
Rohinni: Paper-thin LED lighting - fpp
http://www.rohinni.com
======
jcjray
Nth Degree Technologies invented this product.
[http://www.nthdegreetech.com/](http://www.nthdegreetech.com/)

Here is one relevant patent:
[http://www.freepatentsonline.com/8846457.html](http://www.freepatentsonline.com/8846457.html)

Here is an album of various pictures taken earlier this fall (2014), and also
just a minute ago with two pieces I had around the house:
[http://imgur.com/a/nBB5r](http://imgur.com/a/nBB5r)

The technology is several things: it is real, it is sufficiently bright to
stand up to daylight conditions, and it is mass-producible. It has raised
interest from various industry sectors.

Lastly, this technology is not the work of Rohinni. They bought some pieces
from Nth Degree, and what their business plan is, who knows. They did not
invent it, legally cannot produce it, and it is doubtful they have the the
technical knowhow to do so anyway.

In short, Rohinni is taking credit for a product they did not make.

~~~
flashman
> Lastly, this technology is not the work of Rohinni. They bought some pieces
> from Nth Degree, and what their business plan is, who knows. They did not
> invent it, legally cannot produce it, and it is doubtful they have the the
> technical knowhow to do so anyway.

Well, these seem like some pretty definite claims that should be easy to back
up with evidence?

~~~
mortenjorck
I'd say they are rather extraordinary claims, given the differences between
the Nth Degree prototypes and the Rohinni prototype shown on the website.

Nth Degree's product honestly looks far more plausible, given its unusual
characteristics (speckled luminance distribution, blue cast, restriction to
clearly separated strips). It's considerably harder to find Rohinni's
compromise-free prototype credible, with its consistent, diffuse, apparently-
broad-spectrum light. But that just makes it even harder to believe an
accusation that they ordered a few Nth Degree strips and went to town with
them.

~~~
mojoe
I've only seen pictures, but it seems plausible to be able to take Nth degree
strips and add some kind of thin diffusion film over the surface, to remove
the speckled look. Certain materials can also absorb blue and re-radiate
multi-spectrum light.

------
Osmium
Nothing about this seems plausible to me. I do research on LED technologies
though I can't speak about this specifically because they don't seem to have
released any technical details whatsoever, but that's part of what makes me so
skeptical. The panels they present are so bright, so uniform (both in colour
and intensity), so thin and flexible–and they claim they'll be able to mass
produce them too? Whatever they've got, I'd be very surprised if they manage
to scale it, let alone for it to be "in the wild around the middle of 2015".
I'd be very happy to be proven wrong of course!

I think in cases like this photoshop mockups (assuming that's what they are)
can do more harm than good for setting expectations that might not be
realistic.

~~~
pippy
My guess is they've simply using the backlights of LCD panels:
[https://www.youtube.com/watch?v=jiejNAUwcQ8#t=34](https://www.youtube.com/watch?v=jiejNAUwcQ8#t=34)

They can scatter light and are deceptively thin. Coupling with (maybe) some
fibre cables and you've pretty much got what they're offering. I'd doubt
they're actually offering a unique product that illuminates the product as
advertised.

~~~
dogma1138
LCD panels don't have a paper thin backlight, they are lit from the sides of
the display and the light is refracted and diffused trough a thin layer of
plastic, this is why all LCD's have light bleed to some degree since the
diffusion is not uniform throughout the surface of the display. This
technology seems to be completely different and the LED's are infused evenly
throughout the material rather than being simply located at the edges. The
diodes they use also seem to be very different than commercially available
LED's both in terms of their size(several orders of magnitude smaller) and
resisting/allowing deformation without functional issues. As it's currently
shown this technology is much more similar to OLED and other internally
illuminating displays rather than to LCD's, or traditional LED array displays.

------
sxp
I'm always suspicious of LED room lights when they don't state the price
upfront. They've been pretty price in the past, but the cost is dropping
quickly. Some quick Googling found [http://www.environmentallights.com/led-
light-panels/ultra-th...](http://www.environmentallights.com/led-light-
panels/ultra-thin-led-light-panels.html) which has 24" x 24" 17W panel for
$250. That panel outputs 3000 lux == 3k lumens / sq meter = 1.1k lumens for 4
sq ft. This is the same as a 75W incandescent bulb. A standard 13W LED bulb is
$16 for the same amount of light.

So the price needs to drop by about 1-2 orders of magnitude before these
become practical for most people.

------
crudbug
OLED Lighting is LED 2.0. LG [1] is already pushing this into production.

[1]
[https://www.youtube.com/watch?v=aeoJEog1XYE](https://www.youtube.com/watch?v=aeoJEog1XYE)

------
Gracana
For a glowing-surface product you can get right now, check out
electroluminescent paint.

[http://lumilor.com/](http://lumilor.com/)

[http://www.litcoat.com/](http://www.litcoat.com/)

