Patents by Inventor Koji Tasaka

Koji Tasaka 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: 8952600
    Abstract: A circularly polarizing plate has a polarizer and two ?/4 plates (T1, T2) bonded respectively onto both sides of the polarizer so as to face each other, the circularly polarizing plate is characterized in that the in-plane retardation values Ro of the ?/4 plates (T1) and the ?/4 plates (T2) satisfy (a) to (c) below in an environment with a temperature of 23° C. and RH of 55%. (a) The in-plane retardation value Ro of the ?/4 plates (T1), when measured within the range of 450 to 650 nm, is 3.0 to 20.0 nm smaller than the in-plane retardation value Ro of the ?/4 plates (T2). (b) The in-plane retardation value Ro of the ?/4 plates (T1) (450) falls within the range of 110 to 140 nm. (c) The in-plane retardation value Ro of the ?/4 plates (T2) (650) falls within the range of 145 to 165 nm.
    Type: Grant
    Filed: July 20, 2012
    Date of Patent: February 10, 2015
    Assignee: Konica Minolta, Inc.
    Inventors: Rieko Ren, Koji Tasaka, Kouji Tashiro
  • Publication number: 20140319508
    Abstract: In order to provide an organic electroluminescent display device which does not exhibit redness in reflected external light, and exhibits little fluctuation in the hue of a black image as a result of changes in environmental temperature and differences in the light emitting state, the organic electroluminescent display device according to the present invention comprises, in order from the viewing side, a protective film, a polarizer, a ?/4 phase difference film, and an organic electroluminescent element, and is characterized in that the ?/4 phase difference film satisfies formulas (1) and (2) below. Ro(450)<Ro(550)<Ro(650)??Formula (1) 0.90<photoelastic coefficient ratio(450/650)value<1.
    Type: Application
    Filed: November 7, 2012
    Publication date: October 30, 2014
    Inventors: Norie Tanihara, Rieko Ren, Koji Tasaka, Yukihito Nakazawa, Kenji Mishima, Midori Kogure
  • Publication number: 20140225499
    Abstract: A circularly polarizing plate has a polarizer and two ?/4 plates (T1, T2) bonded respectively onto both sides of the polarizer so as to face each other, the circularly polarizing plate is characterized in that the in-plane retardation values Ro of the ?/4 plates (T1) and the ?/4 plates (T2) satisfy (a) to (c) below in an environment with a temperature of 23° C. and RH of 55%. (a) The in-plane retardation value Ro of the ?/4 plates (T1), when measured within the range of 450 to 650 nm, is 3.0 to 20.0 nm smaller than the in-plane retardation value Ro of the ?/4 plates (T2). (b) The in-plane retardation value Ro of the ?/4 plates (T1) (450) falls within the range of 110 to 140 nm. (c) The in-plane retardation value Ro of the ?/4 plates (T2) (650) falls within the range of 145 to 165 nm.
    Type: Application
    Filed: July 20, 2012
    Publication date: August 14, 2014
    Applicant: Konica Minolta, Inc.
    Inventors: Rieko Ren, Koji Tasaka, Kouji Tashiro
  • Patent number: 8580358
    Abstract: A cellulose ester film containing a polyester represented by Formula (1) or (2), wherein an in-plane retardation value (Ro) is 0 to 5 nm and a retardation value in a thickness direction (Rt) is ?20 to 10 nm, Ro and Rt being measured at 23° C. and 55% RH: B1-(G-A-)mG-B1??Formula (1) wherein B1: monocarboxylic acid, G: dihydric alcohol, A: dibasic acid, B1, G and A contain no aromatic ring, m: repeat number, plural B1 may be the same or different, and plural G may be the same or different; and B2-(A-G-)nA-B2??Formula (2) wherein B2: monoalcohol, G: dihydric alcohol, A: dibasic acid, provided that none of B2, G and A contains an aromatic ring, n: repeat number, plural B2 may be the same or different, and plural G may be the same or different.
