
LG demos transparent LCD - justinireland
http://justinireland.com/lg-transparent-lcd/
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blahedo
I'm not sure what I'm missing here, but I'm pretty sure transparent LCDs have
existed in commercial production for decades. For instance, back in the
mid-90s (and possibly still today) they make displays that emulate TI-8x
calculators and can be placed on an old-school overhead projector, for
classroom use.

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baddox
I thought _all_ LCD's were somewhat transparent. They have backlights _behind_
them, after all, and LCD projectors are clearly transparent.

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T-R
I'd like to see this paired with an e-ink screen on the next Kindle. Turn on
only the e-ink for reading, only the LCD for UI, or both to show highlighting
and notes overlaid onto the text. They could use the touch screen to get rid
of all those buttons, too.

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cma
I think a better scheme would be having embedded OLED dots mingled in around
the eInk microcapsules. Then you don't get the degradation you get with
layering one thing over another.

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bloodnok
Aren't all LCDs transparent? Are they demoing anything more than an LCD
without a backlight?

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mechanical_fish
It's hard to tell because this write-up is so poor, but my guess from the
pictures is that the lighting is much of the actual invention here. Perhaps
they've got a technology for uniformly lighting a color LCD without a typical
backlight. The display looks uniformly bright and the colors look good, which
makes me suspect that they are not merely relying on the background image to
provide the "backlight".

Or maybe it's just a completely normal LCD being demoed in front of a cleverly
lit diorama. ;)

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markszcz
If you go to a casion, look out for WMS slot machines, specifically this one
(Goldfish (the new one, not the old machine)) I played this in Atlantic City
at the Trump Taj Mahal downstairs next to the noodle bar and they use a
transparent LCD over their spinning reels. Pretty cool stuff.

Demo promotion video: [http://www.youtube.com/watch?v=E08IvXQ-
rZI&feature=relat...](http://www.youtube.com/watch?v=E08IvXQ-
rZI&feature=related)

Edit: A pretty nice in game example of the LCD on the slot in action:
[http://www.youtube.com/watch?v=2eEyr6y8kNE&feature=relat...](http://www.youtube.com/watch?v=2eEyr6y8kNE&feature=related)

It looks really really cool in person.

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ZoFreX
Are those actual physical spinning wheels? On the video you can't really tell
that it's not just one giant screen, I bet the effect is cool AFK though.

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markszcz
Yes they are actually spinning. If a Wild shows up on the reel, the LCD screen
pops a "Wild" animation over it.

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rlmw
Have I missed something, surely this is entirely pointless? You need to have a
blank single colour surface behind it, or the images on the transparent screen
get obscured by the colours of whatever is behind it. This is even
demonstrable in their demo video!

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jaekwon
LCDs are supposed to be transparent.

What would be cool is if I could have a sun-powered backlight for my laptop
when I want to use it outdoors.

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bradleyland
They used to use them in PDAs. They're called transreflective LCD [1]
displays. They're nowhere near as bright as a backlit LCD though, and only
look good when you've got a good light source.

1 -
[http://en.wikipedia.org/wiki/Transflective_liquid_crystal_di...](http://en.wikipedia.org/wiki/Transflective_liquid_crystal_display)

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jaekwon
I mean, more like light coming from the back through the LCD screen into your
eyes, unlike transreflective LCDs.

One needs a white tent pitched behind the laptop screen, and one needs to sit
_facing_ the sun. You'd be looking into the space of the tent, which is much
like the display in the OP demonstration except the source of light is the sun
coming through diffused through the tent fabric (and there are no buildings).
The bottom floor could be a mirror.

SUN

    
    
           /\
     fab. /  \  <-- laptop LCD
         /    \
        / tent \
        --------======== <- keyboard
         mirror
    

where fab == white tent fabric

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Groxx
Interesting idea... I don't think I've ever heard of something like that
concept before.

I see two problems, though there may be ways to mitigate them: you're facing
the sun, therefore it's effectively in your eyes, and you'd probably lose all
semblance of color balancing in the screen.

Not that the second is all that important to most people. I've even gotten
used to applications like Flux[1] which change the screen's color over the
day, and I find it's usually easier on my eyes. Just sayin'.

You could probably do away with the mirror, and just have a white piece of
plastic. It'd be diffused by the fabric anyway, there's no need to have
something mirror-like to reflect it accurately. You could possibly use the
entire back panel of a laptop screen, and fold it up when not in use (brain-
farts while looking at my wife's white Macbook).

[1]: <http://stereopsis.com/flux/>

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ChuckMcM
What you are 'missing' and the folks who watched minority report or Avatar are
lusting after, is a transparent piece of material that they can display stuff
on.

True, LCDs are, by their nature, transparent. However their contents are only
'visible' when there is light going through them, and they work by adjusting
how much light passes through them using polarization. If you have a full
spectrum light behind them, and you have red green and blue dots which you use
for color selection, you get a color LCD.

