Automotive head-up display
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An automotive head-up display (automotive HUD) is a head-up display built into a road vehicle that shows driving information as a virtual image in the driver's forward view, so that the driver can read it without looking down at the instrument cluster. Windshield HUDs project the image off the windshield itself, while combiner HUDs use a separate transparent panel mounted on the dashboard.[1] According to its General Motors designers, the first production HUD was introduced in the United States in 1988 on the Oldsmobile Cutlass Supreme Indianapolis 500 pace car parade convertibles.[2]
Conventional car HUDs repeat instrument data such as speed in a small image floating just above the hood. The newer augmented reality head-up display (AR-HUD) has a wider field of view and a more distant image, and it draws graphics such as navigation arrows and markers for the vehicle ahead so that they line up with the road.[1][3] Mercedes-Benz announced an AR-HUD for the S-Class in July 2020 and Volkswagen introduced one in the ID.3 and ID.4 later that year.[4][5] AR-HUDs are a form of optical see-through augmented reality in which the windshield acts as the optical combiner.[6] In Volkswagen's system, the car's own camera, radar and map data are used to place the graphics in the scene.[5]
How it works
An automotive HUD has two main parts. A picture generation unit (PGU) creates the image, and an optical system projects it as a virtual image beyond the windshield. In their 2024 review in Micromachines, Chen Zhou and colleagues at Soochow University write that commercial HUDs mainly use four projection technologies for the PGU: transmissive TFT-LCD panels, digital light processing (DLP) with a digital micromirror device, liquid crystal on silicon (LCoS) and micro-LED. They note that DLP generally keeps better image contrast, because persistent backlighting makes it hard to raise the contrast ratio of LCD and LCoS panels.[1] The optics fold the light path, magnify the image, form the eye box and compensate for the aberration introduced by the windshield.[1]
Volkswagen's description of its own AR-HUD gives a concrete example of the light path. The picture generation unit sits deep inside the dash panel, and an especially bright LCD generates the image. Special lenses separate the near and far display levels, and two flat mirrors deflect the beams onto a large, electrically adjustable concave mirror, which reflects them onto the windscreen.[5] The Mercedes-Benz S-Class AR-HUD instead uses a Texas Instruments digital micromirror device with 1.3 million individual mirrors; Mercedes said it was the first time it had used the technology to generate HUD images.[4]
Eye box, brightness and ghosting
Because the image is formed by optics fixed in the dashboard, the driver's eyes have to stay inside the eye box to see it. A 2018 Texas Instruments white paper explains that the eye box is the exit pupil of the HUD optics. It has to hold both eyes and allow for differences in eye spacing, head position and driver height, so it is often as large as 140 mm x 60 mm and in many cases has to be adjusted mechanically to the driver. The paper names this as one of the main reasons HUD optics are large.[3] Zhou and colleagues write that, because the distance between the eyes is about 65 mm, eye boxes are commonly set larger than 90 x 60 mm.[1]
The windshield reflects only about 25 percent of the projected light, according to the same review, so the PGU must be bright. Raising its output brings heat and power consumption problems.[1] The two surfaces of the windshield also each reflect the image, which can produce a double "ghost" image. One fix is a wedge-shaped polyvinyl butyral (PVB) interlayer in the laminated glass, thicker at the top than at the bottom, so that the two reflections overlap; another is a partly transparent Fresnel reflector used as the combiner.[1]
Registration of AR graphics
An AR-HUD has to know where the road, lanes and other vehicles are in order to place graphics on them. In the Volkswagen ID. models an "AR Creator" running on one of the car's central computers calculates symbol positions from the raw data of the front camera, the radar sensor and the navigation map. Volkswagen says the graphics in the large far-range window are stabilised against the vehicle's movements and adapted to the geometry of the projection optics.[5] According to TechCrunch in 2018, the system of the Swiss company WayRay combined simultaneous localization and mapping with location and mapping information and vision data from a front-facing camera.[7]
