Electrochromic, electroluminescent and electrochemiluminescent displays

• US 5,444,330 A
• Filed: 02/18/1993
• Issued: 08/22/1995
• Est. Priority Date: 02/26/1990
• Status: Expired due to Term

• Current Assignee: BioVeris Corporation (Roche Holding AG)
• Original Assignee: Molecular Displays, Inc.
• Inventors: Leventis, Nicholas, Wrighton, Mark S.
• Primary Examiner(s): O'Shea, Sandra L.
• Assistant Examiner(s): Patel, Vip
• Application Number:
  US08/019,242
• Time in Patent Office: 915 Days
• Field of Search: 313/483, 313/494, 313/504, 313/506, 313/503, 345/76, 345/80
• US Class Current: 313/506
• CPC Class Codes: F21K 2/08 activated by an electric field, i.e. electrochemiluminescence
• 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 1/1523 comprising inorganic material
• CPC Class Codes: G02F 1/1525 characterised by a particular ion transporting layer, e.g. electrolyte
• CPC Class Codes: G02F 1/155 Electrodes
• CPC Class Codes: G02F 2001/1517 Cyano complex compounds, e.g. Prussian blue
• CPC Class Codes: G02F 2001/1555 Counter electrode
• CPC Class Codes: G02F 2001/1557 Side by side arrangements of working and counter electrodes

Abstract

A display having an array of matrix addressable pairs of electrodes mounted face up on the same substrate. The pairs of electrodes are derivatized with either electrochromic materials or electroluminescent material to form the pixels of the display. In the electrochromic embodiment of the invention, a layer of a solid polymer electrolyte is included. The air of electrodes may also be left clean of derivatizing material, but with an electroluminescent substance dissolved in the solid polymer electrolyte. An electrochemiluminescent embodiment is also provided where the electrochemiluminescent substance can be dissolved in the solid polymer electrolyte. A method of patterning the electrolyte layer to form relatively nonconductive borders around each of the pairs by selective exposure of the electrolyte layer in the region of the border to electromagnetic radiation to cause permanent change in the chemical composition of the electrolyte so that the exposed border regions are rendered relatively non-conductive is also provided. An electrically reconfigurable photomask having an area comprised of an arrangement of electrochromic covered electrode pairs constituting pixels, the opacity and transmissivity of which may be controlled by application of an electrical bias to yield complete control over the transmissivity and opacity of each pixel of the areas, is also provided.

Claims

1. An electrochemiluminescent display pixel comprising a substrate, a pair of electrodes mounted face up and side by side on one side of said substrate and in close proximity to each other, and an ionically conductive electrolyte layer over said pair of electrodes, said electrolyte including an electrochemiluminescent chemical substance so that when a bias is imposed between the electrodes of said pair, said electrochemiluminescent chemical substance emits light.

2. The display pixel defined in claim 1, wherein said electrolyte is substantially solid.

3. The display pixel defined in claim 2, wherein said solid electrolyte is a polymer.

4. The display pixel defined in claim 1, wherein said electrodes are interdigitated with each other.

5. The display pixel defined in claim 1, wherein said pixel is less than about 200 microns across.

6. The display pixel defined in claim 1, wherein said electrolyte layer further includes a border region around said pixel comprised of said electrolyte layer rendered relatively non-conductive in place by selective exposure of said border region to electromagnetic radiation.

7. The display pixel defined in claim 6, wherein said relatively non-conductive border surrounding said pixel includes a polymer formed by subjecting a monomer or oligomer previously mixed in the electrolyte to electromagnetic radiation to reduce the mobility of charge carriers in the border region of said electrolyte.

8. The display pixel defined in claim 6, wherein said relatively non-conductive border surrounding said pixel includes a polymer formed by exposing a monomer or oligomer mixed in the electrolyte to electromagnetic radiation to induce cross-linking of said monomer or oligomer with said electrolyte of said border region to reduce the mobility of charge carriers in said exposed region.

9. The display pixel defined in claim 1, wherein said electrolyte includes a photosensitive metal complex that can photorelease a neutralizing substance that reduces the mobility of the current supporting ions upon exposure to UV-light.

10. The display pixel defined in claim 1, wherein said electrolyte includes a photosensitive substance including a base as a constitutent which can release the base upon exposure to UV-light to neutralize the protons that are responsible for charge transport in the electrolyte.

