Heads-up displays sound like something only fighter jet pilots need.
But over the years, heads-up displays – or HUDs – have found their way into cars and commercial vehicles like trucks and buses too.
Even the latest Mazda 3 comes with them as standard on all trim levels.
Their advantages are clear: they keep your hands on the wheel and your eyes on the road.
Having crucial information like your speed, current speed limit and navigation displayed in your line of sight makes you a safer driver.
It ensures you just need to keep looking forward without having to look down at your instruments or screen
HUDs show you the way forward
Continental, one of the largest manufacturers of heads-up displays, says HUDs “reduce driver distraction and increase road safety”.
That’s because when you look at your instruments, your eyes take time to adjust to the shorter distance (called “accommodation”).
The process reoccurs when you shift your focus back to the road.
In fact, your eyes take about half a second to adjust to the shorter distance.
Heads-up displays change all that.
Continental calculates that when drivers shift their gaze at about 120km/h, that means they’ll be driving blind for about 33m.
That’s seriously something to think about, especially if you’re one of those who like to look at your phone while driving!
Heads-up displays help tremendously in giving the driver the critical information he or she needs on the road.
Speed limits, for example, can be displayed right in their sightline, as well as navigation information.
To customise the HUD to your liking, elements like the two above can be turned off or on depending on the driver’s preference.
How do they work?
At the heart of each heads-up display is a picture generation unit (PGU).
That creates the image that the driver will eventually look at.
However, that image must go through several mirrors before being projected on the windscreen.
The first mirror is the “fold mirror”, a planar or aspherical mirror.
Light is reflected off that onto an aspherical rotable mirror and then, finally, onto the windscreen.
A glare trap stops the PGU’s light from blinding the driver.
This application is also particularly important in trucks, where drivers typically spend longer hours compared with passenger cars.
With tech like this, it makes cars (and you) safer on the road.