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E Ink Waveforms are a closely guarded secret (goodereader.com)
226 points by kozmonaut on Sept 15, 2018 | hide | past | favorite | 132 comments

Is it really "closely guarded", or "worst guarded"? Anyone with a logic analyser and a few hours can probably figure it out easily enough... and some have even gone beyond what the official controllers can do:

https://hackaday.io/project/11537-nekocal-an-e-ink-calendar/... (previously discussed at https://news.ycombinator.com/item?id=16140284 )

More research from others:




The waveforms will all likely be disclosed in their patents too:


Certainly a number of drive waveforms and the basic concepts are presented. There are likely implementation subtleties or specific configurations that are not explicitly disclosed.

You can probably figure out a lot about both the implementation, and motivation by digging through the patents.

The patents disclose general categories of waveforms, but they leave out key details of exactly how the final results are achieved. Thus, the final waveform Performance is a combination of patent and trade secret.

Additionally, as others have posted, the waveforms vary for different panels, due to manufacturing variation, so reversing a single example won’t tell you much about how to drive a different panel.

Yes, it would be quite stupid to guard the secret and not patent it. So the title of the article doesn't make much sense.

That’s done all the time. Called a trade secret. https://wikipedia.org/wiki/Trade_secret

As others said, it's quite easy to measure these waveforms, and they have a patent. So "closely guarded secret" just doesn't make sense in this case.

A trade secret that can be reverse engineered by a tinkerer with an oscilloscope in an afternoon.

This is more or less the type of situation patents were invented for: a simple invention anyone can copy once it's invented, but difficult (I assume) to invent in the first place.

Or expensive to invent.

It's why I don't like most software patents, but why I think codecs, especially the modern ones, should be patentable. They're complicated engineering challenges requiring you to make numerous tradeoffs and I feel that just because the result is an algorithm doesn't mean that it shouldn't be patentable.

Other software patents I'm more dubious of, but I feel comfortable saying H.264 should be patentable.

Totally agree. However in many cases, the main technology is invented at universities with public funding. Also, codecs are a means of communication, and I don't think it should be patentable because it can cause problems once everybody settles on a single standard. See the MPEG nightmare, where professional cameras have a license attached to any movie shot with them.

Secrecy and patents are mutually exclusive. The deal you get with the patent is you disclose you invention so secrecy doesn't hinder progress too much and in exchange you get exclusivity.

There is a reason that Coke hasnt patented the Coke formula.

You can patent ideas. Parameter sets are not ideas.

You can measure samples of the waveform, but the tricky part is how the waveform changes with temperature and aging of the e-ink panel to produce minimal ghosting under all conditions.

That's a good machine learning problem. Point a camera at the thing as you change conditions and the waveform and let hill-climbing do the tuning for you.

Wouldn't it be difficult to model the passage of time, without running the experiment for years on end?

Presumably they mean waveform design is a closely guarded secret. At least that's what the quote at the end implies.

You forgot the best resource https://github.com/joukos/PaperTTY discussed at https://news.ycombinator.com/item?id=17896825

You can buy fairly cheap displays from https://www.waveshare.com/ along with Raspberry Pi HATs and the PaperTTY project gives the power to do a partial refresh instead of full screen refresh on these screens. The waveforms are available in the Waveshare open source code and you can modify them as you will.

I am getting my screen next week and hoping to make my own little emacs only laptop using a Rpi Zero.

Recently, I brought a Dasung paperlike HD to use as a monitor. (crazy expensive, prob should've spend money elsewhere...) I thought some things were impossible with eink, but it proved me wrong. (video in a reasonable fps)

It has a few different ways of display. For example: Floyd–Steinberg dithering: essentially only black and white with dithering, and the speed pretty good. A16: uses 16 shades of grey, but the speed is horrible for moving images. So I wonder if a mix of the two can do much better (e.g. moving objects using floyd-steinberg until it stops moving)

Before doing that, I need to know the exact limit of eink. Are some operations slow because the microcontroller or because it is the limit of the display module itself? This article shows such a question is not that easy to answer using the openly available information.

Also, I'm interested if there are algorithmic problems to be solved in this space. (I do research in theoretical computer science). If you are in NYC and knowledgeable I'm very interested to chat (I know little, but I have the monitor you can play with).

Are some operations slow because the microcontroller or because it is the limit of the display module itself?

