US4236792A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrochromic display and method for making same
Assignee: Timex Group USA Inc
•
Filing: 1978-12-28
•
Granted: 1980-12-02
•
Expires: 1998-12-28
Abstract
Abstract Disclosed is an electrochromic display having an electrolyte of optimized cationic mobility and a counter electrode of optimized electronic mobility. Preferably the display comprises (a) a front substrate with selectively actuable transparent electrodes and image-forming electrochromic layers thereon, (b) an acidified aqueous electrolyte containing a sufficient quantity of highly mobile hydrogen ions for coloration of the electrochromic layers and (c) a rear substrate spaced from the front substrate carrying a counter electrode in contact with the electrolyte, the counter electrode being in the form of a layer comprising predominantly an alkali tungsten bronze, preferably sodium and or potassium tungsten bronze, in the high temperature heat treated condition which exhibits enhanced electronic mobility. A process for making the display is also disclosed.
Inventors
- 👤 Saadi J. Bissar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:13
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/15; G02F1/1514; G02F1/1523; G02F1/1524
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
175 words
A process for making an electrochromic display comprising the steps of: (a) providing a front substrate having transparent electrodes and image-forming electrochromic layers thereon; (b) providing a rear substrate for carrying a counter electrode, the front and rear substrates being positioned in spaced working relation; (c) forming a counter electrode on said rear substrate by 1. forming a layer of tungsten trioxide on said substrate; 2. converting a major portion of said tungsten trioxide layer to alkali tungstate to provide a first mixture of alkali tungstate and tungsten trioxide; 3. heating the first mixture to a sufficiently high temperature for a selected time to form a second mixture comprising a major portion of alkali tungsten bronze and a controlled minor portion of tungsten trioxide, the alkali tungsten bronze being in the high temperature heat treated condition which exhibits high electronic mobility for counter electrode purposes; (d) filling the space between the substrates with electrolyte containing sufficient cationic coloring centers to impart coloration to said electrochromic layers; and (e) sealing the front and rear substrates together.
Claim 2
Dependent Claim
175 words
A process for making an electrochromic display comprising the steps of: (a) providing a front substrate having transparent electrodes and image-forming electrochromic layers thereon; (b) providing a rear substrate for carrying a counter electrode, the front and rear substrates being positioned in spaced working relation; (c) forming a counter electrode on said rear substrate by 1. forming a layer of tungsten trioxide on said substrate; 2. converting a major portion of said tungsten trioxide layer to alkali tungstate to provide a first mixture of alkali tungstate and tungsten trioxide; 3. heating the first mixture to a sufficiently high temperature for a selected time to form a second mixture comprising a major portion of alkali tungsten bronze and a controlled minor portion of tungsten trioxide, the alkali tungsten bronze being in the high temperature heat treated condition which exhibits high electronic mobility for counter electrode purposes; (d) filling the space between the substrates with electrolyte containing sufficient cationic coloring centers to impart coloration to said electrochromic layers; and (e) sealing the front and rear substrates together.
Claim 3
Dependent Claim
41 words
The method of claim 1 wherein the heat treated alkali tungsten bronze formed in step (c) (3) is represented by the formula M x WO 3 where M is an alkali metal and X is from about 0.1 to about 0.6.
Claim 4
Dependent Claim
32 words
The method of claim 2 wherein said first mixture is heated to about 800° C. to about 1000° C. in step (c) (3) to form said second mixture containing alkali tungsten bronze.
Claim 5
Dependent Claim
15 words
The method of claim 2 wherein the alkali metal is selected from sodium and potassium.
Claim 6
Dependent Claim
18 words
The method of claim 1 wherein the tungsten trioxide layer is formed by vacuum deposition on a substrate.
Claim 7
Dependent Claim
18 words
The method of claim 1 wherein the tungsten trioxide layer is formed by surface oxidizing a tungsten substrate.
Claim 8
Dependent Claim
37 words
The method of claim 1 including the additional step after step (c) (3) of selectively removing said tungsten trioxide from the second mixture, leaving a layer of predominantly heat treated alkali tungsten bronze as the counter electrode.
Claim 9
Dependent Claim
31 words
The method of claim 7 wherein selective removal is effected by contacting the second mixture with water in which the tungsten trioxide is soluble and the alkali tungsten bronze is not.
Claim 10
Dependent Claim
28 words
The method of claim 1 wherein the major portion of the tungsten trioxide layer is converted to alkali tungstate by reaction with an alcoholic solution of alkali hydroxide.
