Patents by Inventor Tetsuro Mizushima

Tetsuro Mizushima 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: 8089581
    Abstract: A display for illuminating a liquid crystal display panel with laser light of uniform light quantity distribution, and an illuminator for irradiating with laser light of uniform light quantity distribution. The display includes a liquid crystal display panel (204), laser light sources (205, 206, 207) emitting laser light having wavelengths of green, red, and blue colors, a waveguide plate (201) arranged at the back side of the liquid crystal display panel (204) and performing multiple reflection of laser light, and a diffusion plate (202) arranged at the back side of the waveguide plate (201), diffusing laser light propagating in the waveguide plate (201) and emitting the light toward the liquid crystal display panel (204).
    Type: Grant
    Filed: July 26, 2006
    Date of Patent: January 3, 2012
    Assignee: Panasonic Corporation
    Inventors: Kiminori Mizuuchi, Kazuhisa Yamamoto, Shin-ichi Kadowaki, Tetsuro Mizushima, Akihiro Morikawa
  • Patent number: 8068274
    Abstract: A wavelength conversion laser device includes a laser light source which emits a laser beam, two reflective surfaces which reflect therefrom a laser beam, a wavelength converter provided between the two reflective surfaces, which converts a laser beam into a wavelength-converted laser beam, and condensing optics which condense the laser beams to be injected between the two reflective surfaces, wherein at least one of the two reflective surfaces has a curvature for reflecting a laser beam to be re-injected into the wavelength converter between the two reflective surfaces repeatedly while forming multi paths of laser beams injected into the wavelength converter at different incident angles, and the condensing optics are arranged to disperse beam waists of the laser beams in the wavelength converter, which reciprocate between the two reflective surfaces.
    Type: Grant
    Filed: September 30, 2008
    Date of Patent: November 29, 2011
    Assignee: Panasonic Corporation
    Inventors: Tetsuro Mizushima, Hiroyuki Furuya, Koichi Kusukame, Kiminori Mizuuchi, Kazuhisa Yamamoto, Nobuyuki Horikawa, Shinichi Shikii, Tatsuo Itoh
  • Patent number: 8054412
    Abstract: A light source portion having laser light sources emitting red light, green light, and blue light and conventionally disposed integrally with the liquid crystal display panel is spatially separated from the liquid crystal display panel. Accordingly, the power supply, the optical system, and the heat source are incorporated into the light source portion and are thereby completely separated from the liquid crystal display panel. A laser beam emitted from the light source portion is guided to the liquid crystal display panel via a fiber. In this manner, it is possible to achieve a liquid crystal display device capable of significantly reducing the liquid crystal display panel in thickness and weight.
    Type: Grant
    Filed: February 21, 2007
    Date of Patent: November 8, 2011
    Assignee: Panasonic Corporation
    Inventors: Kazuhisa Yamamoto, Tatsuo Itoh, Tetsuro Mizushima, Shinichi Kadowaki
  • Publication number: 20110255149
    Abstract: A wavelength conversion laser light source 100 has: a laser light source configured to generate fundamental wave laser light; and a wavelength conversion element 101 provided with a periodic polarization reversal structure configured to convert the fundamental wave laser light which is incident onto the periodic polarization reversal structure into different laser light in wavelength wherein the wavelength conversion element includes different polarization reversal regions in period; and a polarization reversal axis 102 of at least one of the polarization reversal regions is inclined with respect to an incident optical path of the fundamental wave laser light on the wavelength conversion element.
    Type: Application
    Filed: October 19, 2010
    Publication date: October 20, 2011
    Inventors: Koichi Kusukame, Tetsuro Mizushima, Nobuyuki Horikawa, Hiroyuki Furuya, Tomoya Sugita, Shinichi Kadowaki
  • Patent number: 8029141
    Abstract: The image display apparatus includes a two-dimensional light modulation device for modulating light emitted from a laser light source, a display surface for displaying the modulated light, an optical pixel aperture enlarging member for distributing the luminance of the laser light while introducing the laser light to apertures of pixels of the modulation device; and a display pixel aperture enlarging portion for optically enlarging the modulated light by the apertures of the pixels of the modulation device corresponding to pixels of an image to be displayed. The luminance of a partial area of each pixel of the image displayed on the display surface is controlled to be below the threefold of an average value of the luminance in the area of the entire pixel by the optical pixel aperture enlarging member and the display pixel aperture enlarging portion, accomplishing speckle noise reduction and improved light utilization efficiency.
