Matrix addressable electrochromic display device

• US 6,639,709 B2
• Filed: 03/19/2002
• Issued: 10/28/2003
• Est. Priority Date: 03/19/2001
• Status: Expired due to Term

• Current Assignee: Aveso, Inc. (Thales SA)
• Original Assignee: Dow Global Technologies, Inc. (Dow, Inc.)
• Inventors: Flick, Derrick W., Vincent, John B.
• Primary Examiner(s): Ben, Loha
• Assistant Examiner(s): HASAN, MOHAMMED A
• Application Number:
  US10/102,491
• Publication Number:
  US 20020171907A1
• Time in Patent Office: 588 Days
• Field of Search: 359/265, 359/267, 359/270, 359/273, 359/275, 359/266, 359/269, 359/271, 345/105
• US Class Current: 359/265
• CPC Class Codes: C09K 9/02 Organic tenebrescent materials
• CPC Class Codes: G02F 1/15 based on an electrochromic effect
• CPC Class Codes: G02F 1/1503 caused by oxidation-reduction reactions in organic liquid solutions, e.g. viologen solutions
• CPC Class Codes: G02F 1/155 Electrodes
• CPC Class Codes: G02F 1/176 using acid- based indicators
• CPC Class Codes: G02F 2001/164 the electrolyte is made of polymers

Abstract

The invention is a matrix addressable electrochromic display device comprising a top electrode structure comprising at least one transparent or semi-transparent and substantially ionically isolative, electrically conductive electrode, a bottom electrode structure comprising at least one substantially ionically isolative, electrically conductive electrode, wherein at least one of the top or bottom electrode structures comprises two or more of said electrodes and the top and bottom electrode structures are positioned to form at least two separate regions where the top electrodes are positioned above the bottom electrodes and between the top electrode structure and the bottom electrode structure is positioned an active layer comprising an electrolyte and an electrochromic material.

Claims

1. A matrix addressable electrochromic display device comprising

a top electrode structure comprising at least one transparent or semi-transparent electrically conductive electrode,

a bottom electrode structure comprising at least one, electrically conductive electrode,

wherein at least one of the top or bottom electrode structures comprises two or more of said electrodes and the top and bottom electrode structures are positioned to form at least two separate regions where the top electrodes are positioned above the bottom electrodes and

between the top electrode structure and the bottom electrode structure is positioned an active layer comprising an electrolyte and an electrochromic material wherein the total resistivity of the active layer is greater than 10,000 Ohms-centimeter.

2. The device of claim 1 wherein the total resistivity of the active layer is greater than 25,000 Ohms centimeter.

3. The device of claim 1 wherein the resistivity of the active layer is greater than fifty times the resistivity of the top transparent electrode.

4. The device of claim 1 wherein the resistivity of the active layer is greater than one hundred times the resistivity of the top transparent electrode.

5. The device of claim 1 wherein the active layer comprises (a) a non-aqueous compound that undergoes an electron transfer reaction with a subsequent change in its protic state resulting in a pH gradient in the device, (b) at least one indicator dye, and (c) a charge transport material.

6. The device of claim 1 wherein the active layer is a gelled material.

7. The device of claim 1 wherein the active layer is continuously present between all the electrodes in a plane.

8. The device of claim 1 wherein the active layer exhibits a non-linear optoelectric response curve.

9. The device of claim 1 wherein an image is by pulsing voltage into the electrodes.

10. A matrix addressable electrochromic display device comprising

a top electrode structure comprising at least one transparent or semi-transparent electrically conductive electrode,

a bottom electrode structure comprising at least one, electrically conductive electrode,

wherein at least one of the top or bottom electrode structures comprises two or more of said electrodes and the top and bottom electrode structures are positioned to form at least two separate regions where the ton electrodes are positioned above the bottom electrodes and

between the top electrode structure and the bottom electrode structure is positioned an active layer comprising an electrolyte and an electrochromic material and wherein the resistively of the active layer is greater than twenty timed the resisivity of the top transparent electrode.

11. A matrix addressable electrochromic display device comprising

a top electrode structure comprising at least one transparent or semi-transparent electrically conductive electrode,

a bottom electrode structure comprising at least one, electrically conductive electrode,

wherein at least one of the top or bottom electrode structures comprises two or more of said electrodes and the ton and bottom electrode structures are positioned to form at least two separate regions where the ton electrodes are positioned above the bottom electrodes and

between the top electrode structure and the bottom electrode structure is positioned an active layer comprising an electrolyte and an electrochromic material and wherein the active layer comprises component (a) a compound that undergoes an electron transfer reaction with a subsequent change in its protic state, (b) at least one indicator dye which changes color when a change in pH occurs, and (c) an ionically conductive material, and optionally component (a) a matrix material wherein (b), (c), and (d) are different from one another and component (a) preferentially undergoes the electron transfer reaction when a charge is applied to the composition and provided that if (c) is a fluid, the composition further comprises the matrix material (d).

12. The device of claim 11 characterized in that component (a) is present in an amount from 0.01 to 15 weight percent, component (b) is present in an amount from 0.01 to 15 weight percent, component (c) is present in an amount from 5 to 99.98 weight percent, component (d) is present in an amount from 0 to 90 weight percent, an opacifier component (e) is present in an amount from 0 to 75 weight percent based on total weight of the composition and component (t) a secondary redox couple present in an amount of 0 to 15 weight percent.

13. The device of claim 12 wherein the component (e) one opacifier is selected from the group consisting of titanium dioxide, latexes, and barium titanate.

14. The device of claim 11 wherein the component (f) the secondary redox couple is selected from the group consisting of iodates, bromates, sulfates, metal hydroxides, phosphates, ketones, aldehydes, quinones, quinolines, sulfur compounds, hydroxybenzenes, carboxylic acids, polyoxometallates, and amines.

15. The device of claim 11 wherein component (a) is selected from the group consisting of iodates, bromates, sulfates, metal hydroxides, phosphates, ketones, aldehydes, quinones, quinolines, sulfur compounds, hydroxybenzenes, carboxylic acids, and amines.

16. The device of claim 11 wherein component (b) comprises one or more indicator dyes selected from but not limited to the group consisting of phenylthalein, bromocrescol purple, phenol red, ethyl red, quinaldine red, thymolthalein, thymol blue, malachite green, crystal violet, methyl violet 2B, xylenol blue, cresol red, phyloxine B, congo red, methyl orange, bromochlorophenol blue, alizarin red, chlorophenol red, 4-nitrophenol, nile blue A, aniline blue, indigo carmine, and bromothymol blue.

17. The device of claim 11 wherein the matrix (d) comprises a polymer or other viscosity modifier and the matrix is blended with other components of the composition.

18. The device of claim 11 wherein the total resistivity of the active layer is greater than 1000 Ohm-centimeters.

19. The device of claim 11 wherein an image is formed by pulsing voltage into the electrodes.

20. The device of claim 11 wherein the resistively of the active layer is greater than twenty times the resistively of the top transparent electrode.