With the rumors churning about Google's potential "heads-up display glasses" coming out at the end of the year, we thought it was important to look back at the history of this technlogy.
Heads-up displays allow users to receive data on a screen in front of them, so they don't have to look somewhere else, thus disrupting what they're concentrating on. Each HUD has three parts: the combiner, which is the surface the data is projected on -- like a windshield or lens; the projector unit, which puts out the image; and a video generation computer, which creates the images.
The combiner is coated with a transparent film that allows all other light to pass through, but reflects or refracts the light generated by the projector unit, making it appear to float on the screen. As you can see in the above image of a HUD on an aircraft, the information appears over the sky so the pilot doesn't have to turn his head. The projector units are powered by cathode ray tubes, similar to older televisions, an LED, or a LCD.
Video games are a common way to encounter HUD; interfaces players use to keep track of their health, ammunition or objective are all displayed in some variety of HUD, a technique that evolved especially as first-person perspective games, like shooters and RPGs, became mainstream. They've also appeared in sci-fi movies as part of everyday technology.
But before they were even futuristic concepts, basic HUD's were first put into practice by the military as early as World War II. Read our slideshow to learn the history of heads-up displays, from then, to now, and even into the future.
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