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E Ink Waveforms are a closely guarded secret

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Re: E Ink Waveforms are a closely guarded secret

#91

Post by toast0 »

coldtea wrote: post #63

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 wa…

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.

Re: E Ink Waveforms are a closely guarded secret

#92

Post by tlb »

etaioinshrdlu wrote: post #53

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?

Re: E Ink Waveforms are a closely guarded secret

#93

Post by ddingus »

wpietri wrote: post #47
captainmuon wrote: post #11

Earlier quoted context omitted.

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 pa…

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…

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.

Re: E Ink Waveforms are a closely guarded secret

#94

Post by ByThyGrace »

ehead wrote: post #48
robin_reala wrote: post #20

Earlier quoted context omitted.

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.

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.

Re: E Ink Waveforms are a closely guarded secret

#95

Post by URSpider94 »

sofon wrote: post #42
userbinator wrote: post #3

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: http://essentialscrap.com/eink/ https://news.y…

The waveforms will all likely be disclosed in their patents too: https://patents.google.com/?assignee=E+Ink+Corp 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.

Re: E Ink Waveforms are a closely guarded secret

#96

Post by dbuder »

Avamander wrote: post #72
ben_w wrote: post #49

Earlier quoted context omitted.

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 mess…

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.

LED backlights are current controlled. LEDs don't like having current through them all the time and that's why they are PWM controlled unless it's a crap consumer product.

Re: E Ink Waveforms are a closely guarded secret

#97

Post by dbuder »

ByThyGrace wrote: post #94
ehead wrote: post #48

Earlier quoted context omitted.

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.

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.

Re: E Ink Waveforms are a closely guarded secret

#98

Post by akvadrako »

akvadrako wrote: post #80
abraham_lincoln wrote: post #62

Earlier quoted context omitted.

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.

Re: E Ink Waveforms are a closely guarded secret

#100

Post by userbinator »

rwmj wrote: post #41
Vekz wrote: post #27

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.

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