| 摘要 |
<p>A portable illuminated sign comprises a stencil or transparency 6, a light guide panel 8 and a base compartment 5. A line of LEDs along the top of base compartment illuminate the light guide panel. A frame 3 of a casing 2 overlies the display area and a backing support 9. The LEDs transmit light into the panel 8 through the bottom edge of a transparent-plastics sheet (12; Fig. 4) which has a density and consequent light Âtransmissivity that increases with distance from the LEDs, and which has a rough rear face 13 for refracting light to illuminate the display area. The refracted light is augmented by light reflected back into the sheet by reflector sheets (14, 15; Fig. 4). The sign may be held in a pocket provided on an item of clothing, in particular a high visibility jacket, to improve the wearers visibility and provide a warning.</p> |
