Technology

Introducing the Electrofluidic Display

Technology ExampleThe long-term goal of reflective displays is to mimic the appearance of pigment on paper. This means more than just bright color, the reflection also has to be diffuse (not specular like a mirror).

One could argue that the ultimate reflective display device would simply place the best pigment colorants used by the printing industry directly beneath the front viewing substrate of a display. Click here for video.

Electrofluidic displays do just that. In each pixel, we place a polar pigment dispersion inside a tiny reservoir. The reservoir comprises <5-10% of the viewable pixel area and therefore the pigment is substantially hidden from Pixel Structureview. Voltage is used to pull the pigment out of the reservoir and spread it as a film directly behind the viewing substrate. As a result, the display takes on color and brightness similar to that of conventional pigments printed on paper. When voltage is removed liquid surface tension causes the pigment dispersion to rapidly recoil into the reservoir. This most basic mechanism of operation is shown in the figure below. More advanced pixel structures increase brightness and allow bistable operation, but use similar operating principles and similarly simple device construction.

Several newer technology generations are highlighted below. All technology generations can be implemented in a pixel architecture that is <40 microns thick, thereby satisfying a major requirement for flexible and rollable displays.

Bistable and Video

Gamma Dynamics has now extended the performance of electrofluidic displays to include true bistable operation. Advances also include larger reflectance on par with black and white print on conventional paper, and improved accuracy for grayscale reproduction. First publication information release stated for 2010.

Bistable and Area Color

A variation of an electrofluidic display can also provide area color with brightness equal to magazine print. This solution is ideal for a large number of simple signage and indicator applications.

Bistable, Video, and Full Color

Pixel StructureThe ultimate e-paper technology. Full color electrofluidic display technology will change the way the display industry thinks about creating reflective color. Two versions of the technology are under development. The first version provides full color operation at >50% brightness. The second version is projected to provide even greater color performance on-par with printed office documents.

Our innovation goes beyond just a new pixel structure for e-paper. To achieve record performance, we have also developed an entirely new color system for electrofluidic pixels. This new color system gives the widest possible color-gamut that can be achieved, and just like conventional paper, does so at low cost with a single substrate.