WO1980002462A1 - Electrochromic display using rare-earth diphthalocyanines and a low-freezing-point electrolyte - Google Patents
Electrochromic display using rare-earth diphthalocyanines and a low-freezing-point electrolyte Download PDFInfo
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- WO1980002462A1 WO1980002462A1 PCT/US1980/000340 US8000340W WO8002462A1 WO 1980002462 A1 WO1980002462 A1 WO 1980002462A1 US 8000340 W US8000340 W US 8000340W WO 8002462 A1 WO8002462 A1 WO 8002462A1
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- display
- electrochromic
- display cell
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- electrolyte
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Classifications
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/15—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on an electrochromic effect
- G02F1/1514—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on an electrochromic effect characterised by the electrochromic material, e.g. by the electrodeposited material
- G02F1/1523—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on an electrochromic effect characterised by the electrochromic material, e.g. by the electrodeposited material comprising inorganic material
- G02F1/1525—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on an electrochromic effect characterised by the electrochromic material, e.g. by the electrodeposited material comprising inorganic material characterised by a particular ion transporting layer, e.g. electrolyte
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/15—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on an electrochromic effect
- G02F1/1514—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on an electrochromic effect characterised by the electrochromic material, e.g. by the electrodeposited material
- G02F1/1516—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on an electrochromic effect characterised by the electrochromic material, e.g. by the electrodeposited material comprising organic material
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/15—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on an electrochromic effect
- G02F1/153—Constructional details
- G02F1/1533—Constructional details structural features not otherwise provided for
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/15—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on an electrochromic effect
- G02F1/153—Constructional details
- G02F1/155—Electrodes
Definitions
- the invention relates, generally, to the field of electrically control lable displays and, more particularly, to the field of electrochromic displays.
- Electrochromic displays have been developed which display information through a change in the color of portions in the display via electrochemical reaction of an active material to achieve a color change.
- this color change is from white to blue.
- the change is from white to violet.
- Such displays require substantial power and time to write or erase displayed information. The quantities of power required are undesirably large, especially for battery operation, and the time required to change displayed information makes such materials unacceptable for many display applications. None of these known displays provides more than a single color against a background.
- Rare earth diphthalocyanines are known from prior publications to have electrochromic properties in which the color of the diphthalocyanine can change over a period of about eight seconds upon application of a potential difference across an electrochemical cell having a diphthalocyanine film on one of the electrodes. See for example P. N. Moskalev and I. S. Kirin, "Effect of the Electrode Potential on the Absorption Spectrum of a Rare-Earth Diphthalocyanine Layer," Opt. i Spektrosk, 29, 414 (1970), and P. N. Moskalev and I. S. Kirin, "The Electrochromism of Lanthanide Diphthalocyanines” Russian J. P'nys. Chem., 46, 1019 (1972).
- the diphthalocyanine does not require large amounts of power to change color, but the long period required for the color to change makes known diphthalocyanine performance characteristics unacceptable when measured against display requirements.
- the display of the instant invention overcomes many of the problems of prior art displays via utilization of metal diphthalocyanine complexes as the electrochromically active material and a lowfreezing metal chloride as the electrolyte in an electrochromic display cell. Rapid color changes in less than 50 milliseconds are achieved, thus alleviating the slow switching time previously reported for rare earth diphthalocyanine complexes. Power requirements are small because of the low power switching characteristics of the display material, because of its high optical absorption, and because the display exhibits an open circuit memory of from several minutes to several hours, depending on its construction. A multicolor, i.e. more than two colors, display is achieved through use of a range of voltages applied between display and counter electrodes.
- Color reversal of displayed information and the background against which it is displayed is achieved through use of display electrodes in the background portions of the viewing area as well as in the character segments.
- the use of an aqueous solution of a selected metal chloride for the electrolyte expands the operating range to a very low temperature, for example, on the order of -80°C if the electrolyte is a concentrated solution of lithium chloride.
- FIG. 1 illustrates a cross-section through a typical transmissive display cell configuration.
- Display cells in accordance with the invention may be divided into two general types.
- One type comprises reflective display cells which are designed to be viewed by reflected light only.
- the other type comprises transmissive display cells which are designed to be reviewed by light transmitted therethrough.
- Display cell 10 may include a case or similar structure (not shown) which supports transparent face plate 14 which constitutes the viewing surface or area of the display cell.
- Rear plate 12 is also transparent (in the transmissive cell).
- a plurality of transparent electronically conductive display electrodes are preferably deposited on the inner surface of face plate 14.
