Patents by Inventor Zenta Kikuchi

Zenta Kikuchi 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: 6014195
    Abstract: A liquid crystal display device, for displaying pure white, has a first substrate having first electrodes formed thereon; a second substrate positioned to face the first substrate and having second electrodes formed thereon; a liquid crystal sealed between the first and second substrates; and first and second polarization plates arranged to sandwich the first and second substrates and having such polarization characteristics that when the first and second polarization plates are placed one on the other in such a way as to have substantially perpendicular transmission axes, a value acquired by dividing a transmittance of light with a wavelength of 500 nm by a transmittance of light with a wavelength of 440 nm becomes substantially smaller than 0.4.
    Type: Grant
    Filed: August 29, 1996
    Date of Patent: January 11, 2000
    Assignee: Casio Computer Co., Ltd.
    Inventors: Katsuhito Sakamoto, Zenta Kikuchi, Satoru Shimoda, Hisashi Aoki, Soichi Sato, Tetsushi Yoshida
  • Patent number: 5796378
    Abstract: A color liquid crystal display apparatus comprises an ECB (Electrically Controlled Birifringence) type liquid crystal display device, which has a plurality of dots arranged in a matrix form and displays a plurality of colors in accordance with applied voltages dot by dot, and a driving circuit. The driving circuit includes an image memory, a display controller, a conversion table, a D/A converter and drivers. The display controller reads image data stored in the image memory. This image data defines a display color of a pixel consisting of a plurality of dots and a gradation. The conversion table converts image data to voltage data defining voltages to be applied to a plurality of dots of the liquid crystal display device in order to display the color and gradation defined by the image data. The D/A converter converts this voltage data to an analog voltage and the drivers apply this analog voltage to each dot of the liquid crystal display device.
    Type: Grant
    Filed: March 21, 1995
    Date of Patent: August 18, 1998
    Assignee: Casio Computer Co., Ltd.
    Inventors: Tetsushi Yoshida, Soichi Sato, Zenta Kikuchi
  • Patent number: 5745200
    Abstract: A birefringence control type color liquid crystal display device includes a liquid crystal cell having first and second substrates; first and second electrodes formed on opposing surfaces of the first and second substrates; a first aligning film formed on the first electrode and subjected to an aligning treatment in a first direction; a second aligning film formed on the second electrode and the second substrate and subjected to an aligning treatment in a second direction intersecting the first direction at 90 degrees; and a liquid crystal sealed between the first and second aligning films and twisted at 90 degrees.
    Type: Grant
    Filed: April 24, 1995
    Date of Patent: April 28, 1998
    Assignee: Casio Computer Co., Ltd.
    Inventors: Zenta Kikuchi, Tetsushi Yoshida, Hisashi Aoki
  • Patent number: 5737047
    Abstract: A color liquid crystal display device comprises a liquid crystal cell having liquid crystal molecules twisted by 90.degree., two polarization plates, a reflector and two retardation plates. The product .DELTA.n.d of the refractive anisotropy .DELTA.n and the LC layer thickness d of the liquid crystal cell, the retardations of the retardation plates, the directions of the transmission axes of the polarization plates and the phase delay axes of the retardation plates are set in such a way that the color of outgoing light changes to red, green, blue, black or white in accordance with an applied voltage. The transmission axis of one of the polarization plates is set in a direction of 110.degree. to 130.degree. in an opposite direction to the twist angle of the liquid crystal molecules and the transmission axis of the other of the polarization plates is set in a direction of 127.degree. to 140.degree. in an opposite direction to this twist angle.
    Type: Grant
    Filed: March 25, 1996
    Date of Patent: April 7, 1998
    Assignee: Casio Computer Co., Ltd.
