INDIRECT BACK-LIGHTED INSTRUMENTATION PRESENTATION

摘要

An instrument face constructed and lighted from behind so that only the information displayed thereby is illuminated, and incorporating a visual warning signal visable only over a selected value range of the displayed information. A rotating opaque disc incorporating a translucent pointer is arrayed behind a surrounding opaque ring bearing a translucent scale; such that light from behind may escape only through the scale and pointer. A red translucent area on the disc cooperates with an opening in the ring to provide a warning signal when the pointer registers a dangerous condition.