Patents by Inventor Kazutaka Hara

Kazutaka Hara 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: 7746421
    Abstract: An optical element comprising: a polarizing element (A), separating incident light into polarization to then emit light, and made of a cholesteric liquid crystal, and a linearly polarized light reflection polarizer (B) transmitting linearly polarized light with one polarization axis and selectively reflecting linearly polarized light with the other polarization axis perpendicular to the one polarization axis, wherein the polarizing element (A) has a distortion rate with respect to emitting light to incident light in the normal direction of 0.5 or more and a distortion rate with respect to emitting light to incident light at an angle inclined from the normal direction by 60 degrees or more of 0.2 or less, the polarizing element (A) has a function increasing a linearly polarized light component of emitting light as incidence angle is larger; is capable of condensation and collimation of incident light from a light source and capable of suppressing transmission of light in an arbitrary direction.
    Type: Grant
    Filed: August 24, 2004
    Date of Patent: June 29, 2010
    Assignee: Nitto Denko Corporation
    Inventors: Naoki Takahashi, Kazutaka Hara, Miki Shiraogawa, Kentarou Takeda
  • Patent number: 7746555
    Abstract: A polarization component, capable of efficiently reflecting an obliquely transmitted light beam toward a light source without degrading the transmission-polarization property of a perpendicular incident light beam, is provided. A C-plate having an oblique retardation of at least ?/8 with respect to a light beam inclined by at least 30° is disposed between at least two reflective circular polarizer layers whose selective reflection wavelength bands of polarized light overlapping each other. A combination of a reflective linear polarizer and a quarter wavelength plate may be used instead of the reflective circular polarizer. Alternatively, a combination of two reflective linear polarizer layers and two quarter wavelength plate layers (Nz?2) disposed therebetween can provide a similar effect. Further, a combination of two reflective linear polarizer layers and a half wavelength plate (Nz?1.5) disposed therebetween may be used.
    Type: Grant
    Filed: September 24, 2008
    Date of Patent: June 29, 2010
    Assignee: Nitto Denko Corporation
    Inventors: Kazutaka Hara, Minoru Miyatake
  • Patent number: 7633678
    Abstract: An optical element of the invention comprises at least two laminated layers of reflective polarizer; and at least one retardation layer for changing polarization properties laminated between the reflective polarizers, the combination of the layers being designed so as to provide a incident-light transmittance depending on an incident angle of an incident light and designed such that a shielded light is not absorbed but reflected. The optical element can effectively shield transmitted lights with respect to obliquely incident lights and can control coloring.
    Type: Grant
    Filed: January 7, 2009
    Date of Patent: December 15, 2009
    Assignee: Nitto Denko Corporation
    Inventors: Naoki Takahashi, Kentarou Takeda, Kazutaka Hara, Miki Shiraogawa
  • Patent number: 7630134
    Abstract: An optical element of the invention comprises at least two laminated layers of reflective polarizer; and at least one retardation layer for changing polarization properties laminated between the reflective polarizers, the combination of the layers being designed so as to provide a incident-light transmittance depending on an incident angle of an incident light and designed such that a shielded light is not absorbed but reflected. The optical element can effectively shield transmitted lights with respect to obliquely incident lights and can control coloring.
    Type: Grant
    Filed: January 7, 2009
    Date of Patent: December 8, 2009
    Assignee: Nitto Denko Corporation
    Inventors: Naoki Takahashi, Kentarou Takeda, Kazutaka Hara, Miki Shiraogawa
  • Patent number: 7622055
    Abstract: A polarizing plate is provided that has excellent polarization properties and high surface hardness and can have a reduced thickness. The polarizing plate includes a polarizer and a cured resin layer. The cured resin layer is formed directly on at least one surface of the polarizer. The cured resin layer is formed of a solventless photocurable composition containing the following components (A), (B), and (C): (A) at least one of a polyfunctional acrylic monomer and a polyfunctional methacrylic monomer; (B) a photocurable prepolymer; and (C) a photopolymerization initiator.