It's because the technology is a physical one --- tiny bits of reflective/absorbant particles have to physically move up and down to change the state of the pixel. It's almost like a miniaturised flip-dot display:


The response speed increases with temperature and voltage, but temperature is not really controllable and high-voltage high-frequency drivers are not easy to make in the sizes required. Here's an article about someone making his own segmented eink display:


In the comments you can see a picture illustrating the difference the driving voltage makes.

(Also previously discussed at https://news.ycombinator.com/item?id=14124086 )

Related video of someone playing around with the eink material itself, showing how it responds to voltage changes and that it's possible to "draw" on one: https://www.youtube.com/watch?v=jXxSOR1PHpE

I have done software screen mirroring for RTL languages on an Atari ST ages ago. There I had both full images available and I'd just compare source and target rows, skipping 8 rows (IIRC) until detecting change, in which case I'd swap the local area. The start row was incremented after every scan, so I'd be sure to not have missed any pixel after 8 scans. This allowed to track the mouse quickly and also to respond to local changes (text editing) without letting the mirroring thread fully lock up the computer.

For your case, it seems more reasonable to divide the screen into some kind of rectangular cells, keep checksums for the cells and switch them to A16 if the checksum stays constant for two visits? This would avoid the need for a full extra frame buffer while still being relatively accurate. I think one main problem will be that you'd need to modify the screen firmware to do something like that. Probably would make sense to code a software emulation on a regular screen to see what it would look like...

What fps do u get on those modes?

I don't have an easy way to measure the FPS, but here is a video I just took. https://www.youtube.com/watch?v=xW-gatdEC7w

It is reasonable enough to see what's happening, but obviously, I'm not going to watch a movie on that.

Thanks nice to see it in action, bonus points for the RickRoll

I measured 5 fps in that video - surprisingly good from what I understood of eink :-)

well played

Why do you regret buying it?

For 1,000 dollars you can get a hell of a monitor setup instead.

That wouldn't work outside in bright light, and would send bad blue light though.

Been waiting for an e-ink laptop specifically for working with it outside in the sunlight, and in the evening, since blue light is supposed to be really bad for humans at night.

For 1000 USD you can get a Boox Max 2, which is basically full-fledged Android tablet with a great stylus, and which is better as HDMI-capable display too.

"Dasung Paperlike PRO vs Onyx Boox Max2 Pro Extended Monitor" https://www.youtube.com/watch?v=6pw-oCItgx8

I've heard the main thing is input lag; dasung it's tolerable for typing but onyx boox it isn't. That video basically doesn't measure it.

Me too...E-Ink/Clear Ink/Mirasol whatever I don't care...just something reflective and not an LED backlight shining in my eyes. I am angry the patent greed has stunted this for so long. There is no physical reason we cannot have laptops and desktop displays with this tech, it's all business bullshit.

Is it a patent issue?

E-ink has been mired in patent stagnation for a long time. I remember 5+ years ago when the Kindle was getting huge there were rapid increases in contrast, color prototypes like Mirasol that just disappeared etc. I supsect someone bought them and quashed it so they can ensure low production costs and high sales as they are the only "legal" source and don't have to spend money creating manufacturing for larger/better tech. At least that's my cynical view of it. ClearInk has been teasing relflective color prototypes for a while and a purchasable tablet is always "right around the corner" for years but I am not holding my breath. They said monitors are many years away so to me that means 10 with their progress so far. There is no technological block to large E-ink/reflective tech panels...they don't use some rare or exotic materials or have some super expensive manufacturing process using unicorn blood. We could easily have desktop displays using them but it's far more profitable to sell 6-9" e-reader displays to Amazon etc that have a high profit margin.

This company https://www.visionect.com/blog/32-inch-eink-development-kit-... makes a 32" product for signage that doesn't seem to have any input for normal computer use...but its 3500eur. I don't know if they paid huge licensing fees etc or what but the pricing is mental for the tech/materials involved and seems to be purely business/supply stuff. The largest I have seen otherwise is the Dasung stuff that's 13" and 1000eur or the Onyx Boox MAX 13" that is a self contained E-reader and has terrible lag when used as a monitor. I have not found anything between the 13" and this singular 32" available and nothing but the small Dasung designed to be used as a monitor.

Why would you use an e-ink display for videos? The main advantage is the low power consumption because it needs power only to refresh, using it for a video it will negate that advantage and draw much more power than a traditional display with an awful image quality...

