| 摘要 |
<p>A light modulating apparatus containing cholesteric liquid crystals capable of indefinite zero field retention of optical images, including full color and complete gray scale capability, is described. This invention is predicated on establishment of zero field multistable liquid crystal domains representing a continuous distribution of states ranging from the highly reflective planar to the light-scattering focal-conic structures. The zero field multistable domain structure stability is achieved by controlling solid surface-liquid crystal boundary interactions to provide essential equalization of the total system energy of each of the domain structures. This equalization has been achieved without the use of a polymer gel addition to create rigid polydomains in the liquid crystal mix. The establishment of a particular domain structure is controlled using either a single relative long voltage pulse or a number of shorter duration successive voltage pulses. The zero field multistability achieved is remarkably stable against both mechanical shocks and thermal variations. These displays eliminate the need for backlighting and image refreshing input, and for polarizers, analyzers, retarder and color filters. They can also be fabricated as flexible all-plastic units.</p> |
