Colour eInk in 2020?

[eReader fan]

Originally Posted by Quoth

The eink does (optimistically), black, 14 levels of grey and white. This limits the number of colours (including 14 levels of grey, white, 15 brightnesses of R G B C Y M and a lesser number of tertiary shades and saturations of all shades as well as black).
The 4096 is a mathematical maximum number of possible values set by splitting the underlying "16" levels with R, G and B.

It is not possible to add more layers? If not (I am expecting it), why not?

And, just to be sure I understood well your explanation, are we sacrificing levels of grey for colours?

I am wondering now how it will be to use the colour eInk without having the frontlight turned on. Maybe it is not even possible.

[Neru]

some links. Maybie someone will be interested.
https://www.bilibili.com/video/BV1MC...trigger_reload
https://www.ereader-palace.com/iread...olor-e-reader/
or just search here https://search.bilibili.com/all?keyword=iReader%20C6

[Quoth]

Originally Posted by eReader fan

are we sacrificing levels of grey for colours?

Colour sacrifices the native resolution, not shades of grey. It also reduces the brightness dramatically as each dot now only has a fraction of the spectrum and the layer is attenuating the light twice, unlike LCD.

The 16.7 million colour LCD displays have black, clear and 254 shades of grey. The single layer R G B pattern with one LCD black/grey/ clear dot for each of R G B allows the 16.7 Million possible shades.

Though there are other more complex arrangements of filter rather than R G and B stripes, easier to do with OLED/AMOLED.

The original 256 levels of black, 254 shades and clear is by having dots behind adjacent Red, Green and Blue filter layer the same.
The difference with eink is that "clear" (and thus the backlight) is replaced by "white" and thus the reflected ambient light or front light. On LCD the light from the backlight, through the monochrome shades of grey LCD cell/dot passes through the colour layer filter once. The backlight is strong enough to compensate for light attenuation compared with a bare mono LCD.
With eink, the light is reflected off the rear eink layer so passes through the coloured filter layer twice. Thus what ever losses there are (attenuation), are doubled. This is why eink top colour films are usually less intense R G B resulting in less saturated colour so that it doesn't need too much light. While this makes the colour aspect more "muted", it means that the white is brighter. Better colours would make the contrast poorer without massive front lighting.

So Colour eink needs more light (ambient and/or front lights) compared to mono eink and less saturated colours compared to LCD, Plasma, VFD, OLED/AMOLED, CRT etc.

Likely it's the now near universal (even on Kindle basic now?) front-lights that has revived the 10 year old idea of colour eink. Also plastic based displays rather than multiple glass layers.

LCD has colour shift with view angle due to the thickness of glass between the dot filter and the liquid. It's only visible on finer detail, not large areas. It's a different issue to the polariser / liquid view angle that varies contrast even on mono LCDs.
Hopefully the upper membrane of the eink cell will be thin.

[binaryhermit]

To be fair to what I've said, hasn't color eink been coming RealSoonNow(TM) for a long time?

(And I'm clinging to faint hope of being right until these devices have actually shipped, or at least been announced from a large player in the industry like Amazon or Kobo)

[eReader fan]

Originally Posted by Quoth

Colour sacrifices the native resolution, not shades of grey. It also reduces the brightness dramatically as each dot now only has a fraction of the spectrum and the layer is attenuating the light twice, unlike LCD.

Do you mean by that we are losing DPI achieving colours?

As I understand from your explanation the only possible way to add more colours could be overlap eInk layers, making them thiner. If this is it we will end having monochrome ereaders to read and thick big display ereaders to work/watch videos, etc

As for the lighting being trapped problematic, maybe it will solve the problem having a low backlight and then the usual eReader frontlight. Keeping the backlight at a very low brightness would be a must if we want to keep the eyestrain-free environtment common to eReaders.

I don't know about ClearInk or other technologies development or functionallity, but maybe this 4k colours it will be what we have until those other technologies develop properly on next 5 years

[rcentros]

Originally Posted by binaryhermit

To be fair to what I've said, hasn't color eink been coming RealSoonNow(TM) for a long time?

(And I'm clinging to faint hope of being right until these devices have actually shipped, or at least been announced from a large player in the industry like Amazon or Kobo)

According to GoodEReader (yeah, I know), who is a PocketBook dealer, the PocketBook Color is slated to be released on July 15th. He even has a price on it, $215 and is taking pre-orders (yeah, I know). Supposedly, according to GoodEReader, these were going to be released in April, but the the coronavirus somehow delayed the release date.

https://goodereader.com/blog/product...color-e-reader

I note the description is short on specs, however. But that could be because there (might be) an embargo on releasing that information.

[binaryhermit]

Originally Posted by eReader fan

As for the lighting being trapped problematic, maybe it will solve the problem having a low backlight and then the usual eReader frontlight. Keeping the backlight at a very low brightness would be a must if we want to keep the eyestrain-free environtment common to eReaders.

Except eInk screens are opaque so you'd be lighting the backside of the screen for no good reason since none of the light would make it out the front.

