E Ink Holdings has announced they have developed what they consider to be a breakthrough technology with its Advanced Color ePaper (ACeP), a high quality, full colour reflective display. E Ink said for the first time, an electrophoretic display (EPD) can produce full colour at every pixel without the use of a colour filter array (CFA). ACeP sets a new standard for bright, reflective colour achievable with EPDs. The initial target application for ACeP will be for digital signage.
ACeP achieves a full colour gamut, including all eight primary colours, using only coloured pigments. The display utilises a single layer of electrophoretic fluid, which is controlled using voltages compatible with commercial TFT backplanes. The fluid can be incorporated into either microcapsule or Microcup structures. The richness of the colours is achieved by having all the coloured pigments in every picture element (pixel) rather than the side-by-side pixel colours achieved with a CFA. This eliminates the light attenuation, which can be quite significant. Like regular E Ink ePaper, ACeP maintains the ultra-low-power and paper-like readability under all lighting conditions.
In developing ACeP, E Ink researchers solved the very complex problem of how to get reflective colour at every pixel in a commercially viable structure. Other approaches have utilised stacked backplane structures that are complex, difficult to manufacture and costly.
The E Ink approach utilizes only a single backplane. Many materials and waveform inventions were required to independently control the position of the multiple colour pigments.
Figure: E Ink - Advanced colour ePaper (ACeP) a high quality, full colour reflective display
Multiple 20” displays with a resolution of 1600 X 2500 at 150 ppi have been constructed.
Frank Ko, Chairman of E Ink Holdings, said, "At its heart, E Ink is a materials and technology company." Frank added, "It's this core that provides the energy and the foundation for the stream of products being developed at E Ink. We expect ACeP to become the basis upon which another generation of EPD display products can be developed."
Michael McCreary, CTO for E Ink Corp., said, "The technical team was convinced this was achievable." Michael added, "E Ink's global R&D team has a deep understanding and experience with electrophoretic displays. During the years of hard work applying this experience to full color, the breakthroughs required to achieve this milestone were numerous and frequent. We are very proud of the team’s accomplishment and dedication to this task."