Light conductive controlled shape droplet display device

• US 20070002413A1
• Filed: 06/12/2006
• Published: 01/04/2007
• Est. Priority Date: 06/14/2005
• Status: Active Grant

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Pu, Allen, Psaltis, Demetri
• Granted Patent: US 7,826,125 B2
• Time in Patent Office: Days
• US Class Current: 359/15
• CPC Class Codes: G02B 26/004 based on a displacement or a deformation of a fluid

Abstract

A light conductive controlled shape droplet display device of the invention includes a light source. A light conductive substrate receives and conducts light from the light source. A cover disposed relative to the substrate, conducts light received from the substrate out and away from the display device. Pixels in the display are defined by fluid droplets in optical communication with the substrate and the cover. Hydrophobic layers associated with the substrate and the cover control the shape of the fluid droplet in conjunction with properties of the fluid droplet. Persistent displays are possible, as are displays that require periodic refresh to maintain the display. Electrodes modulate the amount of light conducted by the fluid droplets from the substrate into the cover. In preferred embodiments, each pixel includes sub-pixels formed by different primary colored fluid droplets.

Claims

1. A light conductive controlled shape droplet display device, the device comprising:

a light source;

a light conductive substrate receiving and conducting light from said light source;

a cover disposed relative to said light conductive substrate, said cover conducting light received from said light conductive substrate out and away from said display device; and

a plurality of pixels, each pixel being defined by

a fluid droplet in optical communication with said light conductive substrate and said cover;

at least one hydrophobic layer associated with said light conductive substrate or said cover for controlling the shape of said fluid droplet, properties of said fluid droplet and said at least one hydrophobic layer being set to shape said fluid droplet to conduct a predetermined amount of light through said fluid droplet and into said cover under a condition of no voltage potential applied to said fluid droplet; and

electrodes arranged to modulate the amount of light conducted by said fluid droplet from said light conductive substrate into said cover by application of a voltage potential to said fluid droplet.

2. The display device of claim 1, wherein:

each of said plurality of pixels comprises a plurality of sub-pixels, each sub-pixel having a fluid droplet for modulating the amount of light conducted from said light conductive substrate into said cover; and

sub-pixels in each of said plurality of pixels have different primary colored fluid droplets.

3. The display device of claim 1, wherein properties of said fluid droplet and said at least one hydrophobic layer are set to shape said fluid droplet to conduct a maximum amount of light through said fluid droplet and into said cover under a condition of no voltage potential applied to said fluid droplet.

4. The display device of claim 1, wherein properties of said fluid droplet and said at least one hydrophobic layer are set to shape said fluid droplet to conduct a minimum amount of light through said fluid droplet and into said cover under a condition of no voltage potential applied to said fluid droplet.

5. The display device of claim 1, wherein said electrodes comprise a common electrode and an electrode control line.

6. The display device of claim 5, wherein said common electrode and said electrode control line are commonly arranged on said cover.

7. The display device of claim 6, wherein said electrode control line comprises a pair of electrodes, arranged to move said fluid droplet with respect to a mask to modulate the amount of light conducted through said fluid droplet and into said cover.

8. The display device of claim 7, wherein said pair of electrodes comprise jagged interlocking terminals.

9. The display device of claim 1, further comprising shaped structure means for enhancing fluid droplet shape control.

10. The display device of claim 1, further comprising scattering means associated with said fluid droplet for modulating the amount of light conducted through fluid droplet and into said cover depending on the amount of contact between said fluid droplet and said waveguide means.

11. The display according to claim 1, wherein said electrodes are arranged to change a contact angle that said fluid droplet makes with respect to said substrate to modulate the amount of light conducted through said fluid droplet and into said cover.

12. The display according to claim 1, wherein said electrodes are arranged to change a position of said fluid droplet with respect to a mask to modulate the amount of light conducted through said fluid droplet and into said cover.

13. The display according to claim 1, wherein at least one of said electrodes is transparent to pass light conducted through said fluid droplet into said cover.

14. A light conductive controlled shape droplet display device, the device comprising:

a light source means;

substrate means for receiving and conducting light from said light source;

cover means for conducting light received from said light conductive substrate out and away from said display device; and

fluid droplet light modulation means for modulating the light passed through said fluid droplet modulation means from said substrate means and into said cover; and

electrode means for controlling the modulation of said fluid droplet means.