Eink always could be driven quickly. The issue is that LCDs are more powerful efficient at high refresh rates
EInk needs a lot of power to move the heavier ink particles around. If you are doing that more and more rapidly, then even more power is drawn.
By 75Hz, I'm almost certain that LCD is far more power efficient. The LCD pixel (aka the liquid crystal) is a glorified capacitor, it takes some power to charge but it's exceptionally 'light' compared to eink.
That's why LCDs can go faster and faster. It's just physics. A capacitor / twisted crystal uses less power to turn on or off than EInk.
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EInks advantage is that if you turn off power, the ink stays put. So you spend a ton of power moving the ink around and then save lots and lots of power over the next seconds, minutes or more.
That's why EInk is ideal for once-a-day updates of prices (or other retailer tasks). The less you update, the less power used.
Thanks. That article seems to have the quote I was looking for.
> E-ink screens are quite power hungry when it comes to peak current. Modern high-resolution panels can consume >20 W peak.
This is where I was wondering and yeah, 20+W is pretty hefty to support a relatively small 8" EInk screen or something.
All those updates cost all that power as long as updates are occurring. Maybe you can optimize many of them away (if some parts of the screen don't move, especially if software was rewritten to optimize for the display).
More importantly, it sounds like you've created a full custom FPGA controller over the voltages that go into an EInk display? That's impressive in its own right even if I don't think 75Hz is a good idea lol.
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FPGA or Full Blown Microprocessor are the only choices here. A high power SIMD/NEON arm64 probably could do the job, but I think the Spartan6 is a good choice as well and has more obvious and straightforward parallelism (and probably all the pins required to control the screen. Even a big microprocessor won't have as many low latency pins as an FPGA).
You guys should do a collab with the framework people. I bet they'd be happy to offer an e-ink screen on their laptops just as an option. I've been waiting on an e-ink option for ages.
E-Ink's other advantage is being a non-emissive display. Transflective LCD displays have low contrast. I'm literally holding an e-ink tablet over the transflective monitor I'm typing this on and the difference in contrast at the same ambient illumination is considerable. If the price were right, I'd definitely consider a 75 Hz e-ink monitor even if the power draw was more than a normal LCD monitor.
In my experience using e-ink readers (admittedly I have a Kobo, which may not be the state of the art), I would like to refresh the screen rapidly in bursts -navigating menus, flipping past an index - and then have a non-backlit screen with low power cost to show the same content for a while. In other words, a variable refresh rate.
If you think of the refresh rate not as a constant frequency but as variable with user input, there are some cases where driving eink quickly in short bursts could make sense? It seems like this project offers a foundation for such a controller, where e-reader controllers are strictly optimizing for low refresh rates. E-ink is not going to be competitive for playing a video game or watching a video, but you can create a more responsive experience with less eye strain for typical tasks like marking up documents.
Yes, that’s the mental model I’ve been working from. Variable refresh tied to user input makes a lot of sense: short bursts of speed for navigation or editing, then settling into a low-power static state.
Part of the challenge is deciding what belongs in hardware and what should sit higher up in the OS or software stack.
Hopefully, as more people get the kits and the community grows, we’ll be able to think through these questions together and explore where the right balance between hardware and software should be.
That sounds like the way to go. In terms of reading books (my normal usage of e-ink readers) you don't need 60hz when flipping a page, but it's a must when trying to use an app menu, or using Google Drive for example.
Identifying when to increase the refresh rate may be a challenge but I can see it pretty doable for this kind of "limited" scenarios where you either read or navigate a storage app.
> EInks advantage is that if you turn off power, the ink stays put.
E-ink's other advantage is that it reads like paper. In a desktop context I could not possibly care less about the power consumption, but being able to read a forum thread, chat channel, HN discussion, etc. without a backlight would make my eyes very happy.
Out of curiosity, if you have 75Hz but you're refreshing sparingly (e.g. you're in VSCode writing, unless you're scrolling, most pixels remain unchanged), wouldn't e-ink remain power-efficient?
Probably. E-ink drivers ("waveforms" is, I believe, the term of art) frequently target refreshes only at the portion of the display that has updated, using rectangles or other more-specific geometries to limit that area.
