from Hacker News

LG demos transparent LCD

by justinireland on 2/27/11, 12:36 AM with 36 comments

• by blahedo on 2/27/11, 3:48 AM

  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.

• by T-R on 2/27/11, 1:56 AM

  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.

• by bloodnok on 2/27/11, 12:46 AM

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

• by markszcz on 2/27/11, 3:27 AM

  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...

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

  It looks really really cool in person.

• by rlmw on 2/27/11, 12:55 PM

  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!

• by jaekwon on 2/27/11, 3:00 AM

  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.

• by ChuckMcM on 3/1/11, 1:19 AM

  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.

• by apbitler on 3/3/11, 3:24 AM

  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.puredepth.com/technologyPlatform_sw.php?l=en

• by zbowling on 2/27/11, 2:14 AM

  Just a few steps until I can have my holodeck.

• by stcredzero on 2/27/11, 1:31 PM

  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.

• by jonhohle on 2/27/11, 1:12 AM

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

• by TheEzEzz on 2/27/11, 1:04 AM

  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?

• by Groxx on 2/27/11, 6:24 AM

  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?

• by cies on 2/27/11, 11:02 AM

  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)