Patents by Inventor Keiji Kashima

Keiji Kashima 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: 7256847
    Abstract: In view of the above problems of the prior art, the present invention has been made, and an object of the present invention is to provide a board, which is free from coloring, has high color tone quality, can realize a bright display screen, and imposes no significant restriction on the provision of an electric circuit, and a display device comprising the board, and further provides a liquid crystal display board, which is excellent in color contrast between transmission display and reflection display, and a semi-transmission color liquid crystal display device comprising the liquid crystal display board. A board according to the invention comprises a light transparent substrate and a cholesteric layer provided on the substrate and provided with an optical window of a predetermined pattern.
    Type: Grant
    Filed: November 11, 2002
    Date of Patent: August 14, 2007
    Assignee: Dai Nippon Printing Co., Ltd.
    Inventor: Keiji Kashima
  • Publication number: 20070153164
    Abstract: In a liquid-crystal display (10), unpolarized light from a light source (12) passes through a linear polarization separation layer (14) and strikes a liquid-crystal cell (16). The liquid-crystal cell (16), in response to an applied electrical field, changes the direction of a director, so as to change the direction of the electrical field oscillation vector of the incident linearly polarized light by substantially 0 to 90°, this light then striking a dichroic linear polarization layer (18) on the surface, whereby only a component coincident with the polarization transmission axis thereof is allowed to exit to the outside. The dichroic linear polarization layer (18) transmits 50% of this incident light, and absorbs the remaining 50%.
    Type: Application
    Filed: March 8, 2007
    Publication date: July 5, 2007
    Applicant: DAI NIPPON PRINTING CO., LTD.
    Inventor: Keiji Kashima
  • Publication number: 20070146597
    Abstract: Provided herein is a retardation optical element 10 that produces no bright and dark fringes on a displayed image even when placed between a liquid crystal cell 104 and a polarizer 102B and thus can effectively prevent lowering of display quality. The retardation optical element 10 includes a retardation layer 12 having a cholesteric-regular molecular structure with liquid crystalline molecules in planar orientation. The helical pitch in the molecular structure of the retardation layer 12 is so adjusted that the retardation layer 12 can, owing to its molecular structure, selectively reflect light whose wavelength falls in a range different from the wave range of light incident on the retardation layer 12 (the selective reflection wave range of the retardation layer is either shorter or longer than the wave range of the incident light).
    Type: Application
    Filed: March 5, 2007
    Publication date: June 28, 2007
    Applicant: Dai Nippon Printing Co., Ltd.
    Inventor: Keiji Kashima
  • Publication number: 20070128430
    Abstract: A main object of the present invention is to provide a retardation layer forming coating solution capable of forming a retardation layer showing the property as the optically negative C plate on an optional substrate. To achieve the object, the invention provides a retardation layer forming coating solution used for forming a retardation layer showing the property as the optically negative C plate, comprising a resin having the optical isotropy, a rodlike compound having the refractive index anisotropy, and a solvent for dissolving the resin and the rodlike compound.
    Type: Application
    Filed: September 27, 2006
    Publication date: June 7, 2007
    Inventors: Kenji Shirai, Keiji Kashima
  • Patent number: 7209346
    Abstract: An information processing apparatus has a disk shuttle to mount a magnetic disk unit, a main body case to contain at least one disk shuttle, a connector of magnetic disk provided at the insertion end of the disk shuttle inserted from one side of the main body case, a connector of a main body provided in the other side of the main body case and fitted with the connector of the magnetic disk, a back plane to be fixed with the connector of the main body, an tenon formed at the insertion end of the disk shuttle and extending toward the back plane, and a mortise formed in the back plane to be fitted with the tenon, thereby locking the movement in the direction transverse to the inserting direction of disk shuttle.
