E-ink displays have a number of advantages over other display types, but their refresh rate isn’t one of them. But what exactly makes them slow? According to [Wenting Zhang], it’s not an inherent limitation of the technology. It’s mainly the controller, and this limitation can be overcome to create a high-resolution 60 Hz refresh rate E-ink display, totally suitable for use as a computer monitor.
The reason E-ink displays are so slow is simple. For a long time, they existed for only one purpose: to be screens for e-readers. They had to work on devices that were generally low power, with limited interfaces and slow processors. Accommodating these factors was the primary driver behind the high latency and slow refresh rates associated with these displays.
It was actually the limited interface options rather than the slow refresh that initially led to a custom controller, because [Wenting] wanted to use an E-ink display on a laptop build. But it quickly became apparent that a custom controller could do considerably more than E-ink was known for.
Initial tests with fast refresh rates were so positive that it led to a Hackaday Supercon 2024 talk on how to make E-ink go fast, and more recently has culminated in the Modos Flow, a fully open-source, user-repairable 13.3″ portable E-ink monitor.
The development path from proof of concept to finished product has been a long one for [Wenting]. Not only did a lot of optimization and feature work need to be crafted from scratch in order to effectively balance appearance with responsiveness in different display modes, but the usual hassles of development and bad timing were also in full force. On top of it were wasteful vendor shenanigans, as well.
Check out the story in the video, embedded just below. If you’d like to buy one, there are monochrome and color versions offered through Crowd Supply.
Thanks [TrendMend] for the tip!
Yota Phone was released in 2013, and the Dasung Paperlike (I don’t remember whether 10″ or 13″ ones were around first) has been around since 2016. The slowness of monochrom e-paper displays has (in the eyes of consumers) kept disqualifying them ever since. So while Dasung now have a similarly priced product as well, they’re by no means open source.
One problem down, next up…color.
At the very end of the article they mention monochrome and color versions are available. That price though … :/
“That price though …”
Early adoption comes at a premium. Give it a few product cycles, Let the big names in Ereaders jump on board. Then it will be cheap as.
There’s a concept called “shallow tech”, which is people taking off-the-shelf stuff, putting it in a 3D printed box, and pretending that it’s a great new innovation to sell it on kickstarter at a price point that is only justifiable to early adopters.
Then it never becomes an actual product. Why? Because it was too expensive for too little practical use. Its only point was to run the booster campaign and then move on to the next thing.
For example, having a high refresh rate kills the main advantage that e-ink has: ultra-low power consumption. Instead, you get a monitor with washed out colors and bad contrast. We can already get that with cheap LCD panels under a hundred bucks, so why pay several for this?
Low power is a power of E-Ink, and one that likely still applies to high refresh rate capable in many cases, as the screen is still going to be static often. But it is not the only one. A passive purely reflective screen is vastly nicer on the eyes in most situations than the active illumination eye searingly bright, or not bright enough and quite likely to flicker if you try to make it dimmer screen techs…
Is it the right solution for everyone obviously not, but nothing is ever that. It is however probably a perfectly good screen for almost everyone in all situations as it has adequate looking colour and fast enough refresh to just use like any other screen. Perhaps a touch expensive, but big deal its a rather unique (for now) product.
Nice work, and ugh I feel for the guy. The display chip companies are awful to deal with, their code IS broken, and the supposedly unbroken code doesn’t actually exist. Camera companies are the same. And if you want to implement it on an FPGA? That’s a whole 4 year project itself, or somebody else wants to sell you the IP core for an arm and a leg, and maybe a per unit fee on top of that, and charge you to change timing.. it all sucks, so massive kudos for sticking with it. It looks great.
This is impressive work! This would help usher in some new use cases for eink.
The e-ink displays I can find datasheets for say they’re only rated for 1 million refreshes. At 60hz, that’s under 5 hours. Do we know what the lifespan of this panel is like?
I wonder if that number is that low because they normally have a much much lower refresh rate.
At 1hz that would be more than 11 days of constant refreshing, which most e-ink displays won’t really do.
A e-reader is probably closer to 1 refresh every minute or so, which would turn out to 1.9 years of reading.
I’m definitely interested in some long term usage reports.
Exactly. Even a clock refreshing at 1Hz is too frequent for eInk. 12 days x 24h x 60m x 60s = 1,036,800. A clock that only runs for 12 days ain’t much of a clock.