11. A display comprising an array of matrix addressable pairs of electrodes, said array comprising:

(a) a substrate;

(b) a plurality of substantially parallel and spaced apart electronically conductive means defining columns of bus bars mounted on one side of said substrate, each of said column bus bars being electrically separate from the other column bus bars so that each is independently addressable by electrical biasing means;

(c) a plurality of column electrode means mounted face up on said one side of said substrate and spaced at intervals along each of said column bus bars;

(d) a plurality of substantially parallel and spaced apart electronically conductive means defining row bus bars on said one side of said substrate, said row bus bars crossing but being electrically insulated from said column bus bars, each of said row bus bars being electrically separate from the other row bus bars so that each of said row bus bars is independently addressable by electrical biasing means;

(e) a plurality of row electrode means mounted face up on said one side of said substrate and spaced at intervals along each row bus bar, each of said row electrodes being positioned to have a column electrode in close proximity to and side by side therewith to define an electrode pair; and

(f) an ionically conductive electrolyte layer over said pair of electrodes, said electrolyte including an electrochemiluminescent chemical substance so that when a bias is imposed between the electrodes of one of said pairs, said electrochemiluminescent chemical substance emits light in the vicinity of said pair.

12. The display defined in claim 11, wherein said electrolyte is substantially solid.

13. The display defined in claim 12, wherein said solid electrolyte is a polymer.

14. The display defined in claim 11, wherein said layer of electrolyte is separated into individual zones over each of said pairs by relatively non-conducting borders so that each electrode pair constitutes a substantially separate electrochemical cell.

15. The display defined in claim 11, wherein said relatively non-conductive borders around each of said pairs are comprised of said electrolyte layer rendered relatively non-conductive in place by selective exposure of said electrolyte layer in the region of said border to electromagnetic radiation.

16. The display defined in claim 11, wherein said relatively non-conductive borders surrounding each of said pairs includes a polymer formed by exposing a monomer or oligomer mixed in the electrolyte of said border region to electromagnetic radiation to reduce the mobility of charge carriers in the border region of said electrolyte.

17. The display defined in claim 11, wherein said relatively non-conductive borders include a polymer formed by exposing a monomer or oligomer mixed in said electrolyte to electromagnetic radiation to induce cross-linking of said monomer or oligomer with said electrolyte of said border region to reduce the mobility of charge carriers in the border region of said electrolyte.

18. The display defined in claim 11, wherein said photosensitive electrolyte includes a metal complex that can photorelease a substance that reduces the mobility of the current supporting ions upon exposure to UV-light.

19. The display defined in claim 11, wherein said electrolyte includes a photosensitive substance including a base as a consitutent which can release the base upon exposure to UV-light to neutralize the protons that are responsible for charge transport in the electrolyte.

20. A display comprising an array of matrix addressable pixels, said display comprising:

(a) a first substrate;

(b) a plurality of substantially parallel and spaced apart means defining columns of bus bars mounted on said first substrate, each of said column bus bars being independently addressable by electrical biasing means and having a plurality of column electrode means face up and at spaced intervals along the length of said column;

(c) a second substrate in opposed and facing relationship to said first substrate but spaced apart therefrom,

(d) a plurality of substantially parallel and spaced apart means defining rows of bus bars mounted face up on said second substrate, each of said row bus bars being independently addressable by electrical biasing means and having a plurality of row electrode means at spaced intervals along its length so that each row electrode is in opposed and facing relationship to a corresponding column electrode means but spaced apart therefrom to define an electrode pair; and

(e) an ionically conductive layer of electrolyte sandwiched between each said first and second electrodes, said layer of electrolyte including an electrochemiluminescent substance and being separated into individual zones by relatively non-conducting borders so that each electrode pair constitutes a substantially separate electrochemical cell defining a pixel.

21. The display defined in claim 20, wherein said electrolyte is substantially solid.

22. The display defined in claim 20, wherein said electrolyte is a polymer.

23. The display defined in claim 20, wherein said relatively non-conductive borders around each of said pairs are comprised of said electrolyte layer rendered relatively nonconductive in place by selective exposure of said electrolyte layer in the region of said border to electromagnetic radiation.

24. The display defined in claim 20, wherein said relatively non-conductive borders surrounding each of said pairs includes a polymer formed by exposing a monomer or oligomer mixed in the electrolyte of said border region to electromagnetic radiation to reduce the mobility of charge carriers in the border region of said electrolyte.

25. The display defined in claim 20, wherein said relatively non-conductive borders include a polymer formed by subjecting a monomer or oligomer to electromagnetic radiation to induce cross-linking of said monomer or oligomer with said electrolyte to reduce the mobility of charge carriers in the border region of said electrolyte.

26. The display defined in claim 20, wherein said electrolyte includes a metal complex that can photorelease a substance that reduces the mobility of the current supporting ions upon exposure to UV-light.

27. The display defined in claim 20, wherein said electrolyte includes a photosensitive substance including a base as a consitutent that can release the base upon exposure to UV-light to neutralize the protons that are responsible for charge transport in the electrolyte.