Patents by Inventor Takashi Yamaoka

Takashi Yamaoka 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: 6829026
    Abstract: A laminated phase retarder having: a laminate of a retardation layer A made of a thermoplastic resin exhibiting positive birefringent characteristic and a retardation layer B constituted by an oriented solidified layer of cholesteric liquid crystal exhibiting a selective reflection wavelength range not larger than 350 nm; wherein Re of the laminate is not smaller than 10 nm and Rth−Re of the laminate is not smaller than 50 nm when Re and Rth are given by Re=(nx−ny)×d and Rth=(nx−nz)×d in which nx and ny are in-plane main refractive indices, nz is a thicknesswise refractive index, and d is a layer thickness. A polarizing member having: a laminate of a laminated phase retarder defined above; and a polarizer. A liquid-crystal display device having: a liquid-crystal cell; and a laminated phase retarder or a polarizing member defined above and disposed on at least one of opposite surfaces of the liquid-crystal cell.
    Type: Grant
    Filed: October 7, 2002
    Date of Patent: December 7, 2004
    Assignee: Nitto Denko Corporation
    Inventors: Shinichi Sasaki, Takashi Yamaoka, Nao Murakami, Hiroyuki Yoshimi
  • Patent number: 6819382
    Abstract: By a method for producing a liquid crystal cell substrate having a base and a birefringent layer, which includes producing a precursor layer of the birefringent layer by applying a solution of a polymer that hardens to form the birefringent layer, directly onto one surface of the base, and producing the birefringent layer by hardening the precursor layer, the present invention provides a method for producing a birefringent layer on a liquid crystal cell substrate or a liquid crystal cell substrate of a liquid crystal panel used in a liquid crystal display.
    Type: Grant
    Filed: January 22, 2003
    Date of Patent: November 16, 2004
    Assignee: Nitto Denko Corporation
    Inventors: Takashi Yamaoka, Nao Murakami, Hiroyuki Yoshimi, Tatsuki Nagatsuka
  • Publication number: 20040212767
    Abstract: A laminated quarter-wave plate having: a laminate of a quarter-wave plate and a half-wave plate, wherein: the quarter-wave plate and the half-wave plate are laminated on each other so that directions of in-plane slow axes intersect each other; and each of the quarter-wave plate and the half-wave plate satisfies a relation Nz=(nx−nz)/(nx−ny)>1.05 in which nx and ny are in-plane main refractive indices, and nz is a thicknesswise refractive index; and a circularly polarizing plate having: a laminate of a laminated quarter-wave plate defined above and a polarizer.
    Type: Application
    Filed: May 18, 2004
    Publication date: October 28, 2004
    Applicant: NITTO DENKO CORPORATION
    Inventors: Shinichi Sasaki, Takashi Yamaoka, Hiroyuki Yoshimi
  • Patent number: 6798487
    Abstract: A liquid crystal cell substrate having a polarizing function is disclosed which can be extremely thin and lightweight and is excellent in heat resistance, impact resistance and quality stability. The liquid crystal cell substrate comprises a resin substrate and, closely adhered thereon, at least a gas barrier layer, a crosslinked resin layer and a polarizing layer, wherein the polarizing layer comprises a coating layer. This cell substrate, having a polarizing function and high durability, can be efficiently produced because an exceedingly thin polarizing layer having excellent heat resistance can be deposited on a resin substrate by coating and because a gas barrier layer and a crosslinked resin layer also can be easily formed. It is excellent in moisture resistance, gas resistance and impact resistance, can be extremely thin and lightweight, and has excellent heat resistance.
    Type: Grant
    Filed: September 13, 2000
    Date of Patent: September 28, 2004
    Assignee: Nitto Denko Corporation
    Inventors: Akira Ohtani, Takashi Yamaoka, Daisuke Uenda, Hiroyuki Yoshimi
  • Patent number: 6784954
    Abstract: A laminated optical device is a laminate formed of a polarizing layer having a thickness of not larger than 5 &mgr;m, and at least one birefringent layer including either a solid film of oriented liquid crystal or a polymer layer containing oriented liquid crystal. A liquid-crystal display apparatus includes a liquid-crystal display panel, and at least one laminated optical device defined above and disposed on one of opposite surfaces of the liquid-crystal display panel.
