
Swedish startup Rdot is trying to take on E Ink - danielam
https://goodereader.com/blog/e-paper/swedish-startup-rdot-is-trying-to-take-on-e-ink
======
eximius
I was just today looking at E-inks new 'JustWrite' technology where the screen
pixels are activated by a stylus instead of the backing, so writing feels
instant (and might be just about instant too). If this tech also has that
possibility, then good on them. Edit: though I'm not aware of a product which
incorporates it yet, which is a shame. Maybe I'm wrong - research on mobile is
hard.

What I'd love is a notebook of the stuff that I could write on and save and
swap the contents with an open protocol/app.

I'd also probably love hacking on the stuff. Make a 'spellbook' for one of my
D&D characters where the contents change 'magically'. :)

~~~
eliaspro
You might want to take a look at the reMarkable tablet [1].

Apparently it's quite hacker-friendly/open.

[1] [https://remarkable.com/](https://remarkable.com/)

------
ipsum2
Good. E-ink displays are expensive and have a monopoly on low-energy
persistent displays.

However, Rdot doesn't have nearly the same resolution as E-ink at this time,
it seems:
[https://rdotdisplays.com/technology](https://rdotdisplays.com/technology)

~~~
Scaevolus
The contrast ratio of 3:1 isn't great either! The first generation of e-ink
had a contrast ratio of 7:1, and they've been at 15:1 since 2013.

[1]:
[https://wiki.mobileread.com/wiki/E_Ink_display](https://wiki.mobileread.com/wiki/E_Ink_display)

~~~
dotancohen
1:3 for the grey version. But the RGB versions do much better:

Red: 1:8

Green: 1:11

Blue: 1:7

[https://rdotdisplays.com/technology](https://rdotdisplays.com/technology)

------
int_19h
"Typically, the energy required for a full switch on an E Ink display is about
4mJ/cm2. The corresponding number for the Rdot display is about 1mJ/cm2 with
the addition of 0,25mJ/cm2 every 15 minutes. LCD continuously consumes about
6µW/cm2."

This is some interesting numbers. So, for a 1 cm^2 screen, LCD consumes 6mJ
for every 1000 seconds - i.e. just over 15 minutes. But to redraw the screen
on eInk takes 4mJ. So if you do something that would cause the screen to fully
redraw more than twice every 15 minutes, then eInk actually consumes more
power? But wouldn't that generally be the case while reading?

~~~
otalp
No, the screen is not usually "fully redrawn" when reading, which involves a
full flash visible to the user. Often it's only a fraction of the screen that
has to be redrawn as most of the pixels can remain the same between page turns

~~~
int_19h
For a single page flip, sure. But how many page flips are you going to do in
15 minutes? Wouldn't you have enough changed pixels add up to at least a
couple full repaints?

------
zwayhowder
Considering I'm still waiting for my Indigogo backed 13.3" Good E-Reader from
June 2016 I won't be holding my breath for this.

~~~
shirokuro
Me too, I can't believe the gall they have still taking orders.

~~~
bryanrasmussen
If there's a sucker born every minute that also means every minute there's a
sucker finally able to buy stuff on the internet without parental consent. Why
shut down a scam under those conditions?

------
jonbaer
Interview w/ the CEO @
[https://www.youtube.com/watch?v=hS5_D0bxLWI](https://www.youtube.com/watch?v=hS5_D0bxLWI)
... can someone explain he mentions the display is semi stable + lasts "one
hour" does it need to refresh 24x @ some point to hold an all day display?

------
roel_v
E-ink and similar tech seems to have tapered off the last couple of years, the
only thing (as far as I know) that is doing anything new is the reMarkable. I
was just about to pull the trigger on ordering one - anyone have experience
with it? Is it really as paper-like as they claim?

~~~
llamaz
I was thinking about ordering one, but out of the Boox note and the sony
devices, I ruled out the remarkable first. I can't remember why, but you can
search reviews for yourself.

I choose the boox note over the sony because it's more fully featured (e.g.
better web browsing). I don't regret buying it. The only problem is that you
need to use a screen protector to prevent scratching from the stylus, but the
screen protector is impossible to place without air bubbles. Eventually I
decided that the air bubbles weren't a big deal.

------
plorntus
I don't fully understand from reading the article why this is better than
EInk. Seems it just uses 1/4 of the energy but other than that is there more
benefits to it?

~~~
swsieber
Competition. Eink seems to have stagnated.

~~~
ATsch
My understanding is that E-Ink holds all of the patents and is preventing any
further competition or innovation.

~~~
swsieber
That's my understanding too - if someone can create a screen that competes on
energy use, then they occupy the same market and will hopefully force E-Ink to
innovate/bring down prices.

------
pasta
I love to have a reflective screen in my phone and as monitor.

For those devices energy consumption is just low priority.

Color and refresh-rate is where most reflective screens fail. So if you take
on E ink I think that's where you should shine.

------
gumby
I wonder how fast they change? The time to rewrite the screen is a major
bummer for me when compared to flipping pages with dead-tree paper

~~~
dotancohen
I used to think this too, until I videoed myself reading to test.

I discovered that dead-tree page flips take between 1.8 to 4.2 seconds, pretty
much normally distributed. Granted we're doing more page flips on eink because
the screen is smaller, but by timing my blinks and keeping the eyes closed a
bit longer, I no longer even feel the page flips and my eyes are more rested.

The difference that we feel is because with dead trees are are actively
changing the page, whereas with eink we are waiting.

~~~
dTal
I don't know how you're flipping your pages, but it's possible to flip through
a book at something like 6 to 10 pages per second. Which is how flipbook
animations work.

Even setting aside this specific form of flipping, with a moistened finger and
a small book I can leaf through at a rate of several pages per second.

The annoying part with E Ink update speeds isn't the page turn you do when
you've finished reading the page - it's the inability to rapidly visually scan
the book.

~~~
dotancohen
I am not referring to flipping through a book's pages. I am referring to
reading a book.

------
ATsch
How is this different from the Sharp Memory LCDs?

~~~
MRPockets
My calculations might be wrong, but it looks like these Rdot displays use
significantly less energy than Memory LCDs.

Using numbers from Sharp[0], Memory LCDs use ~226µJ/cm2 each second when
static. I'm assuming they are 60Hz displays & therefore require a refresh 60
times each second but even if they only refresh once a second, that's
~3.8µJ/cm2 a second or 13,680 times the power consumption of the Rdot
displays.

The article claims these Rdot screens use 0.25mJ/cm2 _every 15 minutes_ when
static.

Again, these are my "back-of a napkin" calculations so take with some salt.

[0][https://www.sharpsma.com/products?sharpCategory=Memory%20LCD](https://www.sharpsma.com/products?sharpCategory=Memory%20LCD)

~~~
Gibbon1
Calculating out of my Kiester assuming 2.5cm2 display 3.0V it seems

Sharp Memory LCD is 200uA vs rdot at 0.25ua.

With AA batteries Sharp Memory is only going to last 1 year MAX. That's too
short for most consumer applications. Where rdot is much less than the self
discharge. So 5-10 years.

