Almost buried under the business press’s obsession with Microsoft’s substantial investment in the Barnes & Noble eBook/eReader business were the glowing (sorry) reviews of the new Nook Simple Touch with GlowLight. B&N’s tagline for the new reader is "bedtime reading made perfect," and reviewers agreed. We should note that if you turn the edgelight off, the glowlight Nook reportedly looks just as good in sunlight as the less expensive Simple Touch without glowlight.
The trick to enhancing an E Ink-type eReader with touch interface, lighting, or enhanced system or networking functionality, is not to compromise the marvelously paper-like qualities of the basic electrophoretic display, or to let feature creep increase the weight or reduce the battery life. I have an old Sony Reader, one of the first eReaders to offer a touch interface, in which the touch overlay made the screen glossy and significantly compromised the reading experience. Recent Amazon Kindle readers have used infra-red LED touch technology which puts nothing between the Kindle and the reader. Now, B&N has implemented edgelighting in a way that reportedly does not compromise the viewing experience. (I intend to go into the technical details of this soon.)
Now, sources in the Taiwanese supply chain have told DigiTimes’ Siu Han and Steve Shen that Amazon will launch a color Kindle using a color E Ink display in the second half of this year. Scott Liu, chairman of E Ink Holdings, said E Ink will introduce color electrophoretic panels soon, which is a necessary condition if Amazon is to use them.
Now, this is interesting. Using a matrix color filter (MCF) to obtain color images from what is basically a monochrome reflective display sharply reduces the reflectivity and, therefore, the brightness and contrast ratio of the display. This is the approach E Ink uses in its current Triton color imaging film. The result is a color display with reduced brightness and limited color gamut. It constitutes an enhancement for some applications, but it certainly doesn’t challenge the gamut or contrast of an AMLCD or AMOLED, and E Ink doesn’t claim otherwise. It is this issue that has created space for reflective technologies such as Qualcomm’s Mirasol and Samsung’s Liquavista, which can produce color without an MCF. (Liquavista color prototypes have used an MCF, but there are other approaches.)
The success of the new Kindle color reader, or other color eReaders to follow, will depend on how well E Ink has solved this problem. One can conceive of a version of E Ink’s micro-encapsulated electrophoretic technology that produces color without an MCF, but I have no indication that the new display will be revolutionary rather than evolutionary.
While color is not needed for adult trade books, which are largely black and white, it will be required for the hugely profitable eTextbooks market. Microsoft mentioned the appeal of eTextbooks explicitly when it discussed the rationale for its B&N investment, and Amazon clearly has the same thoughts. I’m very interested in seeing what E Ink comes up with.