- the display electrodes include character segments 28, or other pattern areas, the number and the arrangement ofwhich are determined in accordance with the quantity and types of information the cell is intended to be able to display.
- a thin layer 30 of an electrochromic metal diphthalocyanine is disposed on the display electrode character segments 20, for exposure to the electrolyte 1-18.
- the metal diphthalocyanine film 30 comprises the electrochromic material of the display cell.
- a counter electrode 22 is preferably disposed on a portion of the rear plate 12 which constitutes the back surface of cavity 16.
- the cell also contains a separate reference electrode 24 when a potentiostatic drive system is used.
- the construction of a typical display cell 10 is illustrative only. Reference is made to the Nicholson application noted above in the prior art discussion, the content of which is included herein by reference, for details of cell construction.
- This invention is directed to an electrochromic display which utilizes a metal diphthalocyanine material and an improved electrolyte which permits improved operation.
- the electrolyte is a concentrated aqueous solution of a metal chloride which freezes far below the freezing point of water.
- a particularly desirable electrolyte comprises a solution of 30 weight percent calcium chloride in water. This composition is near that of the eutectic mixture which freezes at approximately -55°C. Consequently, low temperature and fast response time cell operation can be achieved.
- This electrolyte has been used with a lutetium diphthalocyanine display cell and has been successfully operated over at least 900 cycles at approximately -50°C. Multicolor electrochromic switching occurred in this display cell with excellent color quality under these conditions. In addition, no visually detectable change in switching time was observed. The color transformation in the electrochromic material continued to occur in less than 50 milliseconds as the solution was cooled from approximately room temperature to -50°C.
- KCl potassium chloride
- aqueous solution of lithium chloride is appropriate too.
- the eutectic mixture in this chemical system contains 25 weight percent LiCl and has a melting temperature of approximately -80°C.
- the ionized material need not be formed from a chloride salt although metal chloride solutions are among the lowest melting systems which are essentially inert, can be used as aqueous electrolytes. It must be understood, of course, that a ternary - or other type of mixture containing two or more salts in v/ater may also be used.
- a nickel counter electrode was utilized with a three-electrode drive circuitry.
- Counter electrode materials more appropriate for display cells with 2 or 3 electrode drives in concentrated chloride media include silver-silver chloride, lead-lead chloride and a solid mixture consisting of the electrochromic dye in an oxidized and a reduced form.
- the counter electrode generally is kept out of the viewing field to improve operation and viewability.
- a diphthalocyanine electrochromic counter electrode may be preferred over the metal-metal chloride because of the demonstrated fast electrode response of the diphthalocyanine material at low temperature.
- the display cell is characterized by a suitable structural configuration which is similar to the existing cellswhich are known in the art. However, this cell includes the improvement of a new and unique class of electrolyte materials which permit the cells to operate at extremely low temperatures without sacrificing the desirable operating characteristics usually encountered in an electrochromic display cell.
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- Physics & Mathematics (AREA)
- Nonlinear Science (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Inorganic Chemistry (AREA)
- Exposure Control For Cameras (AREA)
- Indication In Cameras, And Counting Of Exposures (AREA)
- Devices For Indicating Variable Information By Combining Individual Elements (AREA)
- Electrochromic Elements, Electrophoresis, Or Variable Reflection Or Absorption Elements (AREA)
Abstract
An electrochromic display (10) utilizing a rare-earth diphthalocyanine complex as the electrochromic material and a low-freezing-point aqueous solution of a metal chloride as the electrolyte (118). Displayed information can be switched in less than 50 milliseconds. The display has multicolor and color reversal capabilities even at very low temperatures.
Description
ELECTROCHROMIC DISPLAY USING RARE-EARTH DI PHTHALOCYANINES AND A LOW-FREEZING-POINT ELECTROLYTE
FIELD OF THE INVENTION
The invention relates, generally, to the field of electrically control lable displays and, more particularly, to the field of electrochromic displays.
BACKGROUND OF THE INVENTION
There are many types of electrically control-lable display devices. A number of such devices have been i n commerci al use for some ti me and i ncl ude l i q ui d crystal di s pl ays , light emitting diode displays, plasma displays and so on. Light emitting diode and plasma display panels are active, light emissive devices which require substantial pov/er for their operation. In addition, it is difficult, if not impossible, to fabricate light emitting diode displays which are easily distinguishable under bright ambient illumination. Liquid crystal displays are operative only over a limited temperature range and have substantially no memory within the liquid crystal material. Further, the visibility of many liquid crystal displays decreases as the viewer moves a few degrees off axis.
