Patents by Inventor Frank M. Leslie

Frank M. Leslie 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: 4328493
    Abstract: A liquid crystal color display comprises a cathode ray tube which emits at two or more wavelengths, a liquid crystal cell, a neutral analyzer and two color selective polarizers. The cell is switched in synchronism with different images supplied to the cathode ray tube so that the different images are observed in the different colors simultaneously. The cell is respectively switched ON and OFF by application of signals at a low frequency f.sub.1 and a high frequency f.sub.h. To avoid a patch appearance due to different parts of the liquid crystal having different twists a gap is allowed between switching the signals f.sub.1 and f.sub.h so that the total shear of the liquid crystal may be kept below a critical shear value.
    Type: Grant
    Filed: January 23, 1980
    Date of Patent: May 4, 1982
    Assignee: National Research Development Corporation
    Inventors: Ian A. Shanks, Michael G. Clark, Frank M. Leslie