E-Ink extreme closeup!
Until the next time I can get my hands on an eBook reader, which I can subject to some hi-res scanning, there is this photo showing some pretty good detail of a Kindle screen. The post this comes from has a lot of interesting observations about the Kindle. The author claims the font used is PMN Caecilia, which is confirmed in this Newsweek article.
Now, PMN Caecilia was designed in 1990. Georgia and Verdana were designed in 1993 and only came out in 1996. Safe to assume Caecilia wasn’t designed as a screen font. It appears the main intention was to create a humanist slab serif that could work well for body text.
I found a review of the Cybook Gen3 with a close-up photo of the screen, magnified x6. Not a great photo, but still instructive. From the article:
As is the case with all e-paper-based devices, the display does not emit light of its own—unlike other widespread technologies, including CRT, LCD, Plasma, and even OLED; in this respect, it is very similar to real paper. However, as mentioned, the contrast level of the Cybook and other e-readers still falls short. To be specific, the white background appears more gray than white. We took a closer look with a 6X magnifying glass and, in doing so, revealed part of the reason why the e-ink display has such a low contrast, and why the background looks the way it does: as you can see from the image we took, the Cybook display has many tiny, dark “pixels” that, when viewed from a typical reading distance, make the screen appear gray. These pixels are actually the microcapsules that create text on the device.
According to E Ink: “Each microcapsule contains positively charged white particles and negatively charged black particles suspended in a clear fluid. When a negative electric field is applied, the white particles move to the top of the microcapsule where they become visible to the user. This makes the surface appear white at that spot. At the same time, an opposite electric field pulls the black particles to the bottom of the microcapsules where they are hidden. By reversing this process, the black particles appear at the top of the capsule, which now makes the surface appear dark at that spot.”
What E Ink doesn’t mention is that it’s still struggling to make all the microcapsules turn white when not needed, and this is essentially the reason why we see all those dots when using a magnifying glass and part of the reason why the contrast is still so low.
There have been some specific close-up photos of ePaper that caught my eye:
Looks like the pixels are not in a perfectly orthogonal grid. Which leads me to believe that a typeface designed for a normal screen may not work as well on ePaper. Hinting may be a totally different kettle of fish.