Patents by Inventor Ryota Kadowaki
Ryota Kadowaki 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).
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Publication number: 20210247676Abstract: A light source apparatus includes a light source unit configured to emit light of a first wavelength, a first fluorescent element and a second fluorescent element each configured to convert at least part of the light of the first wavelength into light of a second wavelength that is different from the first wavelength, and a light amount adjustment unit configured to adjust an amount of light emitted to each of the first fluorescent element and the second fluorescent element. The first fluorescent element converts the light of the first wavelength into the light of the second wavelength at a first ratio. The second fluorescent element converts the light of the first wavelength into the light of the second wavelength at a second ratio that is different from the first ratio.Type: ApplicationFiled: February 4, 2021Publication date: August 12, 2021Inventors: Yuya Kurata, Ryota Kadowaki
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Patent number: 10775686Abstract: The wavelength conversion element converts a wavelength of part of an exciting light to generate a fluorescent light and thereby generate a combined light in which the fluorescent light is combined with a non-converted light whose wavelength is the same as that of the exciting light. The element includes a fluorescent body, a binder contacting the fluorescent body, and multiple diffuser particles included in the binder. A minimum particle diameter of the multiple diffuser particles is ¼ or more and 4 times or less of a wavelength of the fluorescent light, and a ratio of a volume of the multiple diffuser particles to a total volume of the binder and multiple diffuser particles is 25% or more and 50% or less.Type: GrantFiled: May 26, 2017Date of Patent: September 15, 2020Assignee: CANON KABUSHIKI KAISHAInventors: Minoru Ohkoba, Yuya Kurata, Ryota Kadowaki
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Patent number: 9915859Abstract: A fluorescent element includes a fluorescent light layer that converts a light flux from an LD light source into light having a different wavelength, a scattering layer, and a reflective element. The fluorescent light layer is provided between the scattering layer and the reflective element.Type: GrantFiled: June 2, 2016Date of Patent: March 13, 2018Assignee: Canon Kabushiki KaishaInventor: Ryota Kadowaki
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Patent number: 9851552Abstract: Provided is the image display apparatus including: the light source which emits excitation light; a phosphor which converts the excitation light into fluorescent light and rotates; an image display element which modulates the fluorescent light; and a control unit which controls the image display element so that the image display element repeats first displaying based on an image signal and second displaying which is darker than the first displaying, at a predetermined frequency, wherein when a higher frequency of the predetermined frequency and a rotation frequency of the phosphor is represented by Fhigh, and a lower frequency thereof is represented by |Fhigh/2?Flow|<15.Type: GrantFiled: May 26, 2016Date of Patent: December 26, 2017Assignee: CANON KABUSHIKI KAISHAInventor: Ryota Kadowaki
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Publication number: 20170343890Abstract: The wavelength conversion element converts a wavelength of part of an exciting light to generate a fluorescent light and thereby generate a combined light in which the fluorescent light is combined with a non-converted light whose wavelength is the same as that of the exciting light. The element includes a fluorescent body, a binder contacting the fluorescent body, and multiple diffuser particles included in the binder. A minimum particle diameter of the multiple diffuser particles is ¼ or more and 4 times or less of a wavelength of the fluorescent light, and a ratio of a volume of the multiple diffuser particles to a total volume of the binder and multiple diffuser particles is 25% or more and 50% or less.Type: ApplicationFiled: May 26, 2017Publication date: November 30, 2017Inventors: Minoru Ohkoba, Yuya Kurata, Ryota Kadowaki
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Patent number: 9591279Abstract: A light source unit includes a fluorescent member configured to emit, when irradiated with excitation light, fluorescence light having a wavelength different from a wavelength of the excitation light, and a controller configured to adjust a conversion efficiency from the excitation light to the fluorescence light of the fluorescent member so that a gradient T satisfies 0.35G?T?0.8G in a fluorescence characteristic of the fluorescent member when a horizontal axis represents a normalized light intensity of the excitation light so that a maximum light intensity of the excitation light incident on the fluorescent member is normalized to 1, and a vertical axis represents the light intensity of the fluorescence light from the fluorescence member irradiated with the normalized light intensity of the excitation light, where G represents a gradient in the fluorescence characteristic when the normalized light intensity of the excitation light is 0.3.Type: GrantFiled: August 31, 2015Date of Patent: March 7, 2017Assignee: CANON KABUSHIKI KAISHAInventor: Ryota Kadowaki
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Publication number: 20160357097Abstract: A fluorescent element includes a fluorescent light layer that converts a light flux from an LD light source into light having a different wavelength, a scattering layer, and a reflective element. The fluorescent light layer is provided between the scattering layer and the reflective element.Type: ApplicationFiled: June 2, 2016Publication date: December 8, 2016Inventor: Ryota KADOWAKI
