Patents by Inventor Shigeki Oka

Shigeki Oka 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: 9081231
    Abstract: A vertical alignment mode liquid crystal display comprising: a liquid crystal cell; a first polarizer; a second polarizer; a first optical film arranged between the first polarizer and the liquid crystal cell; and a second optical film arranged between the liquid crystal cell and the second optical film, wherein the first and the second optical films each are a resin film having an optically biaxial property, the first and the second optical films meet: Formula (1) Ro1>Ro2; Formula (2) Rth1<Rth2; Formula (3) DSPRo1<DSPRo2; and Formula (4) DSPRth1<DSPRth, wherein Ro1 and Ro2 represent in-plane retardation values of the first and the second optical films, respectively, Rth1 and Rth2 represent retardation values in the thickness direction of the first and the second optical films, respectively, and DSPRo1, DSPRo2, DSPRth1 and DSPRth2 represent wavelength dispersion properties of Ro1, Ro2; Rth1 and Rth2, respectively.
    Type: Grant
    Filed: February 12, 2010
    Date of Patent: July 14, 2015
    Assignee: KONICA MINOLTA OPTO, INC.
    Inventors: Kentaro Yano, Shigeki Oka, Ayako Inagaki, Yuki Kaneko
  • Patent number: 9081133
    Abstract: A polarizing plate protective film forming a polarizing plate by sandwiching a polarizer with two of the polarizing plate protective films, wherein at least one of the two polarizing plate protective films exhibits Ro defined by Expression (I) of 0 to 10 mm and Rt defined by Expression (II) of ?20 to 20 mm, and also at least one of the polarizing plate protective films has a hard coat layer: Expression (I): Ro=(nx?ny)×d; Expression (II): Rt={(nx+ny)/2?nz}×d; wherein nx is a refractive index in a delayed phase axis direction in a plane of the polarizing plate protective film, ny is a refractive index in a direction at right angles to the delayed phase axis in the plane, nz is a refractive index in a film thickness direction, and d is a film thickness (nm).
    Type: Grant
    Filed: October 2, 2014
    Date of Patent: July 14, 2015
    Assignee: KONICA MINOLTA, INC.
    Inventors: Takashi Takebe, Kunio Shimizu, Shigeki Oka
  • Publication number: 20150015951
    Abstract: A polarizing plate protective film forming a polarizing plate by sandwiching a polarizer with two of the polarizing plate protective films, wherein at least one of the two polarizing plate protective films exhibits Ro defined by Expression (I) of 0 to 10 mm and Rt defined by Expression (II) of ?20 to 20 mm, and also at least one of the polarizing plate protective films has a hard coat layer: Expression (I): Ro=(nx?ny)×d; Expression (II): Rt={(nx+ny)/2?nz}×d; wherein nx is a refractive index in a delayed phase axis direction in a plane of the polarizing plate protective film, ny is a refractive index in a direction at right angles to the delayed phase axis in the plane, nz is a refractive index in a film thickness direction, and d is a film thickness (nm).
    Type: Application
    Filed: October 2, 2014
    Publication date: January 15, 2015
    Inventors: Takashi TAKEBE, Kunio SHIMIZU, Shigeki OKA
  • Patent number: 8900676
    Abstract: A polarizing plate protective film forming a polarizing plate by sandwiching a polarizer with two of the polarizing plate protective films, wherein at least one of the two polarizing plate protective films exhibits Ro defined by Expression (I) of 0 to 10 mm and Rt defined by Expression (II) of ?20 to 20 mm, and also at least one of the polarizing plate protective films has a hard coat layer: Expression (I): Ro=(nx?ny)×d; Expression (II): Rt={(nx+ny)/2?nz}×d; wherein nx is a refractive index in a delayed phase axis direction in a plane of the polarizing plate protective film, ny is a refractive index in a direction at right angles to the delayed phase axis in the plane, nz is a refractive index in a film thickness direction, and d is a film thickness (nm).
    Type: Grant
    Filed: June 11, 2007
    Date of Patent: December 2, 2014
    Assignee: Konica Minolta, Inc.
    Inventors: Takashi Takebe, Kunio Shimizu, Shigeki Oka
  • Patent number: 8652591
    Abstract: The purpose of the present invention is to provide: a retardation film which uses a low-substituted cellulose ester and has improved retardation after saponification and improved wet heat stability of internal haze; a polarizing plate which uses the retardation film; and a liquid crystal display device. An optical film of the present invention contains a cellulose ester and a compound represented by general formula (1), and is characterized in that the compound has an average degree of substitution within the range of 3.0-6.0 and contains a component having a degree of substitution of 4 or less in an amount of 30-80% by mass (inclusive). (In the formula, R1-R8 each represents a substituted or unsubstituted alkylcarbonyl group or a substituted or unsubstituted allylcarbonyl group, and R1-R8 may be the same as or different from one another.
