A gauge with a light-transmitting dial plate having a front surface with indicia for a variable represented by the dial, at least one light source spaced rearwardly from the rear surface of the dial plate for illuminating the dial plate, and a light-transmitting pointer mounted for rotational movement...http://www.google.com.tw/patents/US6663251?utm_source=gb-gplus-share專利 US6663251 - Gauge with illuminated dial and pointer