    Type: Grant
    Filed: January 15, 2002
    Date of Patent: August 31, 2004
    Assignee: Nitto Denko Corporation
    Inventors: Takashi Yamaoka, Hiroyuki Yoshimi, Yuuichi Nishikouji, Tomoaki Masuda
  • Patent number: 6771340
    Abstract: A composite retarder plate is constituted by a combination of at least one retarder film and at least one liquid-crystal phase sheet. The liquid-crystal phase sheet includes a transparent substrate, and a liquid-crystal polymer layer provided on the transparent substrate. At least one of refractive indices nx, ny and nz of the retarder film is different from the other refractive indices when nx and ny are main refractive indices (nx≧ny) in in-plane directions and nz is a refractive index in a direction of the thickness of the composite retarder plate, respectively. All the refractive indices nx, ny and nz of the transparent substrate are different from one another. The retarder film, the transparent substrate and the liquid-crystal polymer layer are different in wavelength dependence of birefringence. The retarder film and the transparent substrate are different in Nz defined by the expression (nx−nz)/(nx−ny).
    Type: Grant
    Filed: August 4, 2000
    Date of Patent: August 3, 2004
    Assignee: Nitto Denko Corporation
    Inventors: Hiroyuki Yoshimi, Akira Ohtani, Takashi Yamaoka, Yuichi Nishikoji
  • Patent number: 6762811
    Abstract: A laminated quarter-wave plate having: a laminate of a quarter-wave plate and a half-wave plate, wherein: the quarter-wave plate and the half-wave plate are laminated on each other so that directions of in-plane slow axes intersect each other; and each of the quarter-wave plate and the half-wave plate satisfies a relation Nz=(nx−nz)/(nx−ny)>1.05 in which nx and ny are in-plane main refractive indices, and nz is a thickness wise refractive index; and a circularly polarizing plate having: a laminate of a laminated quarter-wave plate defined above and a polarizer.
    Type: Grant
    Filed: October 2, 2002
    Date of Patent: July 13, 2004
    Assignee: Nitto Denko Corporation
    Inventors: Shinichi Sasaki, Takashi Yamaoka, Hiroyuki Yoshimi
  • Publication number: 20040100599
    Abstract: By a method for producing a liquid crystal cell substrate having a base and a birefringent layer, which includes producing a precursor layer of the birefringent layer by applying a solution of a polymer that hardens to form the birefringent layer, directly onto one surface of the base, and producing the birefringent layer by hardening the precursor layer, the present invention provides a method for producing a birefringent layer on a liquid crystal cell substrate or a liquid crystal cell substrate of a liquid crystal panel used in a liquid crystal display.
    Type: Application
    Filed: January 22, 2003
    Publication date: May 27, 2004
    Inventors: Takashi Yamaoka, Nao Murakami, Hiroyuki Yoshimi, Tatsuki Nagatsuka
  • Patent number: 6717642
    Abstract: A wide viewing angle polarizer having: a polarizing film; and a phase retarder adhesively laminated on at least one surface of the polarizing film through an adhesive layer, the phase retarder being made of a composite phase retarder constituted by a laminate in which a retardation layer B of a cholesteric liquid crystal-oriented solidified layer in a selective reflection wavelength range of not larger than 350 nm is supported by a retardation layer A of a thermoplastic resin exhibiting positive birefringence, the composite phase retarder being formed so that the laminate has Re of not smaller than 10 nm and Rth−Re of not smaller than 50 nm when Re and Rth are defined as Re=(nx−ny)X d and Rth=(nx−nz)X d respectively in which nx and ny are in-plane main refractive indices, nz is a thicknesswise refractive index, and d is a layer thickness.
