Patents by Inventor Akiyoshi Tobe

Akiyoshi Tobe 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: 8992062
    Abstract: Provided is a display device including: a light guide plate arranged so that an edge surface thereof is opposed to a light source, the light guide plate being configured to internally reflect light entering from the edge surface to cause planar light emission from a front surface of the light guide plate; and a reflective sheet arranged so as to be opposed to a rear surface of the light guide plate. Irregularities are formed on the front surface. The irregularities are formed to have a shape of a combination of first convex portions and second convex portions, each of the first convex portions including a first ridge line which continuously extends along a first direction corresponding to a light traveling direction, each of the second convex portions including a second ridge line which continuously extends along a second direction intersecting the first direction.
    Type: Grant
    Filed: January 27, 2012
    Date of Patent: March 31, 2015
    Assignee: Japan Display Inc.
    Inventors: Kentaro Oku, Yasuhisa Shiraishi, Masao Uehara, Akiyoshi Tobe, Takashi Kuwabara
  • Patent number: 8882324
    Abstract: A lighting device includes a light source 30, a light guide 20 provided adjacent to the light source 30 and including a light source light incident surface 21 on which light emitted by the light source 30 enters and a planar light emission surface 22 from which planar light is emitted, and an optical sheet 50 including a planar light incident surface 53 on which the planar light enters, and configured to change a traveling direction of the planar light because a light emission side of the optical sheet 50 has a shape in which plural columnar prisms 51 extending in parallel to the light source light incident surface 21 are arranged side by side. In each of the prisms 51, a distal surface has at least different two kinds of inclination angles.
    Type: Grant
    Filed: June 14, 2012
    Date of Patent: November 11, 2014
    Assignee: Japan Display Inc.
    Inventors: Masaya Adachi, Akiyoshi Tobe, Yasuhisa Shiraishi
  • Patent number: 8345187
    Abstract: Provided is a liquid crystal display device including: an optical switching member; a light guide panel; and a light source, the light guide panel including, on at least one of a front surface and a back surface thereof, a plurality of surface structures including: a first raised surface extending outward being formed as a free surface; a first light reflection surface entering inside from the first raised surface; a second light reflection surface extending outside from the first light reflection surface; and a second raised surface which continues from the second light reflection surface and is formed as a free surface, whereby a liquid crystal display device may be obtained, which includes a thin light guide panel with a thickness of, for example, 1 mm or less.
    Type: Grant
    Filed: January 14, 2010
    Date of Patent: January 1, 2013
    Assignees: Hitachi Displays, Ltd., Panasonic Liquid Crystal Display Co., Ltd.
    Inventors: Hiroshi Nakamoto, Akiyoshi Tobe
  • Publication number: 20120320310
    Abstract: A lighting device includes a light source 30, a light guide 20 provided adjacent to the light source 30 and including a light source light incident surface 21 on which light emitted by the light source 30 enters and a planar light emission surface 22 from which planar light is emitted, and an optical sheet 50 including a planar light incident surface 53 on which the planar light enters, and configured to change a traveling direction of the planar light because a light emission side of the optical sheet 50 has a shape in which plural columnar prisms 51 extending in parallel to the light source light incident surface 21 are arranged side by side. In each of the prisms 51, a distal surface has at least different two kinds of inclination angles.
    Type: Application
    Filed: June 14, 2012
    Publication date: December 20, 2012
    Inventors: Masaya ADACHI, Akiyoshi TOBE, Yasuhisa SHIRAISHI
  • Publication number: 20120195064
    Abstract: Provided is a display device including: a light guide plate arranged so that an edge surface thereof is opposed to a light source, the light guide plate being configured to internally reflect light entering from the edge surface to cause planar light emission from a front surface of the light guide plate; and a reflective sheet arranged so as to be opposed to a rear surface of the light guide plate. Irregularities are formed on the front surface. The irregularities are formed to have a shape of a combination of first convex portions and second convex portions, each of the first convex portions including a first ridge line which continuously extends along a first direction corresponding to a light traveling direction, each of the second convex portions including a second ridge line which continuously extends along a second direction intersecting the first direction.