    Type: Grant
    Filed: May 23, 2007
    Date of Patent: October 4, 2011
    Assignee: Panasonic Corporation
    Inventors: Tetsuro Mizushima, Tatsuo Itoh, Kenichi Kasazumi, Kazuhisa Yamamoto
  • Patent number: 8029179
    Abstract: Laser lights emitted from a light source 30 are diffused in a direction parallel to main surfaces of a light guide plate 9 by a one-dimensional diffuser 5. The diffused laser lights are converted to parallel lights by a first cylindrical lens 6, and are then converged in a direction of the thickness of the light guide plate 9 by a second cylindrical lens 7. The converged laser lights are reflected 90 degrees twice by a mirror 8, and are guided to a side surface of the light guide plate 9.
    Type: Grant
    Filed: September 25, 2007
    Date of Patent: October 4, 2011
    Assignee: Panasonic Corporation
    Inventors: Tatsuo Itoh, Takayuki Nagata, Tetsuro Mizushima, Kazuhisa Yamamoto
  • Patent number: 8014429
    Abstract: A wavelength conversion laser is provided with a pair of fundamental wave reflecting surfaces for reflecting a fundamental wave to define a plurality of fundamental wave paths passing a wavelength conversion element at different angles, and a control unit for controlling wavelength conversion efficiencies so that the wavelength conversion efficiency on a specific one of the plurality of fundamental wave paths extending in different directions between the pair of fundamental wave reflecting surfaces is highest.
    Type: Grant
    Filed: January 20, 2009
    Date of Patent: September 6, 2011
    Assignee: Panasonic Corporation
    Inventors: Tetsuro Mizushima, Hiroyuki Furuya, Shinichi Shikii, Koichi Kusukame, Nobuyuki Horikawa, Kiminori Mizuuchi, Kazuhisa Yamamoto
  • Patent number: 8010975
    Abstract: A disc cartridge accommodating a photon mode optical information recording medium is provided with a disc case having an opening section, and a shutter movably disposed between a closing position to close the opening section and an opening position to open the opening section. The disc case includes a light path bending portion for bending a clearance between the shutter at the closing position and the disc case at least at two points. Stray light propagating in the clearance between the disc case and the shutter is bent at least at two points.
    Type: Grant
    Filed: February 23, 2006
    Date of Patent: August 30, 2011
    Assignee: Panasonic Corporation
    Inventors: Tomoya Sugita, Kenichi Kasazumi, Tetsuro Mizushima, Kazuhisa Yamamoto, Shinichi Kadowaki, Teruyuki Takizawa
  • Patent number: 7997737
    Abstract: A projection display device enhances reliability and reduces speckle noise. A blue laser, a red laser, and a green laser emit blue laser light, red laser light, and green laser light, respectively. A spatial light modulation element modulates the blue laser light emitted from the blue laser, the red laser light emitted from the red laser, and the green laser light emitted from the green laser. A projection lens projects the laser light modulated by the spatial light modulation element onto a screen. First and second light diffusing elements are arranged on an optical axis between the blue laser, the red laser, and the green laser, and the spatial light modulation element to change the degree of diffusion of the blue laser light, the red laser light, and the green laser light temporally and electrically.
    Type: Grant
    Filed: April 5, 2007
    Date of Patent: August 16, 2011
    Assignee: Panasonic Corporation
    Inventors: Tatsuo Itoh, Tetsuro Mizushima, Kazuhisa Yamamoto
  • Patent number: 7988305
    Abstract: Miniaturization is realized and high-output lights are obtained by optimizing the arrangement of a laser light source unit and a homogenizer. A laser light source unit 1 has a light emission region for emitting an elliptical laser light. A focusing lens unit 2 focuses the laser light emitted from the laser light source unit 1. A rod integrator 4 has a rectangular incident surface on luminous flux focused by the focusing lens unit 2. A spatial light modulation element 7 modulates the laser light emitted from the rod integrator 4. A projection lens 8 projects the laser light modulated by the spatial light modulation element 7. The incident surface of the rod integrator 4 has a rectangular shape, and the laser light source unit 1 is arranged such that a longer axis direction of the light emission region and a longer side direction of the incident surface of the rod integrator are parallel.
