All about head-up displays

A head-up display (HUD) can do more than many people think.

We explain the advantages, show possible applications, and innovative head-up displays that go far beyond their use in cars.

Difference between Virtual Reality (VR) and Augmented Reality (AR)

Head-up displays – or HUDs for short – are not a completely new invention. Nevertheless, they are currently very popular and likely to become even more so in the near future – reason enough to summarize the most important facts on this topic and provide anyone interested in them with a little orientation.

Was ist ein Head-Up-Display?
A short definition

A head-up display is meant literally and is an innovative system for displaying information.  The technology projects the information directly into the user’s field of vision and also takes into account key parameters such as the user’s viewing direction and head position. HUDs thus have numerous advantages over conventional display technologies such as traditional screens.

How does a head-up display work?

There are a number of differences between the way HUDs work, depending on the technology used. However, as a rule they consist of two components, namely an image-generating optical unit on the one hand and a projection surface, e.g. the windshield of the car, on the other.  The task of the image-generating unit is to produce the respective information and transmit it visually as an image, video, or 3D animation onto the relevant projection surface.

As the surface needs to be both transparent and reflective, due to the nature of the process, glasslike elements or foils are mainly used as materials. Users then see the information produced by the image-generating unit – or more precisely, the mirrored information – seemingly hovering in space within their field of vision.

Which sizes do head-up displays come in?

HUDs are meanwhile available in a broad variety of sizes. However, the displays are often only relatively small, usually no bigger than 5 to 10 inches. These are the models mostly used in motor vehicles or aircraft. Displays need to be relatively small for these applications so that users can see all the information at a glance.

In the meantime, however, significantly larger versions have been designed for other purposes. Here, currently in top position is what is probably the largest head-up display at over 80 inches in size, the so-called augmented reality head-up display known as “Deep Frame, which is used, for example, for museums, exhibitions, congresses, and trade shows.

Advantages of different head-up displays


virtual reality

Head-up display (HUD) for cars and aircraft

  • Mostly very small between 5 and 10 inches


  • 2D and 3D animations can be displayed via virtual information, mostly in full HD, but partly also in lower quality

  • Less detailed information. Virtual information is usually limited to speed, warnings, and traffic information.

  • The user sees additional information about the real environment (the street, the sky) displayed

  • The information can be seen WITHOUT AR or VR glasses

augmented reality