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Posted by rbanffy 3 days ago

E-paper display reaches the realm of LCD screens(spectrum.ieee.org)
613 points | 204 commentspage 2
cubefox 3 days ago|
This still uses a classic electrophoresis panel, perhaps even one that is produced by E Ink. These work by moving solid particles (pigment) through a liquid. Which is inherently a physically slow process. At high refresh rates there will be significant amounts of ghosting.

To get past that, we would need a different panel technology, a type of reflective ("e-paper") panel that is not based on electrophoresis.

Years ago there were many such display types in development. One option is electrowetting displays. Liquavista was a company that had a screen where tiny oil droplets were switched between being either round and small or flat and large, using high voltage. The flat droplets would cover the background of a pixel and make it dark, while the small ones would "hide" in the corner of the pixel to make most of the background visible. This is pretty fast because the oil droplets are surrounded by air, which doesn't resist the movement of the oil, in contrast to moving solid pigment through a liquid.

Another option was to to have microscopic mechanical (MEMS) plates inside a pixel, which produce color by creating light interference. Qualcomm's Mirasol tried to do that. The wavelength of the reflected light depends on the gap between the plates.

The cool thing with interference e-paper is that you can theoretically make a color display which doesn't need RGB subpixels. Colors could be created by continuously adjusting the gap rather than doing binary switching between black (UV or IR) and either red, green or blue. Not having RGB subpixels greatly increases contrast on colored screens because it can reflect much more light. An issue is that shades of white and magenta can't be straightforwardly created with interference, because those are not monochromatic colors with a single wavelength. Anyway, Qualcomm closed Mirasol just as they tried to make these subpixel-free screens viable.

kayson 3 days ago||
What about cheaper, bigger displays? I want something that's ~16" but doesn't cost an arm and a leg, for displaying sheet music. Still haven't found anything that's suitable. Plenty of people I know use the 13" iPad Pro, but between the glare (stage lights can be intense) and the roughly-letter-paper size, I still prefer sheets of paper.
EGreg 3 days ago||
I want color e-paper that can show large paintings, like 30” x 40”. When is that coming out finally !!
taneliv 3 days ago||
If you're happy with grayscale, biggest from Good-Display[1] offers 25" x 33". If you want bigger, you'll probably have to wait until Samsung's new 75" EMDX panel[2] becomes available for purchase.

[1] https://www.good-display.com/product/452.html

[2] https://news.samsung.com/global/samsung-showcases-color-e-pa...

bgarbiak 3 days ago||
How about mobile monitors? Like Uperfect?
brenf24 3 days ago||
A few thoughts: it would be cool if the controller could do targeted refreshes to conserve power, only flipping pixels that changed.

It would be cool to see a Linux distribution with a gui and windowing system specifically designed for e-ink displays.

Not sure what optimizations would even be needed…

WillAdams 3 days ago|
Presumably the Pine Note folks have been looking into that, and presumably it's one of the goals of their Developer Edition:

https://pine64.org/devices/pinenote/

efitz 3 days ago||
FPGA and e-ink at 75Hz? It sounds like it will have a high power draw.
alex-a-soto 3 days ago||
Our driver board, under continuous use, draws about 1 to 1.5W. A recent article below goes into some detail about our design choices.

https://www.crowdsupply.com/modos-tech/modos-paper-monitor/u...

dotancohen 3 days ago|||
I use E-ink for the reduced eye strain, the battery draw really does not bother me. I like having devices that last weeks on a single charge, but I would gladly charge them more often for an increased refresh rate.
dankwizard 3 days ago||
If your phone screen became a 75hz e-ink display I'm pretty sure that would actually drain your battery faster than currently, which I assume is once per day. Would you accept that compromise of going from weeks to <1 day?

Curious.

