| 摘要 |
A strip lighting device 27 for use in a pointer of a motor vehicle speedometer comprises a source of illumination (22, Fig. 2) for illuminating the device with visible light and a slender main body 28 that has opposite front and rear sides 34, 38. The front side 34 is disposed towards a viewer of the device and the rear side 38 includes a light scattering layer 36 for scattering light from the source of illumination towards the viewer. The main body has a front cladding layer 28 and a rear cladding layer 44 each of which is made of a first light transmissive material. A light pipe 40 made of a second light transmissive material receives light from the source of illumination. The light pipe 40 is sandwiched between and in contact with the front and rear cladding layers at interfaces 46, 48 which extend along the length of the main body. Internal reflection conveys light along the light pipe 40. A rear interface 48 of the light pipe has a plurality of angled portions 50 which allow some light to escape into the rear cladding layer 44 to impinge on the light scattering layer 36 which then scatters light towards the viewer. |