    Type: Application
    Filed: January 27, 2012
    Publication date: August 2, 2012
    Inventors: Kentaro OKU, Yasuhisa SHIRAISHI, Masao UEHARA, Akiyoshi TOBE, Takashi KUWABARA
  • Patent number: 8164711
    Abstract: A liquid crystal display device which can make the surface brightness of an edge-light-type backlight uniform is provided. The liquid crystal display device includes a liquid crystal display panel and a backlight which radiates light to the liquid crystal display panel. The backlight includes a light guide plate which is arranged on a back side of the liquid crystal display panel, a light source arranged on an outer peripheral portion of a first main surface of the light guide plate which faces the liquid crystal display panel in an opposed manner, and a reflection sheet which is arranged on a back side of the light guide plate as viewed from the liquid crystal display panel. The light guide plate is made of a transparent resin having a refractive index of 1.53 or less.
    Type: Grant
    Filed: May 12, 2009
    Date of Patent: April 24, 2012
    Assignees: Hitachi Displays, Ltd., Panasonic Liquid Crystal Display Co., Ltd.
    Inventors: Yasuhisa Shiraishi, Atsushi Tsuruoka, Akiyoshi Tobe, Shigeki Nishizawa, Toshihiro Yajima
  • Patent number: 8066393
    Abstract: In a backlight which arranges light emitting diodes on a side surface of a light guide plate, irregularities of radiation light from the backlight can be decreased. In a liquid crystal display device having a backlight which radiates light to a liquid crystal panel, LEDs which constitute a light emitting element are mounted on a light guide plate formed on the backlight, and teardrop-shaped lenses are formed on a light radiation surface of the light guide plate. By changing the advancing directions of lights radiated from the light emitting element using the teardrop-shaped lenses, it is possible to decrease irregularities of a planar light source by scattering the radiation lights from the light guide plate.
    Type: Grant
    Filed: August 26, 2008
    Date of Patent: November 29, 2011
    Assignee: Hitachi Displays, Ltd.
    Inventors: Yoshiaki Takahashi, Masayuki Mifune, Hiroshi Nakamoto, Michihide Shibata, Akiyoshi Tobe
  • Patent number: 7999887
    Abstract: A liquid crystal display device includes a display panel, a backlight which radiates light to the display panel, a light emitting element which is mounted on the backlight, and a light guide plate on which light from the light emitting element is incident. The light guide plate has an upper surface and a bottom surface. The bottom surface has grooves formed therein delimited by at least one surface which extends at a slant with respect to the bottom surface. A reflection sheet is provided which reflects the light radiated from the bottom surface. The grooves are formed to produce a first light which is reflected on the grooves and a second light which is radiated from the grooves and is reflected on the reflection sheet, and an asymmetric prism sheet is arranged on the light guide plate.
    Type: Grant
    Filed: September 8, 2010
    Date of Patent: August 16, 2011
    Assignee: Hitachi Displays, Ltd.
    Inventors: Yasuhisa Shiraishi, Akiyoshi Tobe, Nobuyuki Koganezawa
  • Publication number: 20100328581
    Abstract: A liquid crystal display device includes a display panel, a backlight which radiates light to the display panel, a light emitting element which is mounted on the backlight, and a light guide plate on which light from the light emitting element is incident. The light guide plate has an upper surface and a bottom surface. The bottom surface has grooves formed therein delimited by at least one surface which extends at a slant with respect to the bottom surface. A reflection sheet is provided which reflects the light radiated from the bottom surface. The grooves are formed to produce a first light which is reflected on the grooves and a second light which is radiated from the grooves and is reflected on the reflection sheet, and an asymmetric prism sheet is arranged on the light guide plate.
    Type: Application
    Filed: September 8, 2010
    Publication date: December 30, 2010
    Inventors: Yasuhisa SHIRAISHI, Akiyoshi TOBE, Nobuyuki KOGANEZAWA
  • Patent number: 7817357
    Abstract: The present invention provides a display device having a large-area display region which is capable of performing an image display of high quality by making, even when two display panels abut on each other, an abutting portion becomes inconspicuous. Two optical path changing lenses LPL1, LPE2 are arranged in a state that respective optical path changing lenses LPL1, LPE2 have respective one sides thereof abutted on each other above an abutting portion BE of two display panels PNL1, PNL2. The abutted ends form a straight-line shape on the abutting portion BE.
