| 摘要 |
<p>By incorporating behind the lens 1 of a cat's eye a reflector- construction 6 comprising a layer of matter having a light reflective property which changes as the temperature of the road surface falls to about 0 DEG C, the possibility of ice formation at night can be indicated to vehicle drivers. The light-reflecting matter may be a thermochromic liquid crystal material, and preferably is a cholesteric liquid crystal material containing one or more chiral nematic liquid crystals. The cat's eye may be made to reflect light over a wide range of temperatures by incorporating therein two layers of different cholesteric liquid crystal materials-for example, one material which reflects green light at above 0 DEG C and a second material which reflects red light at below 0 DEG C. <IMAGE></p> |
