How Head-up Displays Work

How Head-up Displays Work
BY CHRISTOPHER NEIGER
Browse the article How Head-up Displays Work
The 2012 GMC Acadia's heads-up display allows drivers to safety merge onto the highway
using technology similar to what fighter pilots use to guide precise movements at
supersonic speeds. See more car safety pictures.
© GENERAL MOTORS
Two of the most important parts of driving are being able to see well and
knowing where you're going. Head-up display technology works with both of
those ideas in mind -- and it's going to change the way we see the road
forever.
The days of looking away from the road, missing a turn because you didn't
understand the GPS or driving blind in the fog may soon be a thing of the
past.

Heads-up display (HUD) systems can project information on the windshield,
tell you where to turn, notify you of lane markings, identify how close the car in
front of you is and even give you restaurant information all right in front of your
eyes -- and while you're actually able to see those objects or places.
Believe it or not -- and yes, you should believe it -- head-up displays are not a
new technology.
Head-up Display Technology
Fighter jets have used a rudimentary HUD system since the 1950s to display
altitude, speed and even targeting systems on the front of the cockpit canopy.
So if you grew up playing fighter jet video games, you know what we're talking
about. Driving is about to get a lot more fun.
So what exactly is a heads-up display? It's best to think of your windshield as
a transparent screen for information. Instead of taking your eyes off the road
to see your speed, navigation directions or other info, the HUD system
projects the information at eye level onto the windshield. No more glancing
down and away at a small GPS screen. It's all right in front of you.
The tech for HUD varies on the system. Some cars use transparent
phosphors on the windshield that reacts when a laser shines on it. When the
laser is off, you don't see anything, but when the light is on the information is
projected on the glass. Others use a similar system but incorporate mirrors to
project the images on the windshield.
If you think heads-up displays are only available for high-end vehicles, you're
going to be pleasantly surprised. In 2012 Pioneer released an aftermarket
head-up display unit that mounts to the top of a car's cabin and can project
information on the windshield. The system connects to a smartphone app
through Bluetooth wireless technology and displays navigation instructions,
points of interest and even road hazards.
So why do we need this, anyway? Well, not only because it's a cool
technology to have and use, but also because the information, pictures,
symbols and other gadgets we're adding to our vehicles are distracting us

from the road. We need a new way to display this information that keeps our
eyes up and on the road -- hence, the heads-up display.
The Evolution of Head-Up Displays
GM's full windshield head-up display technology, combined with night vision technology,
allows for objects, such as deer, to be highlighted for the driver, preventing potential
accidents.
© GENERAL MOTORS
General Motors introduced the first heads-up display in a car in 1988 and the
systems were originally used for showing speed, tachometer and other basic
readings from the dashboard. But as the technology advanced, much more
sophisticated and critical information is being displayed.
The original head-up displays are being replaced with newer technology
called augmented reality (AR). These AR systems are the new version of
head-up displays, but are far more advanced. ARs can integrate with GPS