    Type: Grant
    Filed: June 23, 2011
    Date of Patent: February 18, 2014
    Assignee: Konical Minolta Advanced Layers, Inc.
    Inventors: Takashi Sera, Takahiro Takagi, Shigeki Oka, Ayako Inagaki
  • 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
  • Publication number: 20130135565
    Abstract: The purpose of the present invention is to provide: a retardation film which uses a low-substituted cellulose ester and has improved retardation after saponification and improved wet heat stability of internal haze; a polarizing plate which uses the retardation film; and a liquid crystal display device. An optical film of the present invention contains a cellulose ester and a compound represented by general formula (1), and is characterized in that the compound has an average degree of substitution within the range of 3.0-6.0 and contains a component having a degree of substitution of 4 or less in an amount of 30-80% by mass (inclusive). (In the formula, R1-R8 each represents a substituted or unsubstituted alkylcarbonyl group or a substituted or unsubstituted allylcarbonyl group, and R1-R8 may be the same as or different from one another.
    Type: Application
    Filed: June 23, 2011
    Publication date: May 30, 2013
    Applicant: KONICA MINOLTA ADVANCED LAYERS, INC.
    Inventors: Takashi Sera, Takahiro Takagi, Shigeki Oka, Ayako Inagaki
  • Patent number: 8416369
    Abstract: A polarizer protective film containing a cellulose acylate having a total acyl substitution degree of from 2.2 to less than 2.5 and a polymer prepared by polymerizing an acrylate ester or a methacrylate ester.
    Type: Grant
    Filed: March 5, 2007
    Date of Patent: April 9, 2013
    Assignee: Konica Minolta Opto, Inc.
    Inventor: Shigeki Oka
  • Publication number: 20120002143
    Abstract: A vertical alignment mode liquid crystal display comprising: a liquid crystal cell; a first polarizer; a second polarizer; a first optical film arranged between the first polarizer and the liquid crystal cell; and a second optical film arranged between the liquid crystal cell and the second optical film, wherein the first and the second optical films each are a resin film having an optically biaxial property, the first and the second optical films meet: Formula (1) Ro1>Ro2; Formula (2) Rth1<Rth2; Formula (3) DSPRo1<DSPRo2; and Formula (4) DSPRth1<DSPRth, wherein Ro1 and Ro2 represent in-plane retardation values of the first and the second optical films, respectively, Rth1 and Rth2 represent retardation values in the thickness direction of the first and the second optical films, respectively, and DSPRo1, DSPRo2, DSPRth1 and DSPRth2 represent wavelength dispersion properties of Ro1, Ro2; Rth1 and Rth2, respectively.
    Type: Application
    Filed: February 12, 2010
    Publication date: January 5, 2012
    Applicant: KONICA MINOLTA OPTO, INC.
    Inventors: Kentaro Yano, Shigeki Oka, Ayako Inagaki, Yuki Kaneko
  • Patent number: 7973883
    Abstract: Disclosed is a polarizing plate protective film having high dimensional stability against moisture. Also disclosed are a polarizing plate using such a polarizing plate protective film, and a liquid crystal display. Specifically disclosed is a polarizing plate protective film which is characterized by containing a cellulose ester and a polymer X which is obtained by copolymerizing at least a styrene derivative monomer Xa having no hydroxyl group and an ethylenically unsaturated monomer Xb having a hydroxyl group or a carboxyl group, and has a weight average molecular weight of 500-100,000.
    Type: Grant
    Filed: April 2, 2007
    Date of Patent: July 5, 2011
    Assignee: Konica Minolta Opto, Inc.
    Inventors: Shigeki Oka, Kunio Shimizu
  • 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: 7751005
    Abstract: An IPS (In Plane Switching) mode type liquid crystal display apparatus having polarizing plates on both sides of a liquid crystal cell, wherein the polarizing plate protective film used between a liquid crystal cell and polarizer on a backlight light-source side is a cellulose ester film having a thickness of 20-50 ?m and a retardation value of 0 nm?Ro?2 nm and ?5 nm?Rt?5 nm, and this cellulose ester film is characterized by temperature variation ?Rt(t) lying in the range 0 nm??Rt(t)?7 nm and humidity variation ?Rt(h) lying in the range 0 nm??Rt(h)?20 nm.
    Type: Grant
    Filed: September 27, 2007
    Date of Patent: July 6, 2010
    Assignee: Konica Minolta Opto, Inc.
