Patents Assigned to Polatechno Co., Ltd.
  • Publication number: 20070079740
    Abstract: The present invention relates to an azo compound represented by the following formula (1): wherein A denotes a phenyl group having 1 to 3 substituents such as sulfonic acid group, amino group, lower alkyl groups and lower alkoxyl groups, or a naphthyl group, B denotes hydrogen atom, sulfonic acid group, a lower alkyl group, a lower alkoxyl group or the like, each of R1 to R4 independently denotes hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxyl group or the like, D denotes —NHCO—, —N?N— or —NH—, E denotes hydrogen atom, a lower alkyl group or a phenyl group having 1 to 3 substituents such as hydroxyl group and amino group, n denotes 0 or 1, and m denotes 0 or 1, or a salt thereof, or a copper complex compound of either of them, which is used for a polarizing plate having excellent polarization performance and durability and furthermore little color leakage in visible light range.
    Type: Application
    Filed: April 15, 2004
    Publication date: April 12, 2007
    Applicants: NIPPON KAYAKU KABUSHIKI KAISHA, POLATECHNO CO., LTD.
    Inventors: Yuichi Sadamitsu, Kazuyuki Kawabe
  • Patent number: 7163723
    Abstract: A phase difference film which comprises a liquid crystal film having a liquid crystal comprised of a cellulose derivative as a liquid crystal compound (cellulose derivative liquid crystal) being oriented in a specific direction, preferably said phase difference film wherein said orientation in a specific direction is fixed. In said liquid crystal film, through changing appropriately the molecular weight of the cellulose derivative, the composition of the liquid crystal, the degree of the orientation, and the like, films having various wave length dispersion characteristics can be prepared with ease, and further a phase difference film satisfying the following relationship: ?n450=?n550=?n650 (1) wherein ?n550 represents a double refractive index at a wave length of 550 nm, ?n450 represents a double refractive index at a wave length of 450 nm, and ?n650 represents a double refractive index at a wave length of 650 nm, can be prepared without laminating a plurality of phase difference films.
    Type: Grant
    Filed: May 9, 2002
    Date of Patent: January 16, 2007
    Assignees: Nippon Kayaku Kabushiki Kaisha, Polatechno Co., Ltd.
    Inventors: Kouichi Tanaka, Kenichiro Yoshioka, Junji Toda, Hideyoshi Fujisawa
  • Patent number: 6912029
    Abstract: The invention provides an optical film prepared by laminating at least one of a first retardation film (2), having a mean in-plane refractive index of no and refractive index in the thickness direction of ne wherein ne?no>0, and at least one of a second retardation film (3) having an in-plane refractive index of nx in the direction showing the maximum refractive index, refractive index of ny in the direction perpendicular to the direction described just before, and refractive index in the thickness direction of nz wherein nx>ny?nz. The light leakage occurred as the observation point is tilted from the front direction to a direction different from the direction of each absorption axis can be reduced when a plolarizing film is arranged so that the absorption axes will be perpendicular to each other.
    Type: Grant
    Filed: December 17, 2001
    Date of Patent: June 28, 2005
    Assignees: Nippon Kayaku Kabushiki Kaisha, Polatechno Co., Ltd.
    Inventor: Kouichi Tanaka
  • Patent number: 6552849
    Abstract: The invention is to develop a color polarizing plate with a support, the polarizing plate having both good brightness and polarizing efficiency for a blue channel (for blue light). The color polarizing plate with a support for a liquid crystal projector comprises a polarizing plate containing a stilbene type water-soluble azo dye as a dichroic molecule and a support, wherein the polarizing plate has an average single transmittance of 39% or more and an average crossed transmittance of 0.4% or less at 420 to 500 nm and an average crossed transmittance of 4% or more at 50 to 780 nm.
    Type: Grant
    Filed: August 6, 2001
    Date of Patent: April 22, 2003
    Assignees: Nippon Kayaku Kabushiki Kaisha, Polatechno Co., LTD
    Inventors: Shigeki Furuhashi, Tadashi Matsuo, Kazuyuki Kawabe
  • Patent number: 6535337
    Abstract: Reflective type and transflective type liquid crystal display devices can be improved in the visibility of their display image and can also provide very definite display images when they use a reflector or transflector having a light-scattering layer and a light reflective or transflective layer wherein the light-scattering layer comprises a resin layer containing fine particles dispersed therein, the ten-point average roughness “Rz” on the surface of the light scattering-layer is less than 2 &mgr;m, the refractive index ratio of the fine particles to the resin layer excluding the fine particles is from 1.001:1 to 1.2:1, and the light-scattering layer has a thickness of 3-50 &mgr;um.
    Type: Grant
    Filed: March 17, 2001
    Date of Patent: March 18, 2003
    Assignees: Nippon Kayaku Kabushiki Kaisha, Polatechno Co., Ltd.
    Inventors: Kouichi Tanaka, Hiroyuki Emori