E Ink, the company that developed the screens used on e-readers such as Amazon’s Kindle, has announced a coloured version.
The new technology could expand the capabilities of e-readers allowing for full colour media such as magazines and comic books.
Dubbed ‘Advanced Color ePaper’ (ACeP), E Ink said the screens can produce ‘full colour at every pixel’ without the use of a color filter array.
Although colour e-reader displays have been around for several years, they were severely limited in their abilities, only able to display 16 shades of grey, and 4096 colours.
Yet ACeP is capable of showing the full gamut with up to 32,000 colours derived from coloured pigments.
The display utilises a single layer of electrophoretic fluid, which is controlled by using different voltages to manage colours shown.
The technology is currently only commercially available in 20 inch sizes with a relatively slow refresh rate of two seconds. Yet with a resolution of 1600 x 2500, which equates to 150 pixels per inch (ppi), an e-reader-sized display would still be sharp enough to display legible text and pictures.
For comparison, the latest Kindle has a 300ppi screen, but earlier generations were equipped with 167ppi screens.
The larger displays will be initially targeted for use in shops as advertising or information boards.
Like regular E Ink displays, ACeP maintains its ultra-low-power usage and improved readability under all lighting conditions.
“At its heart, E Ink is a materials and technology company,” said Frank Ko, E Ink’s Chairman. “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 electrophoretic display products can be developed.”
In developing ACeP, E Ink researchers solved the 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.
Yet the new approach uses only a single backplane. Many materials and waveform inventions were required to independently control the position of the multiple colour pigments.
“The technical team was convinced this was achievable,” said E Ink CTO Michael McCreary.
“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 colour, 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.”