    Type: Grant
    Filed: May 14, 2007
    Date of Patent: November 24, 2009
    Assignee: Nitto Denko Corporation
    Inventors: Shinya Nakano, Kazutaka Hara, Takehito Fuchida, Naoto Ooe
  • Patent number: 7593079
    Abstract: An optical element of the invention comprises at least three laminated circular-polarization-type-reflection polarizers (a) whose wavelength bands for selective reflection of polarized light overlap one another; a layer (b1) which is placed between at least a pair of the circular-polarization-type-reflection polarizers (a) and has a front retardation of substantially zero (in the normal direction) and a retardation of at least ?/8 with respect to incident light inclined by at least 30° relative to the normal direction; and a layer (b2) which is placed between at least another pair of the circular-polarization-type-reflection polarizers (a) and has a front retardation of substantially zero (in the normal direction) and a retardation of at most ?/2 with respect to incident light inclined by 60° relative to the normal direction.
    Type: Grant
    Filed: April 15, 2004
    Date of Patent: September 22, 2009
    Assignee: Nitto Denko Corporation
    Inventors: Kentarou Takeda, Naoki Takahashi, Kazutaka Hara, Takahiro Fukuoka
  • Publication number: 20090128907
    Abstract: An optical element of the invention comprises at least two laminated layers of at least one kind of reflective polarizer (a); and at least one layer of at least one kind of retardation layer (b) for changing polarization properties laminated between the reflective polarizers (a), the combination of the layers being designed so as to provide a incident-light transmittance depending on an incident angle of an incident light and designed such that a shielded light is not absorbed but reflected, wherein at least one layer of the reflective polarizer (a) is a circular polarization type reflective polarizer (a1) capable of transmitting a certain circularly polarized light and selectively reflecting an oppositely circularly polarized light; at least one layer of the reflective polarizer (a) is a linear polarization type reflective polarizer (a2) capable of transmitting one of perpendicular linearly polarized lights and selectively reflecting the other of the perpendicular linearly polarized lights; and the retardati
    Type: Application
    Filed: January 7, 2009
    Publication date: May 21, 2009
    Applicant: NITTO DENKO CORPORATION
    Inventors: Naoki Takahashi, Kentarou Takeda, Kazutaka Hara, Miki Shiraogawa
  • Publication number: 20090128905
    Abstract: An optical element of the invention comprises at least two laminated layers of at least one kind of reflective polarizer (a); and at least one layer of at least one kind of retardation layer (b) for changing polarization properties laminated between the reflective polarizers (a), the combination of the layers being designed so as to provide a incident-light transmittance depending on an incident angle of an incident light and designed such that a shielded light is not absorbed but reflected, wherein at least one layer of the reflective polarizer (a) is a circular polarization type reflective polarizer (a1) capable of transmitting a certain circularly polarized light and selectively reflecting an oppositely circularly polarized light; at least one layer of the reflective polarizer (a) is a linear polarization type reflective polarizer (a2) capable of transmitting one of perpendicular linearly polarized lights and selectively reflecting the other of the perpendicular linearly polarized lights; and the retardati
    Type: Application
    Filed: January 7, 2009
    Publication date: May 21, 2009
    Applicant: NITTO DENKO CORPORATION
    Inventors: Naoki Takahashi, Kentarou Takeda, Kazutaka Hara, Miki Shiraogawa
  • Patent number: 7492516
    Abstract: An optical element of the invention comprises at least two laminated layers of reflective polarizer; and at least one retardation layer for changing polarization properties laminated between the reflective polarizers, the combination of the layers being designed so as to provide a incident-light transmittance depending on an incident angle of an incident light and designed such that a shielded light is not absorbed but reflected. The optical element can effectively shield transmitted lights with respect to obliquely incident lights and can control coloring.
    Type: Grant
    Filed: March 19, 2004
    Date of Patent: February 17, 2009
    Assignee: Nitto Denko Corporation
    Inventors: Naoki Takahashi, Kentarou Takeda, Kazutaka Hara, Miki Shiraogawa
  • Publication number: 20090034070
    Abstract: A polarization component, capable of efficiently reflecting an obliquely transmitted light beam toward a light source without degrading the transmission-polarization property of a perpendicular incident light beam, is provided. A C-plate having an oblique retardation of at least ?/8 with respect to a light beam inclined by at least 30° is disposed between at least two reflective circular polarizer layers whose selective reflection wavelength bands of polarized light overlapping each other. A combination of a reflective linear polarizer and a quarter wavelength plate may be used instead of the reflective circular polarizer. Alternatively, a combination of two reflective linear polarizer layers and two quarter wavelength plate layers (Nz?2) disposed therebetween can provide a similar effect. Further, a combination of two reflective linear polarizer layers and a half wavelength plate (Nz?1.5) disposed therebetween may be used.
