Process of aligning and realigning liquid crystal media
Patent 5032009 Issued on July 16, 1991. Estimated Expiration Date: August 13, 2010. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
A process of aligning or realigning a liquid crystal medium adjacent to a substrate which process comprises (1) exposing anisotropically absorbing molecules disposed on the substrate, disposed in the liquid crystal medium or which themselves are the liquid crystal medium to linearly polarized light of a wavelength or wavelengths within the absorption band of the anisotropically absorbing molecules, wherein (a) the exposed anisotropically absorbing molecules induce alignment of the liquid crystal medium at an angle + and - θ with respect to the direction of the linear polarization of the incident light beam and along a surface of the liquid crystal medium, (b) the liquid crystal medium comprises liquid crystals having a molecular weight of less than 1500, and (c) the anisotropically absorbing molecules are exposed by (i) linearly polarized light transmitted through at least one mask having a pattern, (ii) a beam of linearly polarized light scanned in a pattern or (iii) patterns created by interference of coherent linearly polarized light beams, and (2) terminating exposure, whereby the liquid crystal medium aligned or realigned by the exposure step remains aligned or realigned and has two or more discrete regions having different alignments, and liquid crystal devices prepared by this process, are disclosed.
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