For text updates, where there's literally a cursor which moves at typing speeds, update frequency is quite low. Where you're updating or paging through documents, paginated navigation (where the whole screen refreshes at once, then remains unchanged for several seconds to minutes or longer) is quite efficient.
That requires the operating system to “hint” to the display that there’s no refresh necessary and for the display to shut down during those times. That’s currently not supported as these kits just take a video signal, but it’s something being worked on for a future version!
Is this saying that it is an either-or situation? Ideal would be a device that can be written fast when needed, but can also hold. Is there some more fundamental thing at a pixel level that links agility with retention?
E Ink uses microscopic ink bubbles that gets attracted to positive and negative voltages. The ink stays around when attraction stops, holding image. But the ink also require much stronger force than regular LCDs to move around.
LCDs use articulation of liquid crystal chemicals that change shape thus polarization upon application of voltages. They tend to slowly deform back to "the other" state when voltages are removed, and also tend to chemically break down if not moved back to the neutral state. LCDs are driven in pseudo-alternating current for this reason, and never held at either extremes for long time, for this reason.
So you can drive E Ink at 75Hz or whatever, it'll just take more power than it takes LCD to do so, and the last pixel states will persist. Or you can leave LCDs at extremes and disconnect the power, but it will lead to degradation if intentionally used that way.
What you can't do is 1) "watt per frame" figures of LCD, with 2) persistence, and 3) long life. (1, 3) is LCD, (2, 3) is E Ink, (1, 2) is LCD abused as if it's E Ink at expense of rapid degradation, and (1, 2, 3) is the holy grail.
That's what I'm wondering about. I wouldn't mind temporary higher energy usage to get smoother interactions, but I'm not sure what the long-term impact on the screen is.
Flipping pages right now is very annoying. Slow and with the weird redrawing flashing. If they can find a way to fix that it'll be 100% worth it, even if it means high power draw on page changes.
It is not as easy as that. The nature of EInk displays allows them to be usable without a backlight LCDs need backlights constantly, any analysis which doesn't take this into account is irrelevant.
In any case, it is not clear that, even if EInk Displays are somewhat worse in power consumption, they aren't a superior display technology.
IANAE but won't e-ink at high refresh rates have the same benefit as OLED in terms of only refreshing what needs changing? perhaps in practical situations the power consumption should be lower than the worst-case scenario.
In the DIY electronics scene, I’ve occasionally come across posts about small cheap e-ink displays essentially burning in and how to try and avoid it (shifting things around like on OLED)
This could be actual burn in, or it could be a failure in how they are refreshing (with some potential fix if refreshed properly). I’m not familiar enough to be certain myself, but I personally suspect they are likely being driven too hard and are truly damaged.
In normal e-reader use I’ve never seen this as a practical issue.
I have an e-ink display that's now 15 years old. It's definitely a bit less clean, there is sometimes mild ghosting even after doing a full refresh. Doing two refreshes in quick succession fixes that.
I also have another display that was exposed to full sunlight through a window for about 8 years. It's now a bit faded as a result.
Yes you can kill or degrade them if you drive them too hard, but achieving higher refresh rates and less ghosting is mostly about finer calibration and faster lookups on bigger tables
So I guess an e-ink display would not be good with my book reading habits then. I will often scroll a few lines at a time and that sounds power expensive.
I assume that's what Sharp Memory LCDs are doing to reach their absurdly low power specs.
I dunno if LCD screens are multiplexed, but embedded LCDs could need as many as 8x on/off cycles per pixel (because you save 87% fewer wires if you chain 8x pixels on the same line and then put them on different biases and have weird COMmon pins and rows and crap).
Sharp claims that a bit of storage is on each LCD/capacitor and this saves power somehow with smarter decision making. I assume it's minimizing the wasted power somehow (or even recycling the previous power shoved into the capacitor, which typically just goes to waste).
It's some proprietary formula in any case, so it's all guesswork. Only the Sharp Engineer/Inventor would know for sure.
I am absolutely not surprised to see his name behind this startup. I've been following his work for years at this point; his YouTube channel has always deeply impressed me, and he's done wonderful open source work in the realm of E-paper for quite some time now.
