ELECTROOPTICAL DISPLAY

摘要

A compensating drive circuit for an electrochromic display cell (1) wherein writing and erasing of a segment (a-g) is effected by relatively high write (Vwt) and erase (Vet) transition potentials. After a predetermined transition period, the written and erased segments are stabilized at a desired coloration or transparency by application of a maintaining write potential(s) (Vwm) and a maintaining erase potential(s) (Vem) respectively. The write maintain potential (Vwm) is periodically adjusted to a level whereby a predetermined charge level is maintained on the written segments. In this manner, a maintain potential on the segment(s) is periodically adjusted to compensate for degradation of the electrochromic material and to thereby maintain the desired contrast ratio between the written and erased segments.