    Type: Grant
    Filed: January 2, 2009
    Date of Patent: October 19, 2010
    Assignee: Hitachi Displays, Ltd
    Inventors: Hideo Mitani, Yuuichi Kanesaka, Akiyoshi Tobe
  • Patent number: 7796213
    Abstract: In a liquid crystal display device using a light emitting diode as a light source, even when a plurality of light emitting elements are provided, an inclined surface is formed on a light guide plate as a reflection surface, and a light is converged in the liquid-crystal-panel direction using the reflection surface. In a liquid crystal display device which includes a backlight for radiating a light toward a liquid crystal panel, LEDs are formed on the light guide plate which is mounted on the backlight as light emitting elements. The plurality of LEDs are arranged along a side surface of the light guide plate, and a first reflection surface and a second reflection surface are formed on a bottom surface of the light guide plate. The second reflection surface is arranged closer to the LEDs than the first reflection surface and an angle of the second reflection surface is set larger than an angle of the first reflection surface.
    Type: Grant
    Filed: December 20, 2007
    Date of Patent: September 14, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Yasuhisa Shiraishi, Akiyoshi Tobe, Nobuyuki Koganezawa
  • Publication number: 20100182542
    Abstract: Provided is a liquid crystal display device including: an, optical switching member; a light guide panel; and a light source, the light guide panel including, on at least one of a front surface and a back surface thereof, a plurality of surface structures including: a first raised surface extending outward being formed as a free surface; a first light reflection surface entering inside from the first raised surface; a second light reflection surface extending outside from the first light reflection surface; and a second raised surface which continues from the second light reflection surface and is formed as a free surface, whereby a liquid crystal display device may be obtained, which includes a thin light guide panel with a thickness of, for example, 1 mm or less.
    Type: Application
    Filed: January 14, 2010
    Publication date: July 22, 2010
    Inventors: Hiroshi Nakamoto, Akiyoshi Tobe
  • Patent number: 7719632
    Abstract: The present invention provides a liquid crystal display device which can largely enhance a property of focusing light from a backlight. The backlight arranged on a back surface of a liquid crystal panel includes a light guide plate, a light source, a first asymmetrical prism sheet, and a second asymmetrical prism sheet. A reflection surface having an inclination of 2° or less for guiding light from the light source toward the liquid crystal display panel is formed on a back surface of the light guide plate. The first asymmetrical prism sheet and the second asymmetrical prism sheet respectively include projecting portions which extend in the arrangement direction of the light source and are arranged in parallel to each other in the direction which intersects the arrangement direction of the light source.
    Type: Grant
    Filed: July 2, 2008
    Date of Patent: May 18, 2010
    Assignees: Hitachi Displays, Ltd., Hitachi Display Devices, Ltd.
    Inventors: Nobuyuki Koganezawa, Akiyoshi Tobe, Yasuhisa Shiraishi
  • Patent number: 7690830
    Abstract: The present invention makes a radiation angle of light at a portion of a light guide plate in front of an LED formed on one edge of a light guide plate and a radiation angle of light at a corner portion of the light guide plate equal to each other as much as possible. A shape of beam control elements which are arranged on a lower surface of a light guide plate is arranged concentrically about the LED.
    Type: Grant
    Filed: March 29, 2007
    Date of Patent: April 6, 2010
    Assignees: Hitachi Displays, Ltd., Hitachi Display Devices, Ltd.
    Inventors: Nobuyuki Koganezawa, Akiyoshi Tobe, Fumiyuki Sato
  • Patent number: 7663713
    Abstract: A liquid crystal display device includes a liquid crystal panel and an illumination device. The illumination device has a light guide plate and at least one spot light source on at least one side surface of the light guide plate. The light guide plate includes a large number of upper-surface arcuate cross-sectional grooves in a direction orthogonal to the one side surface on a surface thereof which faces the liquid crystal panel, and a large number of light-incident-surface arcuate cross-sectional grooves are formed in a thickness direction of the light guide plate on at least a portion of the one side surface which faces a position at which the spot light source is arranged. A relationship is provided between a contact angle Oa of the upper-surface arcuate cross-sectional grooves and a contact angle Ea of the light-incident-surface arcuate cross-sectional grooves.
    Type: Grant
    Filed: November 28, 2005
    Date of Patent: February 16, 2010
    Assignee: Hitachi Displays, Ltd.