    Type: Grant
    Filed: October 9, 2002
    Date of Patent: April 6, 2004
    Assignee: Nitto Denko Corporation
    Inventors: Shinichi Sasaki, Takashi Yamaoka, Nao Murakami, Hiroyuki Yoshimi
  • Publication number: 20030164905
    Abstract: A laminated optical device is a laminate formed of a polarizing layer having a thickness of not larger than 5 &mgr;m, and at least one birefringent layer including either a solid film of oriented liquid crystal or a polymer layer containing oriented liquid crystal. A liquid-crystal display apparatus includes a liquid-crystal display panel, and at least one laminated optical device defined above and disposed on one of opposite surfaces of the liquid-crystal display panel.
    Type: Application
    Filed: January 15, 2002
    Publication date: September 4, 2003
    Applicant: NITTO DENKO CORPORATION
    Inventors: Takashi Yamaoka, Hiroyuki Yoshimi, Yuuichi Nishikouji, Tomoaki Masuda
  • Publication number: 20030103180
    Abstract: An optical compensating film using a norbornene-based resin film in which the durability at an interface surface of the adhesive of a LCD is improved, a polarizing plate, and a liquid crystal display using the same is provided. The optical compensating film of the present invention is formed by coating an adhesive on a stretched norbornene-based resin film. In the optical compensating film, the adhesive force between the optical compensating film and the adhesive layer is 10 N/20 mm or more.
    Type: Application
    Filed: December 4, 2001
    Publication date: June 5, 2003
    Inventors: Tomoaki Masuda, Takashi Yamaoka
  • Publication number: 20030103186
    Abstract: A wide viewing angle polarizer having: a polarizing film; and a phase retarder adhesively laminated on at least one surface of the polarizing film through an adhesive layer, the phase retarder being made of a composite phase retarder constituted by a laminate in which a retardation layer B of a cholesteric liquid crystal-oriented solidified layer in a selective reflection wavelength range of not larger than 350 nm is supported by a retardation layer A of a thermoplastic resin exhibiting positive birefringence, the composite phase retarder being formed so that the laminate has Re of not smaller than 10 nm and Rth-Re of not smaller than 50 nm when Re and Rth are defined as Re=(nx−ny)×d and Rth=(nx−nz)×d respectively in which nx and ny are in-plane main refractive indices, nz is a thicknesswise refractive index, and d is a layer thickness.
    Type: Application
    Filed: October 9, 2002
    Publication date: June 5, 2003
    Applicant: NITTO DENKO CORPORATION
    Inventors: Shinichi Sasaki, Takashi Yamaoka, Nao Murakami, Hiroyuki Yoshimi
  • Publication number: 20030086033
    Abstract: A laminated phase retarder having: a laminate of a retardation layer A made of a thermoplastic resin exhibiting positive birefringent characteristic and a retardation layer B constituted by an oriented solidified layer of cholesteric liquid crystal exhibiting a selective reflection wavelength range not larger than 350 nm; wherein Re of the laminate is not smaller than 10 nm and Rth−Re of the laminate is not smaller than 50 nm when Re and Rth are given by Re=(nx−ny)×d and Rth=(nx−nz)×d in which nx and ny are in-plane main refractive indices, nz is a thicknesswise refractive index, and d is a layer thickness. A polarizing member having: a laminate of a laminated phase retarder defined above; and a polarizer. A liquid-crystal display device having: a liquid-crystal cell; and a laminated phase retarder or a polarizing member defined above and disposed on at least one of opposite surfaces of the liquid-crystal cell.
    Type: Application
    Filed: October 7, 2002
    Publication date: May 8, 2003
    Applicant: NITTO DENKO CORPORATION
    Inventors: Shinichi Sasaki, Takashi Yamaoka, Nao Murakami, Hiroyuki Yoshimi
  • Publication number: 20030067574
    Abstract: A laminated quarter-wave plate having: a laminate of a quarter-wave plate and a half-wave plate, wherein: the quarter-wave plate and the half-wave plate are laminated on each other so that directions of in-plane slow axes intersect each other; and each of the quarter-wave plate and the half-wave plate satisfies a relation Nz=(nx−nz)/(nx−ny)>1.05 in which nx and ny are in-plane main refractive indices, and nz is a thickness wise refractive index; and a circularly polarizing plate having: a laminate of a laminated quarter-wave plate defined above and a polarizer.
