Claims
- 1. In an electrochromic display of the type having a first substrate with selectively actuable transparent electrodes and amorphous, water-bearing electrochromic layers thereon, a second spaced substrate with a counter electrode and electrolyte means between the substrates in contact with the electrochromic layers and counterelectrode, wherein the electrochromic layers are subject to degradation, such as etching, with time as a result of contacting the electrolyte means, the improvement which comprises: electrochromic layers each having at least a free surface portion in contact with said electrolyte means comprising crystallized electrochromic material which exhibits substantially increased resistance to the degrading effect of said electrolyte means as compared to the resistance of said amorphous material, thereby increasing the useful life of said electrochromic layers and display, each electrochromic layer having sufficient water retained therein to provide electrochromic properties suitable for display purposes.
- 2. The display of claim 1 wherein the electrochromic layers are selected from tungsten trioxide, molybdenum trioxide or admixtures thereof.
- 3. An electrochromic display device comprising:
- a display electrode;
- an electrochromic coloring layer formed on the display electrode to constitute a display section and having a first surface portion in contact with the display electrode and a crystallized second surface portion;
- a counter electrode spaced from the display electrode; and
- an electrolyte within the space between the display section and the counter electrode, the electrolyte being in contact with the crystallized second surface portion of the electrochromic coloring layer;
- the crystallized second surface portion of said coloring layer which contacts the electrolyte having a higher density than that of the remaining portion of the electrochromic coloring layer.
Parent Case Info
This is a divisional of application Ser. No. 953,716 filed: Oct. 23, 1978, U.S. Pat. No. 4,233,339.
US Referenced Citations (4)
Number |
Name |
Date |
Kind |
3708220 |
Meyers et al. |
Jan 1973 |
|
4120568 |
Deb et al. |
Oct 1978 |
|
4170406 |
Giglia et al. |
Oct 1979 |
|
4182551 |
Washida et al. |
Jan 1980 |
|
Non-Patent Literature Citations (1)
Entry |
Schirmer et al., "Dependence of WO.sub.3 Electrochromic Absorption on Crystallinity", J. Electrochem. Soc. of Solid State Science and Technology May 1977 pp. 749-753. |
Divisions (1)
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Number |
Date |
Country |
Parent |
953716 |
Oct 1978 |
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