Not the OP, but the main reason I want an e-ink display (for programming, which may include animations) is so that I can do it in full sunlight. I work remotely and often work in public places. Working on a park bench, for example, is normally impossible, unless it happens to be cloudy and I'm in a shady place. I'm just hoping e-ink becomes a mainstream thing before I retire.

The new MacBook Pro screen work in full sunlight - it's just about being bright enough.

Another option is to place the back of a plastic screen towards the sun, using it as a backlight.

That's a very power-intensive way of doing it. Sunlight is about 120 watts per square meter[0]. My 14-inch laptop (a Thinkpad T430) display has an area of 0.0543 square meters, so in full sunlight it is illuminated by 6.5 watts of light.

White LEDs are currently approximately 25% efficient (and have a limit of 44%)[1], so my LCD display needs to use 26 watts of electricity to be as bright as direct sunlight landing on it.

My laptop's backlight can't actually do that, but if it could, it would exhaust 70 watt-hour battery in less than 3 hours, without accounting for any power used by the CPU, network card, RAM, or hard drive.

[0] https://en.wikipedia.org/wiki/Sunlight

[1] https://en.wikipedia.org/wiki/Luminous_efficacy#Examples_2

Have you seen an e-ink display?

It is about contrast, not brightness.

You need brightness too. I have both e-ink and MBP screens - both work in the sun.

Just to give some numbers:

e-ink has a contrast ratio of about 20:1 with 40% reflectance. A sunny day is 10000 - 30000 nits, giving at least 4000 nits of brightness.

The 2018 MPB screen has a 1500:1 contrast ratio and about 500 nits of brightness.

So if e-ink is really easier to read in the sun (which I think) then brightness is much more important.

It's not that simple. I cannot explain the physics/physiology of it with any authority, but as someone who suffers from severe strain and headaches with LED (and some CCFL) backlighting I can you it's feeling like something to do with direct vs reflected lighting vs some brightness or contrast metric. Looking at E-Ink or print on paper in a variety if lighting is generally fine (as long as it's bright enough for a normal person to read..obv too dark and different strain occurs)...but an LED backlit LCD even on low settings (so maybe 10% of those 500 nits) results in problems. Stare at a lightbulb vs staring at a white wall that bulb is shining on for a simple illustration. I don't believe it's polarisation either since wearing polarized sunglasses doesn't result in strain and just like an LCD polarizes the light that reaches your eyes, so do the glasses.

1. Currently, I use it for writing code and reading papers. However, I still want the monitor to be a good enough drop-in monitor for things I need to occasionally do. For example, I need to switch to a browser window to check what was that error I'm getting.

2. Visual snow syndrome: Many had their first experience of visual snow after staring into the screen for too long. People who believe in that is the cause of visual snow would want a screen that does not emit light.

What exactly about emitted light is a problem? Light doesn't carry a memory of how it was generated, so it must be some difference in some measurable property, e.g. brightness/contrast/color spectrum/flicker/polarization, or the way these change at different viewing angles. If you know which attributes are important then you might be able to match them with an emissive display.

Emissive displays don’t generally match the brightness of their surroundings; even with automatic adjustment, most are physically incapable of being as bright as a newspaper in daylight, and many cannot be as dim as a newspaper lit only by one of those small book-reading lights without being switched off entirely.

There’s also the spikey spectrum, which looks the same consciously but I’ve seen claims [1] that is messes with our circadian rhythm.

[1] I lack the skill to tell if this is real science or neo-mystic woo.

I found this command that works, so far, on all my Linux laptops, to give much greater control over backlight intensity.

  sudo su -c "echo 200 >/sys/class/backlight/intel_backlight/brightness"
Replace 200 with another number for different brightness.

Haven't found a Windows nor MacOS equivalent though.

I've used it a fair bit in conjunction with Redshift to get a screen that's reasonable for reading ebooks in low light.

I'd buy an e-ink laptop tomorrow if there was one.

I think most people are forgetting that LED backlights are controlled usually using PWM which flickers, fast, but still flickers. I haven't found any research about how it might affect humans. I suspect it would be better if no-flicker current-controlled LED backlight was used instead of PWM.

According to notebookcheck only about half the devices they tested use PWM:


It seems to be well known that it for low frequency PWM it causes headaches for some people, so I would expect that there is at least some research in that direction. That said, it seems to only be a problem for few people and only for very low frequencies.

>Emissive displays don’t generally match the brightness of their surroundings

How so? You can set any brightness you want to match the environment. Usage under direct sunlight is one edge case e-paper is clearly better at, and any usage with poor environmental lighting is detrimental to your eyes itself, regardless of technology.