The article doesn't even touch on what I think is one of the coolest features: the ability to change update modes locally in subregions of the panel. And even better, they're already working on integrating that with the Wayland Content Type Hint protocol to let the compositor automatically pick the right mode for a given application for you, which then would work even if multiple applications are on the screen[0].
Yes, this is one of the areas I’m most excited about; it makes e-ink more practical for everyday use and opens the space for experimentation. In the long run, as the community grows and more people get involved, we’ll see even more possibilities.
I play chess on a e-ink smartphone and it is a nice break for my eyes in the evening.
I can not wait for the moment when I would be able to code on a nice colored e-ink desktop screen
BOOX has 13" Tab X C color e-ink reader, which runs Android. I have non-color version (Tab X), and used it few times to work under bright sun (in vim, connected over mosh/ssh to my laptop + wireless keyboard). It was okay experience - not perfect, but quite comfortable.
Be warned: each layer of eink reduces contrast. With 4 layers, the contrast of the color boox tablet is terrible. Also, if you buy from boox, you have to pay about $50 to return it. Not worth it at all in my experience, unless you will always be in direct sunlight.
I went through that and then bought a Carta 1200 display BOOX 13.9 and it's amazing. Black and white only, but the contrast makes the device usable.
If you know you won't return the device, get it on their website because they'll give you extra pen tips and a case. I got mine on Amazon, so I missed out on the extra stuff because of my return experience.
The article is oddly written. It's not the e-ink display panels that are different; they're off-the-shelf modules from E-Ink that their controller is driving at 75 Hz. Presumably E-Ink themselves know that the panel can be driven at that rate.
And pixel-level addressing isn't innovative either. If you've written on an e-ink tablet and observed that the screen doesn't refresh with every pixel change under the stylus, that is surely because pixels are being toggled individually instead of doing a full screen refresh.
So perhaps the only difference is that it's an open source controller that's competitive with commercial e-ink display controllers? That's no small achievement and worth celebrating in and of itself. But it's not at all made clear by the article.
- Making the project open allows people to reuse displays they already own.
- Others can contribute and build on what’s been created.
- Open source firmware, documentation, and the driver board make development more accessible and help remove barriers that previously slowed community projects.
- It’s designed to work with a variety of electrophoretic panels, not only those from E Ink.
In the long run, this openness will strengthen the ecosystem, making it easier for new ideas to take shape and spread.
Regardless of manufacturer (remarkable, boox, supernote…), all e-paper tablets have one major performance problem: quickly scrolling through multiple pages of notes. No idea if the display is the limiting factor, or the cpu, but I’ve hit this issue on all tablets I’ve used. If you like riffling through pages in you paper notebook, you will hit the limit too. I know at least 2 people who stopped using their tablets over time because of this issue.
If this tech helps solve that problem, it’s more important to me than an eink monitor.
Edit: this is mainly important for notes, because sketches, scribbled diagrams and quick notes half-taken in meetings are not really searchable. PDFs and ebooks don’t have this problem.
I'm pretty sure it is the CPU.
On my Kobo Elipsa I've had it freeze a few times, mainly when going to pages with high resolution graphics or pages with a ton of vector graphics / markups.
Their demos most definitely show scrolling through long websites very quickly, and they show playing computer games and playing videos on e-ink displays as well. Amazing stuff really.
I've seen (in kobo documentation) statements that e-ink displays are good for up to about a million refreshes overall. At 75Hz that means a display might last about 4 hours total. Other displays claim up to 10 million, so that would be about a week's worth of regular work.
That could still get annoying though, since maybe the middle third of the display is going to get rapidly flipped on + off as you scroll through text/browse around websites. If that part of the display dies, but the outside 2 thirds still works, I think the panel is basically useless anyway.
I emailed Modos and they replied basically that the 1 million or 10 million refresh limits have been pessimistic in their testing — that they have not seen a display significantly “wear out”
>Modos, a two-person startup with open-hardware roots, thinks it has cracked part of that problem with a development kit capable of driving an e-paper display at refresh rates up to a record 75 hertz.