Electrochromic displays have been developed which display information through a change in the color of portions in the display via electrochemical reaction of an active material to achieve a color change. In the familiar case of the tungsten oxide electrochromic, this color change is from white to blue. In the viologen electrochromics, the change is from white to violet. Because of their specific electrochemical mechanisms, such displays require substantial power and time to write or erase displayed information. The quantities of power required are undesirably large, especially for battery operation, and the time required to change displayed information makes such materials unacceptable for many display applications. None of these known displays provides more than a single color against a background.
Rare earth diphthalocyanines are known from prior publications to have electrochromic properties in which the color of the diphthalocyanine can change over a period of about eight seconds upon application of a potential difference across an electrochemical cell having a diphthalocyanine film on one of the electrodes. See for example P. N. Moskalev and I. S. Kirin, "Effect of the Electrode Potential on the Absorption Spectrum of a Rare-Earth Diphthalocyanine Layer," Opt. i Spektrosk, 29, 414 (1970), and P. N. Moskalev and I. S. Kirin, "The Electrochromism of Lanthanide Diphthalocyanines" Russian J. P'nys. Chem., 46, 1019 (1972). The diphthalocyanine does not require large amounts of power to change color, but the long period required for the color to change makes known diphthalocyanine performance characteristics unacceptable when measured against display requirements.
However, electrochromic display devices with more rapid switching characteristics are described in U. S. Patent No. 4,184,751, issued January 22, 1980 entitled Phthalocyanine Electrochromic Display, by M. M. Nicholson. This display device includes an electrolyte of potassium chloride (KCl). This device has an operating temperature range of approximately 100 to -11°C. As a result, many applications for using electrochromic displays are foreclosed because of the limited operational range.
SUMMARY OF THE INVENTION
The display of the instant invention overcomes many of the problems of prior art displays via utilization of metal diphthalocyanine complexes as the electrochromically active material and a lowfreezing metal chloride as the electrolyte in an electrochromic display cell. Rapid color changes in less than 50 milliseconds are achieved, thus alleviating the slow switching time previously reported for rare earth diphthalocyanine complexes. Power requirements are small because of the low power switching characteristics of the display material, because of its high optical absorption, and because the display exhibits an open circuit memory of from several minutes to several hours, depending on its construction. A multicolor, i.e. more than two colors, display is achieved through use of a range of voltages applied between display and counter electrodes. Color reversal of displayed information and the background against which it is displayed is achieved through use of display electrodes in the background portions of the viewing area as well as in the character segments. The use of an aqueous solution of a selected metal chloride for the electrolyte expands the operating range to a very low temperature, for example, on the order of -80°C if the electrolyte is a concentrated solution of lithium chloride.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 illustrates a cross-section through a typical transmissive display cell configuration.
DESCRIPTION OF A PREFERRED EMBODIMENT
Display cells in accordance with the invention may be divided into two general types. One type comprises reflective display cells which are designed to be viewed by reflected light only. The other type comprises transmissive display cells which are designed to be reviewed by light transmitted therethrough.
A transmissive display cell construction is illustrated generally at 10 in FIG. 1. Display cell 10 may include a case or similar structure (not shown) which supports transparent face plate 14 which constitutes the viewing surface or area of the display cell. Rear plate 12 is also transparent (in the transmissive cell). Rear plate 12 and face plate 14, together with spacers 18 and seals 20, form a chamber 16 within which the electrochromic material, the cell electrodes and an electrolyte are contained.
A plurality of transparent electronically conductive display electrodes are preferably deposited on the inner surface of face plate 14. The display electrodes include character segments 28, or other pattern areas, the number and the arrangement ofwhich are determined in accordance with the quantity and types of information the cell is intended to be able to display. A thin layer 30 of an electrochromic metal diphthalocyanine is disposed on the display electrode character segments 20, for exposure to the electrolyte 1-18. The metal diphthalocyanine film 30 comprises the electrochromic material of the display cell. A counter electrode 22 is preferably disposed on a portion of the rear plate 12 which constitutes the back surface of cavity 16. The cell also contains a separate reference electrode 24 when a potentiostatic drive system
is used. The construction of a typical display cell 10 is illustrative only. Reference is made to the Nicholson application noted above in the prior art discussion, the content of which is included herein by reference, for details of cell construction.