    Inventors: Katsuhito Sakamoto, Zenta Kikuchi, Satoru Shimoda
  • Patent number: 5724112
    Abstract: A color liquid crystal display device including a transparent first substrate having an inner surface and at least one transparent electrode formed thereon, and an insulating second substrate having an inner surface arranged to oppose the inner surface of the first substrate and at least one electrode formed on the inner surface of the second substrate. A liquid crystal layer is sandwiched between the inner surfaces of the first and second substrates and has a predetermined initial aligned state. A polarizing member is arranged on a first substrate side of the liquid crystal layer, and at least one retardation plate is provided for coloring light which emerges from the liquid crystal display. The retardation plate is arranged between the liquid crystal layer and the polarizing member such that an optical axis of the retardation plate with respect to a transmission axis of the polarizing member is not parallel to or perpendicular to the transmission axis.
    Type: Grant
    Filed: June 16, 1995
    Date of Patent: March 3, 1998
    Assignee: Casio Computer Co., Ltd.
    Inventors: Tetsushi Yoshida, Zenta Kikuchi, Hisashi Aoki
  • Patent number: 5680188
    Abstract: A polymer dispersed liquid crystal display device includes first and second substrates arranged to oppose each other, a polymer dispersed liquid crystal layer arranged between the first and second substrates, first electrodes arranged on the inner surface of the first substrate, a reflecting member arranged on the inner surface of the second substrate and designed to reflect light transmitted through the polymer dispersed liquid crystal layer, a coloring film for coloring light transmitted through the polymer dispersed liquid crystal to display a color image, and second electrodes arranged between the inner surface of the second substrate and the liquid crystal layer. At least a portion of each second electrode opposes a corresponding first electrode.
    Type: Grant
    Filed: January 30, 1996
    Date of Patent: October 21, 1997
    Assignee: Casio Computer Co., Ltd.
    Inventors: Tetsushi Yoshida, Jiro Takei, Zenta Kikuchi
  • Patent number: 5629783
    Abstract: A liquid crystal device includes a TFT or active element substrate on which TFTs and pixel electrodes are arranged in the form of a matrix, a counter substrate having a counter electrode formed thereon and arranged to oppose the active element substrate, a polymer dispersed liquid crystal layer arranged between the active element substrate and the counter substrate and having a polymer resin and a liquid crystal which are dispersed, and a fluorescent film arranged on the pixel electrode. The device displays an image by controlling scattering, absorption, and transmission of light passing through the polymer dispersed liquid crystal layer. The phosphor film converts part of supplied light into fluorescent light having a predetermined wavelength and outputs colored light. Light used for a display is increased in intensity by the fluorescent light emitted from the phosphor film, thereby displaying a bright image.
    Type: Grant
    Filed: October 3, 1994
    Date of Patent: May 13, 1997
    Assignee: Casio Computer Co., Ltd.
    Inventors: Minoru Kanbara, Tetsushi Yoshida, Zenta Kikuchi, Jiro Takei
  • Patent number: 5559615
    Abstract: A polymer dispersed liquid crystal display device includes an active element substrate on which active elements and pixel electrodes are arranged in the form of a matrix, a counter substrate having a counter electrode formed on a surface, of the counter substrate, opposing the active element substrate, and a polymer dispersed liquid crystal film arranged between the active element substrate and the counter substrate and formed by dispersing a polymer resin and a cholesteric liquid crystal. The cholesteric liquid crystal is in a randomly aligned state to be twisted at a specific helical pitch in the absence of an electric field. When an electric field is applied across the pixel electrodes and the counter electrode, the cholesteric liquid crystal is aligned along the electric field, and the polymer dispersed liquid crystal film is set in a light-transmitting state, thereby setting a display in a bright state.
    Type: Grant
    Filed: October 3, 1994
    Date of Patent: September 24, 1996
    Assignee: Casio Computer Co., Ltd.