~~~
KaiserPro
Aha! this looks promising, I've been looking for something similar for a
while. I want to make this [http://www.secretbatcave.co.uk/electronics/tron-
case/](http://www.secretbatcave.co.uk/electronics/tron-case/) much neater.

At the moment its held on with tape, and its not long lasting.

------
Animats
Why are they talking about this and not taking over the backlight market for
LCD displays? That market wants flat light sources right now and will pay for
them. Because, maybe, this doesn't really work?

------
Shivetya
and why not show off Tron suits? Considering the price of light tapes this
might be appealing if its cheap enough to fiddle with.

I would like to see it on clothing, particularly bicycle and motorcycle gear.
Might be awesome for safety persons too (first responders)

~~~
fpp
I guess that's one of the applications the two inventors have in mind (outdoor
clothing).

Came across their early announcement beginning of this year
([http://www.cdapress.com/news/local_news/article_6c1e49d6-8f2...](http://www.cdapress.com/news/local_news/article_6c1e49d6-8f2e-5e67-a6d2-88abd2c33d92.html))
- now it seems they are getting ready to deliver / having every day use
applications on the market in the next 6 months (by 3rd party industry
members).

------
thrownaway2424
There's something to be said in favor of light emitted from a point, like an
HID bulb, or along a line like an incandescent light bulb. The advantages of
points and lines is ease of constructing lenses and optics to put the light
where you want. This is a problem for LEDs where the light is emitted on a
plane, or multiple parallel lines, or space-filling curves depending on the
semiconductor process used. What would be some advantages of a planar light
like these, if they existed?

~~~
tghw
Light from large sources is "softer", meaning the shadows are not as harsh.
This is why you see photographers use soft boxes or umbrellas, or
videographers using light panels.

Indoor lighting is usually more appealing, and more functional, from a large
source, as well.

Imagine being in a dark room with only one, small light source, and trying to
do some sort of fine motor work. If the room is evenly lit, from a large
source, it's easy to see what you're doing. But if there's just one small
source, you end up casting a shadow on what you're trying to work on, making
it much more difficult.

------
solistice
Fascinating piece of tech if they actually manage to deliver on it. It'd be
amazing if there was some more information on it though, the only stuff I can
find is them explaining that it's LEDs mixed with ink between two conductive
layers and an additional protective layer. Then a lot of fancy mockups that
don't tell me anything about the tech they're selling.

Even if this vastly underdelivers, it might do away with the inverters needed
for el-wire/panels which would be neat.

~~~
TheSoftwareGuy
> It'd be amazing if there was some more information on it though

I suspect that there is little information on it, either because they are not
entirely solid on the information themsilves, or that they do not want to risk
letting others make similar products before they have a chance to hit market,
or some combination of the two.

I hope it is the latter, as that would mean it is a lot more likely this will
ever come to market.

~~~
solistice
Yeah, a video of it in action would be incredible though. The single picture
of it isn't quite convincing yet. Reading through articles on it it appears
they're on the first iteration of the design though, which appearently suffers
from problems with uniform lighting they're hoping to resolve in the comming
months, so that might be the reason they're not showing any more proof of
their claims.

------
driverdan
This will be really cool when it's a real thing. Right now it seems to be
limited to very small scale samples and Photoshopped mockups.