Claim 11
Dependent Claim
34 words
The method of claim 9 wherein the alkali hydroxide is selected from sodium hydroxide or potassium hydroxide so that after step (c) (3) a sodium or potassium tungsten bronze remains as the counter electrode.
Claim 12
Dependent Claim
106 words
In making a counter electrode useful in electrochromic displays, the steps of: (a) forming a layer of tungsten trioxide by vacuum deposition on a substrate; (b) converting a major portion of said tungsten trioxide layer to alkali tungstate to provide a first surface mixture of alkali tungstate and tungsten trioxide; (c) heating the first mixture to a sufficiently high temperature for a selected time to form a second mixture comprising a major portion of alkali tungsten bronze and a controlled minor portion of tungsten trioxide, the alkali tungsten bronze being in the high temperature heat treated condition which exhibits high electronic mobility for counter electrode purposes.
Claim 13
Dependent Claim
106 words
In making a counter electrode useful in electrochromic displays, the steps of: (a) forming a layer of tungsten trioxide by vacuum deposition on a substrate; (b) converting a major portion of said tungsten trioxide layer to alkali tungstate to provide a first surface mixture of alkali tungstate and tungsten trioxide; (c) heating the first mixture to a sufficiently high temperature for a selected time to form a second mixture comprising a major portion of alkali tungsten bronze and a controlled minor portion of tungsten trioxide, the alkali tungsten bronze being in the high temperature heat treated condition which exhibits high electronic mobility for counter electrode purposes.
Claim 14
Dependent Claim
40 words
The method of claim 11 wherein the heat treated alkali tungsten bronze formed in step (c) is represented by the formula M x WO 3 where M is an alkali metal and X is from about 0.1 to about 0.6.
Claim 15
Dependent Claim
27 words
The method of claim 12 wherein said first mixture is heated in step (c) to about 800°-1000° C. to form said second mixture containing alkali tungsten bronze.
Claim 16
Dependent Claim
15 words
The method of claim 12 wherein the alkali metal is selected from sodium and potassium.
Claim 17
Dependent Claim
36 words
The method of claim 11 including the additional step after step (c) of selectively removing said tungsten trioxide from the second mixture, leaving a layer of predominantly heat treated alkali tungsten bronze as the counter electrode.
Claim 18
Dependent Claim
31 words
The method of claim 15 where selective removal is effected by contacting the second mixture with water in which the tungsten trioxide is soluble and the alkali tungsten bronze is not.
Claim 19
Dependent Claim
27 words
The method of claim 11 wherein the major portion of tungsten trioxide layer is converted to alkali tungstate by reaction with an alcoholic solution of alkali hydroxide.
Claim 20
Dependent Claim
33 words
The method of claim 17 wherein the alkali hydroxide is selected from sodium hydroxide and potassium hydroxide so that after step (c) a sodium or potassium tungsten bronze remains as the counter electrode.
Claim 21
Dependent Claim
106 words
In making a counter electrode useful in electrochromic displays, the steps of: (a) forming a layer of tungsten trioxide by surface oxidizing a tungsten substrate; (b) converting a major portion of said tungsten trioxide layer to alkali tungstate to provide a first surface mixture of alkali tungstate and tungsten trioxide; (c) heating the first mixture to a sufficiently high temperature for a selected time to form a second mixture comprising a major portion of alkali tungsten bronze and a controlled minor portion of tungsten trioxide, the alkali tungsten bronze being in the high temperature heat treated condition which exhibits high electronic mobility for counter electrode purposes.
Claim 22
Dependent Claim
106 words
In making a counter electrode useful in electrochromic displays, the steps of: (a) forming a layer of tungsten trioxide by surface oxidizing a tungsten substrate; (b) converting a major portion of said tungsten trioxide layer to alkali tungstate to provide a first surface mixture of alkali tungstate and tungsten trioxide; (c) heating the first mixture to a sufficiently high temperature for a selected time to form a second mixture comprising a major portion of alkali tungsten bronze and a controlled minor portion of tungsten trioxide, the alkali tungsten bronze being in the high temperature heat treated condition which exhibits high electronic mobility for counter electrode purposes.
Claim 23
Dependent Claim
40 words
The method of claim 19 wherein the heat treated alkali tungsten bronze formed in step (c) is represented by the formula M x WO 3 where M is an alkali metal and X is from about 0.1 to about 0.6.
