Researchers at the Massachusetts Institute of Technology have demonstrated a new kind of display technology that uses nanoparticles, or "quantum dots," to scatter light on a transparent surface.
The technology could pave the way for some of the futuristic heads-up displays (HUDs) promised by LED devices, but with a wider field-of-view, cheaper production costs, and the option to plaster it across virtually any transparent sheet of glass or plastic.
Most existing transparent displays use a complex system of lasers, mirrors, and diodes to project an image that is only visible at a precise viewing angle, and even then may be compromised by adverse lighting conditions. Transparent LCDs, for example, require a substantial backlight, while HUDs may falter in an abundance of light. Now, manufacturers may have another option.
The proof-of-concept display unveiled at MIT this week can be observed from a wider range of viewing angles and requires no backlight, because images are projected onto the unit itself using "commercially available laser projectors or conventional projectors."
Using nanoparticles that are embedded within the transparent display material and "tuned" to an extremely narrow waveband, the display can reflect specific colors (in MIT's demonstration, blue) while remaining otherwise fully transparent.
“The glass will look almost perfectly transparent,” said MIT professor Marin
Soljačić in a statement, "because most light is not of that precise wavelength."
This means that, at least in this iteration, only a single color tone can be reproduced. However, researchers believe the technology will eventually allow them to select three narrow bands (red, green, and blue) that could be blended and manipulated into a full-color display—even with 99 percent of ambient tones passing right through the screen, thereby maintaining transparency.
Basically, you could get something like this:
But at a significantly lower cost to manufacturing, and without the need for built-in transparent electronics.
Quantum dots are an interesting area of research. Reviewed's own Dr. Timur Senguen even says these nano-dots "bridge the gap between the quantum and classical world," because they combine some of the counter-intuitive properties of quantum particles (Einstein’s "spooky action at a distance") with the controllability of more massive objects.
Basically, nanoparticles are large enough to manipulate for manufacturing purposes, but small enough to produce some of the odd interactions of quantum particles, like color scattering.
"It's great that scientists and engineers are finding interesting ways to exploit some of these 'weird' properties and implement them in practical ways, like display technologies," Senguen adds.
If taken to their logical extreme, the report points out, color-scattering nanoparticles could be incorporated into thin plastic coatings for glass, just like tinting is applied to car windows. Storefronts could display sale information on their windows, while still displaying the merchandise behind them. Subway trains and billboards could be projected with digital information, and car dashboards or cockpit controls could be augmented by nano-dot displays.
You're probably wondering: Could TVs be built with this technology? The answer is yes, but we don't think it'll happen. For one thing, a transparent display wouldn't be able to produce the deep black levels viewers love, except in a pitch-black room. For another, the separate projector would probably be seen by many as a backward step from today's self-contained units.
But even if it doesn't invade your home, this could be a breakthrough in display tech for commercial and automotive applications, and it's certainly something we'll be watching closely in the years to come.