I'm really sceptical about the entire "E Ink is better for your eyes" thing until I see some serious studies. People managed to ruin their eyesight centuries before computer screens. There's just too many factors at play here, from genetics to typography.

It’s not that they don’t auto adjust. It’s that they’re physically incapable of the range of light intensity we encounter in a normal day. For example, full afternoon sunlight is something like 150,000 lux, but normal house lighting is ~200(in a good scenario as high as 500-1000). The same is true on the other end of the scale.

Staring directly at a light source strains the eyes more than watching reflected light.

By what mechanism of action? It can't possibly be true in general: e.g. staring at the reflection of the sun in a mirror strains the eyes more than staring at a candle.

If I had to guess it is probably a few things.

Firstly staring directly at a light source means that you are seeing most the rays directly. The only attenuation you will receive will be scattering from the medium - presumably air which will be low.

Seeing it from a second surface adds more effects - the surface may have absorb some of the light. Any real surface is also not going to have perfect reflectivity (everything from scattering, internal diffraction and destructive interference could occur). In short there will be loads of secondary/tertiary effects causing attenuation. Someone also mentioned polarisation, I also wonder about interaction between reflective surfaces which could cause additional attenuation via interference but the physics of waves has never been a strong point.

The other major factor is the physiology of the eye - we evolved from a world that didn't have abundant light sources and it's hard to know the effect of focusing on a source of light that differs from the ambient profile.

A reflection of the sun on a mirror is a reflection of a very strong light source through a perfectly reflective medium.. A book or an e-ink screen is still ultimately sunlight, but it has scattered (which is reflection too) while passing through the atmosphere many times before reaching what you are looking at.

Could this be some unknown effect of polarized light vs. non-polarized?

So it's a question of total light intensity, not of being reflected or "direct" (whatever that means).

I don't think so myself because I don't have pain in full sunlight reading print or E-Ink which is much brighter "nits" than an LED backlight produces ....but even low settings on an LED backlit computer hurt. There is in my opinion a difference between looking into a light source and looking at things that are visible due to reflected light like E-Ink, paper, the objects around us even if I cannot quantify it with scientific explanation.

This makes no sense to me. There is only one kind of light and it has just so many parameters: basically, the distribution of intensities along the spectrum. If reflected and emitted light have the same intensities there is no physical way to distinguish them.

Ok. Regardless of the intuition, staring into a light source feels different to everyone I have ever known that staring at normal objects reflecting light, like paper etc. Someone above claimed that reflected daylight was a lot more nits than a laptop could put out so I was going with the idea that this is true. I can look at paper in bright daylight with no eye strain. I cannot look at most LCDs even at low brightness without bad eye strain. It's not PWM in my case as I have ruled that out. Its much worse on LED displays. Fact remains that staring at backlit stuff gives people eye strain in ways printed or reflective never does and it seems logical that staring at the direct light source is a part of this.

I know its not scientifically measuring nits/lumens etc but stare into even a low wattage (15w etc) light bulb for a few min and see how it leaves you feeling...seeing spots etc. Then stare at a newspaper or book or E-Reader under a 250w lightbulb or even brighter sunlight outside...and notice how you do NOT have that same problem. Even with a much brighter light source there is something different about how/how much actually enters your eye. I'd love an answer as this is a major life problem for me.

I think the difference may be in the contrast between the letters. A printed paper under the sun is very bright, but the black letters absorb most of the light and they are very dark and easy to tell apart. For a bright computer monitor, both the black and the white pixels are very bright, forcing the eye to strain itself to distinguish between two very bright intensities, which is difficult. Does it add up?

I am sure contrast is a variable but overall this still doesn't seem to solve the issue for me. A faint grey pencil on paper is not straining, but even the best contrast displays like OLED are very straining. It's literally again the light shining at you and the entire thing you are looking at being a light source that I believe is the problem. I don't see sparkles or glows or any of those sorts of things looking at printed text or reflective tech...but I do see it when an LCD display is backlit. Even the blackest black on an LCD, on a white background, has an illuminated feel vs a printed/flat feel. The only time reflective tech/paper bothers me is if there isn't enough light to see normally as with anyone. LCD's, esp most LED ones, it's nearly all the time.