    Type: Grant
    Filed: March 22, 2007
    Date of Patent: August 2, 2011
    Assignee: Panasonic Corporation
    Inventors: Tatsuo Itoh, Tetsuro Mizushima, Kenichi Kasazumi, Kazuhisa Yamamoto
  • Publication number: 20110170173
    Abstract: A wavelength conversion laser has: an exciting LD1, a solid state laser including a resonator, and a wavelength conversion element 7 disposed in the resonator. The solid state laser includes a first laser medium and a second laser medium as at least two types of laser media, and is configured to oscillate the solid state laser beams of the first emission wavelength and the second emission wavelength in the resonator as a result of the excitation light entering a region 3 configured from the first laser medium, thereafter entering a region 4 configured from the second laser medium, and subsequently entering a region 5 configured from the first laser medium. The wavelength conversion element 7 simultaneously generates a second harmonic and a sum frequency of the first emission wavelength and the second emission wavelength.
    Type: Application
    Filed: June 9, 2010
    Publication date: July 14, 2011
    Inventors: Tetsuro Mizushima, Tatsuo Itoh, Kenji Nakayama, Koichi Kusukame, Tomoya Sugita
  • Publication number: 20110170172
    Abstract: A wavelength conversion laser device includes a laser light source which emits a laser beam, two reflective surfaces which reflect therefrom a laser beam, a wavelength converter provided between the two reflective surfaces, which converts a laser beam into a wavelength-converted laser beam, and condensing optics which condense the laser beams to be injected between the two reflective surfaces, wherein at least one of the two reflective surfaces has a curvature for reflecting a laser beam to be re-injected into the wavelength converter between the two reflective surfaces repeatedly while forming multi paths of laser beams injected into the wavelength converter at different incident angles, and the condensing optics are arranged to disperse beam waists of the laser beams in the wavelength converter, which reciprocate between the two reflective surfaces.
    Type: Application
    Filed: September 30, 2008
    Publication date: July 14, 2011
    Inventors: Tetsuro MIZUSHIMA, Hiroyuki FURUYA, Koichi KUSUKAME, Kiminori MIZUUCHI, Kazuhisa YAMAMOTO, Nobuyuki HORIKAWA, Shinichi SHIKII, Tatsuo ITOH
  • Patent number: 7969532
    Abstract: A surface illuminator has a uniform luminance over a large area by using a laser light source, has a wide color reproduction range, and is capable of suppressing a speckle noise. A liquid crystal display uses such a surface illuminator. The surface illuminator includes the laser light source that emits a laser beam; a beam scan section that deflects and scans the laser beam; and a first plate-shaped light guide that causes the laser beam deflected and scanned by the beam scan section to be incident from an end face portion and causes the incident laser beam to emit from a first major surface. Further, the liquid crystal display includes a liquid crystal display panel and the surface illuminator, wherein the surface illuminator is used as a backlight illuminator that lights the liquid crystal display panel from the backside in this liquid crystal display.
    Type: Grant
    Filed: November 15, 2006
    Date of Patent: June 28, 2011
    Assignee: Panasonic Corporation
    Inventors: Tetsuro Mizushima, Ken'ichi Kasazumi, Kiminori Mizuuchi, Kazuhisa Yamamoto, Shin-ichi Kadowaki, Tatsuo Itoh
  • Publication number: 20110147566
    Abstract: A wavelength conversion laser light source includes: a fundamental light source for outputting fundamental light; a wavelength conversion element with a nonlinear optical effect for converting the fundamental light into harmonic light of a different wavelength; a first optical receiver for receiving light of a specific polarization direction contained in the fundamental light output from the fundamental light source and converting an amount of light thereof into an electrical signal; a second optical receiver for receiving the harmonic light output from the wavelength conversion element and converting an amount of light thereof into an electrical signal; a temperature holding unit for holding a temperature of the wavelength conversion element constant; a fundamental light control unit for performing first control of controlling an amount of light of the fundamental light output from the fundamental light source based on the electrical signal from the second optical receiver, and second control of controlling
    Type: Application
    Filed: July 8, 2009
    Publication date: June 23, 2011
    Inventors: Hiroyuki Furuya, Koichi Kusukame, Tetsuro Mizushima, Toshifumi Yokoyama, Kenji Nakayama, Kazuhisa Yamamoto, Shinichi Kadowaki, Tomoya Sugita, Nobuyuki Horikawa
  • Patent number: 7954962
    Abstract: A laser image display including a laser light source emitting laser light, a beam deflector element for receiving laser light and deflecting its advancing direction, a beam deflecting element control section for controlling the degree of deflection performed by the beam deflector element, an optical integrator for receiving and guiding the deflected laser light to output from its outputting end face, a pseudo surface light source element for scattering the deflected laser light, and a modulation element for receiving and modulating the laser light scattered by the false surface light source element.
