| 摘要 |
<p>A display sign has a flow surface (10) such as the inner face (9) of a viewing panel (2) or front face (4) of a backing panel (3) over which liquid flows. A liquid pump (13, 107, 161) supplies liquid which runs over the flow surface (10) and encounters means (20) such as projecting interruptions (21) for causing irregularities in the transient light effects are created which accentuate a sign element (25). The means for causing flow irregularities may also comprise means (5) for intermittently varying the volume of liquid. The sign element (25) may comprise a part of the flow surface (10) and may be defined by the conformation of the interruptions (21).</p> |
