Including Liquid Crystal Detector Patents (Class 250/331)
  • Optical system for thermal imager
    Patent number: 4051370
    Abstract: An infrared chopper device for use with a starting thermal imaging system, uch as a pyroelectric vidicon, is provided which utilizes liquid crystal technology.
    Type: Grant
    Filed: August 24, 1976
    Date of Patent: September 27, 1977
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Vincent T. Bly
  • Thermal method for controlling the optical properties of a liquid crystal and devices for the application of said method
    Patent number: 4031529
    Abstract: In a liquid crystal whose molecules have temperature-dependent dielectric anisotropy within a range such that the liquid crystal retains the same phase, the optical properties of a liquid crystal film are controlled by applying an electric field of predetermined frequency to the film and by bringing the temperature of the film to a value within the range mentioned. The dielectric anisotropy then assumes a predetermined value in respect of said frequency and the liquid crystal film assumes a predetermined optical state.
    Type: Grant
    Filed: December 22, 1975
    Date of Patent: June 21, 1977
    Assignee: Commissariat a l'Energie Atomique
    Inventors: Joseph Borel, Jacques Robert
  • Beam addressed liquid crystal cells
    Patent number: 3999838
    Abstract: A beam addressed liquid crystal cell having an absorbing layer adapted to absorb energy in the infrared spectrum while transmitting substantial energy in the visible spectrum is disclosed. In a preferred embodiment the absorbing layer contains the reaction product of bis (dithiobenzil) nickel and a polyamide. This absorbing layer absorbs at least 90% of the gallium arsenide laser wavelengths and at the same time permits transmission in the visible spectrum to be of the order of 80%.
    Type: Grant
    Filed: June 5, 1975
    Date of Patent: December 28, 1976
    Assignee: International Business Machines Corporation
    Inventor: Gerard John Sprokel
  • Led image tube light valve
    Patent number: 3971931
    Abstract: A projection display for producing a bright image of pictorial quality from a large time bandwidth video signal produced by a plurality of light emitting diodes (LED's).
    Type: Grant
    Filed: January 23, 1975
    Date of Patent: July 27, 1976
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Robert E. Jehle
  • Imaging method
    Patent number: 3957349
    Abstract: An electro-optic device comprising, in turn, a first electrode, a photoconductive layer, a liquid crystalline layer, and a second electrode, and imaged with background at a voltage v.sub.o, is imaged without background by relatively slowly applying v.sub.o. Optionally, v.sub.o is relatively slowly reduced to zero to prevent background creation during removal of v.sub.o.
    Type: Grant
    Filed: July 29, 1974
    Date of Patent: May 18, 1976
    Assignee: Xerox Corporation
    Inventor: Kyler F. Nelson
  • Imaging method with U.V. excitation of liquid crystal
    Patent number: 3952193
    Abstract: The electrical resistivity of pure trans-stilbene nematic liquid crystalline materials is altered by exposure to ultraviolet radiation. These stilbenes can therefore be made to dynamically scatter uniformly or in imagewise configuration and can be added to liquid crystalline compositions to alter the compositions' resistivities.
    Type: Grant
    Filed: September 25, 1974
    Date of Patent: April 20, 1976
    Assignee: Xerox Corporation
    Inventors: Werner E. L. Haas, James E. Adams
  • Liquid crystalline image converter
    Patent number: 3942007
    Abstract: The optical transitions of extrinsicially optically active insoluble materials become optically active and circularly dichroic when in contact with optically negative liquid crystalline materials thereby producing unusual and highly advantageous properties. The circularly dichroic optical properties induced in the extrinsically optically active insoluble materials can be utilized for converting infrared images to visible images.
    Type: Grant
    Filed: April 29, 1974
    Date of Patent: March 2, 1976
    Assignee: Xerox Corporation
    Inventor: Franklin D. Saeva
  • Imaging system
    Patent number: 3936640
    Abstract: Method and apparatus for maintaining the conductance of liquid crystalline compositions comprising pure transstilbene liquid crystalline materials at a level sufficient to allow dynamic scattering of the composition.
    Type: Grant
    Filed: September 25, 1974
    Date of Patent: February 3, 1976
    Assignee: Xerox Corporation
    Inventors: Werner E. L. Haas, Joseph F. Stephany