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Japan Display Demos a 600 PPI E-ink Backplane

E-ink screen tech hit a plateau three years ago when the Kindle Voyage was released with a 300 ppi screen. We haven’t seen any increase in E-ink screen resolution (and not much in the way of new E-ink tech, either) since the Voyage was released, but that changed today.

Japan Display is demoing a pair of new backplanes at SID Display Week this week. When used as parts of E-ink screens, the backplanes will allow for 400 ppi and 600 ppi screens.

JDI described the new backplanes as using LTPS (Low Temperature PolySilicon) tech, and said that it could be used for higher resolution screens on par with high-end smartphones screens.

Right now the sharpest e-ink screens on the market can be found on the Kindles, the Kobo Aura One, the Boyue T63, and a handful of other ereaders.

The new screen would be twice as sharp and have four times as many pixels.

It will also require a more powerful CPU to drive the extra pixels, and that means either a bigger battery or shorter battery life.

So while enthusiasts may one day get the high-res E-ink screens they’ve alway wanted, those screens are going to come at a price – a price that some won’t want to pay because we can’t really see the difference between a 300 ppi screen and one with 400 ppi, or 600 ppi – not when we’re reading text, anyway.

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Feda May 24, 2017 um 7:27 am

"It will also require a more powerful CPU to drive the extra pixels, and that means either a bigger battery or shorter battery life."
That’s not a given. A lot of emphasis is being given to efficiency with new processor designs. The problem with e-readers is that manufacturers are not keeping up with new developments these days. They keep trying to squeeze the last bit of profit they can from old hardware and software.

tired May 24, 2017 um 7:49 am

Contrast is #1, resolution is easy but not as important. A low res screen with 10x the contrast would look far superior to a high res screen.

The plateau was not achieved by hitting 300 ppi density, it was achieved by the halt of generations improving contrast. A light helps but it’s no replacement for having a screen that is actually on par with the native contrast of paper.

Nate Hoffelder May 24, 2017 um 9:03 am

Contrast matters less to me because I don’t even know what that means in real terms.

I’ve used ereaders with Vizplex screens and not really been able to tell the difference between Vizplex, Carta, and Pearl (other than resolution). And I’ve seen Carta screens that vary significantly in terms of quality.

Screen resolution is easier to measure.

tired May 24, 2017 um 2:45 pm

I’ll put it in real terms. If you sit in a room that’s not brightly lit you can read off paper and not eink (with no use of a front light). If you put eink next to paper the paper looks white and the eink looks grey in background and the ink on the paper looks black while the ink on the eink looks again grey.

Just try that, open up a paper book and then put it next to an ereader with the light turned off and then you’ll see what I mean. It should matter considerably more to you than resolution. Resolution is more easily MARKETED, not what is the most important.

The front light on eink readers is a bandaid but doesn’t truly address that fundamental shortcoming.

Contrast is easy to measure with equipment. It has been rarely done with ereaders but is done by many, many sites for all other display tech. The punchline is that no ereader breaks 10:1 in real world performance. The human eye can perceive up to 300:1 ANSI contrast.

When you say that "screen resolution is easier to measure" I think you really mean that it’s easier to MARKET. Yeah no kidding that’s why idiots buy 4k tvs at a size where they can’t see better than 720p. Bigger numbers is easier to sell.

Now the elephant in the room is the frontlight… so does that solve the problem? No. People don’t understand that it shifts the luminance of the page up but it doesn’t actually help contrast. It makes it more readable, but it doesn’t make it pop.

Is this still an issue? Yes. People still return kindles because they are surprised that eink readers look like reading old newspapers. In my mind this is the most important issue with eink, but out of ignorance and marketing buzz people don’t recognize or understand it.

Frank May 24, 2017 um 9:38 am

I notice the different between the 212 PPI Paperwhite 1 and the Paperwhite 2 with the same 212 PPI while having a higher contrast ratio.

It is unfortunate that all Kindles since the 2014 Voyage (except the basic one) have the same screen tech.

Stefan May 25, 2017 um 8:42 pm

I’ll make a wild assumption that we might get a somewhat better "sense" that the contrast is higher, even if the quality of each point has the same qualitative character. My speculation goes on the notion that since it is front-lit and the light we see is a bounce back to our eyes off the reflective back surface, the higher density field of capsules might prevent as much perceived leakage, making the overall "darkest" portions of the image appear closer to "black", even if the relative contrast between each element using the same dithering pattern wouldn’t be increased. Of course, given the 600 ppi resolution capabilty of the higher-end panel, when displaying image content, the dithering algorithm might be changed to possibly produce a smoother graduated effect between shades, depending on the base resolution of the image. ( OK, that last part might be wishful or fanciful thinking. 🙂 )

Stefan May 27, 2017 um 8:50 pm

I wonder if it is e-ink as we know it, though. Details seem a bit sketchy. LTPS has been used in displays before,as we know, with equal resolutions, namely in LCD displays. It’s known for that aspect and the flexibility that it offers.

What if they’ve just shared techniques between companies for employing Bistable displays, with a reflective back layer, low refresh rate and the result it is just a regularly addressed high-resolution LCD, instead of using the "half-toning" technique associated with print and e-ink? Would we even be able to tell at those resolutions? 😉 Would we mind…?

Plus side is the contrast could be much higher, they could use a plastic substrate, making it less prone to breakage, but it wouldn’t be the product we know. It might serve functionally work in a similar fashion, might even improve on visual clarity, but… those reflective beads, the whole print mystique..


Nate Hoffelder May 27, 2017 um 9:06 pm

JDI has had a partnership with E-ink for several years now. This is E-ink film on a backplane made by JDI.

Stefan May 27, 2017 um 9:16 pm

Ahh.. Thank you. Sometimes my speculation out-bounds my knowledge, so thanks for the grounding. 😉 Cheers!

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