    Type: Grant
    Filed: November 2, 2005
    Date of Patent: April 24, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shingo Fujimoto, Keiji Kashima
  • Patent number: 7206041
    Abstract: In a liquid-crystal display (10), unpolarized light from a light source (12) passes through a linear polarization separation layer (14) and strikes a liquid-crystal cell (16). The liquid-crystal cell (16), in response to an applied electrical field, changes the direction of a director, so as to change the direction of the electrical field oscillation vector of the incident linearly polarized light by substantially 0 to 90°, this light then striking a dichroic linear polarization layer (18) on the surface, whereby only a component coincident with the polarization transmission axis thereof is allowed to exit to the outside. The dichroic linear polarization layer (18) transmits 50% of this incident light, and absorbs the remaining 50%.
    Type: Grant
    Filed: March 3, 2005
    Date of Patent: April 17, 2007
    Assignee: Dai Nippon Printing Co., Ltd.
    Inventor: Keiji Kashima
  • Patent number: 7202926
    Abstract: Provided herein is a retardation optical element 10 that produces no bright and dark fringes on a displayed image even when placed between a liquid crystal cell 104 and a polarizer 102B and thus can effectively prevent lowering of display quality. The retardation optical element 10 includes a retardation layer 12 having a cholesteric-regular molecular structure with liquid crystalline molecules in planar orientation. The helical pitch in the molecular structure of the retardation layer 12 is so adjusted that the retardation layer 12 can, owing to its molecular structure, selectively reflect light whose wavelength falls in a range different from the wave range of light incident on the retardation layer 12 (the selective reflection wave range of the retardation layer is either shorter or longer than the wave range of the incident light).
    Type: Grant
    Filed: June 26, 2003
    Date of Patent: April 10, 2007
    Assignee: Dai Nippon Printing Co., Ltd.
    Inventor: Keiji Kashima
  • Publication number: 20070076153
    Abstract: A main object of the invention is to provide a phase difference layer laminated body which has a very high freedom in orienting molecules of its phase difference layer, and which is manufactured with ease. To achieve the above object, the invention provides a phase difference layer laminated body including a base material having orientability, and a phase difference layer made of a liquid crystal material that can form a nematic phase and formed in a pattern on the base material such as to have refractive index anisotropy.
    Type: Application
    Filed: November 21, 2006
    Publication date: April 5, 2007
    Applicant: Dai Nippon Printing Co., Ltd.
    Inventor: Keiji Kashima
  • Publication number: 20070042189
    Abstract: A main object of the present invention is to provide a highly reliable retardation film without the problems of peeling off of the retardation layer from the base material or the like generated in the case of forming the retardation layer, capable of easily obtaining an optional retardation value even for a small amount, and capable of improving the adhering property with a hydrophilic film such as a polarizing layer. In order to achieve the above-mentioned object, the present invention provides a retardation film, comprising a polymer film containing a material having refractive index anisotropy, wherein the material having refractive index anisotropy has a concentration gradient in a thickness direction of the polymer film.
    Type: Application
    Filed: August 15, 2006
    Publication date: February 22, 2007
    Inventors: Kenji Shirai, Keiji Kashima, Takashi Kuroda, Takeshi Haritani
  • Publication number: 20070036918
    Abstract: The main object of the present invention is to provide a highly reliable biaxial retardation film without the problems of peeling off of the retardation layer from the base material or the like generated in the case of forming the retardation layer, capable of enlarging the range of the thickness direction and in-plane direction retardation values to be obtained, easily obtaining optional thickness direction and in-plane direction retardation values even for a small amount, a method for producing the same, an optical functional film using the retardation layer, a polarizing film and a display device. In order to achieve the above-mentioned object, an optically biaxial retardation film, comprising a polymer film containing a material having refractive index anisotropy, wherein the material having refractive index anisotropy has a concentration gradient in a thickness direction of the polymer film, is provided.
