Compensation scheme for electrochromic displays
First Claim
1. An electrochromic display comprising:
- a first transparent substrate with a selectively actuatable transparent electrode thereon and an electrochromic layer on said transparent electrode;
a second substrate having a conductive counterelectrode thereon;
electrolyte means sealed between the first and second substrates and in electrical contact with said counterelectrode and said electrochromic layer;
first means for selectively applying a transition write potential between said electrodes for a predetermined transition period;
second means for selectively applying a first maintain write potential between said electrodes; and
third means responsive to the charge storage ability of said electrochromic layer with application of said first maintain write potential for selectively applying a second maintain write potential between said electrodes.
1 Assignment
0 Petitions
Accused Products
Abstract
A driving circuit for an electrochromic display cell wherein writing and erasing of a segment is effected by relatively high write and erase 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) and a maintaining erase potential(s) respectively. The write maintain potential 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 segments(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.
-
Citations
4 Claims
-
1. An electrochromic display comprising:
-
a first transparent substrate with a selectively actuatable transparent electrode thereon and an electrochromic layer on said transparent electrode; a second substrate having a conductive counterelectrode thereon; electrolyte means sealed between the first and second substrates and in electrical contact with said counterelectrode and said electrochromic layer; first means for selectively applying a transition write potential between said electrodes for a predetermined transition period; second means for selectively applying a first maintain write potential between said electrodes; and third means responsive to the charge storage ability of said electrochromic layer with application of said first maintain write potential for selectively applying a second maintain write potential between said electrodes. - View Dependent Claims (2)
-
-
3. An electronic timepiece comprising:
-
an electrochromic display having a plurality of segment indicia each comprising a selectively actuatable transparent electrode with an electrochromic layer thereon; means for providing electrical signals representing information; display control means responsive to said signals representing information for providing a write potential on a selected written segment indicia for a predetermined transition write period, said display control means being responsive to the write charge level on sid written segment indicia to selectively provide one of a plurality of maintain write charging potentials on said written indicia whereby a predetermined write charge is substantially maintained on said written segment indicia for compensating with dissolution of the electrochromic layer on said written indicia.
-
-
4. An electrooptical display comprising:
-
a first transparent substrate with a selectively actuatable transparent electrode thereon and a layer having electro-chemical controllable optical properties on said transparent electrode; a second substrate; a counterelectrode between said layer and said second substrate; electrolyte means sealed between the first and second substrate and in contact with said counterelectrode and said layer; first means for selectively applying a transition write potential between said electrodes; and second means responsive to a charge on a written layer for selectively applying a first and a second maintain write potential each at a different voltage-potential level with respect to said transition write potential to substantially maintain a predetermined state of coloration of the written layer.
-
Specification