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Publication number: 20160353066Abstract: Provided is the image display apparatus including: the light source which emits excitation light; a phosphor which converts the excitation light into fluorescent light and rotates; an image display element which modulates the fluorescent light; and a control unit which controls the image display element so that the image display element repeats first displaying based on an image signal and second displaying which is darker than the first displaying, at a predetermined frequency, wherein when a higher frequency of the predetermined frequency and a rotation frequency of the phosphor is represented by Fhigh, and a lower frequency thereof is represented by |Fhigh/2?Flow|<15.Type: ApplicationFiled: May 26, 2016Publication date: December 1, 2016Inventor: Ryota Kadowaki
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Publication number: 20160065922Abstract: A light source unit includes a fluorescent member configured to emit, when irradiated with excitation light, fluorescence light having a wavelength different from a wavelength of the excitation light, and a controller configured to adjust a conversion efficiency from the excitation light to the fluorescence light of the fluorescent member so that a gradient T satisfies 0.35G?T?0.8G in a fluorescence characteristic of the fluorescent member when a horizontal axis represents a normalized light intensity of the excitation light so that a maximum light intensity of the excitation light incident on the fluorescent member is normalized to 1, and a vertical axis represents the light intensity of the fluorescence light from the fluorescence member irradiated with the normalized light intensity of the excitation light, where G represents a gradient in the fluorescence characteristic when the normalized light intensity of the excitation light is 0.3.Type: ApplicationFiled: August 31, 2015Publication date: March 3, 2016Inventor: Ryota Kadowaki
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Patent number: 7976166Abstract: An optical system for image projection is disclosed which is capable of improving contrast while suppressing reduction of light amount. The optical system includes a converging optical system, and a polarization beam splitting surface transmitting an incoming light flux having a first polarization direction from the converging optical system, to introduce it to the image-forming element and causing light having a second polarization direction, of an outgoing light flux from the image-forming element, to proceed to a projection optical system. In a first cross-section parallel to a normal to the polarization beam splitting surface, the converging optical system has a configuration causing an incident angle on the splitting surface of a light ray passing through a barycenter of intensity distribution of the outgoing light flux to be larger than an incident angle thereon of a light ray passing through a barycenter of intensity distribution of the incoming light flux.Type: GrantFiled: June 7, 2007Date of Patent: July 12, 2011Assignee: Canon Kabushiki KaishaInventors: Atsushi Okuyama, Yu Yamauchi, Takashi Sudo, Ryota Kadowaki
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Patent number: 7878659Abstract: An illumination optical system configured to guide a light flux from a light source unit onto an illuminated surface includes a compression system configured to compress the light flux at a different compression ratio in a first cross section and a second cross section which are orthogonal to each other, and a polarized light splitting unit including a polarization split surface. The second cross section includes a line normal to the polarization split surface. Where a compression ratio for compressing a light flux in the first cross section is ?, a compression ratio in the second cross section is ?, and an F number smaller of F numbers calculated according to a maximum angle of a light flux incident on an illuminated surface in the first and the second cross sections is Fno, the following conditions are satisfied: ?0.18*(Fno)+1.245*(Fno)?1.260<?/?<1 1.4?Fno?3.6.Type: GrantFiled: June 24, 2008Date of Patent: February 1, 2011Assignee: Canon Kabushiki KaishaInventors: Ryota Kadowaki, Yu Yamauchi
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Publication number: 20090002634Abstract: An illumination optical system configured to guide a light flux from a light source unit onto an illuminated surface includes a compression system configured to compress the light flux at a different compression ratio in a first cross section and a second cross section which are orthogonal to each other, and a polarized light splitting unit including a polarization split surface. The second cross section includes a line normal to the polarization split surface. Where a compression ratio for compressing a light flux in the first cross section is ?, a compression ratio in the second cross section is ?, and an F number smaller of F numbers calculated according to a maximum angle of a light flux incident on an illuminated surface in the first and the second cross sections is Fno, the following conditions are satisfied: ?0.18*(Fno)+1.245*(Fno)?1.260<?/?<1 1.4?Fno?3.6.Type: ApplicationFiled: June 24, 2008Publication date: January 1, 2009Applicant: CANON KABUSHIKI KAISHAInventors: Ryota Kadowaki, Yu Yamauchi
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Publication number: 20070291594Abstract: An optical system for image projection is disclosed which is capable of improving contrast while suppressing reduction of light amount. The optical system includes a converging optical system, and a polarization beam splitting surface transmitting an incoming light flux having a first polarization direction from the converging optical system, to introduce it to the image-forming element and causing light having a second polarization direction, of an outgoing light flux from the image-forming element, to proceed to a projection optical system. In a first cross-section parallel to a normal to the polarization beam splitting surface, the converging optical system has a configuration causing an incident angle on the splitting surface of a light ray passing through a barycenter of intensity distribution of the outgoing light flux to be larger than an incident angle thereon of a light ray passing through a barycenter of intensity distribution of the incoming light flux.Type: ApplicationFiled: June 7, 2007Publication date: December 20, 2007Inventors: Atsushi OKUYAMA, Yu Yamauchi, Takashi Sudo, Ryota Kadowaki