However, these don't _generate_ light. And no, nobody has built one of those
yet. To build such a display would no doubt require that you build a pixel out
of three (or four) LEDs that are nominally transparent, such that turning them
on would cause the pixel to appear.

That would then make for a display which was clear, except for where it had
data showing. So far, this technology (outside of using a projector to project
the display on to a window where the user sees the reflection as the display)
does not exist.

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apbitler
1 point by apbitler 0 minutes ago | link | edit | delete

So to the person asking about the slot machines.. they technology behind this
is called "multi-layer LCD". I was in Vegas for the CES and I saw these slot
machines.. and I couldn't believe my eyes! I did some research and found out
that it is actually 2 LCD screens, and one of them.. or both are able to go
completely transparent.. thats how you get the 3d effect. Check it out for
yourself:
[http://www.pcworld.com/article/130233/new_slot_machines_prom...](http://www.pcworld.com/article/130233/new_slot_machines_prom..).
<http://www.puredepth.com/technologyPlatform_sw.php?l=en>

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zbowling
Just a few steps until I can have my holodeck.

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noonespecial
Hey, I've waited since the 90's for my PADD and its finally here, I have no
doubt now that my holodeck is not far behind.

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stcredzero
I can envision augmented reality applications for something with a smaller
form factor and higher contrast. A camera could track the user's relative
position, and overlay data about objects in the actual view for the user. If
the device could do iris tracking, it could even react to the region of the
screen the person is looking at.

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jonhohle
The resulting image looked about as unusable as I expected. Besides HUD
applications, what is the use case?

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Stormbringer
I think it is just the standard "hey look at this nifty _but completely
impractical_ thing we can do".

For me, behind my monitor is a window because I want to be in an area with
lots of natural lighting (I've worked in rooms with no windows, and its no
fun, after a while it just gets you down). So a see-through LCD would be a
total disaster for me.

Apple used to have a Cinema Display monitor with a see through bezel, the see
through LCD would look gorgeous in combo with that, if a little impractical.

Maybe the use case is what it looks like not when it is on, but when it is
off? I imagine in this scenario it would be something that you wouldn't use as
your day to day computer that you spend hours on.

You could build your LCD _into_ the window, then when you're not using it it
doesn't impair the view? Or maybe it is useful for HUDs in cars or other
vehicles? Build it right into the windscreen?

(But wait - aren't there cars that already have this? Isn't there a merc with
nightvision built into it or something like that?)

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CognitiveLens
I think almost all passenger vehicle HUDs are displays in the dashboard that
are reflected off the windshield - I suspect they also sometimes put a lens on
it so that it appears to be further away than it actually is, because it might
cause major headaches for people to frequently change focus from the road to
the windscreen.

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Stormbringer
I remember test driving a Yaris, which was the first car I'd driven with a
digital speedo. _That_ was incredibly distracting, because I kept trying to
get _exactly_ on the speed limit. It was actually dangerous.

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Derbasti
I drove a Renault with one of these. You get used to it. After a few days, it
is no longer distracting. Actually, I found the usual analogue gauges
distracting when switching back!

Mercedes now uses a high resolution screen that displays an analogue speedo
gauge. That is an interesting combination!

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TheEzEzz
I'm confused. The image behind the LCD is clearly not from the LCD (there is a
parallax effect), but the background image still seems artificial. Is this
just two screens stacked on top of each other?

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CognitiveLens
Pretty sure it's just a little model of buildings in a box right behind the
display.

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Groxx
So they've taken a regular screen, added a touch-sensing layer like loads of
things have already added, and made it harder to read what's on it. Is this
supposed to be good?

If they got it to be self-lit (ie, via the edges), it might be interesting,
but it doesn't look to me like that's what it is - it looks like the box
behind it is providing all the light. So it is, _very precisely_ , a large,
expensive rear-projection display.

Wow. Congrats to the research team, how many DIY LCD hacks did you have to see
to realize you could do this?

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Groxx
Yeah, I suppose I deserve the down-vote, too much snark. Apologies! Especially
due to this info alok-g linked:
[http://en.wikipedia.org/wiki/Liquid_crystal_display_televisi...](http://en.wikipedia.org/wiki/Liquid_crystal_display_television#Efficiency)
Important bit: _3M suggests that, on average, only 8 to 10% of the light being
generated at the back of the set reaches the viewer._

I'd always thought they were more transparent than that, given that I've seen
LCD screens used as projectors: <http://www.instructables.com/id/DIY-LCD-
PROJECTOR/> in which case (though there's no way to detect how bright the box
behind it is) a highly-transparent screen could indeed be a fairly significant
breakthrough.

[1]: <http://news.ycombinator.com/item?id=2267436>

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cies
these products (as other pointed out) exist for year. they have been sold to
use with overhead projectors.

i ones has this old tech-hippie show me one and telling me: with this device
you can actually watch television together! (he put the frame in between our
faces with it showing some picture, and he smiled -- i saw the picture AND his
smile)