    Type: Application
    Filed: September 24, 2008
    Publication date: February 5, 2009
    Applicant: NITTO DENKO CORPORATION
    Inventors: Kazutaka HARA, Minoru Miyatake
  • Patent number: 7446848
    Abstract: An optical element of the invention comprises at least two laminated circular-polarization-type-reflection polarizers (a) whose wavelength bands for selective reflection of polarized light overlap one another, wherein the at least two circular-polarization-type-reflection polarizers (a) each have a side capable of selectively reflecting a relatively short wavelength in the wavelength bands for selective reflection, and the sides of said at least two circular-polarization-type-reflection polarizers (a) capable of selectively reflecting the relatively short wavelength are arranged opposite to each other. The optical element condenses or collimates incident light from a light source and can control transmission of light at large incident angles relative to the normal direction, increase front brightness and reduce coloration.
    Type: Grant
    Filed: April 15, 2004
    Date of Patent: November 4, 2008
    Assignee: Nitto Denko Corporation
    Inventors: Kentarou Takeda, Kazutaka Hara, Naoki Takahashi
  • Patent number: 7443585
    Abstract: A polarization component, capable of efficiently reflecting an obliquely transmitted light beam toward a light source without degrading the transmission-polarization property of a perpendicular incident light beam, is provided. A C-plate having an oblique retardation of at least ?/8 with respect to a light beam inclined by at least 30° is disposed between at least two reflective circular polarizer layers whose selective reflection wavelength bands of polarized light overlapping each other. A combination of a reflective linear polarizer and a quarter wavelength plate may be used instead of the reflective circular polarizer. Alternatively, a combination of two reflective linear polarizer layers and two quarter wavelength plate layers (Nz?2) disposed therebetween can provide a similar effect. Further, a combination of two reflective linear polarizer layers and a half wavelength plate (Nz?1.5) disposed therebetween may be used.
    Type: Grant
    Filed: April 17, 2003
    Date of Patent: October 28, 2008
    Assignee: Nitto Denko Corporation
    Inventors: Kazutaka Hara, Minoru Miyatake
  • Patent number: 7393570
    Abstract: A broad band cholesteric liquid crystal film of the present invention is a cholesteric liquid crystal film obtained by coating a liquid crystal mixture containing a polymerizable mesogen compound (a), a polymerizable chiral agent (b) and a photoisomerizable material (c) on a substrate to ultraviolet polymerize a coat of the liquid crystal mixture, and has a reflection bandwidth of 200 nm or more. A broad band cholesteric liquid crystal film of the present invention has a broad reflection band, is of a thin type and can be manufactured in less of manufacturing steps.
    Type: Grant
    Filed: January 8, 2004
    Date of Patent: July 1, 2008
    Assignee: Nitto Denko Corporation
    Inventors: Kentarou Takeda, Kazutaka Hara, Naoki Takahashi, Takahiro Fukuoka
  • Publication number: 20080049317
    Abstract: The present invention provides an optical element including: a translucent resin; minute regions dispersedly distributed in the translucent resin and having a birefringence different from the translucent resin; and at lest one kind of luminous body dispersed in the translucent resin and/or the minute regions and having a particle size smaller than the emission wavelength thereof, the optical element having a plate-like shape; a polarized-light-emitting planar light source including the optical element and the excitation light source; and a display device including the polarized-light-emitting planar light source.
    Type: Application
    Filed: September 28, 2005
    Publication date: February 28, 2008
    Inventors: Kazutaka Hara, Minoru Miyatake
  • Patent number: 7326451
    Abstract: A rotatory polarization plate capable of extracting an emission polarized light from an incident polarized light and rotating an azimuth angle of an polarization axis of the incident polarized light, wherein a rotatory polarization angle of the azimuth angle is changed by an incidence angle of the incident polarized light, is useful for an optical element capable of condensing and collimating incident light from a light source in a specific direction.
