Method of manufacturing an optical display

1. A method of using a first fluid and a second fluid for providing the first fluid on a surface of a substrate for manufacturing an electrowetting device, the method including:

immersing part of the substrate in the second fluid, the surface of the substrate having at least one first area with a greater wettability for the first fluid than for the second fluid, the second fluid being immiscible with the first fluid, and a surface of the second fluid adjoining the surface of the substrate to form a gutter along the surface of the substrate;

providing a quantity of the first fluid in the gutter; and

moving the gutter along the surface of the substrate, the surface of the substrate and a horizontal plane forming an angle between 100 degrees and 170 degrees.

2. A method according to claim 1 , wherein the first fluid floats on the second fluid and is substantially confined to the gutter.

3. A method according to claim 1 , including:

arranging the substrate in a container; and

providing the second fluid into the container, thereby moving the gutter along the surface of the substrate.

4. A method according to claim 1 , including arranging a plate parallel to the substrate before moving the gutter along the surface of the substrate.

5. A method according to claim 4 , wherein the angle between the surface of the substrate and the horizontal plane is between 135 degrees and 160 degrees.

6. A method according to claim 4 , wherein the plate is a further substrate or a support plate for a substrate.

7. A method according to claim 4 , wherein the first fluid is provided in the gutter through a hole in the plate or through a tube passing between the substrate and the plate.

8. A method according to claim 1 , including:

removing the first fluid from the surface of the second fluid after the first fluid has been provided on the surface of at least part of the substrate; and

removing the substrate from the second fluid.

9. A method according to claim 3 , wherein the providing of the second fluid into the container moves the gutter so as to immerse further of the substrate in the second fluid.

10. A method according to claim 1 , including providing a further fluid, immiscible with the first and second fluids, which covers a surface of the first and/or the second fluids.

11. A method of providing a first fluid on a surface of a substrate for manufacturing an electrowetting device, the method including:

providing at least part of the substrate in a container for holding a quantity of a second fluid, the second fluid being immiscible with the first fluid;

providing the second fluid into the container;

providing a quantity of the first fluid on the second fluid and adjacent a surface of the substrate;

providing further of the second fluid into the container, thereby moving the quantity of first fluid along a surface of the substrate.

12. A method according to claim 1 , wherein the gutter comprises a depression in the surface of the second fluid, adjacent the substrate.

13. A method according to claim 1 , wherein a surface of the second fluid, different from the surface forming the gutter, defines the horizontal plane.

14. A method according to claim 1 , wherein the surface of the substrate comprises a pattern including the at least one first area and at least one second area with a greater wettability for the second fluid than for the first fluid.

15. A method according to claim 14 , wherein the at least one first area comprises a plurality of first areas separated by at least one of said at least one second area.

16. A method according to claim 15 , wherein each said first area is a pixel area for an electrowetting display device and each said at least one second area forms at least one inter-pixel wall.

17. A method according to claim 1 , wherein the substrate has a further surface substantially parallel to said surface of the substrate along which the gutter is formed, wherein during said method there is an absence of first fluid in contact with the further surface.

18. A method according to claim 1 , wherein during said moving the gutter along the surface of the substrate, second fluid is moved along a further surface of the substrate without providing first fluid on the further surface, the further surface being substantially parallel to said surface of the substrate on which the first fluid is provided.

19. A method according to claim 1 , wherein the substrate has a further surface substantially parallel to said surface of the substrate along which the gutter is formed, wherein the further surface has a greater wettability for the second fluid than for the first fluid.

20. A method according to claim 1 , wherein the substrate has a further surface substantially parallel to said surface of the substrate along which the gutter is formed, wherein the second fluid adjoins the further surface to form an inverse gutter along the further surface.

21. A method according to claim 1 , wherein said providing the quantity of the first fluid in the gutter is performed after said immersing part of the substrate in the second fluid.

22. A method according to claim 2 , wherein, with the second fluid being substantially confined to the gutter, there is a part of the second fluid without first fluid floating thereon.