    Type: Application
    Filed: August 15, 2006
    Publication date: February 15, 2007
    Inventors: Keiji Kashima, Takeshi Haritani, Kenji Shirai
  • Publication number: 20060170859
    Abstract: The present invention provides a method of efficiently and precisely patterning cholesteric films. A cholesteric film 13 is firstly formed on an alignment film 12 provided on a glass substrate 11. The cholesteric film 13 is then patterned by partially volatilizing and removing a part of the cholesteric film 13 by the application of laser light 20 having a wavelength not falling in the selective reflection wave range of the cholesteric film 13. It is preferred that the wavelength of the laser light 20 be shorter than that of visible light. Alternatively, there may be used laser light 20 containing, as its main component, a component circularly polarized in the direction opposite to that of optical rotation of a component selectively reflected by the cholesteric film.
    Type: Application
    Filed: March 29, 2006
    Publication date: August 3, 2006
    Applicant: DAI NIPPON PRINTING CO., LTD.
    Inventors: Keiji Kashima, Koji Ishizaki
  • Patent number: 7079207
    Abstract: A liquid crystal display improves light utilization efficiency with a cholesteric liquid crystal filter to ensure color density enough to enable both transmission and reflection type displays. The display comprises a liquid crystal display device comprising a liquid crystal layer between transparent substrates, a voltage applying electrode, a driving circuit, an illumination light source, and a pair of circularly polarizing plates. A cholesteric liquid crystal filter semitransparent to red, green and blue wavelength ranges is located on the illumination light-directing side. The liquid crystal layer viewing side has a cholesteric liquid crystal color filter array capable of transmitting red, green and blue wavelength ranges and reflecting light in other wavelength ranges depending on a pixel arrangement, and absorption type color filter array is located in alignment therewith and capable of transmitting only red, green and blue wavelength ranges and absorbing light in other wavelengths.
    Type: Grant
    Filed: November 4, 2002
    Date of Patent: July 18, 2006
    Assignee: Dai Nippon Printing Co., Ltd.
    Inventor: Keiji Kashima
  • Publication number: 20060152656
    Abstract: A retardation layer capable of effectively restraining the display quality deterioration without generating a bright and dark pattern in the display image even when a retardation layer is disposed in between a liquid crystal cell and a polarizing plate. The retardation layer includes a plurality of minute units (domains) having molecular structure of cholesteric structure. Moreover, in the retardation layer, the helical pitch of the molecular structure is adjusted such that the selective reflected wavelength of the selected reflected light deriving from the molecular structure is shorter than the wavelength of the incident light on the retardation layer.
    Type: Application
    Filed: July 20, 2004
    Publication date: July 13, 2006
    Inventors: Keiji Kashima, Takashi Kuroda
  • Publication number: 20060139531
    Abstract: A wavelength-selecting optical element includes a cholesteric layer that reflects or transmits either of a right-handed circularly polarized light component and a left-handed circularly polarized light component in a selected wavelength band of an incident light; and a diffusing layer disposed on the exit side of the cholesteric layer to diffuse the circularly polarized light component reflected or transmitted by the cholesteric layer. The cholesteric layer may be a color filter having a red, a green and a blue pixel region for each of pixels. Each of the pixel regions reflects or transmits either of a right-handed circularly polarized light component and a left-handed circularly polarized light component in a selected wavelength band of an incident light.
    Type: Application
    Filed: February 28, 2006
    Publication date: June 29, 2006
    Applicant: DAI NIPPON PRINTING CO., LTD.
    Inventor: Keiji Kashima
  • Patent number: 7068345
    Abstract: An optical device in which a polymerizable liquid crystal material various optical characteristics of which is stable even against heating during manufacture of an optical apparatus such as an image display is cured. The optical device has a support and an optical functional layer made of a cured polymerizable liquid crystal material having a predetermined liquid crystal regularity and provided on the support. The optical device is characterized in that the optical device is subjected to a heat treatment at a predetermined temperature and in that the thickness decrease of the optical functional layer defined by (A-B)/A is 5% or less where A is the thickness of the optical functional layer after the heat treatment, and B is the thickness of the optical functional layer after the optical device is heated for 60 minutes at the heat-treatment temperature.
    Type: Grant
    Filed: November 7, 2002
    Date of Patent: June 27, 2006
    Assignee: Dai Nippon Printing Co., Ltd.