    Type: Grant
    Filed: October 21, 2004
    Date of Patent: February 5, 2008
    Assignee: Nitto Denko Corporation
    Inventors: Kentarou Takeda, Kazutaka Hara, Naoki Takahashi, Miki Shiraogawa
  • Patent number: 7317498
    Abstract: A viewing angle magnification liquid crystal display of this invention comprising: at least a backlight system containing a polarization element (A) obtained by disposing a retardation layer (b) between at least two layers, included in a reflection polarizer (a), and having respective selective reflection wavelength bands of polarized light superimposed on each other to conduct collimation for a diffusion light source; a liquid crystal cell transmitting collimated lights; a polarizing plate disposed on both sides of the liquid crystal cell; and a viewing angle magnifying layer disposed on the viewer side of the liquid crystal cell to diffuse transmitted light. The liquid crystal display can realize a thin type and have a wide viewing angle.
    Type: Grant
    Filed: April 18, 2003
    Date of Patent: January 8, 2008
    Assignee: Nitto Denko Corporation
    Inventors: Kazutaka Hara, Naoki Takahashi, Minoru Miyatake
  • Publication number: 20070269616
    Abstract: A polarizing plate is provided that has excellent polarization properties and high surface hardness and can have a reduced thickness. The polarizing plate includes a polarizer and a cured resin layer. The cured resin layer is formed directly on at least one surface of the polarizer. The cured resin layer is formed of a solventless photocurable composition containing the following components (A), (B), and (C): (A) at least one of a polyfunctional acrylic monomer and a polyfunctional methacrylic monomer; (B) a photocurable prepolymer; and (C) a photopolymerization initiator.
    Type: Application
    Filed: May 14, 2007
    Publication date: November 22, 2007
    Applicant: NITTO DENKO CORPORATION
    Inventors: Shinya NAKANO, Kazutaka HARA, Takehito FUCHIDA, Naoto OOE
  • Patent number: 7294303
    Abstract: A broad band cholesteric liquid crystal film of the present invention comprises a cholesteric liquid crystal film obtained by polymerizing a liquid crystal mixture containing a polymerizable mesogen compound (a), a polymerizable chiral agent (b) and a photopolymerization initiator (c) between two substrates with ultraviolet light, and has a reflection bandwidth of 200 nm or more. The broad band cholesteric liquid crystal film of the present invention has a broad reflection band and is excellent in durability.
    Type: Grant
    Filed: January 8, 2004
    Date of Patent: November 13, 2007
    Assignee: Nitto Denko Corporation
    Inventors: Takahiro Fukuoka, Naoki Takahashi, Kazutaka Hara
  • Publication number: 20070132914
    Abstract: An optical element comprising: a polarizing element (A), separating incident light into polarization to then emit light, and made of a cholesteric liquid crystal, and a linearly polarized light reflection polarizer (B) transmitting linearly polarized light with one polarization axis and selectively reflecting linearly polarized light with the other polarization axis perpendicular to the one polarization axis, wherein the polarizing element (A) has a distortion rate with respect to emitting light to incident light in the normal direction of 0.5 or more and a distortion rate with respect to emitting light to incident light at an angle inclined from the normal direction by 60 degrees or more of 0.2 or less, the polarizing element (A) has a function increasing a linearly polarized light component of emitting light as incidence angle is larger; is capable of condensation and collimation of incident light from a light source and capable of suppressing transmission of light in an arbitrary direction.
    Type: Application
    Filed: August 24, 2004
    Publication date: June 14, 2007
    Applicant: Nitto Denko Corporation
    Inventors: Naoki Takahashi, Kazutaka Hara, Miki Shiraogawa, Kentarou Takeda
  • Publication number: 20070064168
    Abstract: An optical element comprising: a polarizing element (A), separating incident light into polarization to then emit light, and made of a cholesteric liquid crystal, wherein the polarizing element (A) has a distortion rate with respect to emitting light to incident light in the normal direction of 0.5 or more and a distortion rate with respect to emitting light to incident light at an angle inclined from the normal direction by 60 degrees or more of 0.
    Type: Application
    Filed: August 24, 2004
    Publication date: March 22, 2007
    Applicant: NITTO DENKO CORPORATION
    Inventors: Miki Shiraogawa, Kentarou Takeda, Kazutaka Hara, Naoki Takahashi