HUD (Head-Up Display) suppliers including Denso, Nippon Seiki, Continental, and Delphi are developing HUDs to project larger, brighter and more detailed images onto the windscreen. Developers are touting HUDs that could, in theory, project a warning symbol in the motorist’s line of vision to draw attention to a pedestrian or obstacle in the road. And if the motorist is using route guidance, an arrow might be superimposed over the correct route to highlight turns, highway exits, and suchlike.
A HUD also could highlight familiar functions such as speed, turn-by-turn navigation or radio stations. The idea is to keep the motorist’s eyes on the road. But the range of information for display is limited, engineers and planners say.
Nippon Seiki are the world’s leading producer of HUDs. They are expected to account for half of the estimated 500,000 HUDs to be produced globally next year, according to “The Hansen Report on Automotive Electronics” newsletter.
Global HUD sales are expected to increase 16% annually, says Paul Hansen, publisher of the newsletter. Hansen expects the number of automakers using head-up displays to rise by 2016 to 14 from today’s nine. But he’s skeptical of suppliers’ claims about devices with large displays. The technical challenges are daunting. The hardware—now the size of a college textbook—would have to be even larger to accommodate the optics required to project such a large image. A HUD big enough to project onto an entire windshield—or a substantial portion of it—would take up half the space behind the instrument panel. And such projectors emit lots of heat.
To solve some of these problems, suppliers have experimented with head-up displays that project laser beams to create the images. But lasers tend to be fragile in very hot or very cold weather.
Another reason for head-up displays’ high cost and low takeup rate is that each device must be calibrated to its vehicle’s windshield. Windshields have tiny warps in the glass, which usually don’t matter to motorists looking through them at the road. But when head-up displays project information onto a windshield, those flaws can lead to highly visible distortions unless the device has been carefully calibrated—and that’s without even getting into the challenge brought by eventual windscreen replacement.
