Transparent screens just aren’t very practical these days — bigger models are frequently expensive and bulky while smaller heads-up displays  tend to have very narrow viewing angles.
However, MIT may have solved all those problems at once with its prototype nano-particle display  The device creates color images on a glass surface simply by ‘tuning’ a silver nano-particle coating until it lets only certain light wavelengths pass through. The technique is both cheap and compact, since it requires little more than the coating and some off-the-shelf projector technology.
There’s also no need for beam splitters or mirrors, so you can see the picture from just about any angle.
While there’s a lot of work left before there’s a finished product, researchers note that their display would be as easy to implement as window tinting; don’t be surprised if MIT’s screen shows up on a car windshield  or storefront near you