Utilizing Change Between Diverse Phases (e.g., Cholesteric To Nematic) Patents (Class 349/168)
  • Patent number: 5847798
    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: May 6, 1997
    Date of Patent: December 8, 1998
    Assignee: Kent State University
    Inventors: Deng-Ke Yang, Ruiqing Ma
  • Patent number: 5844653
    Abstract: Disclosed and claimed is a liquid crystal mixture, a liquid crystal device and a display device using the liquid crystal mixture. The liquid crystal display device according to the present invention has improved contrast due to the specific temperature of the liquid crystal mixture. More specifically, the liquid crystal mixture has a temperature range generating a chiral smectic C phase and a temperature range generating a smectic A phase, and having a difference between the cone angle at (T.sub.C/A -10).degree. C. and the cone angle at (T.sub.C/A -40).degree. C. in the temperature range generating the chiral smectic C phase of from zero (0) degree to ten (10) degrees.
    Type: Grant
    Filed: November 13, 1995
    Date of Patent: December 1, 1998
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Ayako Takeichi, Thoshiaki Nonaka, Kazuya Nagao, Hidemasa Yamaguchi
  • Patent number: 5746939
    Abstract: A liquid crystal device having a cell structure comprising a pair of base plates and a smectic liquid crystal having cholesteric phase at a higher temperature side; the ratio (P/d) of the spiral pitch of the cholesteric phase (P) to the spacing between the pair of base plates (d) is 0.5 or more.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: May 5, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventors: Osamu Taniguchi, Shinjiro Okada, Kazuharu Katagiri, Junichiro Kanbe
  • Patent number: 5748274
    Abstract: A liquid crystal device comprising a pair of parallel base plates and a ferroelectric liquid crystal disposed between the base plates. One of the pair of parallel base plates is provided with a plurality of stepwise elevations disposed in the form of stripes, and has been implemented with a uniaxial orientation treatment in a direction parallel to the edges of the stepwise elevations. The stepwise elevation may be formed by a transparent electrode alone or in combination with an alignment control film disposed thereon. Because of the above features, alignment defects liable to develop from the edges of the elevations are removed.
    Type: Grant
    Filed: March 20, 1995
    Date of Patent: May 5, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventors: Osamu Taniguchi, Shinjiro Okada, Yutaka Inaba, Hitoshi Shindo, Hirofumi Shibata
  • Patent number: 5648830
    Abstract: A liquid crystal device is constituted by (a) a pair of base plates each having an orientation control film thereon, and (b) a liquid crystal composition interposed between the base plates. The liquid crystal composition comprises at least two liquid crystal compounds including at least one liquid crystal compound which has a temperature range in which it shows cholesteric phase. The liquid crystal composition has a temperature range in which it shows cholesteric phase and is placed in chiral smectic phase which has been formed through cholesteric phase on temperature decrease. The liquid crystal composition comprises liquid crystal molecules having long axes forming a pre-tilt in the chiral smectic phase.
    Type: Grant
    Filed: April 19, 1995
    Date of Patent: July 15, 1997
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kazuharu Katagiri, Kazuo Yoshinaga, Shinjiro Okada, Junichiro Kanbe
  • Patent number: 5604616
    Abstract: A dual function electro-optical display device operates as a bistable display when driven at one voltage, and operates as a nematic display when driven at another voltage. In the first mode, the image in the display zone is formed by applying a first electrical signal to the device, and the image persists upon removal of the first electrical field. In the second mode, the image is formed by applying a second electrical signal to the device, and the image disappears upon removal of the second electrical signal. In a liquid crystal display, the liquid crystal fluid (9) is a blend of at least one liquid crystal nematic compound and at least one liquid crystal cholesteric compounds, and is maintained in a gap (4) between two substrates (1).
    Type: Grant
    Filed: April 3, 1995
    Date of Patent: February 18, 1997
    Assignee: Motorola, Inc.
    Inventors: Patrick M. Dunn, Thomas J. Swirbel