This invention is directed to an electrochromic display which utilizes a metal diphthalocyanine material and an improved electrolyte which permits improved operation. In particular, the electrolyte is a concentrated aqueous solution of a metal chloride which freezes far below the freezing point of water. A particularly desirable electrolyte comprises a solution of 30 weight percent calcium chloride in water. This composition is near that of the eutectic mixture which freezes at approximately -55°C. Consequently, low temperature and fast response time cell operation can be achieved. This electrolyte has been used with a lutetium diphthalocyanine display cell and has been successfully operated over at least 900 cycles at approximately -50°C. Multicolor electrochromic switching occurred in this display cell with excellent color quality under these conditions. In addition, no visually detectable change in switching time was observed. The color transformation in the electrochromic material continued to occur in less than 50 milliseconds as the solution was cooled from approximately room temperature to -50°C.
Other low melting electrolytes are suggested to replace the aqueous solution of potassium chloride (KCl) which is used in some of the known display cells. For example, an aqueous solution of lithium chloride is appropriate too. The eutectic mixture in this chemical system contains 25 weight percent LiCl and has a melting temperature of approximately -80°C.
In fabricating the electrolyte, the ionized material need not be formed from a chloride salt although metal chloride solutions are among the lowest melting systems which are essentially inert, can be used as aqueous electrolytes. It must be understood, of course, that a ternary - or other type of mixture containing two or more salts in v/ater may also be used.
Even without these low melting point electrolytes, the rare earth diphthalocyanine displays (see U. S. Patent No. 4,184,751 of M. M. Nicholson cited above) offer a number of advantages over other electrochromic materials such as tungsten oxide or viologens and clearly over liquid crystals. However, the very low temperature capability which is attainable with the electrolytes described in this application cannot be approached by other display technology.
In the display cell in which the experiements were conducted, a nickel counter electrode was utilized with a three-electrode drive circuitry. Counter electrode materials more appropriate for display cells with 2 or 3 electrode drives in concentrated chloride media include silver-silver chloride, lead-lead chloride and a solid mixture consisting of the electrochromic dye in an oxidized and a reduced form. The counter electrode generally is kept out of the viewing field to improve operation and viewability. A diphthalocyanine electrochromic counter electrode may be preferred over the metal-metal chloride because of the demonstrated fast electrode response of the diphthalocyanine material at low temperature.
Thus, there is shown and described an electrochromic display cell. The display cell is characterized by a suitable structural configuration which is similar to the existing cellswhich are known in the art. However, this cell includes the improvement of a new and unique class of electrolyte materials which permit the cells to operate at extremely low temperatures without sacrificing the desirable operating characteristics usually encountered in an electrochromic display cell.
Having thus described a preferred embodiment of the invention, what is claimed is:
Claims
1. An electrochromic display cell capable of assuming a plurality visually distinct optical states at very low temperatures comprising transparent electronically conductive display electrode means, counterelectrode means for establishing a potential difference relative to said display electrode means, a layer of electrochromic material disposed on said display electrode means, and an electrolyte material interposed between said film on said display el ectrode means and said counterel ectrode means in order to pass ionic current, characterized in that said electrolyte material is a concentrated aqueous solution of metal salt which solution freezes at a low temperature.
2. The display cell recited in claim l characterized in that said electrochromic material comprises a diphthalocyanine complex of lutetium or another rare earth element in the lanthanide series, or yttrium, scandium, or any other electrochromic diphthalocyanine.
3. The display cell recited in claim 1 characterized in that said electrolyte material comprises an aqueous calcium chloride solution.
4. The display cell recited in claim 1 characterized in that said electrolyte material comprises an aqueous lithium chloride solution.
5. The display cell recited in claim 3 characterized in that said calcium chloride represents about 30% by weight of said solution.
