Using Reflection Characteristic Patents (Class 349/176)
  • Patent number: 5920368
    Abstract: A composite material includes a cholesteric liquid crystal; a polymer which is distributed in phase-separated domains and provides an effective form-retention property for the composite material; and an additional material which is dissolved in the cholesteric liquid crystal and maintains a cholesteric phase of the liquid crystal and bistability of a focal conic state and a planar state of the liquid crystal.
    Type: Grant
    Filed: December 3, 1997
    Date of Patent: July 6, 1999
    Assignee: Minolta Co., Ltd.
    Inventors: Takuji Hatano, Kiyofumi Hashimoto, Nobuyuki Kobayashi
  • Patent number: 5835166
    Abstract: Monocular and stereoscopic color display systems, wherein passive cholesteric liquid crystal (LC) filter/mirrors and active variable retarder type LC arrays are used in combination to produce low cost, high resolution, multicolor and full color displays, suitable for use as advertising, automotive, aircraft, computer, games and electron instrumentation displays.
    Type: Grant
    Filed: September 16, 1996
    Date of Patent: November 10, 1998
    Inventors: Dennis R. Hall, Philip A. Johnson
  • Patent number: 5808711
    Abstract: A liquid crystal display assembly (10) can function in either a transparent or reflective mode. The assembly consists of a reflective-type liquid crystal display cell (12) placed in front of an electrochromic panel (14). When a display driver (16) activates the electrochromic panel, it absorbs light. When the driver energizes segments (15) of the reflective-type liquid crystal display cell, they become reflective, providing a visual image to an observer. When the electrochromic panel is not activated by the driver, it is transparent or translucent, allowing the observer to see completely through the liquid crystal display assembly.
    Type: Grant
    Filed: August 22, 1997
    Date of Patent: September 15, 1998
    Assignee: Motorola, Inc.
    Inventors: Anthony J. Suppelsa, Michael F. Shaw, Thomas J. Swirbel
  • Patent number: 5796454
    Abstract: A cholesteric liquid crystal display ("LCD") and methods of operating and manufacturing the LCD. The LCD includes: (1) a controllable cholesteric liquid crystal (CLC) located between first and second substrates, the controllable CLC selectively exhibiting an "on" state and an "off" state and having a circular polarity of a predetermined handedness when the controllable CLC is in the "on" state and (2) a circular polarizer, located proximate the first substrate and having a circular polarity of a particular handedness, that cooperates with the controllable CLC to increase the difference between the relative brightness of the "on" state and the "off" state, whereby a contrast ratio of the cholesteric LCD is increased.
    Type: Grant
    Filed: December 4, 1996
    Date of Patent: August 18, 1998
    Assignee: Advanced Display Systems, Inc.
    Inventor: Yao-Dong Ma
  • Patent number: 5731861
    Abstract: A composite material includes a cholesteric liquid crystal; a polymer which is distributed in phase-separated domains and provides an effective form-retention property for the composite material; and an additional material which is dissolved in the cholesteric liquid crystal and maintains a cholesteric phase of the liquid crystal and bistability of a focal conic state and a planar state of the liquid crystal.
    Type: Grant
    Filed: May 1, 1996
    Date of Patent: March 24, 1998
    Assignee: Minolta Co., Ltd.
    Inventors: Takuji Hatano, Kiyofumi Hashimoto, Nobuyuki Kobayashi
  • Patent number: 5724109
    Abstract: A liquid crystal display panel including at least two liquid crystal layers, and a color filter having two color portions. One of the liquid crystal layers includes solid regions and liquid crystal dispersing regions arranged adjacent to the solid regions. Picture electrodes are arranged on the first plate, on the liquid crystal dispersing regions, and on the solid regions, at positions corresponding to the color portions of the color filter. A common electrode is arranged on the second plate. The picture elements on the liquid crystal dispersing regions and on the solid regions are connected to the conductors on the first plate by connecting members extending through the solid regions. Therefore, the liquid crystal layers can be independently controlled.
    Type: Grant
    Filed: September 1, 1995
    Date of Patent: March 3, 1998
    Assignee: Fujitsu Limited
    Inventors: Kimiaki Nakamura, Hidefumi Yoshida, Kazutaka Hanaoka, Hideaki Tsuda, Hideo Chida, Takahiro Sasaki
  • Patent number: 5715023
    Abstract: A compact lightweight display system which can be used as a collimating eyepiece is provided. The system utilizes a cholesteric liquid crystal device in combination with an optical doublet. A partially reflective coating is at the interface between the two singlets which comprise the doublet. The design of this system reduces the number of element to air and/or element to element interfaces, thus reducing losses and ghosting while making a sturdier, more vibration tolerant display system.