If I look at a matte LCD display (glossy doesn't work in this example due to reflection) in bright sunlight there is a narrow window of display brightness where the things are bright enough to be readable but the sunlight overwhelms the "lit" effect and it appears sort of like you would expect color E-ink too...more flat and printed like the display is now reflective rather than backlit..but it's a very narrow sweet spot that's hard to maintain and I cannot seem to replicate well with artificial lighting inside as it takes a lot more than a 60w bulb even directed right at the display and glare starts to become a factor with a more concentrated light source vs ambient, indirect light from outside. Brightness too low and it's unreadable due to contrast, too high and you get the glow again. To me the root problem is the backlighting somehow...possible combined with dithering or other rendering games that cause even static images to be moving as far as the eye is concerned. But it's not a common enough issue for industry to care about, and as with most things, until individuals suffer from something themselves, they often refuse to believe it's an issue for others.

How well does it fare for those tasks (code and papers)? I'd very much like to have such a screen but the price tags of what I've seen so far is probihitive…

> I use it for writing code and reading papers.

Does it look good with white text on black background ?

It does not look good, and black causes ghosting.

I was under the impression that Visual Snow was a symptop of anxiety?

Visual snow could also be to to flickering from PWM, or more likely temporal/spatial dithering (a leading theory in LED LCD based eyestrain but as yet unproven as the cause). Even a white background on a monitor, even a static image, isn't just static white...it's constant flickering of pixels to make a certain "white" and to smooth moving images as well. Whatever the ultimate cause it's not normal or healthy to stare at emitted light most of the day and most of us do...add flickering and other visual tricks displays use and it's no wonder eyestrain exists. Nobody would stare at a 300 nit lightbulb for hours and call that reasonable, but that's what backlit LCD displays are. I didn't have a problem for most of my life, and still don't with books under proper lighting, but now I have a severe one with LCDs that and cannot find a definitive answer or fix and frankly it's crushing a last chance I have to be somewhat independent and survive.

anxiety is a symptom of an underlying nervous system dis-order. so staring at a screen for long periods of time is hard on an organisms nervous system (to remain in place for so long without movement). So visual snow and anxiety both stem from the underlying structure being at dis-ease.

Visual snow was a thing years before computer monitor existed.

> The main advantage is the low power consumption


The main advantage is that it's easier on the eyes

People keep saying eInk is better than reflective black and white LCD, such as that found on calculators.

I’m unconvinced, but (obviously) to test this I would have to actually get a monitor sized black and white reflective display, and I can’t find any of those — largest I have found so far is 320x240 for about £200

I haven't seen a reflective black and white LCD matrix that didn't suck. Think TI-82 calculators.

That being said the segmented LCDs like those found in 4 function calculators and wrist watches usually look fantastic.

IMO you do not have to go that far for graphical reflective LCD that didn't suck: TI-89 has one. Also LCDs in Psion handhelds were quite reasonable.

I can't find my TI-89 to compare but I have a TI-85 and TI-83 from the late 90s and the newer 83 has a noticably better screen so you're probably right. I recall being impressed by the TI-92's screen but I sold mine long ago so I have no basis for comparison.

I had a TI-83. Yes, the resolution was terrible by modern standards. The contrast was fine until the batteries started to die.

If I didn’t already have way too much on my personal to-do list, I’d be interested in converting an LCD with a backlight into a reflective one. I assume it’s not possible with all models, but also that it is possible with some.

Ben Krasnow (Applied Science on YouTube) did some research into driving e-Ink displays, and he made some similar observations:

> All of the lookup table information has been removed from this datasheet, because the industry thrives on secrecy or something

Highly recommended, as usual for him it's a great video/write-up:

* https://www.youtube.com/watch?v=MsbiO8EAsGw

* http://benkrasnow.blogspot.com/2017/10/fast-partial-refresh-...

Yeah, his series is really great and it made me realize the FW flashed on these CARTA panels are actually nothing but the raw waveforms themselves.

One thing that I want to note is that while their documentation might be closely guarded secret, the actual waveforms are actually available out in the open.