------
remon
This is one of three HN links on the front page that uses this new fad where
the landing consists of nothing but a full screen image, no content and a less
than obvious notification that you should scroll down to see something
actually useful. Stahp.

------
fpp
some more editorial information at:
[http://www.fastcolabs.com/3038890/rohinnis-lightpaper-is-
inc...](http://www.fastcolabs.com/3038890/rohinnis-lightpaper-is-incredibly-
thin-and-printable)

------
mortenjorck
One thing I've disliked about the current crop of thin, high-PPI LCD screens
is the unavoidable unevenness in backlighting caused by their thin, hard-to-
make-optically-perfect diffusers. Even the Retina Display on the MacBook Pro
isn't immune from it.

Though Rohinni doesn't visualize it in their applications section, Lightpaper
looks like it could enable diffuser-less, razor-thin LCD displays with
potentially far greater luminance uniformity than current backlight solutions.

~~~
thrownaway2424
These would be much worse. They're essentially an array of tiny LEDs and a
consequence of the distribution of LED forward voltages will mean that some of
the LEDs are going to hog current and others will get less. This will lead to
bright spots, and the human eye is actually very sensitive to this. You get
the same problem with OLED displays and people have complained a lot about the
visible noise on OLED phones like the Samsung Galaxy Nexus.

~~~
msandford
Usually what you do to solve that problem is chain a bunch of LEDs together in
series and then those groups together in parallel. If your process technology
is +- 5% then chaining 5 LEDs in a row will even out your average error to
+-1% instead. Which makes a big difference. Of course, if they don't do that
then you're right that there can be problems.

------
Alex3D
Hello my name is Alexander and I am the founder of a French information site
for 3D printing. It happens that I wrote an article on "lightpaper" (
[http://www.priximprimante3d.com/led/](http://www.priximprimante3d.com/led/) )
and wanted to know if the process used to manufacture this device is similar
to that used to manufacture OLED.

------
femto
Given that an LED can act "in reverse", as photovoltaic source, what would be
the efficiency of this as a solar cell? Any ideas?

~~~
benjamincburns
Short answer: no. I just wrote a long diatribe attempting to explain why using
my very limited knowledge of semiconductor physics, but realized I couldn't do
so without making some substantial guesses.

So instead, I'll offer some (probably fallacious, but likely still correct in
its conclusion) logical deduction -- If this was likely to be a good
photovoltaic source, the inverse would also likely be true. That is, that good
photovoltaic sources would emit heaps of light when a current was applied.

In short, LEDs are semi conductors optimized to have a very specific direct
energy band gap which produces photons in the visible light spectrum. This
causes the semiconductor to shed excess electrons as visible light energy.

Photodiodes (used for PV arrays) are similar, but optimized for a completely
different goal. They attempt to maximize the size of their depletion region. I
don't know that the energy band gap is as important, though I'd imagine the
narrower the better. Either way, this is done to maximize the likelihood that
an incident photon will excite one of the molecules in that region of the
diode, thereby freeing up an electron and causing it to flow around the
circuit.

~~~
reportingsjr
We just replied with very similar responses!

FYI solar cells would not make good light sources since the most common ones
(silicon based) are indirect band gap. For LEDs (and lasers) a direct band gap
material is required.

You are correct about the depletion region needing to be large for solar
cells, but narrower is not necessarily better. This is because if you make the
band gap super narrow (say 0.5eV) and most of your energy comes in as much
higher energy photons (1eV+) you are discarding all of the energy besides that
0.5eV from those photons. The band gap is tuned to get the highest
responsivity at wavelengths where the most energy is coming in if it is tuned
at all.

~~~
benjamincburns
So in the case of a narrow band gap, where does the excess energy go? I'd
guess it must be shed as a lower energy photon?

~~~
reportingsjr
Nope! In very rare cases it can generate multiple electron hole pairs the
photon if it has enough energy to do that. Almost all of the time however it
will generate a _phonon_ (aka heat) rather than a photon with the extra
energy. A phonon is a wave in matter rather than electromagnetism (photon).

