[int_19h]

That's an interesting question - the article doesn't say if it's included or not. Are you saying that it's not?

But even then, reflective passive LCD is a thing (I mean, we've been using it in calculators for ages, for one!). So this still invites the question - is it possible to make a reader that is even more energy efficient than eInk-based ones, with that tech?

[Klover]

Correct, I am under the assumption that it is not included. Some examples from real life: a phone’s battery life is often greatly improved by simply lowering the backlight. Around 2010 we started putting LEDs as backlight in devices, greatly improving battery life, and if you take a laptop with Linux you can often disable the backlight and power usage of 0 in backlight compared to screen off and using external only is the same for me (so rendering and output still occurs the same amount, but in one case there’s just LCD and no backlight and in the other it’s no LCD no backlight).

[loxs]

While it's indeed interesting to geek out on this and I am not to say that we shouldn't be moving in this direction if we can... I don't think this is the limiting factor for this technology. Energy efficiency is already good enough with e-ink. For me more important is to try and build bigger (and cheaper) displays with higher resolution. For these I would sacrifice some energy efficiency.

[int_19h]

On the broader market, you're right of course, as evidenced by the fact that many people read from regular phones or tablets. I'm mainly curious about how far this single parameter (power usage) could be pushed if desired.