    Type: Grant
    Filed: June 23, 2006
    Date of Patent: November 12, 2013
    Assignee: Konica Minolta Opto, Inc.
    Inventors: Takashi Takebe, Kunio Shimizu, Koji Tasaka, Shigeki Oka
  • Patent number: 7924379
    Abstract: A liquid crystal display comprising: a brightness enhancing film, polarizing plate (A), a liquid crystal cell, polarizing plate (B) laminated in that order, Wherein (i) polarizing plate (A) has a polarizing plate protective film facing the brightness enhancing film; (ii) the polarizing plate protective film is a cellulose ester film; (iii) an in-plane retardation value Ro(550) of the of the cellulose ester film represented by Formula (I) is 0 to 5 nm; and (iv) a retardation value in a thickness direction Rt(550) of the of the cellulose ester film represented by Formula (II) is ?15 to 15 nm, Ro(550)=(Nx?Ny)×d??Formula (I) Rt(550)={(Nx+Ny)/2?Nz}×d.
    Type: Grant
    Filed: August 25, 2006
    Date of Patent: April 12, 2011
    Assignee: Konica Minolta Opto, Inc.
    Inventor: Koji Tasaka
  • Patent number: 7854864
    Abstract: A manufacturing method of an optical film provided with a convexoconcave structure, comprises the steps of: coating a resin solution including a first resin solved by a solvent onto an endless or roll-like mold provided with a convexoconcave structure, and forming a resin solution layer on the mold; laminating a film substrate onto the resin solution layer to make a laminated film before the solvent in the resin solution layer is completely dried, the film substrate including a second resin, which is capable of absorbing the solvent or is soluble by the solvent; and peeling the laminated film from the mold before the solvent in the laminated film is completely dried.
    Type: Grant
    Filed: April 19, 2007
    Date of Patent: December 21, 2010
    Assignee: Konica Minolta Opto, Inc.
    Inventors: Akira Sato, Masaru Iwagaki, Hirokazu Sato, Shigeto Ohmori, Kazuhiro Miyazawa, Takashi Murakami, Hirokazu Koyama, Nobuo Kubo, Koji Tasaka, Shigeki Oka
  • Patent number: 7740919
    Abstract: A manufacturing method of a cellulose ester film satisfying the relationships, Nx>Ny>Nz, and 0.8?Rt/R0?3.5, the method comprising casting a cellulose ester dope containing a solvent of a good solvent and a poor solvent on a support to form a web; peeling the web from the support; transporting the peeled web (step D0); holding the edges in the transverse direction of the web (step A); stretching the resulting web in the transverse direction while applying a tension; reducing the tension in the transverse direction of the web; and drying the stretched web, wherein the residual solvent content of the web is 5 to 90% by weight at the beginning in the step A, and the residual poor solvent content in the residual solvent content of the web is from 15 to 95% by weight at the terminal point in the Step D0.
    Type: Grant
    Filed: March 20, 2007
    Date of Patent: June 22, 2010
    Assignee: Konica Corporation
    Inventors: Koji Tasaka, Hiroki Umeda, Noriyasu Kuzuhara, Takatoshi Yajima
  • Patent number: 7709067
    Abstract: A cellulose ester film comprising a compound represented by Formula (1): Formula (1) B-(G-A)n-G-B, wherein B represents a benzene monocarboxylic acid residue; G represents an alkylene glycol residue having 2-12 carbon atoms, an aryl glycol residue having 6-12 carbon atoms, or an oxyalkylene glycol residue having 4-12 carbon atoms; A represents an alkylene dicarboxylic acid residue having 4-12 carbon atoms or an aryldicarboxylic acid residue having 6-12 carbon atoms; and n represents an integer of 1 or more.
    Type: Grant
    Filed: May 1, 2006
    Date of Patent: May 4, 2010
    Assignee: Konica Minolta Opto, Inc.