Call me crazy, but I'd rather see these guys get a couple million than yet another chatgpt wrapper.
I would love to see the performance trade-offs. I don't mind more battery draw, but how many shades of grey does it support? How bad is the ghosting? How white is the background? Is it clear enough to be used white-on-black? How often does it need a full screen refresh?
Readit News
EInk needs a lot of power to move the heavier ink particles around. If you are doing that more and more rapidly, then even more power is drawn.
By 75Hz, I'm almost certain that LCD is far more power efficient. The LCD pixel (aka the liquid crystal) is a glorified capacitor, it takes some power to charge but it's exceptionally 'light' compared to eink.
That's why LCDs can go faster and faster. It's just physics. A capacitor / twisted crystal uses less power to turn on or off than EInk.
---------
EInks advantage is that if you turn off power, the ink stays put. So you spend a ton of power moving the ink around and then save lots and lots of power over the next seconds, minutes or more.
That's why EInk is ideal for once-a-day updates of prices (or other retailer tasks). The less you update, the less power used.
https://www.crowdsupply.com/modos-tech/modos-paper-monitor/u...
> E-ink screens are quite power hungry when it comes to peak current. Modern high-resolution panels can consume >20 W peak.
This is where I was wondering and yeah, 20+W is pretty hefty to support a relatively small 8" EInk screen or something.
All those updates cost all that power as long as updates are occurring. Maybe you can optimize many of them away (if some parts of the screen don't move, especially if software was rewritten to optimize for the display).
More importantly, it sounds like you've created a full custom FPGA controller over the voltages that go into an EInk display? That's impressive in its own right even if I don't think 75Hz is a good idea lol.
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FPGA or Full Blown Microprocessor are the only choices here. A high power SIMD/NEON arm64 probably could do the job, but I think the Spartan6 is a good choice as well and has more obvious and straightforward parallelism (and probably all the pins required to control the screen. Even a big microprocessor won't have as many low latency pins as an FPGA).
If you think of the refresh rate not as a constant frequency but as variable with user input, there are some cases where driving eink quickly in short bursts could make sense? It seems like this project offers a foundation for such a controller, where e-reader controllers are strictly optimizing for low refresh rates. E-ink is not going to be competitive for playing a video game or watching a video, but you can create a more responsive experience with less eye strain for typical tasks like marking up documents.
Part of the challenge is deciding what belongs in hardware and what should sit higher up in the OS or software stack.
Hopefully, as more people get the kits and the community grows, we’ll be able to think through these questions together and explore where the right balance between hardware and software should be.
Identifying when to increase the refresh rate may be a challenge but I can see it pretty doable for this kind of "limited" scenarios where you either read or navigate a storage app.
E-ink's other advantage is that it reads like paper. In a desktop context I could not possibly care less about the power consumption, but being able to read a forum thread, chat channel, HN discussion, etc. without a backlight would make my eyes very happy.
For text updates, where there's literally a cursor which moves at typing speeds, update frequency is quite low. Where you're updating or paging through documents, paginated navigation (where the whole screen refreshes at once, then remains unchanged for several seconds to minutes or longer) is quite efficient.
LCDs use articulation of liquid crystal chemicals that change shape thus polarization upon application of voltages. They tend to slowly deform back to "the other" state when voltages are removed, and also tend to chemically break down if not moved back to the neutral state. LCDs are driven in pseudo-alternating current for this reason, and never held at either extremes for long time, for this reason.
So you can drive E Ink at 75Hz or whatever, it'll just take more power than it takes LCD to do so, and the last pixel states will persist. Or you can leave LCDs at extremes and disconnect the power, but it will lead to degradation if intentionally used that way.
What you can't do is 1) "watt per frame" figures of LCD, with 2) persistence, and 3) long life. (1, 3) is LCD, (2, 3) is E Ink, (1, 2) is LCD abused as if it's E Ink at expense of rapid degradation, and (1, 2, 3) is the holy grail.
Mysterious future Tech#3 will break the rules. OLED for example uses far less power on black pixels. It's just different.
Color was lower contrast of course.
There are refresh modes now which are very good at partial updates.