    Type: Grant
    Filed: April 30, 1996
    Date of Patent: February 3, 1998
    Assignee: Kaiser Electro-Optics, Inc.
    Inventor: Michael J. Hoppe
  • Patent number: 5691795
    Abstract: A new liquid crystalline light modulating cell and material are characterized by liquid crystalline light modulating material of liquid crystal and polymer, the liquid crystal being a chiral nematic liquid crystal having positive dielectric anisotropy and including chiral material in an amount effective to form focal conic and twisted planar textures, the polymer being distributed in phase separated domains in the liquid crystal cell in an amount that stabilizes the focal conic and twisted planar textures in the absence of a field and permits the liquid crystal to change textures upon the application of a field. In one embodiment, the material is light scattering in a field-OFF condition and optically clear in a field-ON condition, while in another embodiment, the material is optically clear in a field-OFF condition and light scattering in a field-ON condition.
    Type: Grant
    Filed: April 20, 1995
    Date of Patent: November 25, 1997
    Assignee: Kent State University
    Inventors: J. William Doane, Deng-Ke Yang, Liang-Chy Chien
  • Patent number: 5682212
    Abstract: The invention relates to optical elements having image-forming, color- and polarization-selective reflection and containing cholesteric liquid crystals, and to the preparation and use of these elements. In the wavelength- and polarization-selective elements which form an optical image, at least one cholesteric liquid crystal is enclosed in the cavity of constant thickness between two light-transmitting substrates having curved surfaces in such a way that the helix axis of the liquid crystal is aligned perpendicular to the curved surface of the light-transmitting substrates. The elements are suitable for use as beam splitters or recombiners in projection displays.
    Type: Grant
    Filed: August 22, 1994
    Date of Patent: October 28, 1997
    Assignee: Consortium fur elektrochemische Industrie GmbH
    Inventors: Robert Maurer, Stefan Beiergroesslein, Franz-Heinrich Kreuzer
  • Patent number: 5668614
    Abstract: An improvement in a light modulating chiral nematic liquid crystal adapted to form focal conic and twisted planar textures and a liquid crystal device employing such a material, the improvement wherein the liquid crystal material includes a plurality of essentially distinct regions within which the liquid crystal has different pitch lengths, whereby the liquid crystal can be made to reflect different wavelengths of light in different regions. The regions are created by including in the chiral nematic liquid crystal composition, a chiral material adapted to change its chirality upon photo-irradiation, in an amount effective to change the pitch length of the liquid crystal composition upon photo-irradiation. By exposing different regions of the material to increasing amounts of photo-irradiation, the pitch length of each region can be selectively tuned to reflect light of a different wavelength.
    Type: Grant
    Filed: May 1, 1995
    Date of Patent: September 16, 1997
    Assignee: Kent State University
    Inventors: Liang-Chy Chien, Joseph William Doane
  • Patent number: 5661533
    Abstract: Surfactant-containing multistable cholesteric liquid crystal displays exhibit ultra fast response times with both video speed and gray scale capability.
    Type: Grant
    Filed: May 19, 1995
    Date of Patent: August 26, 1997
    Assignee: Advanced Display Systems, Inc.
    Inventors: Bao-Gang Wu, Hongxi Zhou, Yao-Dong Ma
  • Patent number: 5625477
    Abstract: A light modulating apparatus containing cholesteric liquid crystals capable of indefinite zero field retention of optical images, including full color and complete gray scale capability, is described. This invention is predicated on establishment of zero field multistable liquid crystal domains representing a continuous distribution of states ranging from the highly reflective planar to the light-scattering focal-conic structures. The zero field multistable domain structure stability is achieved by controlling solid surface-liquid crystal boundary interactions to provide essential equalization of the total system energy of each of the domain structures. This is the first time this equalization, and thus zero field multistability, has been achieved without the use of a polymer gel addition to create rigid polydomains in the liquid crystal mix.
    Type: Grant
    Filed: April 11, 1994
    Date of Patent: April 29, 1997
    Assignee: Advanced Display Systems, Inc.
    Inventors: Bao-Gang Wu, Jianmi Gao, Hongxi Zhou, Yao-Dong Ma