Electrochromic display device having auxiliary electrode
US4773741A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 9, 1987 |
| Grant date | Sep 27, 1988 |
| Priority date | — |
| Expiry date | Apr 9, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F2001/1517
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention relates to an electrochromic (EC) display device having a transparent electrode layer coated with a first EC material which takes on color in its electrochemically oxidized state, such as Prussian blue, and an opposite transparent electrode layer coated with a second EC material which takes on color in its reduced state, such as WO.sub.3. For use in initial bleaching or coloration of one of the two EC layers, an auxiliary electrode is disposed in a marginal region of the space between the two opposite electrodes, and an electrolyte occupies the remaining space. An insulating covering permeable to ions intervenes between the electrolyte and the body of the auxiliary electrode, and an insulating layer substantially impermeable to ions intervenes between the auxiliary electrode body and each transparent electrode layer or the overlying EC layer to prevent leakage current. This manner of insulation of the auxiliary electrode is effective in shortening the length of time required for the initial bleaching or coloration treatment and extending memory time of the display device in actual operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.