Thermochromic liquid crystal displays

摘要

A thermochromic liquid crystal display comprises a layer of short pitch cholesteric liquid crystal material between two walls. An absorber covers the back of the rear wall. At least one wall is surface profiled with a fine grating to align the liquid crystal material. Typically the grating pitch is 0.05 to 12 mu m. The profile may be fine on one wall e.g. 0.05 to 12 mu m pitch, 0.1 mu m depth and coarse e.g. 125 mu m pitch groove width 100 mu m, depth 10 mu m on the other wall. The cholesteric pitch is arranged to give the desired a selective reflection of light whereby the display is observed to change color with temperature. Using thin flexible walls small displays may be cut from large sheets of embossed polyester plastic materials.