    Inventors: Takahiro Takagi, Isamu Michihata, Noriyasu Kuzuhara, Koichi Saito, Koji Tasaka, Hiroki Umeda, Minori Tamagawa, Shinji Inagaki
  • Patent number: 7599028
    Abstract: A polarizing plate used in a vertical alignment mode liquid crystal display comprising a liquid crystal cell is disclosed, wherein the polarizing plate comprises a polarizing film and a mixed fatty acid cellulose ester film with optical biaxiality provided between the polarizing film and the liquid crystal cell, and wherein the mixed fatty acid cellulose ester film has a retardation in plane R0 of from 31 to 120 nm, and a retardation in the thickness direction Rt of from 60 to 300 nm, in which R0 is represented by the following formula (1) and Rt is represented by the following formula (2): R0=(nx?ny)×d??formula (1) Rt={(nx+ny)/2?nz}×d.
    Type: Grant
    Filed: December 15, 2006
    Date of Patent: October 6, 2009
    Assignee: Konica Corporation
    Inventors: Noriyasu Kuzuhara, Koji Tasaka, Hiroki Umeda, Takatoshi Yajima
  • Publication number: 20080129934
    Abstract: An optical compensation film wherein: (i) molecules of a liquid crystalline compound are oriented in a manner that an average tilt angle of the compounds is not more than 4 degrees; (ii) the orientation is fixed; (iii) Ro(?) values are: at wavelength 589 nm: 40-130 nm; at 600 nm: 35-125 nm; and at 630 nm: 35-120 nm; (iv) Rt(?) valuea are 120-400 nm in ? range of 500-630 cm; and (v) Values of Ro(589), Ro(600) and Ro(630) satisfy the following formulae: 1.0<B<7.0 B=(Ro(589)?Ro(630))/(Ro(600)?Ro(630)).
    Type: Application
    Filed: January 23, 2008
    Publication date: June 5, 2008
    Applicant: KONICA MINOLTA OPTO, INC.
    Inventors: Hiroki UMEDA, Takatoshi YAJIMA, Noriyasu KUZUHARA, Koji TASAKA
  • Patent number: 7345725
    Abstract: An optical compensation film wherein: (i) molecules of a liquid crystalline compound are oriented in a manner that an average tilt angle of the compounds is not more than 4 degrees; (ii) the orientation is fixed; (iii) Ro(?) values are: at wavelength 589 nm: 40-130 nm; at 600 nm: 35-125 nm; and at 630 nm: 35-120 nm; (iv) Rt(?) value are 120-400 400 nm in ? range of 500-630 nm; and (v) Values of Ro(589), Ro(600) and Ro(630) satisfy the following formulae: 1.0<B<7.0 B=(Ro(589)?Ro(630))/(Ro(600)?Ro(630)).
    Type: Grant
    Filed: July 7, 2004
    Date of Patent: March 18, 2008
    Assignee: Konica Minolta Opto, Inc.
    Inventors: Hiroki Umeda, Takatoshi Yajima, Noriyasu Kuzuhara, Koji Tasaka
  • Patent number: 7306832
    Abstract: A manufacturing method of a cellulose ester film satisfying the relationships, Nx>Ny>Nz, and 0.8?Rt/R0?3.5, the method comprising casting a cellulose ester dope containing a solvent of a good solvent and a poor solvent on a support to form a web; peeling the web from the support; transporting the peeled web (step D0); holding the edges in the transverse direction of the web (step A); stretching the resulting web in the transverse direction while applying a tension; reducing the tension in the transverse direction of the web; and drying the stretched web, wherein the residual solvent content of the web is 5 to 90% by weight at the beginning in the step A, and the residual poor solvent content in the residual solvent content of the web is from 15 to 95% by weight at the terminal point in the Step D0.
