IMAGE DISPLAY CELL

• US 3,854,794 A
• Filed: 12/11/1972
• Issued: 12/17/1974
• Est. Priority Date: 12/23/1971
• Status: Expired due to Term

• Current Assignee: Cornelis Johannes Schoot, Hendrik Tajapko Van Dam, Johannes Jacobus Ponjee
• Original Assignee: Cornelis Johannes Schoot, Hendrik Tajapko Van Dam, Johannes Jacobus Ponjee
• Inventors: Ponjee, Johannes Jacobus, Schoot, Cornelis Johannes, Van Dam, Hendrik Tajapko
• Primary Examiner(s): Wibert, Ronald L.
• Assistant Examiner(s): Godwin, Paul K.
• Application Number:
  US05/313,822
• Time in Patent Office: 736 Days
• Field of Search: 350/160,190,311
• US Class Current: 359/272
• CPC Class Codes: C09K 9/02 Organic tenebrescent materials
• CPC Class Codes: G02F 1/1503 caused by oxidation-reduction reactions in organic liquid solutions, e.g. viologen solutions

Abstract

An image display cell having a transparent wall portion, electrodes and an oxidizable redox substance and a reducible redox substance in an electrochemically inert liquid in contact with electrodes. The cell includes at least two electrodes which are in contact with a cell liquid in which a colourless viologen salt (formula I) has been dissolved. When a potential difference of at least 0.5 Volt is applied to the electrodes, this salt is reduced to a coloured insoluble compound which adheres to the cathode, so that the latter is coloured, thereby producing an image.

Claims

1. AN IMAGE DISPLAY CELL COMPRISING A CASING HAVING A TRANSPARENT WALL PART A RDUCIBLE REDOX SUBSTANCE AND AN OXIDIZABLE REDOX SUBSTANCE IN WATER WITHIN SAID CASING AND AT LEAST TWO INERT ELECTRODES IN CONTACT WITH SAID WATER, BOTH THE REDUCIBLE REDOX SUBSTANCE AND THE OXIDIZABLE REDOX SUBSTANCE BEING PRESENT IN THE CELL, SAID REDUCIBLE REDOX SUBSTANCE HAVING A SOLUBILITY IN WATER IN EXCSS OF 10**-2 MOLE/LITER AND BEING A COMPOUND OF THE FORMULA 1

2. An image display cell as claimed in claim 1 wherein the formulae I and II X is a moiety selected from the group consisting of ClO4 , BF4 , NO3 , Cl , Br , F and C6H5SO3 ,

3. An image display cell as claimed in claim 1, wherein each anode is arranged at an angle to each cathode.

4. An image display cell as claimed in claim 3 wherein each anode is coplanar with each cathode.

5. An image display cell as claimed in claim 1 wherein a white insoluble substance is dispersed in the cell liquid.

6. An image display cell as claimed in claim 1, wherein a porous screen is interposed in the cell between the anode and each cathode.

7. An image display cell as claimed in claim 1 wherein the cell contains at least one reference electrode positioned relatively close to the cathode.

8. An image display cell as claimed in claim 1 wherein the cell liquid contains a salt which increases its conductivity.