    Inventors: Ken Saito, Shigeo Shimano, Hiroshi Nakamoto, Hiroyuki Yoshida, Hirokazu Yabe, Toshitsugu Miyawaki, Akiyoshi Tobe
  • Publication number: 20090284688
    Abstract: A liquid crystal display device which can make the surface brightness of an edge-light-type backlight uniform is provided. The liquid crystal display device includes a liquid crystal display panel and a backlight which radiates light to the liquid crystal display panel. The backlight includes a light guide plate which is arranged on a back side of the liquid crystal display panel, a light source arranged on an outer peripheral portion of a first main surface of the light guide plate which faces the liquid crystal display panel in an opposed manner, and a reflection sheet which is arranged on a back side of the light guide plate as viewed from the liquid crystal display panel. The light guide plate is made of a transparent resin having a refractive index of 1.53 or less.
    Type: Application
    Filed: May 12, 2009
    Publication date: November 19, 2009
    Inventors: Yasuhisa SHIRAISHI, Atsushi Tsuruoka, Akiyoshi Tobe, Shigeki Nishizawa, Toshihiro Yajima
  • Patent number: 7614777
    Abstract: The present invention provides a liquid crystal display device of high quality having high brightness and uniform brightness distribution by focusing the light radiation direction from a light guide plate in the vertical direction with respect to a light radiation surface of the light guide plate. The liquid crystal display device includes a liquid crystal display panel and a flat lighting device which radiates an illumination light to a back surface of the liquid crystal display panel. The flat lighting device includes a light guide plate which has an upper surface facing a back surface of the liquid crystal display panel in an opposed manner and constituting a light radiation surface and a bottom surface which is arranged opposite to the upper surface. One LED is arranged at a first corner portion of the light guide plate and another LED is arranged at a second corner portion of the light guide plate arranged adjacent to the first corner portion.
    Type: Grant
    Filed: March 30, 2007
    Date of Patent: November 10, 2009
    Assignees: Hitachi Displays, Ltd., Hitachi Display Devices, Ltd.
    Inventors: Nobuyuki Koganezawa, Akiyoshi Tobe
  • Patent number: 7554628
    Abstract: The present invention provides a display device having a large-area display region which is capable of performing an image display of high quality by making, even when two display panels abut on each other, an abutting portion becomes inconspicuous. Two optical path changing lenses LPL1, LPE2 are arranged in a state that respective optical path changing lenses LPL1, LPE2 have respective one sides thereof abutted on each other above an abutting portion BE of two display panels PNL1, PNL2. The abutted ends form a straight-line shape on the abutting portion BE.
    Type: Grant
    Filed: April 21, 2006
    Date of Patent: June 30, 2009
    Assignee: Hitachi Displays, Ltd.
    Inventors: Hideo Mitani, Yuuichi Kanesaka, Akiyoshi Tobe
  • Publication number: 20090122415
    Abstract: The present invention provides a display device having a large-area display region which is capable of performing an image display of high quality by making, even when two display panels abut on each other, an abutting portion becomes inconspicuous. Two optical path changing lenses LPL1, LPE2 are arranged in a state that respective optical path changing lenses LPL1, LPE2 have respective one sides thereof abutted on each other above an abutting portion BE of two display panels PNL1, PNL2. The abutted ends form a straight-line shape on the abutting portion BE.
    Type: Application
    Filed: January 2, 2009
    Publication date: May 14, 2009
    Inventors: Hideo Mitani, Yuuichi Kanesaka, Akiyoshi Tobe
  • Publication number: 20090059621
    Abstract: In a backlight which arranges light emitting diodes on a side surface of a light guide plate, irregularities of radiation light from the backlight can be decreased. In a liquid crystal display device having a backlight which radiates light to a liquid crystal panel, LEDs which constitute a light emitting element are mounted on a light guide plate formed on the backlight, and teardrop-shaped lenses are formed on a light radiation surface of the light guide plate. By changing the advancing directions of lights radiated from the light emitting element using the teardrop-shaped lenses, it is possible to decrease irregularities of a planar light source by scattering the radiation lights from the light guide plate.
    Type: Application
    Filed: August 26, 2008
    Publication date: March 5, 2009
    Inventors: Yoshiaki Takahashi, Masayuki Mifune, Hiroshi Nakamoto, Michihide Shibata, Akiyoshi Tobe