    Inventors: Jiro Takei, Tetsushi Yoshida, Zenta Kikuchi
  • Patent number: 5548426
    Abstract: A polarizer is arranged on the incident side of a TN type liquid crystal cell in which the arrangement of liquid crystal molecules is twist-aligned through substantially 90.degree. in a direction from one substrate to the opposite substrate and the value of a product .DELTA.n.sub.c.d.sub.c of a refractive index anisotropy .DELTA.n.sub.c and a gap d.sub.c is set within a range of 300 to 600 nm, and an analyzer is arranged on the exit side of the liquid crystal cell. A twist-aligned retardation plate, in which the arrangement of polymer molecules is twist-aligned through 90.degree. in a direction opposite to the twist direction of the twist orientation of the liquid crystal molecules and the value of .DELTA.n.d ranges between 100 and 600 nm, is arranged between the liquid crystal cell and the analyzer.
    Type: Grant
    Filed: June 16, 1993
    Date of Patent: August 20, 1996
    Assignee: Casio Computer Co., Ltd.
    Inventors: Takashi Miyashita, Yoshinaga Miyazawa, Zenta Kikuchi
  • Patent number: 5440413
    Abstract: A polarizer and an analyzer are respectively arranged on the incident and exit sides of a twisted nematic liquid crystal cell, and at least one biaxial retardation plate is arranged between the polarizer and the analyzer. The biaxial retardation plate is arranged such that its phase delay axis is parallel or perpendicular to the aligning treatment direction of an aligning film on the incident side of the liquid crystal cell. The polarizer is arranged such that its light-transmitting axis is parallel or perpendicular to the incident-side aligning treatment direction. The light-transmitting axis of the analyzer is set to be perpendicular to the light-transmitting axis of the polarizer. A liquid crystal material sealed in the twisted nematic liquid crystal cell is twisted at about 90.degree.. The biaxial retardation plate has a refractive index n.sub.X in an extending direction of the retardation plate, a refractive index n.sub.Y in a direction perpendicular to the extending direction, and a refractive index n.
    Type: Grant
    Filed: September 22, 1992
    Date of Patent: August 8, 1995
    Assignee: Casio Computer Co., Ltd.
    Inventors: Zenta Kikuchi, Takashi Miyashita
  • Patent number: 5227903
    Abstract: An STN liquid crystal display device includes a polarizer and an analyzer which are arranged to sandwich an STN liquid crystal cell, and two biaxial retardation plates arranged between a substrate of the liquid crystal cell and the analyzer. The polarizer is arranged such that its light-transmitting axis is inclined at about 140.degree. with respect to an incident-side aligning treatment direction of the liquid crystal cell. The analyzer is arranged such that its light-transmitting axis is inclined at about 55.degree. with respect to the incident-side aligning treatment direction. The biaxial retardation plate on the liquid crystal cell side is arranged such that its phase delay axis is inclined at about 40.degree. with respect to the incident-side aligning treatment direction. The biaxial retardation plate on the analyzer side is arranged such that its phase delay axis is inclined at about 5.degree. with respect to the incident-side aligning treatment direction.
    Type: Grant
    Filed: September 15, 1992
    Date of Patent: July 13, 1993
    Assignee: Casio Computer Co., Ltd.
    Inventors: Yoshinaga Miyazawa, Takashi Miyashita, Zenta Kikuchi
  • Patent number: 5184236
    Abstract: A liquid crystal display device includes first and second substrates bonded with each other with an annular seal sandwiched therebetween. A liquid crystal is filled in a sealed space between the substates, molecules of which are so aligned that they are twisted at 90.degree.. The value of a product .DELTA.nd of the refractive-index anisotropy .DELTA.n of a LC layer and the LC layer thickness d falls from 350 nm to 700 nm. A first electrode and a first aligning film executed by an aligning treatment in a predetermined first direction and covering the electrode are formed on an inner surface of the first substrate. Second electrodes and a second aligning film executed by an aligning treatment in a second direction different at 90.degree. from the first direction and covering the electrode are formed on an inner surface of the second substrate.
    Type: Grant
    Filed: August 2, 1991
    Date of Patent: February 2, 1993
    Assignee: Casio Computer Co., Ltd.
    Inventors: Takashi Miyashita, Yoshinaga Miyazawa, Zenta Kikuchi