For instance here are the raw waveforms for one of the latest Carta generation e-paper panel:


  ~ hexdump -C epdc_ES103CS1.fw | head -10
  00000000  34 88 c4 7c 01 2d 01 00  dd 09 00 00 07 06 a4 00  |4..|.-..........|
  00000010  03 58 21 1d 3c ca 01 85  02 00 00 00 40 00 00 fe  |.X!.<.......@...|
  00000020  47 00 00 01 00 04 0d 00  ff fc 00 00 00 00 00 54  |G..............T|
  00000030  00 03 06 09 0c 0f 12 15  18 1b 1e 21 26 2b 30 28  |...........!&+0(|
  00000040  00 00 00 00 00 00 00 08  3e 05 00 00 00 00 00 e8  |........>.......|
  00000050  cb 06 00 00 00 00 00 c8  8d 0a 00 00 00 00 00 a8  |................|
  00000060  4f 0e 00 00 00 00 00 98  00 00 00 00 00 00 00 a0  |O...............|
  00000070  65 00 00 00 00 00 00 a8  bc 00 00 00 00 00 00 b0  |e...............|
  00000080  0b 01 00 00 00 00 00 b8  5a 01 00 00 00 00 00 c0  |........Z.......|
  00000090  aa 01 00 00 00 00 00 c8  31 02 00 00 00 00 00 d0  |........1.......|

E Ink seems to be one of the technologies that is hampered solely by patents. It's too sad that we're only going to get major innovations in e ink tech in 15-20 Years...

We shall see if you are correct very soon (for display tech anyway). Key (initial) patents have already stared expiring and will continue to do so quite quickly (1-5 years).

Check : - https://patents.google.com/?assignee=E+Ink+Corp - https://patents.google.com/patent/US6422687B1/en?assignee=E+...

I don't understand how that is even possible. Patent owners want their cut, but in the end they want the product to be made, too, because that's the only way they get money. So they will take as high a cut they can negotiate, reducing the margins of the end manufacturer to a marginal price. But that is the case with every "supplier".

At work I looked into integrating e-ink into a product, and the problem seems not patent fees, but availability. Granted, that could be due to patents itself, but the answers I got why it's hard to procure e-ink display were sadly "the end customers don't want it" and "e-ink is dead".

It's possible because people have different theories of what will benefit themselves. In a functioning marketplace, different suppliers will explore different options. With a monopoly, which is what patents are, you're stuck with whatever notion the patent-owner has.

One perfectly reasonable theory of self-interest is to keep prices very high. Yes, they could drop the price and possibly make more. But they could end up making less, and they'll certainly have to do a lot more negotiation work.

As an analogy, look at Apple. They have less than 20% of the smartphone market, but make 80% of the profit. [1] They were way ahead of everybody and could have captured a much larger share of both the phone and tablet markets. They're using a different theory of self-interest than the other players.

[1] https://www.investors.com/news/technology/click/apple-rakes-...

I think that theory boils down to margins.

The people making zillions of phones make a fraction of the margin Apple does on it's cool phones.

A VC will not invest in a firm, if someone else has the ability to extract all future profits via patent licensing

Funny how the name of the company (E Ink) became almost synonymous with the actual tech (EPD, or electronic paper if you want to generalize).

You can't keep things secret by patenting them. These are trade secrets, which last indefinitely. However, trade secrets are granted fewer protections.

and the historic basis of patents is “Strong protection for 20 years, but you gotta share your invention”.

Would/could/do Chinese manufacturers ignore those patents? Are they not able to sell abroad if they do?

It's a common misconception that there is no IP law in China. Patents do exist, and you do have to respect them (at least if it is a chinese patent or you intend to sell into the patent's country). Of course, as with many things there, enforcement is spotty, so you might get away with it for a while. But the days are over where you could completely fly under the radar with a grey market production. It's hard to completely hide your big ass illegal factory in Shenzhen, especially when you have to register every little thing with the state. As in every other country, your competitors or patent owners can just get a lawyer, look up your address, and sue you.

Granted, I do understand that from the perspective of a western entrepreneur trying to do business in China it seems to be a lawless space, especially if you've been burnt by fake products from Alibaba etc..

Importers would likely get their shipments seized. It's not illegal for manufacturers to export their goods out of China, but US customs doesn't look too highly on importing goods that contravene on registered US IP.

Small time shipments are unlikely to be looked at (eg. if someone buys a single electronic ink display off of AliExpress), but someone actually importing many displays for resale would likely eventually get caught.

Honestly how would you even know if the e-ink displays infringe on IP? I can’t imagine them doing anything.

A patent gives you a monopoly which makes things easy.

You occasionally search the market for products that contain your tech (in this case eink), then look in your records to see if they bought/licensed from you.

But is it that infringement can be proven only by a court? So can US customs do any thing in such cases, even if we assume they have the competency to judge if a particular import violates IP.