    Type: Grant
    Filed: October 14, 2004
    Date of Patent: December 11, 2007
    Assignee: Konica Corporation
    Inventors: Koji Tasaka, Hiroki Umeda, Noriyasu Kuzuhara, Takatoshi Yajima
  • Publication number: 20070252293
    Abstract: A manufacturing method of an optical film provided with a convexoconcave structure, comprises the steps of: coating a resin solution including a first resin solved by a solvent onto an endless or roll-like mold provided with a convexoconcave structure, and forming a resin solution layer on the mold; laminating a film substrate onto the resin solution layer to make a laminated film before the solvent in the resin solution layer is completely dried, the film substrate including a second resin, which is capable of absorving the solution or is soluble by the solvent; and peeling the laminated film from the mold before the solvent in the laminated film is completely dried.
    Type: Application
    Filed: April 19, 2007
    Publication date: November 1, 2007
    Applicant: KONICA MINOLTA OPTO, INC.
    Inventors: Akira SATO, Masaru IWAGAKI, Hirokazu SATO, Shigeto OHMORI, Kazuhiro MIYAZAWA, Takashi MURAKAMI, Hirokazu KOYAMA, Nobuo KUBO, Koji TASAKA, Shigeki OKA
  • Publication number: 20070178252
    Abstract: A manufacturing method of a cellulose ester film satisfying the relationships, Nx>Ny>Nz, and 0.8?Rt/R0<3.5, the method comprising casting a cellulose ester dope containing a solvent of a good solvent and a poor solvent on a support to form a web; peeling the web from the support; transporting the peeled web (step D0); holding the edges in the transverse direction of the web (step A); stretching the resulting web in the transverse direction while applying a tension; reducing the tension in the transverse direction of the web; and drying the stretched web, wherein the residual solvent content of the web is 5 to 90% by weight at the beginning in the step A, and the residual poor solvent content in the residual solvent content of the web is from 15 to 95% by weight at the terminal point in the Step D0.
    Type: Application
    Filed: March 20, 2007
    Publication date: August 2, 2007
    Applicant: KONICA CORPORATION
    Inventors: Koji TASAKA, Hiroki UMEDA, Noriyasu KUZUHARA, Takatoshi YAJIMA
  • Publication number: 20070116898
    Abstract: A polarizing plate used in a vertical alignment mode liquid crystal display comprising a liquid crystal cell is disclosed, wherein the polarizing plate comprises a polarizing film and a mixed fatty acid cellulose ester film with optical biaxiality provided between the polarizing film and the liquid crystal cell, and wherein the mixed fatty acid cellulose ester film has a retardation in plane R0 of from 31 to 120 nm, and a retardation in the thickness direction Rt of from 60 to 300 nm, in which R0 is represented by the following formula (1) and Rt is represented by the following formula (2): R0=(nx?ny)×d??formula (1) Rt={(nx+ny)/2?nz}×d??formula (2)
    Type: Application
    Filed: December 15, 2006
    Publication date: May 24, 2007
    Applicant: KONICA CORPORATION
    Inventors: Noriyasu Kuzuhara, Koji Tasaka, Hiroki Umeda, Takatoshi Yajima
  • Patent number: 7218367
    Abstract: An optical compensation sheet comprising at least two optically anisotropic layers each formed by orienting an optically anisotropic compound, the orientation direction in the optically anisotropic layer plane of the optically anisotropic compound in the two optically anisotropic layers intersecting each other at an angle of from 80 to 100 degrees, wherein, viewing the two layers from one side of the sheet, one of the two layers, when the compound is uniaxial, is oriented so that a first angle of optic axis of the uniaxial optically anisotropic compound to the sheet plane increases continuously or stepwise in the thickness direction of the sheet, or when the compound is biaxial, is oriented so that a second angle of a direction giving maximum refractive index of the biaxial optically anisotropic compound to the sheet plane increases continuously or stepwise in the thickness direction of the sheet, and the other layer, when the compound is uniaxial, is oriented so that the first angle decreases continuously or
    Type: Grant
    Filed: March 29, 2001
    Date of Patent: May 15, 2007
    Assignee: Konica Corporation
    Inventors: Hiroki Umeda, Noriyasu Kuzuhara, Nobuo Kubo, Sota Kawakami, Nobuyuki Takiyama, Koji Tasaka
  • Patent number: 7199848
    Abstract: An optical compensation film used for a liquid crystal display comprising a support and an optically anisotropic layer is disclosed. The optically anisotropic layer is a layer on which orientation of the liquid crystalline compound is fixed and the support is an optically biaxial cellulose ester film. A polarizing plate used for a liquid crystal display and a liquid crystal display employing the optical compensation film are also disclosed.
