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).

  • Publication number: 20100182545
    Abstract: The present invention provides 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 comprises 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: March 30, 2010
    Publication date: July 22, 2010
    Applicant: DAI NIPPON PRINTING CO., LTD.
    Inventors: Keiji KASHIMA, Takashi KURODA
  • Publication number: 20100165258
    Abstract: A main object of the present invention is to provide a rotating plate hardly generating variation in the rotation angle of the liner polarization so as to easily realize a desired rotation angle, and a liquid crystal display device enabling observation of a bright image by use thereof even in a state with a polarizing glasses put on. To attain the object, the present invention provides an optical rotation plate comprising a transparent substrate, and an optical rotation layer formed on the transparent substrate and containing a rod-shaped compound for forming a cholesteric structure and having a function of rotating transmitted liner polarization, wherein the cholesteric structure has a 90 degrees or larger twist angle and a pitch in a range of 450 nm to 4,000 nm.
    Type: Application
    Filed: December 23, 2009
    Publication date: July 1, 2010
    Applicant: DAI NIPPON PRINTING CO., LTD.
    Inventors: Satoru HAMADA, Keiji KASHIMA, Takashi KURODA, Hirofumi YUMOTO
  • Publication number: 20100159158
    Abstract: An optical functional film exhibiting optical biaxiality which has a high degree of freedom in optical characteristics design. The optical functional film which exhibits optical biaxiality and includes: a substrate; and an optical functional layer formed on the substrate and having a rodlike compound. The rodlike compound forms irregular-random homogeneous alignment in the optical functional layer.
    Type: Application
    Filed: May 14, 2007
    Publication date: June 24, 2010
    Inventors: Takayuki Shibata, Keiji Kashima, Shoji Takeshige, Kenji Shirai, Takeshi Haritani, Yusuke Hiruma, Runa Nakamura, Hiroki Nakagawa, Masanori Fukuda, Takashi Kuroda, Yuya Inomata
  • Publication number: 20100149638
    Abstract: An optical functional film which exhibits excellent optical characteristics without using an alignment film, and having the excellent adhesion property between layers. The optical functional film includes: a substrate having a property as an optically negative C-plate, and an optical functional layer formed on the substrate and having a rodlike compound. The optical functional layer is formed directly on the substrate, and the rodlike compound forms a random homogeneous alignment in the optical functional layer.
    Type: Application
    Filed: September 28, 2006
    Publication date: June 17, 2010
    Inventors: Keiji Kashima, Kenji Shirai, Takashi Kuroda, Takeshi Haritani
  • Patent number: 7719643
    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: Grant
    Filed: July 20, 2004
    Date of Patent: May 18, 2010
    Assignee: Dai Nippon Printing Co., Ltd.
    Inventors: Keiji Kashima, Takashi Kuroda
  • Patent number: 7623201
    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: August 15, 2007
    Date of Patent: November 24, 2009
    Assignee: Dai Nippon Printing Co., Ltd.
    Inventor: Keiji Kashima
  • Patent number: 7508474
    Abstract: The invention relates to a liquid crystal display that incorporates a laminated retardation layer 10 comprising a combination of a negative C-plate having a specific chromatic dispersion and a positive A-plate having a specific chromatic dispersion, used to improve the viewing angle characteristics thereof, thereby presenting high-contrast images with high color reproducibility yet with neither interference variations nor color shifts. The laminated retardation layer 10 is obtained by lamination of a retardation layer 11 having positive index anisotropy and an optical axis in a layer plane and a retardation layer 12 having negative index anisotropy and an optical axis in a normal direction to a layer plane.
    Type: Grant
    Filed: March 31, 2004
    Date of Patent: March 24, 2009
    Assignee: Dai Nippon Printing Co., Ltd.
    Inventor: Keiji Kashima
  • Patent number: 7411645
    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: Grant
    Filed: November 21, 2006
    Date of Patent: August 12, 2008
    Assignee: Dai Nippon Printing Co., Ltd.
    Inventor: Keiji Kashima
  • Publication number: 20080180619
    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: March 7, 2008
    Publication date: July 31, 2008
    Applicant: Dai Nippon Printing Co., Ltd.
    Inventor: Keiji Kashima
  • Patent number: 7405786
    Abstract: In a liquid crystal display 90, a laminated retardation optical element 10 is placed between a polarizer 102A on the incident side and a liquid crystal cell 104, and a ˜/4 retardation film 102C 10 is placed between a polarizer 102B on the emergent side and the liquid crystal cell 104. The laminated retardation optical element 10 comprises: a ˜/4 retardation layer 14 having the function of bringing, to light that passes through this retardation layer, a 15 phase difference corresponding to a quarter of the wavelength of the light; and a C plate-type retardation layer 16 that acts as a negative C plate. The ˜/4 retardation layer 14 and the C plate-type retardation layer 16 are laminated to a transparent substrate 12 in 20 the order mentioned, and are optically bonded to each other.
    Type: Grant
    Filed: August 30, 2007
    Date of Patent: July 29, 2008
    Assignee: Dai Nippon Printing Co., Ltd
    Inventor: Keiji Kashima
  • Patent number: 7405780
    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 8, 2007
    Date of Patent: July 29, 2008
    Assignee: Dai Nippon Printing Co., Ltd.
    Inventor: Keiji Kashima
  • Publication number: 20080143931
    Abstract: In a liquid-crystal display, unpolarized light from a light source passes through a linear polarization separation layer and strikes a liquid-crystal cell. The liquid-crystal cell, 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 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 transmits 50% of this incident light, and absorbs the remaining 50%.
