Recently I've been reading about E-ink displays and the benefit over LCDs, as I understand it, is that there is no backlight in E-ink displays and thus, physical light is reflected, making reading under direct sunlight possible.
However, this got me wondering, is there any difference, apart from power consumption, that would prohibit the use of monochrome, reflective LCDs (like the ones found in calculators, watches etc.) in eReaders, replacing the slow eInk screens?
This would enable us to have a nicer UI with animation.
Best Answer
Thanks to a different recent question, I found that it has been tried and is called "memory LCD" and is used in the Pebble smartwatch.
The key is that normally LCDs are driven by a pulse every refresh period, and will fade if voltage is not maintained across them. Sharp have addressed this by adding to the conventional thin film transistors a memory element of some sort. Their power consumption for static images is very small, although not zero.
I think the LCDs are still necessarily glass, while e-ink displays can be slightly more flexible. This is a fragility disadvantage.