They file a case, and ask for a preliminary injunction. And once that's granted (which is likely), they take that order to customs, and customs will start looking for those devices in shipments from your supplier or to you.

Enough market/distribution and either the patent owner or a patent troll will find out.

Nobody in their right mind would invest 100M in a production line that is likely to be shut down.

Usually you don't have to buy the line, you order sub-assemblies from different suppliers and do final assembly.

Considering that you can buy 5$-20$ E ink panels on Alixpress today, I would guess those manufacturers do ignore western patents.

I think there are already some which do --- we just don't hear about them much because they tend to be fairly anonymous (for good reason).

I remember reading about "fake" Kindle replacement displays showing up on eBay a while ago, not as good as the real thing in terms of image quality etc. but certainly usable, so someone is clearly making them...

Some info https://hackaday.io/list/35814-e-paper here and especially from the links provided, everyone is working from http://essentialscrap.com/eink/waveforms.html and http://spritesmods.com/?art=einkdisplay

And https://hackaday.io/project/21168-fpga-eink-controller has an FPGA doing waveforms by extracting them from existing firmware. So while it might be a closely guarded secret, just replicating it is possible.

In my experience, memory LCD has been a better technology to work with: https://www.sharpsma.com/sharp-memory-lcd-technology

No crazy +/- 40V lines, no external driver circuitry, and extremely low power. Not as low power as E Ink, but since you don’t need to drive wacky voltages, your power budget math will come out the same or better.

I’ve never seen one in real life. How are the display characteristics compared to eInk?

If you’ve ever seen an OG Pebble, you’ve seen that display. It looks like a better resolution gameboy display. Very little space between pixels.

Some models are different, though, and basically turn into a mirror when their pixels are turned on, rather than become matte black.

Adafruit sells a dev board for 25 bucks. Perfect for low power wearables, much better than E Ink.

I disagree that memory LCD is better than e-ink. Although, mLCD can do colors and better refresh rates but the colors are washed out, in sunlight grayscale e-ink is much much more readable in my opinion. mLCD also consumes more power in certain cases which isn't ideal.

Is this tech relatively new? Is it merchandised as "memory LCD"? I would like to know when searching for e-reader displays in the future.

It is not new and rarely mentioned in advertising or product information. The memory LCD I've seen are too small for a normal e-reader but if you are doing a large production run you can have something custom made.

Unfortunately, what the article described sounds a lot like a thermometer coded delta-sigma DAC or other similar design.

How these are constructed and used are well known, and they're probably lying about "closely guarded" to make sure people don't realize it is just a clever usage of an off the shelf part, and none of the magic is in-house.

Where would one anonymously publish an E-ink data sheet with waveforms if they had one?

Traditionally, PUDN -- but it has never worked for me. Otherwise libgen comes to mind.

You can send it to me.

Are you author of the linked article? What's contact info?

use the contact form on the website for the linked article.


Here is a teardown of a 13.3 high perf E-ink monitor I did a few months ago: https://kevzettler.com/2018/02/11/dasung-paperlike-pro-teard...

The post identifies some on market E-ink display components and discusses the design of a proprietary display driver.

"On closer inspection all the chip components have had their labels chemically peeled off to prevernt reverse engineering."

Wow, I've never seen that. Is it a common thing? It also puts me off buying one of these (assuming the $900 price tag hadn't put me off already).

I've seen it a lot in Chinese electronics, and it only deters the least effort of reverse-engineers.

Erased markings are usually a sign of off-the-shelf parts; they didn't go to the effort of printing their own branding on them.

Did you eventually switch the panel to ES133UT2? Dasung released a new version called paperlike HD (also called paperlike 3). In that version, it does not look like having a glass panel.

I have acquired an ES133UT2 (and data-sheet with what appears to be waveforms) but have not replaced it because I damaged the cover of the Dasung during disassembly which means the display module would not be held securely to the screen.

The article doesn't mention this anywhere, but the "waveform" is usually a 4D lookup table with target and previous grayscale value, temperature, and frame number.

For extra fun for all the people trying to reverse it, the exact waveform data changes per batch of displays. The overall strategy will remain the same though.

If you want to see a more complete list of waveform names you could probably go look at the gpl releases of popular readers...

I wonder if eink would be really useful to make a low powered smartphone. As long as you use software which doesn't burn a lot of power, like email and other stuff which is designed to run with fewer cycles.