    Type: Application
    Filed: February 11, 2008
    Publication date: June 19, 2008
    Applicant: DAI NIPPON PRINTING CO., LTD.
    Inventor: Keiji Kashima
  • Publication number: 20080129940
    Abstract: The present invention provides a laminated retardation optical element that never lowers contrast and thus never degrades display performance even when placed between a liquid crystal cell and a ?/4 retardation film. In a liquid crystal display 90, a laminated retardation optical element 10 is placed between a polarizer 102A on the incident side and a liquid crystal cell 104, and a ?/4 retardation film 102C is placed between a polarizer 102B on the emergent side and the liquid crystal cell 104. The laminated retardation optical element 10 comprises: a ?/4 retardation layer 14 having the function of bringing, to light that passes through this retardation layer, a phase difference corresponding to a quarter of the wavelength of the light; and a C plate-type retardation layer 16 that acts as a negative C plate. The ?/4 retardation layer 14 and the C plate-type retardation layer 16 are laminated to a transparent substrate 12 in the order mentioned, and are optically bonded to each other.
    Type: Application
    Filed: December 28, 2007
    Publication date: June 5, 2008
    Applicant: Dai Nippon Printing Co., Ltd.
    Inventor: Keiji Kashima
  • Patent number: 7359018
    Abstract: The present invention provides a retardation optical element comprising a negative C plate (retardation layer) and an A plate (retardation layer), never causing the appearance of bright-and-dark patterns on the displayed image even when placed between a liquid crystal cell and a polarizer, thus being capable of effectively preventing lowering of display quality. A retardation optical element 10 comprises: a C plate type retardation layer 12 that has a cholesteric structure with liquid crystalline molecules in planar orientation and functions as a negative C plate; and an A plate type retardation layer 14 that has a nematic structure and functions as an A plate.
    Type: Grant
    Filed: August 25, 2003
    Date of Patent: April 15, 2008
    Assignee: Dai Nippon Printing Co., Ltd
    Inventor: Keiji Kashima
  • Patent number: 7352422
    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: March 5, 2007
    Date of Patent: April 1, 2008
    Assignee: Dai Nippon Printing Co., Ltd.
    Inventor: Keiji Kashima
  • Patent number: 7342619
    Abstract: A polarization light splitting film having a light receiving side and a light transmitting side. The polarization light splitting film includes an optical rotation selection layer at the light receiving side for reflecting one of right and left circularly polarized components of a light beam that is incident on the light receiving side and for transmitting the other one of the right and left circular polarization components of the light beam, and a quarter-wave layer laminated over the optical rotation selection layer at the light transmitting side.
    Type: Grant
    Filed: March 7, 2003
    Date of Patent: March 11, 2008
    Assignee: Dai Nippon Printing Co., Ltd.
    Inventors: Fumihiro Arakawa, Keiji Kashima
  • Patent number: 7324180
    Abstract: In a liquid crystal display 90, a laminated retardation optical element 10 is placed between a polarizer 102A on the incident side and a liquid crystal cell 104, and a ˜/4 retardation film 102C 10 is placed between a polarizer 102B on the emergent side and the liquid crystal cell 104. The laminated retardation optical element 10 comprises: a ˜/4 retardation layer 14 having the function of bringing, to light that passes through this retardation layer, a 15 phase difference corresponding to a quarter of the wavelength of the light; and a C plate-type retardation layer 16 that acts as a negative C plate. The ˜/4 retardation layer 14 and the C plate-type retardation layer 16 are laminated to a transparent substrate 12 in 20 the order mentioned, and are optically bonded to each other.
    Type: Grant
    Filed: September 5, 2003
    Date of Patent: January 29, 2008
    Assignee: Dai Nippon Printing Co., Ltd.
    Inventor: Keiji Kashima
  • Publication number: 20080002108
    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: August 15, 2007
    Publication date: January 3, 2008
    Applicant: DAI NIPPON PRINTING CO., LTD.
    Inventor: Keiji Kashima
  • Publication number: 20070296892
    Abstract: The present invention provides a laminated retardation optical element that never lowers contrast and thus never degrades display performance even when placed between a liquid crystal cell and a ?/4 retardation film. In a liquid crystal display 90, a laminated retardation optical element 10 is placed between a polarizer 102A on the incident side and a liquid crystal cell 104, and a ?/4 retardation film 102C is placed between a polarizer 102B on the emergent side and the liquid crystal cell 104. The laminated retardation optical element 10 comprises: a ?/4 retardation layer 14 having the function of bringing, to light that passes through this retardation layer, a phase difference corresponding to a quarter of the wavelength of the light; and a C plate-type retardation layer 16 that acts as a negative C plate. The ?/4 retardation layer 14 and the C plate-type retardation layer 16 are laminated to a transparent substrate 12 in the order mentioned, and are optically bonded to each other.
    Type: Application
    Filed: August 30, 2007
    Publication date: December 27, 2007
    Applicant: Dai Nippon Printing Co., Ltd.
    Inventor: Keiji Kashima
  • Patent number: RE40655
    Abstract: A polarization light splitting film having a light receiving side and a light transmitting side. The polarization light splitting film includes an optical rotation selection layer at the light receiving side for reflecting one of right and left circularly polarized components of a light beam that is incident on the light receiving side and for transmitting the other one of the right and left circular polarization components of the light beam, and a quarter-wave layer laminated over the optical rotation selection layer at the light transmitting side.
    Type: Grant
    Filed: December 16, 2005
    Date of Patent: March 10, 2009
    Assignee: Dai Nippon Printing Co., Ltd.
    Inventors: Fumihiro Arakawa, Keiji Kashima