    Type: Application
    Filed: October 2, 2002
    Publication date: April 10, 2003
    Applicant: NITTO DENKO CORPORATION
    Inventors: Shinichi Sasaki, Takashi Yamaoka, Hiroyuki Yoshimi
  • Patent number: 6417904
    Abstract: An optically compensatory film in which a birefringent phase retarder layer is adhesively supported by a transparent film base is provided. The transparent film base has a specific gravity of not larger than 1.15 or a water absorption coefficient of not higher than 1.0% (at 23° C. and for 24 hours), and has an photoelastic coefficient of not larger than 30×10−12 m2/N. An optically compensatory polarizing plate is constituted of a laminate of the optically compensatory film and a polarizing plate, the optically compensatory film including a phase retarder layer composed of a liquid-crystal polymer. A liquid-crystal display device in which the optically compensatory film or a combination of the optically compensatory film and a polarizing plate are disposed on at least one side of a liquid-crystal cell is provided.
    Type: Grant
    Filed: September 12, 2000
    Date of Patent: July 9, 2002
    Assignee: Nitto Denko Corporation
    Inventors: Takashi Yamaoka, Hiroyuki Yoshimi
  • Patent number: 6025958
    Abstract: A wavelength plate which shows little undesirable retardation in a specific wavelength range while substantially maintaining the function of 1/2 wavelength plate or 1/4 wavelength plate over the entire visible light range and a circular polarizing plate which shows little reflection at the interface and exhibits an anti-reflection effect over a wide wavelength range and an excellent thermal stability. A laminated wavelength plate comprising a plurality of oriented films giving a retardation having a wavelength half that of monochromatic light laminated with their optical axes crossing each other, wherein the dependence of the birefringence differences .DELTA.n.sub.1 and .DELTA.n.sub.2 of said oriented films on wavelength each satisfy the relationship .DELTA.n.sub.1 /.DELTA.n.sub.2 <1.05 based on light having wavelength of 400 nm (.DELTA.n.sub.1) and 550 nm (.DELTA.n.sub.
    Type: Grant
    Filed: November 5, 1998
    Date of Patent: February 15, 2000
    Assignee: Nitto Denko Corporation
    Inventors: Takashi Yamaoka, Hiroyuki Yoshimi, Yasuo Fujimura
  • Patent number: 5880800
    Abstract: An optical film comprising an optical base film having one surface or both surface thereof multilayers of pressure-sensitive adhesive layers, wherein the multilayers comprise a combination of pressure-sensitive adhesive layers each having a different stress relaxation time, the pressure-sensitive adhesive layer having the longest stress relaxation time is disposed at the outermost side, and the thickness thereof is 80% or less of the total thickness of the pressure-sensitive layers. The optical film is excellent in heat resistance and moisture resistance, is not difficult to cause foaming and pealing at the interface between a liquid crystal cell and the film even in using at high temperature and high moisture atmosphere, and is suitable for providing a liquid crystal display.
    Type: Grant
    Filed: January 6, 1997
    Date of Patent: March 9, 1999
    Assignee: Nitto Denko Corporation
    Inventors: Chiemi Mikura, Takashi Yamaoka, Akira Wakabayashi
  • Patent number: D364603
    Type: Grant
    Filed: November 21, 1994
    Date of Patent: November 28, 1995
    Assignees: Sanyo Electric Co., Ltd., Tottori Sanyo Electric Co., Ltd.
    Inventors: Masao Tanaka, Susumu Maeta, Takashi Yamaoka
  • Patent number: D373759
    Type: Grant
    Filed: November 21, 1994
    Date of Patent: September 17, 1996
    Assignees: Sanyo Electric Co., Ltd., Tottori Sanyo Electric Co., Ltd.
    Inventors: Masao Tanaka, Susumu Maeta, Takashi Yamaoka
  • Patent number: D405426
    Type: Grant
    Filed: August 5, 1997
    Date of Patent: February 9, 1999
    Assignee: Sanyo Electric Co., Ltd
    Inventors: Takashi Yamaoka, Toshiyuki Hokimoto