EDIT: I mean, if backlighting were going to work there would have been lit eInk readers before it happened and they would have been backlit because that's the obvious solution.

[DNSB]

Originally Posted by eReader fan

Do you mean by that we are losing DPI achieving colours?

As I understand from your explanation the only possible way to add more colours could be overlap eInk layers, making them thiner. If this is it we will end having monochrome ereaders to read and thick big display ereaders to work/watch videos, etc

eInk is opaque so you can't add layers and current eInk displays are limited to 16 levels (white, 14 greys and black). Going by the pre-release specs for the Pocketbook 6" colour eInk reader, it has 100 PPI in colour and 300 PPI in greyscale using the eInk Kaleido display.

Originally Posted by eReader fan

As for the lighting being trapped problematic, maybe it will solve the problem having a low backlight and then the usual eReader frontlight. Keeping the backlight at a very low brightness would be a must if we want to keep the eyestrain-free environtment common to eReaders.

Go back to the first sentence of my reply. The reason that eInk displays use a front light is that the display is opaque. A back light will not work. Take a look at the image attached for an idea of the structure of an eInk EPD capsule.

Originally Posted by eReader fan

I don't know about ClearInk or other technologies development or functionallity, but maybe this 4k colours it will be what we have until those other technologies develop properly on next 5 years

LiquaVista, Mirasol, etc. have come and gone. ClearInk is a moving target -- "we'll be in production next year".

[pdurrant]

Originally Posted by Quoth

With eink, the light is reflected off the rear eink layer so passes through the coloured filter layer twice. Thus what ever losses there are (attenuation), are doubled.

Going through the filter twice does reduce the light a little compared to going through once, but it doesn't double. The main attenuation is by restricting the light to just one range of colour (red, green or blue). That only happens once.

It is a problem with reflective LCDs - they polarise light, and so lose 50% of the light on the way in, and then 50% on the way out, because the reflection from the back of the LCD scrambles to polarisation again.

[Apache]

Originally Posted by pdurrant

Going through the filter twice does reduce the light a little compared to going through once, but it doesn't double. The main attenuation is by restricting the light to just one range of colour (red, green or blue). That only happens once.

It is a problem with reflective LCDs - they polarise light, and so lose 50% of the light on the way in, and then 50% on the way out, because the reflection from the back of the LCD scrambles to polarisation again.

So you are only getting back 25% of the light. That seems very dim to me.
Apache

[Nate the great]

Originally Posted by rcentros

According to GoodEReader (yeah, I know), who is a PocketBook dealer, the PocketBook Color is slated to be released on July 15th. He even has a price on it, $215 and is taking pre-orders (yeah, I know). Supposedly, according to GoodEReader, these were going to be released in April, but the the coronavirus somehow delayed the release date.

https://goodereader.com/blog/product...color-e-reader

I note the description is short on specs, however. But that could be because there (might be) an embargo on releasing that information.

Pocketbook hasn't told me anything about the release date, nor even when they will send me a review unit.

So Bad ereader is probably lying here.

[eReader fan]

Originally Posted by DNSB

eInk is opaque so you can't add layers and current eInk displays are limited to 16 levels (white, 14 greys and black). Going by the pre-release specs for the Pocketbook 6" colour eInk reader, it has 100 PPI in colour and 300 PPI in greyscale using the eInk Kaleido display

100DPI on colour eInk?? Thats clearly not enough. Maybe the good news weren't so good after all

[Quoth]

Originally Posted by pdurrant

Going through the filter twice does reduce the light a little compared to going through once, but it doesn't double. The main attenuation is by restricting the light to just one range of colour (red, green or blue). That only happens once.

Even for the colours, the attenuation mathematically HAS to be doubled with reflection rather than single pass. That's not saying you lose half the light!

But you are right, the main attenuation is losing the light from most of the spectrum, to leave a narrow band of colour. If you have less saturated colour, you lose less light.

But the red on a red dot, green on a green dot and blue on a blue dot IS attenuated somewhat, and that is doubled for reflective rather than transmissive.

Triple sensor cameras (and maybe triple chip DLP projectors) avoid this extra loss by using three way dichroic splitter prismatic mirrors, no dye filter, though they may have filters to block UV or IR (interestingly most camera phones don't seem to bother, IR or UV invisible to the eye makes a bright dot, point your TV remote at phone, or UV invisible security marker lamp).

[Marinolino]

https://goodereader.com/blog/e-paper...-color-e-paper

" E INK has confirmed with Good e-Reader that the company has developed a 2nd generation ACEP, which is Advanced Color E-Paper. They have a subset of the technology that utilizes the the codename E INK Gallery 4100. This technology is not going to be employed for digital signage, but instead will be marketed towards e-reader companies who want a high resolution alternative to E INK Kaleido 2. Development kits for Gallery 4100, are being sent to all of the big players in the e-reader space. Sources have confirmed that it is likely this technology will be refined over 2021 and it is likely we will start seeing the first commercially viable devices released in 2022. ..."

[binaryhermit]

Given GoodEReader's history of PIDOOMA, take that with a grain of salt.