Completion of potentiostatic erasure of an electrochromic display is detected by monitoring the erase current supplied to addressed display electrodes by potentiostatic erase drive means. The occurrence of a fall in erase current, corresponding to completion of the erasure of the addressed display electrodes,...http://www.google.de/patents/US4649382?utm_source=gb-gplus-sharePatent US4649382 - Electrochromic display employing potentiostatic erasure