6. The display cell recited in claim 4 characterized in that said lithium chloride represents about 25% by weight of said solution.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US3696779A | 1979-05-08 | 1979-05-08 | |
| US36967 | 1979-05-08 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO1980002462A1 true WO1980002462A1 (en) | 1980-11-13 |
Family
ID=21891695
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/US1980/000340 WO1980002462A1 (en) | 1979-05-08 | 1980-03-17 | Electrochromic display using rare-earth diphthalocyanines and a low-freezing-point electrolyte |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JPH038524B2 (en) |
| FR (1) | FR2456357A1 (en) |
| WO (1) | WO1980002462A1 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0054587A1 (en) * | 1980-12-19 | 1982-06-30 | International Business Machines Corporation | Metal diphthalocyanine electrochromic displays and electrolytes therefor |
| EP0076060A2 (en) * | 1981-09-25 | 1983-04-06 | Imperial Chemical Industries Plc | Method of applying thin films to substrates |
| US4474433A (en) * | 1981-12-11 | 1984-10-02 | Rockwell International Corporation | Chemical color conversion of electrochromic display material |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20080186559A1 (en) * | 2005-02-09 | 2008-08-07 | Koninklijke Philips Electronics, N.V. | Display Device With Solid Redox Centres |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2024269A1 (en) * | 1970-05-19 | 1971-12-02 | Merck Patent Gmbh | Nematic mixtures - of low melting point, used in electronics |
| US3704057A (en) * | 1971-06-02 | 1972-11-28 | American Cyanamid Co | Electrochromic device having identical display and counter electrode materials |
| US3819252A (en) * | 1972-12-21 | 1974-06-25 | American Cyanamid Co | Additives that increase the stability of electrochromic films in electrochromic devices |
| US4006585A (en) * | 1974-01-08 | 1977-02-08 | Citizen Watch Co., Ltd. | Electronic timepiece with electrochromic display element |
| US4036551A (en) * | 1975-03-22 | 1977-07-19 | Sony Corporation | Display apparatus |
| US4059341A (en) * | 1975-05-07 | 1977-11-22 | Bbc Brown, Boveri & Company, Limited | Electrochromic display device with electrolytes and a method of producing the same |
| DE2756551A1 (en) * | 1976-12-20 | 1978-06-22 | Rockwell International Corp | ELECTROCHROME DISPLAY |
| US4184751A (en) * | 1976-12-20 | 1980-01-22 | Rockwell International Corporation | Phthalocyanine electrochromic display |
-
1980
- 1980-03-17 WO PCT/US1980/000340 patent/WO1980002462A1/en unknown
- 1980-03-17 JP JP55501328A patent/JPH038524B2/ja not_active Expired - Lifetime
- 1980-05-07 FR FR8010203A patent/FR2456357A1/en active Granted
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2024269A1 (en) * | 1970-05-19 | 1971-12-02 | Merck Patent Gmbh | Nematic mixtures - of low melting point, used in electronics |
| US3704057A (en) * | 1971-06-02 | 1972-11-28 | American Cyanamid Co | Electrochromic device having identical display and counter electrode materials |
| US3819252A (en) * | 1972-12-21 | 1974-06-25 | American Cyanamid Co | Additives that increase the stability of electrochromic films in electrochromic devices |
| US4006585A (en) * | 1974-01-08 | 1977-02-08 | Citizen Watch Co., Ltd. | Electronic timepiece with electrochromic display element |
| US4036551A (en) * | 1975-03-22 | 1977-07-19 | Sony Corporation | Display apparatus |
| US4059341A (en) * | 1975-05-07 | 1977-11-22 | Bbc Brown, Boveri & Company, Limited | Electrochromic display device with electrolytes and a method of producing the same |
| DE2756551A1 (en) * | 1976-12-20 | 1978-06-22 | Rockwell International Corp | ELECTROCHROME DISPLAY |
| US4184751A (en) * | 1976-12-20 | 1980-01-22 | Rockwell International Corporation | Phthalocyanine electrochromic display |
Non-Patent Citations (2)
| Title |
|---|
| Chemical Abstracts, Volume 74, Abstract No. 17653r, Issued 1971, Moskalev, P.N. et al, Opt. Spektrosk., Volume 29(2), pp 414-415, issued 1970 * |
| Chemical Abstracts, Volume 77, Abstract No. 107,325b, Issued 1972, Moskalev, P.N. et al, Zh. Fiz. Khim., Vol. 46(7), pp 1778-1781, Issued 1972 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0054587A1 (en) * | 1980-12-19 | 1982-06-30 | International Business Machines Corporation | Metal diphthalocyanine electrochromic displays and electrolytes therefor |
| EP0076060A2 (en) * | 1981-09-25 | 1983-04-06 | Imperial Chemical Industries Plc | Method of applying thin films to substrates |
| EP0076060A3 (en) * | 1981-09-25 | 1984-05-02 | Imperial Chemical Industries Plc | Method of applying thin films to substrates |
| US4474433A (en) * | 1981-12-11 | 1984-10-02 | Rockwell International Corporation | Chemical color conversion of electrochromic display material |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH038524B2 (en) | 1991-02-06 |
| FR2456357B1 (en) | 1984-12-28 |
| JPS56500822A (en) | 1981-06-18 |
| FR2456357A1 (en) | 1980-12-05 |
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