    Inventors: Shigeki Oka, Noriki Tachibana
  • Patent number: 7749578
    Abstract: An object of the present invention is to provide a polarizing plate protective film exhibiting a reduced variation value retardation, which is highly stable against polarizing plate degradation, polarizing plate dimension, and polarizing plate curl. Disclosed is a cellulose ester film possessing cellulose ester, polymer X having a weight average molecular weight of 2000-30000 prepared by copolymerizing ethylenic unsaturated monomer Xa containing no aromatic ring and hydrophilic group within a molecule and ethylenic unsaturated monomer Xb containing no aromatic ring but a hydrophilic group within a molecule, and polymer Y having a weight average molecular weight of 500-3000 prepared by polymerizing ethylenic unsaturated monomer Ya containing no aromatic ring.
    Type: Grant
    Filed: June 2, 2006
    Date of Patent: July 6, 2010
    Assignee: Konica Minolta Opto, Inc.
    Inventors: Shigeki Oka, Kunio Shimizu, Takashi Takebe
  • Publication number: 20100157206
    Abstract: Disclosed is a polarizing plate protective film having high dimensional stability against moisture. Also disclosed are a polarizing plate using such a polarizing plate protective film, and a liquid crystal display. Specifically disclosed is a polarizing plate protective film which is characterized by containing a cellulose ester and a polymer X which is obtained by copolymerizing at least a styrene derivative monomer Xa having no hydroxyl group and an ethylenically unsaturated monomer Xb having a hydroxyl group or a carboxyl group, and has a weight average molecular weight of 500-100,000.
    Type: Application
    Filed: April 2, 2007
    Publication date: June 24, 2010
    Applicant: KONICA MINOLTA OPTO, INC.
    Inventors: Shigeki Oka, Kunio Shimizu
  • Patent number: 7704570
    Abstract: A polarizing plate includes two transparent supports A and B; and a polarizer sandwiched between the two transparent supports A and B; wherein (i) the transparent support A is a stretched cellulose ester film (a) which contains a non-phosphoric acid ester plasticizer and substantially does not contain a phosphoric acid ester plasticizer, and wherein (ii) the transparent support B is a stretched cellulose ester film (b) which has a retardation value R0 of from 0 nm to 10 nm and a retardation value Rt of from ?30 nm to 20 nm, and the retardation value R0 and the retardation value Rt are defined by the following formulas (I) and (II): Ro=(nx?ny)×d??Formula (I): Rt={(nx+ny)/2?nz}×d.
    Type: Grant
    Filed: August 25, 2006
    Date of Patent: April 27, 2010
    Assignee: Konica Minolta Opto, Inc.
    Inventors: Takashi Takebe, Kunio Shimizu, Shigeki Oka
  • Publication number: 20090207491
    Abstract: A polarizing plate protective film forming a polarizing plate by sandwiching a polarizer with two of the polarizing plate protective films, wherein at least one of the two polarizing plate protective films exhibits Ro defined by Expression (I) of 0 to 10 mm and Rt defined by Expression (II) of ?20 to 20 mm, and also at least one of the polarizing plate protective films has a hard coat layer: Expression (I): Ro=(nx?ny)×d; Expression (II): Rt={(nx+ny)/2?nz}×d; wherein nx is a refractive index in a delayed phase axis direction in a plane of the polarizing plate protective film, ny is a refractive index in a direction at right angles to the delayed phase axis in the plane, nz is a refractive index in a film thickness direction, and d is a film thickness (nm).
    Type: Application
    Filed: June 11, 2007
    Publication date: August 20, 2009
    Applicant: Konica Minolta Opto, Inc.
    Inventors: Takashi Takebe, Kunio Shimizu, Shigeki Oka
  • Publication number: 20080084523
    Abstract: An IPS (In Plane Switching) mode type liquid crystal display apparatus having polarizing plates on both sides of a liquid crystal cell, wherein the polarizing plate protective film used between a liquid crystal cell and polarizer on a backlight light-source side is a cellulose ester film having a thickness of 20-50 ?m and a retardation value of 0 nm?Ro?2 nm and ?5 nm?Rt?5 nm, and this cellulose ester film is characterized by temperature variation ?Rt(t) lying in the range 0 nm??Rt(t)?7 nm and humidity variation ?Rt(h) lying in the range 0 nm??Rt(h)?20 nm.
    Type: Application
    Filed: September 27, 2007
    Publication date: April 10, 2008
    Applicant: KONICA MINOLTA OPTO, INC.
    Inventors: Shigeki OKA, Noriki TACHIBANA
  • 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: 20070222920
    Abstract: A polarizer protective film containing a cellulose acylate having a total acyl substitution degree of from 2.2 to less than 2.5 and a polymer prepared by polymerizing an acrylate ester or a methacrylate ester.
    Type: Application
    Filed: March 5, 2007
    Publication date: September 27, 2007
    Applicant: KONICA MINOLTA OPTO, INC.
    Inventor: Shigeki OKA
  • 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