| 摘要 |
<p>A lamp unit comprising a box-like body which is provided with one or more apertures covered with a sheet of material transparent to visible light and which houses a light source. In accordance with the invention, the side (10) of the sheet (6) or sheets facing inwardly of the body (1) is, or are, covered totally or partially with a layer of a substance which fluouresces when irradiated with ultraviolet light, and the light source (7) is arranged to transmit ultraviolet light. In accordance with one preferred embodiment of the invention the sheet (6), or sheets, is, or are, made of a material which is transparent to visible light but impermeable to ultraviolet radiation.</p> |