Claim 24
Dependent Claim
27 words
The method of claim 20 wherein said first mixture is heated in step (c) to about 800°-1000° C. to form said second mixture containing alkali tungsten bronze.
Claim 25
Dependent Claim
15 words
The method of claim 20 wherein the alkali metal is selected from sodium and potassium.
Claim 26
Dependent Claim
36 words
The method of claim 19 including the additional step after step (c) of selectively removing said tungsten trioxide from the second mixture, leaving a layer of predominantly heat treated alkali tungsten bronze as the counter electrode.
Claim 27
Dependent Claim
28 words
The method of claim 19 wherein the major portion of the tungsten trioxide layer is converted to alkali tungstate by reaction with an alcoholic solution of alkali hydroxide.
Claim 28
Dependent Claim
103 words
An electrochromic display of sandwich construction, comprising: (a) a front substrate with selectively actuable transparent electrodes and image-forming electrochromic layers thereon; (b) an electrolyte having sufficient cationic coloring centers therein to impart coloration to said layers when the display is actuated; (c) a rear substrate spaced from the front substrate for carrying a counter electrode layer in contact with the electrolyte, said counter electrode layer comprising a major portion of high temperature heat treated alkali tungsten broze and a controlled minor portion of tungsten trioxide, said heat treated alkali tungsten bronze functioning as a highly mobile electronic center during actuation of the display.
Claim 29
Dependent Claim
103 words
An electrochromic display of sandwich construction, comprising: (a) a front substrate with selectively actuable transparent electrodes and image-forming electrochromic layers thereon; (b) an electrolyte having sufficient cationic coloring centers therein to impart coloration to said layers when the display is actuated; (c) a rear substrate spaced from the front substrate for carrying a counter electrode layer in contact with the electrolyte, said counter electrode layer comprising a major portion of high temperature heat treated alkali tungsten broze and a controlled minor portion of tungsten trioxide, said heat treated alkali tungsten bronze functioning as a highly mobile electronic center during actuation of the display.
Claim 30
Dependent Claim
42 words
The display of claim 25 wherein the alkali tungsten bronze is heat treated to about 800° to 1000° C. and is represented by the formula M x WO 3 where M is an alkali metal and X is about 0.1 to 0.6.
Claim 31
Dependent Claim
15 words
The display of claim 26 wherein the alkali metal is selected from sodium and potassium.
Claim 32
Dependent Claim
20 words
The display of claim 25 wherein the rear substrate on which the alkali tungsten bronze layer is disposed is tungsten.
Claim 33
Dependent Claim
28 words
The display of claim 25 wherein the electrolyte is an acidified aqueous solution and said counter electrode layer comprises from about 90 to 100 wt.% alkali tungsten bronze.
Claim 34
Dependent Claim
90 words
An electrochromic display of sandwich construction, comprising: (a) a front substrate with selectively actuable transparent electrodes and image forming electrochromic layers thereon; (b) an acidified aqueous electrolyte having sufficient hydrogen ion coloring centers therein to impart coloration to said electrochromic layers when the display is actuated; (c) a rear substrate spaced from the front substrate for carrying a counter electrode layer in contact with the electrolyte, said counter electrode layer comprising alkali tungsten bronze in the high temperature heat treated condition which exhibits high electronic mobility for counter electrode purposes.
Claim 35
Dependent Claim
90 words
An electrochromic display of sandwich construction, comprising: (a) a front substrate with selectively actuable transparent electrodes and image forming electrochromic layers thereon; (b) an acidified aqueous electrolyte having sufficient hydrogen ion coloring centers therein to impart coloration to said electrochromic layers when the display is actuated; (c) a rear substrate spaced from the front substrate for carrying a counter electrode layer in contact with the electrolyte, said counter electrode layer comprising alkali tungsten bronze in the high temperature heat treated condition which exhibits high electronic mobility for counter electrode purposes.
Claim 36
Dependent Claim
42 words
The display of claim 30 wherein the alkali tungsten bronze is heat treated at about 800° to 100° C. and is represented by the formula M x WO 3 where M is an alkali metal and X is about 0.1 to 0.6.
Claim 37
Dependent Claim
15 words
The display of claim 31 wherein the alkali metal is selected from sodium and potassium.
References Cited (Backward Citations)
US4012831A
Cited
US4106862A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-12-02 | 1984-06-02 | 1984-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-02 | 1988-06-02 | 1988-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-02 | 1992-06-02 | 1992-12-02 | $7700.00 | Window Closed / Lapsed |