    Type: Grant
    Filed: July 19, 2001
    Date of Patent: April 3, 2007
    Assignee: Konica Corporation
    Inventors: Noriyasu Kuzuhara, Nobuo Kubo, Hiroki Umeda, Nobuyuki Takiyama, Takatoshi Yajima, Koji Tasaka
  • Publication number: 20070046872
    Abstract: A liquid crystal display comprising: a brightness enhancing film, polarizing plate (A), a liquid crystal cell, polarizing plate (B) laminated in that order, Wherein (i) polarizing plate (A) has a polarizing plate protective film facing the brightness enhancing film; (ii) the polarizing plate protective film is a cellulose ester film; (iii) an in-plane retardation value Ro(550) of the of the cellulose ester film represented by Formula (I) is 0 to 5 nm; and (iv) a retardation value in a thickness direction Rt(550) of the of the cellulose ester film represented by Formula (II) is ?15 to 15 nm, Ro(550)=(Nx?Ny)×d??Formula (I) Rt(550)={(Nx+Ny)/2?Nz}×d.
    Type: Application
    Filed: August 25, 2006
    Publication date: March 1, 2007
    Inventor: Koji Tasaka
  • Publication number: 20070048462
    Abstract: A cellulose ester film containing a polyester represented by Formula (1) or (2), wherein an in-plane retardation value (Ro) is 0 to 5 nm and a retardation value in a thickness direction (Rt) is ?20 to 10 nm, Ro and Rt being measured at 23° C. and 55% RH: B1-(G-A-)mG-B1??Formula (1) wherein B1: monocarboxylic acid, G: dihydric alcohol, A: dibasic acid, B1, G and A contain no aromatic ring, m: repeat number, plural B1 may be the same or different, and plural G may be the same or different; and B2-(A-G-)nA-B2??Formula (2) wherein B2: monoalcohol, G: dihydric alcohol, A: dibasic acid, provided that none of B2, G and A contains an aromatic ring, n: repeat number, plural B2 may be the same or different, and plural G may be the same or different.
    Type: Application
    Filed: June 23, 2006
    Publication date: March 1, 2007
    Applicant: KONICA MINOLTA OPTO, INC.
    Inventors: Takashi Takebe, Kunio Shimizu, Koji Tasaka, Shigeki Oka
  • Patent number: 7184112
    Abstract: A polarizing plate used in a vertical alignment mode liquid crystal display comprising a liquid crystal cell is disclosed, wherein the polarizing plate comprises a polarizing film and a mixed fatty acid cellulose ester film with optical biaxiality provided between the polarizing film and the liquid crystal cell, and wherein the mixed fatty acid cellulose ester film has a retardation in plane R0 of from 31 to 120 nm, and a retardation in the thickness direction Rt of from 60 to 300 nm, in which R0 is represented by the following formula (1) and Rt is represented by the following formula (2): R0=(nx?ny)×d??formula (1) Rt={(nx+ny)/2?nz}×d.
    Type: Grant
    Filed: December 5, 2005
    Date of Patent: February 27, 2007
    Assignee: Konica Corporation
    Inventors: Noriyasu Kuzuhara, Koji Tasaka, Hiroki Umeda, Takatoshi Yajima