| 摘要 |
<p>A variable sign comprises an electro-optical layer, in particular an electro-chromic layer, that changes appearance in response to an electrical stimulus, and a stimulator adapted to apply an electrical stimulus to the layer. An external signal may be applied to change the sign, such signal being a clock, a radio control signal, an environmental sensor, a temperature sensor, a light sensor or a traffic sensor. A multilayered sign may be formed having multiple electro-optic layers which can be selectively changed to form a particular sign. The electro-optical layer preferably changes colour or from opaque to transparent, so that the visual detail of the sign is concealed or revealed. Such signs may be used in traffic management applications and for speed limit signs, for example.</p> |