At that point I would really care for software with a minimum amount of non fancy feature that doubles or triple battery life. If you make extensive use of text, and don't use high resolution image or set low limits, there are surely ways to make a more durable device.

Cheap androids are awesome, but I have no idea why they're becoming slow as they age, and I'm sure software is always to blame. I really crave minimalist designs when it comes to hardware and software.

The display is only part of the story. You could save some battery life with an e-paper display sure, but you still have the CPU and radio grinding away at the battery. The ultra power saving mode on my Samsung phone is a good example, it throttles the CPU, sleeps the radio aggressively, restricts the phone to only running a few basic apps, and turns off most of the OLED display. I can increase battery lifetime by almost a factor of 5 with that on.

An e-paper display would save a bit more, sure, but the type of display isn't the only limitation to a low-power smart phone. You need to design the whole thing to work together to save power; changing one component isn't gonna be enough.

This is really frustrating as if you already have an FPGA (and appropriate regulators), the controller is just redundant overhead (in every metric conceivable). I'm glad to see at least the beginning of reverse engineering as some of the panels (typically kindle replacement panels) are quite affordable and even the $450 13.3" panel isn't unreasonably expensive. (An FPGA-powered PocketCHIP-like device with e-Ink would be a lot of fun).

Is Waveforms what is in Epsons eink controller chips?


Japan display has made 600 dpi controllers. http://www.j-display.com/english/news/2017/20170522.html

Further been thinking of building an Eink based smartphone, the eink display would have low power. Some kind of low power small system board running Linux and a 4g modem. Not sure what system board to pick. Batteries should be LifePo4 Lithium iron for battery safety. What kind of high resolution touch based eink displays are out there which are easy to drive from a small Linux system board?

Anyone interested in running linux on their Kindle should check out http://fread.ink

Juul spent a good amount of time working out how to read the stored waveform configurations (different for each unit) and getting them to run at a reasonable speed.

I'm looking for an e-ink monitor (along the lines of https://cloudconfusing.com/2018/09/18/e-ink-monitors-ready-f... ). Would this work for that?

Seems like a good use case for PID loops -- drive the pixel really hard for a brief moment to bring it to the target value faster than might otherwise be possible.

Seems limited only by the voltages that just end up frying parts.

For a PID loop, you'd need to be able to measure the position and velocity of the black dots. Velocity seems very hard. You could conceivably measure the position with a camera looking at the image, but will people want an ebook reader with a camera sticking out in front?

Good point. Maybe not a PID loop at all, but rather an well tuned open-loop controller that compensates for the natural time response of the e-ink pixel.

Usually when a piece of tech is protected purely by obscurity in this way, the tech isn't really tech. It is more likely something that a decent programmer/hacker could figure out in a day or two. That's why they are scared to share any info - because even just a single sentence could be enough of a hint to a competitor in how it works.

Is E Ink anything more than a marketed technology with no real purpose?

One can calibrate the brightness, white balance (e.g. Apple's True Tone), resolution, etc of a regular LCD or OLED display so that the same amount of photons hit your eye (and are more tightly controlled when you move the display around) as with an E Ink display, and get better resolution color, and saturation to boot.

Besides the idea that it was easier on the eyes was never backed by any substantial scientific studies, it was just "but it's like paper, so it should be" plus some manufacturer sponsored crap.

Well, there's the extended battery life I guess...

Screen persistance with zero power can be a pretty big deal. It's always nice (ish) when my Kindle has the 'your battery is dead' screen on when I go to use it, so I know what's going on even before I try to turn it on.

Other than that, it's hard to compare because nobody makes large monochrome lcd displays. Monochrome is actually a feature for the intended use: newspapers and books use a pretty limited amount of color, so you get improved pixel density and geometry without having to split pixels into colors.

OLED won't work for dark text on a light background, and tends to be rather expensive -- I can't imagine a Kindle sized device with an oled display for less than $200, so that limits it to the high end models.

Eizo still makes monocrome LCD monitors. They are for medical diagnostic purposes. https://www.eizo.com/products/radiforce/gx550/

I have a Kindle reader with an E Ink display. It is much more pleasant to look at in daylight, especially when ambient light is very bright.

Battery life is also much, much better. My tablet lasts two to three days at most, under light load, with power saving turned up to eleven. The Kindle can easily last one to two weeks. (It all depends on usage patterns, of course, but for my case those are the numbers I come up with.)

I do agree, though, that it is hard for me to think of a use case other than an ebook reader. For that particular case it is perfect, though.

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