------
huuu
This paper (2012) shows that it is possible to create LEDs by printing zinc
oxide and a conducting polymer on paper: [http://liu.diva-
portal.org/smash/get/diva2:515790/FULLTEXT01](http://liu.diva-
portal.org/smash/get/diva2:515790/FULLTEXT01)

Maybe it's derived from this technique?

------
sebie
Trying to find it, but does anyone know the battery life of it? Or does it
have to have a constant source of power?

~~~
wyager
It's not powered internally. You apply it to a surface and power it like you
would a normal LED.

~~~
sebie
Makes sense now, thank you!

------
lovemenot
That photo of the team is hilarious.As if the men wore masks to wind up the
woman.

------
bane
I'd be a lot more interested in this if the photos of their office showed
their product actually being used in the spaces.

------
thatmiddleway
Anyone have an idea as to the lumens per sqft?

~~~
dognotdog
Since they aren't saying, it's doubtful they do better than current OLED
panels, which framkly are pitifully dim.

~~~
aidenn0
How do those compare to a standard drop-ceiling Fluorescent fixture?

------
ratsbane
Where can I buy a sample of this?

~~~
myth_buster
From the FastCo link [1] in another comment:

"Consumers should start to see Lightpaper in the wild around the middle of
2015. But Rohinni won't be aiming at the home hobbyist market until after it
takes hold in the commercial and industrial space."

Bummer!

1: [http://www.fastcolabs.com/3038890/rohinnis-lightpaper-is-
inc...](http://www.fastcolabs.com/3038890/rohinnis-lightpaper-is-incredibly-
thin-and-printable)

~~~
CamperBob2
An unenlightened plan, for a category like this where it's not immediately
obvious what can be done with your product.

~~~
joezydeco
It's a typical plan when your initial product cost is going to be way high.
Commercial/industrial users will pay high prices if the application is what
they want. Home users will not.

~~~
CamperBob2
You might be surprised.

------
Ccecil
They are local to me...maybe I will swing in.

------
thoughtpalette
I would love those wall-decals for my room. Beautiful

~~~
Gracana
You can always buy and cut up electroluminescent panels, like this:

[https://www.youtube.com/watch?v=aPCwM9TxMqA](https://www.youtube.com/watch?v=aPCwM9TxMqA)

~~~
chrissyb
Agreed, i was just about to say the same thing with this vid:
[https://www.youtube.com/watch?v=qkA0YdNEsqU](https://www.youtube.com/watch?v=qkA0YdNEsqU)

------
LitCoat
Perhaps more useful information can be found here:
[http://www.marketwatch.com/story/litcoat-takes-paint-to-a-
ne...](http://www.marketwatch.com/story/litcoat-takes-paint-to-a-new-level-
with-electroluminescence-2014-10-17)
[http://www.12newsnow.com/story/26828656/litcoat-announces-
av...](http://www.12newsnow.com/story/26828656/litcoat-announces-availability-
of-three-new-electroluminescent-paint-packages)
[http://www.prnewswire.com/news-releases/litcoat-
revolutioniz...](http://www.prnewswire.com/news-releases/litcoat-
revolutionizes-the-painting-industry-with-paramagnetic-electroluminescent-
paint-282324651.html)

------
LitCoat
This is called LitCoat and more information is on litcoat.com LitCoat is nano
coating and consist of spray paint layers working together:

(1) Conductive - (2) Dielectric - (3) EL (Electroluminescent) - (4) Conductive
layer and then you seal it off with the (5) Top layer. (Once applied save to
touch)

From principle it can be applied on everything but it is depending on the
under-layer trace thickness and uniformity. In case of irregularity of the
surface it would require treatment for a more homogeneous surface.

DIY: [http://www.litcoat.com/product/litcoat-electroluminescent-
pa...](http://www.litcoat.com/product/litcoat-electroluminescent-paint-rd-
kickstarter-package)

~~~
dogshoes
> This is called LitCoat and more information is on litcoat.com LitCoat is
> nano coating and consist of spray paint layers working together:

Is your claim that the Rohinni Light Paper is actually based on the technology
that LitCoat is pushing?

