The light reflectivity control for use with an automotive rearview mirror according to the present invention has a first and second photosensors to detect the brightness of the surroundings including the front of a car in which the inside rearview mirror is equipped and that of the surroundings including...http://www.google.ca/patents/US4896030?utm_source=gb-gplus-sharePatent US4896030 - Light-reflectivity controller for use with automotive rearview mirror using electrochromic element