Dead Comment
In any case, it is not clear that, even if EInk Displays are somewhat worse in power consumption, they aren't a superior display technology.
If so, won't high refresh rates degrade eink rapidly.
https://github.com/esphome/feature-requests/issues/1109#issu...
This could be actual burn in, or it could be a failure in how they are refreshing (with some potential fix if refreshed properly). I’m not familiar enough to be certain myself, but I personally suspect they are likely being driven too hard and are truly damaged.
In normal e-reader use I’ve never seen this as a practical issue.
https://www.youtube.com/live/okjJURIejIY?feature=shared&t=24...
I also have another display that was exposed to full sunlight through a window for about 8 years. It's now a bit faded as a result.
All in all, I consider it pretty good.
https://files.waveshare.com/upload/4/4e/2.13inch_e-Paper_V4_...
https://files.waveshare.com/upload/6/60/7.5inch_e-Paper_V2_S...
Would it be possible to re-use the power that is stored in them?
I dunno if LCD screens are multiplexed, but embedded LCDs could need as many as 8x on/off cycles per pixel (because you save 87% fewer wires if you chain 8x pixels on the same line and then put them on different biases and have weird COMmon pins and rows and crap).
Sharp claims that a bit of storage is on each LCD/capacitor and this saves power somehow with smarter decision making. I assume it's minimizing the wasted power somehow (or even recycling the previous power shoved into the capacitor, which typically just goes to waste).
It's some proprietary formula in any case, so it's all guesswork. Only the Sharp Engineer/Inventor would know for sure.
I am absolutely not surprised to see his name behind this startup. I've been following his work for years at this point; his YouTube channel has always deeply impressed me, and he's done wonderful open source work in the realm of E-paper for quite some time now.
Kudos to him, and I wish him all the best.
[0] https://www.crowdsupply.com/modos-tech/modos-paper-monitor/u...
I went through that and then bought a Carta 1200 display BOOX 13.9 and it's amazing. Black and white only, but the contrast makes the device usable.
If you know you won't return the device, get it on their website because they'll give you extra pen tips and a case. I got mine on Amazon, so I missed out on the extra stuff because of my return experience.
And pixel-level addressing isn't innovative either. If you've written on an e-ink tablet and observed that the screen doesn't refresh with every pixel change under the stylus, that is surely because pixels are being toggled individually instead of doing a full screen refresh.
So perhaps the only difference is that it's an open source controller that's competitive with commercial e-ink display controllers? That's no small achievement and worth celebrating in and of itself. But it's not at all made clear by the article.
- Making the project open allows people to reuse displays they already own.
- Others can contribute and build on what’s been created.
- Open source firmware, documentation, and the driver board make development more accessible and help remove barriers that previously slowed community projects.
- It’s designed to work with a variety of electrophoretic panels, not only those from E Ink.
In the long run, this openness will strengthen the ecosystem, making it easier for new ideas to take shape and spread.
Regardless of manufacturer (remarkable, boox, supernote…), all e-paper tablets have one major performance problem: quickly scrolling through multiple pages of notes. No idea if the display is the limiting factor, or the cpu, but I’ve hit this issue on all tablets I’ve used. If you like riffling through pages in you paper notebook, you will hit the limit too. I know at least 2 people who stopped using their tablets over time because of this issue.
If this tech helps solve that problem, it’s more important to me than an eink monitor.
Edit: this is mainly important for notes, because sketches, scribbled diagrams and quick notes half-taken in meetings are not really searchable. PDFs and ebooks don’t have this problem.
https://www.crowdsupply.com/modos-tech/modos-paper-monitor
Is there anything mitigating that issue?
Call me crazy, but I'd rather see these guys get a couple million than yet another chatgpt wrapper.
16 levels of grayscale support.
> How bad is the ghosting?
Ghosting depends on the mode you're using and the content.
> How white is the background?
Varies, depends on the panel you're using.
> Is it clear enough to be used white-on-black?
Yes
> How often does it need a full screen refresh?
That's up to you; you can manually clear with a button press, use auto-clear mode, or programmatically control it.
https://www.youtube.com/watch?v=AoDYEZE7gDA&ab_channel=Modos