Regarding any given light source in an array thereof, apparatus according to the invention comprises a shift register adapted to store bits corresponding to the ON times for the light source. The output of the shift register is applied to the light source and, when a ONE bit occurs at the shift register...http://www.google.com.au/patents/US4455578?utm_source=gb-gplus-sharePatent US4455578 - Electronics for arrayed photosources
