Addition of color to electrochromic displays

• US 5,891,511 A
• Filed: 09/26/1996
• Issued: 04/06/1999
• Est. Priority Date: 12/26/1995
• Status: Expired due to Fees

• Current Assignee: Monsanto Company (Bayer AG)
• Original Assignee: Monsanto Company (Bayer AG)
• Inventors: Lynch, Anne T., Coleman, James Patrick
• Primary Examiner(s): Bell, Janyce
• Application Number:
  US08/721,105
• Time in Patent Office: 922 Days
• Field of Search: 427/162, 427/165, 427/108, 427/106, 427/64, 427/404, 427/419.1
• US Class Current: 427/64
• CPC Class Codes: G02F 1/1523 comprising inorganic material
• CPC Class Codes: G02F 1/155 Electrodes
• CPC Class Codes: G02F 2001/1557 Side by side arrangements of working and counter electrodes

Abstract

Disclosed herein is a method of enhancing colors displayed by an electrochromic display. The method involves incorporating an inert pigment into the display.

Claims

1. A method of enhancing color displayed by an electrochromic display comprising the steps of:

mixing at least one inert pigment comprising an organic pigment with an electrochromically active substance; and

coating the resulting mixture onto an electrode of an electrochromic display.

2. The method of claim 1, wherein the inert pigment further comprises a resin base.

3. A method of enhancing colors displayed by an electrochromic display comprising the steps of:

mixing an inert pigment with a binder and an electrochromically active material comprising antimony-doped tin oxide to form an ink; and

coating the resulting mixture onto an electrode of the electrochromic display.

4. A method of enhancing colors displayed by an electrochromic display comprising the steps of:

mixing a fluorescent inert pigment with an electrochromically active substance; and

coating the resulting mixture onto an electrode of the electrochromic display.

5. A method of enhancing colors displayed by an electrochromic display comprising the steps of:

mixing an inert pigment with an electrochromically active substance comprising Prussian blue and a binder to form an ink; and

coating the resulting mixture onto an electrode of the electrochromic display.

6. A method of enhancing colors displayed by an electrochromic display comprising the steps of:

depositing an electrochemically active, conductive material comprising antimony-doped tin oxide on an inert TiO₂ --Ni--Sb pigment to form coated pigment particles;

firing the coated substrate particles at 600°

C. for three hours; and

coating the fired substrate particles on an electrode of the display.

7. A method of enhancing colors displayed by an electrochromic display comprising the steps of:

depositing an electrochromically active, conductive material on TiO₂ -based, colored, inert pigment substrate particles to form coated pigment particles containing 36 wt % of antimony-doped tin oxide; and

coating the coated pigment particles on an electrode of a display.

8. A method of enhancing colors displayed by an electrochromic display comprising the steps of:

coating a mixture of the inert pigment and a light-colored, conductive material over an electrode of the display to form a first layer; and

coating an electrochromically active layer above the first layer, so that a visibility of the first layer is dependent upon an oxidation state of the electrochromically active layer.

9. The method of claim 8, wherein the light-colored, conductive material comprises a metal oxide.

10. The method of claim 9, wherein the light-colored, conductive material comprises antimony-doped tin oxide and TiO₂.

11. The method of claim 8, wherein the electrochromically active layer comprises Prussian blue.

12. A method of enhancing colors displayed by an electrochromic display, comprising the steps of:

coating a mixture of the inert pigment and a light-colored, conductive material over an electrode of the display to form a colored layer; and

covering the colored layer with an electrolyte containing a dissolved ion that is removed from solution to form an opaque coating over the colored layer when a first polarity of electric charge is applied to the electrode, and that redissolves upon application of an opposite electric charge to the electrode.

13. The method of claim 12 wherein the electrolyte comprises a soluble bismuth salt.

14. A method of enhancing colors displayed by an electrochromic display comprising the step of:

dissolving transparent, inert coloring matter in a liquid electrolyte solution of the display.