IDTechEx Explores the Potential of Holographic Projections in Automotive HUDs

Automotive heads-up displays (HUDs) are currently being met with great enthusiasm and expectations. The increased usage of technology while driving and drivers having to deviate from the road to look at the dashboard and centre information displays (CID) in vehicles have resulted in more road accidents.

Drivers must deviate from the road to examine onboard diagnostics (OBDs), check the GPS, select music, etc. HUDs present these images directly in the driver’s line of sight, thus reducing the need for the driver to look away from the road.

This need helps increase road safety, making the automotive industry consider HUDs a viable option to reduce driver distraction.

The IDTechEx report, “Automotive Heads-up Displays 2024-2034: Technologies, Players, Opportunities”, provides a comprehensive coverage of this space, from the most renowned 2-dimensional technologies to the more futuristic 3-dimensional imaging techniques that are set to revolutionize the automotive sector.

The report also covers key trends, market analysis, opportunities, and granular 10-year forecasts for display volume (number of displays) and value (US$), segmenting the industry by display type, technology, and region.

TFT-LCD

The current dominant technology in this space is TFT-LCD, which provides good image quality, durability, and maturity. Most importantly, it is also very scalable and comparably inexpensive compared to alternatives in the market. However, it is two-dimensional and lacks depth when signalling objects on the road when used as a HUD.

More than just displaying OBDs and car information, it is envisioned HUDs will be able to signal potential hazards on the road and further assist drivers while driving. These are also known as augmented reality HUDs (AR-HUDs). Due to this increased immersiveness, it is essential to have a technology that provides depth to the images and extended field of view (FOV) while signalling critical areas of interest on the road.

Computer-Generated Holography

Two technologies, computer-generated holography (CGH) and light field displays (LFDs), can enable three-dimensional imaging and are being experimented with on HUDs.

Unlike two-dimensional or stereoscopic displays, these 3D technologies project virtual objects with accurate depth cues. LCDs, OLEDs, and micro-LEDs are all examples of 2D technologies that display images directly onto a flat surface. They sometimes create an illusion of 3D images, where a 2D image is shown to the left eye and a slightly different image is shown to the right.

This is known as a parallax effect. However, the extended use of these 2D techniques to display 3D images induces a vergence-accommodation conflict (VAC) effect. VAC is the disparity in distances between the virtual object and the eye.

For instance, a virtual object is displayed 3m from the eye, but the eye naturally focuses on a screen a few centimetres from the eye. This distance mismatch causes user discomfort and nausea, meaning users cannot use these stereoscopic displays for too long.

Therefore, several companies and research groups are evaluating 3D display technologies such as holography and LFDs.

Holography, in particular, appears to be gaining more attraction when applied to automotive HUDs, and there are some notable reasons for this increased interest.

The first was addressed earlier and related to its ability to project virtual images with accurate depth cues without losing resolution. The driver experience is significantly more comfortable when road obstacles are signalled by images that have depth.

Much like our everyday vision, we can seamlessly focus and defocus on virtual objects, which is not readily achievable using 2D technologies. The varying depth cues offer a more comfortable driving experience for the driver and can become more helpful with signalling road obstacles that naturally have varying depths.

Brightness

Secondly, brightness is fundamentally essential in HUDs. A display technology that works well under varied ambient conditions is vital, as crucial information must be visible in very bright or dark conditions. CGH uses a coherent light source, which is most often a laser. Lasers are naturally cheerful and perform consistently under various ambient light environments.

Companies specializing in holographic HUDs are focusing on two key areas to compete with the dominant TFT-LCD technology: lowering the cost of these devices and reducing their form factor. More prominent form factors and increased cost mean these devices are only suitable for larger, more expensive, premium vehicles. Cost and form factors must decrease to become more competitive and benefit from the enormous market potential.

Holographic Technology

While holographic technology is considered suitable for automotive HUDs, the comparatively poorer image quality when compared to LCDs and OLEDs, mainly due to an effect known as speckle, means that it requires further maturity to be adopted in other applications in the long term.

IDTechEx’s “Automotive Heads-up Displays 2024-2034: Technologies, Players, Opportunities” report analyses the leading technologies and HUD types being developed and expected to grow over the next decade.

The challenge in developing automotive HUDs is more than ensuring the technology works accordingly; it must comply with the regulations the sector demands. This report covers critical innovations in manufacturing and coating requirements to enhance the performance of HUDs.