    Inventor: Keiji Kashima
  • Patent number: 7057687
    Abstract: The present invention provides a method of efficiently and precisely patterning cholesteric films. A cholesteric film 13 is firstly formed on an alignment film 12 provided on a glass substrate 11. The cholesteric film 13 is then patterned by partially volatilizing and removing a part of the cholesteric film 13 by the application of laser light 20 having a wavelength not falling in the selective reflection wave range of the cholesteric film 13. It is preferred that the wavelength of the laser light 20 be shorter than that of visible light. Alternatively, there may be used laser light 20 containing, as its main component, a component circularly polarized in the direction opposite to that of optical rotation of a component selectively reflected by the cholesteric film.
    Type: Grant
    Filed: March 28, 2002
    Date of Patent: June 6, 2006
    Assignee: Dai Nippon Printing Co., Ltd.
    Inventors: Keiji Kashima, Koji Ishizaki
  • Publication number: 20060105115
    Abstract: The main object of the present invention is to provide a highly reliable biaxial retardation film without the problems of peeling off of the retardation layer from the base material or the like generated in the case of forming the retardation layer, capable of enlarging the range of the thickness direction and in-plane direction retardation values to be obtained, easily obtaining optional thickness direction and in-plane direction retardation values even for a small amount, a method for producing the same, an optical functional film using the retardation layer, a polarizing film and a display device. In order to achieve the above-mentioned object, an optically biaxial retardation film, comprising a polymer film containing a material having refractive index anisotropy, wherein the material having refractive index anisotropy has a concentration gradient in a thickness direction of the polymer film, is provided.
    Type: Application
    Filed: January 19, 2005
    Publication date: May 18, 2006
    Inventors: Keiji Kashima, Takeshi Haritani, Kenji Shirai
  • Patent number: 7030949
    Abstract: A wavelength-selecting optical element includes a cholesteric layer that reflects or transmits either of a right-handed circularly polarized light component and a left-handed circularly polarized light component in a selected wavelength band of an incident light; and a diffusing layer disposed on the exit side of the cholesteric layer to diffuse the circularly polarized light component reflected or transmitted by the cholesteric layer. The cholesteric layer may be a color filter having a red, a green and a blue pixel region for each of pixels. Each of the pixel regions reflects or transmits either of a right-handed circularly polarized light component and a left-handed circularly polarized light component in a selected wavelength band of an incident light.
    Type: Grant
    Filed: May 29, 2002
    Date of Patent: April 18, 2006
    Assignee: Dai Nippon Printing Co., Ltd.
    Inventor: Keiji Kashima
  • Publication number: 20060073340
    Abstract: A main object of the present invention is to provide a highly reliable retardation film without the problems of peeling off of the retardation layer from the base material or the like generated in the case of forming the retardation layer, capable of easily obtaining an optional retardation value even for a small amount, and capable of improving the adhering property with a hydrophilic film such as a polarizing layer. In order to achieve the above-mentioned object, the present invention provides a retardation film, comprising a polymer film containing a material having refractive index anisotropy, wherein the material having refractive index anisotropy has a concentration gradient in a thickness direction of the polymer film.
    Type: Application
    Filed: January 19, 2005
    Publication date: April 6, 2006
    Inventors: Kenji Shirai, Keiji Kashima, Takashi Kuroda, Takeshi Haritani
  • Publication number: 20060073326
    Abstract: A main object of the present invention is to provide a retardation film capable of easily obtaining an optional retardation value even for a small amount without problems, of peeling off of the retardation layer from the base material or the like, generated in a case of forming the retardation layer. In order to achieve the above-mentioned object, the present invention provides a retardation film, wherein a material having refractive index anisotropy is contained in a polymer film, and the material having refractive index anisotropy has a concentration gradient in a thickness direction of the polymer film.
    Type: Application
    Filed: October 6, 2004
    Publication date: April 6, 2006
    Inventors: Kenji Shirai, Takashi Kuroda, Keiji Kashima