| 摘要 |
A sign 1 has a sign plate 4 mounted in a frame 2 to display an image such as the word "EXIT" when illuminated. The sign 1 includes an electrically powered light source 14 configured for edge lighting of the sign 1. The sign plate 4 has a front portion 8, a rear portion 10 and an intermediate portion 12 between the front and rear portions. The rear portion 10 provides a photoluminescent light source for back lighting the sign 1. The sign 1 is edge lit when the electrically powered light source 14 is in use and is backlit by the photoluminescent light source 10 in darkness or low ambient light conditions when the electrically powered light source 14 is not in use. |