8organicbits 3 days ago|||
Just an anecdote, but my phone ran out of battery most often when a full charge lasted almost two days. It made me lazy about charging at night. Now I have a wireless charger next to my work computer and in my car, I probably don't need to charge at night any more. Granted, I'd prefer a large battery when I'm traveling, but battery size is less important to me recently.
dotancohen 3 days ago|||
I'm curious too. But I would definitely take the risk and purchase such a device, so long as it comes with an EMR stylus.
amarant 3 days ago||
Compared to other e-ink devices, yes.

Compared to LCD, oled or what have you, my understanding is that it uses significantly less.

dragontamer 3 days ago|||
LCDs can have superior power draw than EInk.

See the microwatts of power that Sharps MemoryLCD displays have. They often beat comparable EInk screens in power draw.

aydyn 3 days ago|||
Is that because it doesnt have a backlight?
amarant 3 days ago||
I think a large part of it is because modos is really good at partial screen updates. This is also, in my understanding, how they achieve the high FPS rate.

The parts of the screen that doesn't update, courtesy of being e-ink, don't use any power at all. LCD will use power if you're looking at a static image, eink won't. And a lot of the time, 95% of the screen is a static image and only 5 percent actually updates. One of Modos' biggest innovations is successfully taking advantage of that.

ranger_danger 3 days ago|||
So it's not actually 75hz all the time then? Depending on what's on the screen?

That's unfortunate.

I'm imagining a fast scrolling game with complex backgrounds where most of the pixels are changing values every frame, I assume it completely breaks down in that case.

amarant 3 days ago|||
It's 75hz when it needs to be, but if 2 frames are mostly identical, it doesn't needlessly move ink around. Effect: 75hz always as far as the user is concerned, but sometimes it uses less power than that when possible, due to very clever optimisations at the firmware level.

Or that's how I understand it anyway.

I saw that Alex Soto himself is in this comment thread, he'll know a lot more than me, I'm just spreading what little knowledge I've gathered from his blog posts and some of the discussions in the modos mastodon server.

I've probably misunderstood a lot of that too, I'm not a hardware engineer, just a lowly java dev with a strong but hobby level interest in eink.

Modos is my dream laptop, but it's currently unclear when that'll become reality.

Again, Alex Soto will know more.

carlosjobim 1 day ago|||
For a fast scrolling game it makes more sense to use a display which is made for that.
lo0dot0 2 days ago|||
The display can only show a video well that has this property of only updating parts of the screen but not everything at the same time? What if the video content is like so?
pathikrit 3 days ago||
I made a e-ink newspaper display: https://github.com/pathikrit/newswall

This would be amazing

justinclift 1 day ago||
Wonder if you could make some kind of epaper laptop by combining one of these displays + controller, with a Framework motherboard/keyboard/components and 3D printing your own chassis?
ChrisMarshallNY 3 days ago||
> instead of our secret sauce, we have open sauce

I enjoyed that quote.

Not really knowledgeable enough about the tech, to comment further, but I like EInk, and look forward to seeing it be more useful.

Thanks!

notepad0x90 3 days ago||
I'm ok with E-paper's capabilities, the problem is cost. Even though it can't display all the content TFT & LCD can, it costs a LOT more. I'm not a hardware person, I just looked into the cost of working on an E-paper based wall-spanning display and just stacking LCD's and doing something ugly was much cheaper. I suspect it has to do with the wholesale economics and its demand.
schaefer 2 days ago||
Congrats to Alex and Wenting on the reaching your funding goals for the Modos Developer Kit! I'm a backer and soon to be hacker.

[1]: https://www.crowdsupply.com/modos-tech/modos-paper-monitor

Nelkins 3 days ago|
I would love to have an eInk tablet that I can watch videos on (color not required). I frequently watch educational YouTube videos before bed, but I’d prefer to have something that isn’t beaming light into my eyes. Does something like this exist on the market today, or do I need to wait until this product gets released?
fdsfdsfdsaasd 3 days ago|
That's about the worst use case for existing eink panels, as they have a limited number of switching cycles before the dots start to degrade.
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