The head-up display is a new, high-end feature that Audi makes available as an option in the A7 Sportback and the new A6. It projects the most important data onto the windshield as symbols and digits. The display takes the form of a virtual image inside a window, the “eyebox”, measuring 262 x 87 millimeters (10.31 x 3.43 in). It appears to hover above the engine compartment lid, about 2.3 meters (7.55 ft) in front of the driver, directly in their primary field of vision. The height of the eyebox can be adjusted.
The driver does not need to look away from the road in order to register the information; their eyes, already accustomed to long-range vision, do not need to adjust. It takes only about half the time to glance at the head-up display that it does to read the display in the instrument cluster – an important advantage especially at higher speeds. People whose close-range vision is not optimal will find the new solution particularly helpful.
The driver can select what information they wish to have shown in the head-up display via the MMI – for instance the speed, the navigation symbols, the lists of infotainment systems and the displays for the assistance systems. Traffic Sign Recognition in the instrument cluster also uses the system.
Audi is the first automotive manufacturer in the world to offer a full-color head-up display with TFT screen technology. As well as RGB color filters, new polarization filters are used; their high contrast is sufficient even for very difficult light conditions. 15 white LEDs give the TFT monitor on which the images are generated particularly bright back-lighting. A sensor adjusts the display to the ambient brightness; the driver can also adjust it at any time.
The power consumption of the light-emitting diodes and all other components is extremely low. All components are designed so that they easily withstand the temperatures occurring in the head-up display. The system operates without any active cooling – another factor that boosts efficiency.
The windshield on which the image is projected acts like a concave mirror – it enlarges the image, with the typical distortion. Two convex corrector mirrors in the optical path made from plastic, with a special coating, compensate for this and increase the optical imaging performance.
To avoid double images, the windshield and its soundproofing safety film have a slightly tapered profile. They are manufactured with utmost precision; minute deviations from the ideal surface nevertheless cannot be avoided entirely. Audi has therefore installed an optical measuring system at the end of the production line on which the A7 Sportback and the new A6 are built. It analyzes the deviations to a thousandth of a millimeter and recalibrates the mirrors in the head-up display accordingly.
The equipment, data and prices specified in this document refer to the model range offered in Germany. Subject to change without notice; errors and omissions excepted.