Patents Examined by Tarifura R. Chowdhury
  • Patent number: 6377325
    Abstract: Disclosed are novel reflective films having symmetrical reflection characteristics on the upper and lower surfaces thereof. Preferably, such films are made from cholesteric liquid crystal (CLC) material, wherein the pitch of the helices of the liquid crystal molecules therein varies along the thickness dimension (i.e. transverse to the surface) of the film. Depending on the final spiral structure of the materials utilized, the CLC circularly polarizing film materials reflect either left-handed or right-handed circularly polarized light. In a first illustrative embodiment, the CLC film has a laminated construction in order that both the upper and lower surfaces thereof have substantially the same reflection characteristics over its tuned reflection band. In second illustrative embodiment, the CLC film has a laminated construction in order that both the upper and lower surfaces thereof have substantially the same reflection characteristics over its broadband reflection band.
    Type: Grant
    Filed: July 9, 1997
    Date of Patent: April 23, 2002
    Inventors: Sadeg M. Faris, Le Li