E Ink: New e-paper display produces more colors directly

The next generation of color e-paper displays is set to improve image quality further. E Ink has updated its Spectra lineup, following the Spectra 6, whose color combinations produced attractive images, at least from a distance. That generation added blue to the displays. The latest revision of Spectra 6 now supports nine colors at the pixel level, a design called the "9-color system."

The existing black, white, red, yellow, green and blue are joined by light green, cyan and orange. Orange was previously available on Spectra 5 but was dropped for Spectra 6. The original Spectra 6 had to reproduce orange through dithering, which combines pixels of different colors. E Ink has sometimes included these blended colors in its color counts.

It remains unclear how the new Spectra 6 9-color system produces its colors from the available pigments. The "How it Works" webpage has yet to be updated. Spectra 6 uses four pigment colors to produce six base colors at the pixel level, with additional colors created by combining pixels. Whether the new system also produces all nine colors from just four pigment colors is still unknown.

E Ink has not provided any information about refresh speeds either. Spectra 6 displays are relatively slow and unsuitable for video, but they work well for signage. Their limited operating temperature range has so far restricted them to indoor use. The black-and-white panels are more robust.

E Ink's decision to retain the Spectra 6 name rather than call the new version Spectra 7 adds to the confusion, as displays using the original color system will remain on the market. The 9-color system is initially available only on 10-inch displays.

The new panels are intended to improve results particularly when displaying photos. According to E Ink, the Auras Ink 10" is the first product to use the panel. The photo frame costs $349 in the US. The Auras Ink 13" uses the original Spectra 6 panel, which E Ink says has a pixel density of 150 PPI, compared with 200 PPI for the new 10-inch model. E Ink says dithering will further improve the results.