Indicator device with electric control of displacement of a fluid

• US 4,636,785 A
• Filed: 03/22/1984
• Issued: 01/13/1987
• Est. Priority Date: 03/23/1983
• Status: Expired due to Fees

• Current Assignee: Thomson-CSF
• Original Assignee: Thomson-CSF
• Inventors: Le Pesant, Jean-Pierre
• Primary Examiner(s): Brigance, Gerald L.
• Assistant Examiner(s): Brier, Jeffery
• Application Number:
  US06/592,282
• Time in Patent Office: 1,027 Days
• Field of Search: 340/753, 340/763, 340/783, 340/787, 340/788, 350/355, 350/363
• US Class Current: 345/37
• CPC Class Codes: G02B 26/005 based on electrowetting
• CPC Class Codes: G09F 9/372 the positions of the elements being controlled by the application of an electric field

Abstract

The displacement of a fluid is controlled electrically in a device employed primarily for storage and display of digital data. The device comprises a capillary space delimited by two confinement plates, the internal faces of which are fitted with electrodes connected to an electric generator. The capillary space is shared by two immiscible fluids and at least one displaceable fluid marker is created within the capillary space in the form of a globule of the fluid which has the highest dielectric permittivity.

Claims

1. A device providing electric control of displacement of a fluid which performs a display function, wherein said device comprises two confinement plates which define two internal faces and which are a small distance from each other to form a first volume which is shared by at least two immiscible fluids having different dielectric permittivities, a first fluid having a globular structure and a second volume and immersed in the second fluid, an electric generator connected to a plurality of electrode pairs where the electrodes of each pair are disposed opposite each other on the internal faces of said confinement plates, for inducing an electric field gradient so as to cause one of the two fluids having a higher permittivity to converge toward those regions of said first volume which are subjected to said electric field,

wherein at least two of said electrode pairs constrict said second volume of said first fluid for the purpose of splitting said fluid, said electrode pairs being adapted to cooperate with said electric generator for splitting said second volume.

2. A device according to claim 1, wherein said electrode pairs are arranged in at least one row in order to produce the displacement of at least one display constituted by a volume of said fluid having a globular structure.

3. A device according to claim 1, wherein the internal faces of said confinement plates are coated with deposits which are not wetted by said second fluid.

4. A device according to claim 3, wherein the deposits are thin.

5. A device according to claim 1, wherein said first volume is delimited by two equidistant smooth surfaces.

6. A device according to claim 1, wherein said first volume is delimited by two surfaces, at least one of said surfaces being provided with recessed portions and projecting portions.

7. A device according to claim 1, wherein said first volume comprises at least one reservoir region and wherein a short central electrode is placed between said two electrode pairs, the width of said central electrodes being shorter than said electrode pairs and said electrode pairs being shorter than the remaining electrodes for withdrawing predetermined volumes of fluid from said reservoir region.

8. A device according to claim 7, wherein said electrode pairs each have a main portion and a narrowed extension, where the narrowed extension is equal to the width of the central electrode.

9. A device according to claim 7, wherein said first volume comprises at least one drainage region for collecting said predetermined volumes of fluid.

10. A device according to claim 1, wherein the fluid which has said globular structure is a liquid.

11. A device according to claim 1, wherein the second fluid is a gas or a vapor.

12. A device according to claim 1, wherein said first volume is an enclosed space.

13. A device according to claim 1, wherein at least one of said plates is formed of material which is transparent to light radiation.

14. A device according to claim 2, wherein the display is provided in the form of a fluid globule having a volume which extends across said small distance defined by said confinement plates.

15. A device according to claim 1, wherein said electrodes have a triagular shape and are arranged in a row with alternate electrodes being inverted, with the sides of adjoining electrodes being parallel and near each other, two contiguous electrodes being energized at each stage of progression of the display.

16. A device according to claim 1, wherein said electrode pairs are constituted by deposits of an electrically conductive material which is transparent to light radiation.

17. A device according to claim 1, wherein the field gradient induction means comprise electrodes of indium oxide and tin.

18. A device according to claim 17, wherein the electrodes are coated with a deposit of N, N-dimethyl-N-octadecyl-3-aminopropyltrimethoxysilyl chloride.

19. A device according to claim 17, wherein the fluid having the highest dielectric permittivity is cyclohexanone, nitrobenzene or hexane.