Heads-Up Display Technology
HUD has become standard in both military and commercial aviation during the past decade. The technology allows pilots to review information more quickly, more easily, and more safely by keeping pertinent flight information in their line of sight on the windshield.
How does a heads-up display work?
Nearly all vehicle-based HUD systems use a small cathode ray tube (CRT) to project vehicle data onto a special element on the windshield. The information is typically superimposed in the lower half of the glass, which is inside the driver's immediate line of sight. To reduce eye strain and allow faster comprehension of the information, HUD data is displayed at "infinity focus" (a focal point equal to that of the roadway in front of the vehicle). There is no need for the driver to refocus their eyes to view the HUD information.
Recent advances in display technology have improved the design of most heads-up display units; many now utilize liquid crystal display (LCD) and light-emitting diode (LED) technology to offer the driver brighter images. These technologies are less expensive to manufacture, and more reliable when compared to a CRT display.
What are the typical uses of a HUD?
The earliest automotive HUD systems simply projected the speed of the vehicle onto the windshield in front of the driver. Today, these systems project speed, turn signal information, high-beam indicator usage, radio status, outside air temperature, compass, and a full assortment of warning messages. Most systems allow the driver to customize the information they would like to see, or to turn the system off completely.
Advanced HUD systems provide navigation information via satellite to the driver, including turn-by-turn instructions. Collision-avoidance systems, which use infrared or low-light cameras, use HUD to superimpose an enhanced view of the roadway onto the display, offering the driver a much better view outside the vehicle during inclement weather or darkness.
Do I need HUD?
Heads-up displays can be expensive. If it is not offered as standard equipment on your vehicle, purchasing it as an option can add thousands of dollars to the purchase price.
Like many new automotive electronic systems, a heads-up display requires the driver to become familiar with and comfortable with the system over time. Most drivers will adapt quickly, but some may find it an annoyance or distraction. In either case, an extended test drive of a HUD-equipped vehicle is recommended before purchase.
HUD technology is a big step toward reducing the driver's workload and increasing automotive safety. As the technology is refined and improved and becomes standard on many new vehicles, HUD may replace many of the instruments and gauges found on today's dashboards.