    Type: Grant
    Filed: June 1, 2006
    Date of Patent: June 7, 2011
    Assignee: Panasonic Corporation
    Inventors: Tetsuro Mizushima, Ken'ichi Kasazumi, Tatsuo Itoh, Tomoya Sugita, Kazuhisa Yamamoto, Shin-ichi Kadowaki
  • Patent number: 7948579
    Abstract: An optical fiber of which one end is optically coupled to a laser light source propagating, from the one end to other end, a laser light emitted from the laser light source. A light-guiding plate includes a light-guiding section in which a plurality of right prisms of the same shape for extracting the laser light by contacting the optical fiber are arranged parallel to each other in the same direction at equal intervals. A planar section diffuses the laser light extracted from the light-guiding section and emits the diffused laser light from one main surface. The optical fiber is bent more than twice to form a plurality of straight line portions arranged parallel to each other at unequal intervals, and the optical fiber and the light-guiding plate are positioned such that the laser light is extracted at equal intervals from each of the plurality of straight line portions.
    Type: Grant
    Filed: July 25, 2008
    Date of Patent: May 24, 2011
    Assignee: Panasonic Corporation
    Inventors: Tatsuo Itoh, Tetsuro Mizushima, Kenichi Kasazumi, Kazuhisa Yamamoto, Shinichi Kadowaki
  • Patent number: 7938541
    Abstract: The laser picture formation device includes a two-dimensional modulation element performing video image modulation as well as four or more laser light sources having different center wavelengths. The video images which have no speckle noises at the wavelength region that has high visibility, which are realized by simultaneously emitting the laser lights of green (G) and yellowish green (Y) which have particularly high visibility, and video images which are vivid as cannot be represented by the conventional display, and which can be realized by controlling the laser lights of respective colors independently, can be displayed. Particularly, by modulating the two-dimensional modulation element and the laser light output with synchronized with each other, various video displays are enabled.
    Type: Grant
    Filed: September 1, 2006
    Date of Patent: May 10, 2011
    Assignee: Panasonic Corporation
    Inventors: Tetsuro Mizushima, Ken'ichi Kasazumi, Akihiro Morikawa, Hiroyuki Furuya, Kazuhisa Yamamoto, Yoshimasa Fushimi
  • Patent number: 7926950
    Abstract: A laser image display device includes: a first laser light source capable of outputting a laser light having a first wavelength; a second laser light source capable of outputting a laser light having a second wavelength; and a color output conversion controller capable of individually controlling power of the first and the second laser light source displaying the pixels constituting an image according to an input signal.
    Type: Grant
    Filed: May 29, 2006
    Date of Patent: April 19, 2011
    Assignee: Panasonic Corporation
    Inventors: Tetsuro Mizushima, Ken'ichi Kasazumi, Akihiro Morikawa, Kazuhisa Yamamoto
  • Patent number: 7922373
    Abstract: An image display apparatus includes a laser source for emitting ultraviolet or blue display-use laser light having a wavelength of 420 nm or less; and a display unit including a fluorescent light generating section for generating fluorescent light when irradiated with the display-use laser light, wherein the display unit displays an image using the fluorescent light generated by the fluorescent light generating section, wherein the display unit further includes an extraneous light shielding section for shielding an extraneous light which is emitted from a back side of the display unit and which has a wavelength in a range where the fluorescent light is generated so as to prevent the extraneous light from entering in the fluorescent light generating section.
    Type: Grant
    Filed: November 14, 2008
    Date of Patent: April 12, 2011
    Assignee: Panasonic Corporation
    Inventors: Kazuhisa Yamamoto, Tetsuro Mizushima, Shinichi Kadowaki
  • Publication number: 20110080927
    Abstract: The light sources according to the present invention include a laser oscillator including a semiconductor laser, a drive circuit for the semiconductor laser, an ACC circuit, an APC circuit, and a switch, and a starting drive current storage device, and is controlled in such a manner that the driving current at the start of the laser driving be always constant, and after the start of the lighting, it is switched to the APC operation to carry out the power control of the laser light output.
    Type: Application
    Filed: December 14, 2010
    Publication date: April 7, 2011
    Inventors: Akihiro MORIKAWA, Ken'ichi KASAZUMI, Tetsuro MIZUSHIMA, Kazuhisa YAMAMOTO, Shin-ichi KADOWAKI