the color separation element and the light modulation element. An optic axis of the phase difference plate and the normal of the color separation surface are substantially parallel or perpendicular to each other, in a cross section parallel to a normal of the color separation surface and a normal of the light modulation element.
    Type: Application
    Filed: September 7, 2012
    Publication date: March 14, 2013
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Yutaka Yamaguchi, Takehito Kawasumi