Types
Zhou and colleagues divide automotive HUDs into three generations. A combiner HUD (C-HUD) projects onto a small separate panel above the dashboard; because its image sits inside the car, at about 1 m, the driver still has to refocus away from the road. A windshield HUD (W-HUD) uses the windshield itself as the combiner, which allows a larger field of view and a longer virtual image distance (VID). An AR-HUD enlarges both again so that navigation, warning and other information can be merged with the real road.[1] The review gives these typical values:[1]
| Type | Field of view | Virtual image distance | Volume |
|---|---|---|---|
| C-HUD | under 5 x 1.4 degrees | about 1 m | under 2 L |
| W-HUD | 6 x 2 degrees | under 4.5 m | under 4 L |
| AR-HUD | over 13 x 5 degrees | over 7 m | under 10 L |
| Ideal target | over 20 x 10 degrees | over 20 m | under 3 L |
Texas Instruments described the starting point in similar terms in 2018. Many HUDs then on the market had a field of view of about 5 degrees and an image about 2.5 m in front of the driver, just over the hood, and mainly duplicated cluster instruments such as speed and rpm. Carmakers wanted an image spanning the width of the road (more than 15 degrees) and placed on the road up to 20 m ahead, so that information from driver-assistance systems could be shown where the driver is already looking.[3] Zhou and colleagues point out that a road about 3.5 m wide calls for a horizontal field of view of at least 20 degrees, while a typical AR-HUD offers 10 degrees.[1]
Holographic and waveguide HUDs
Because conventional HUD optics grow with the field of view and eye box, researchers and suppliers have looked for thinner optics. The Texas Instruments white paper describes two approaches. Waveguides carry light by total internal reflection and expand the pupil without adding volume, removing the large curved mirrors; holographic films placed on or in the windshield, or on a separate combiner, can combine the functions of several traditional lens elements in one recording. Both work best with narrow-band laser light, and layered holographic films can produce full color and more than one image plane.[3] Zhou and colleagues list research prototypes using geometric waveguides with a 24 x 15 degree field of view, and a holographic waveguide using volume holographic gratings with a 24 x 12.6 degree field of view, both with virtual images beyond 10 m.[1] They also note open problems for computer-generated holographic HUDs: speckle noise, a small space-bandwidth product, removal of zeroth-order light and computing holograms at video rate.[1]
A 2022 review in Advanced Materials by Jana Skirnewskaja and Timothy Wilkinson of the University of Cambridge covers holographic HUDs in detail, including full 3D augmented reality with depth perception for information projected onto the road, and the use of personalized machine learning in such displays.[8]
History
Early production HUDs
According to an SAE paper by its General Motors designers, the first production HUD was introduced in the United States on the 1988 Oldsmobile Cutlass Supreme Indianapolis 500 Pace Car parade convertibles. It used a vacuum fluorescent display tube and reflective optics, with the standard windshield as the final optical element, and produced a virtual image of a digital speedometer and selected warning lights just above the hood line, at about the distance of the front bumper.[2] PistonHeads reports that the system was unveiled in May 1988 and that 50 cars were offered to selected customers. Nissan had finished its first HUD in December 1987 but did not offer it on the Maxima and 240SX until late 1988; Toyota followed with the Crown Majesta in 1991, BMW in 2003, Audi in 2010 and Mercedes-Benz in 2014.[9]
Laser holographic HUDs
In September 2014 a HUD based on laser holographic projection became an available option on Jaguar Land Rover vehicles. According to the University of Cambridge, the technology originated with Professor Bill Crossland in 2001, was licensed to and developed by Alps Electric and then by Two Trees Photonics of Milton Keynes; products were designed by Two Trees Photonics and Alps and manufactured by Alps; the university called it the first car HUD to use laser holographic techniques.[10] Envisics, founded by Jamieson Christmas, traces its technology to his PhD research at Cambridge. When Envisics agreed a joint development deal with Panasonic Automotive in January 2021, TechCrunch reported that the first generation of the technology was already in more than 150,000 Jaguar Land Rover vehicles.[11]
AR-HUDs in production
The table lists AR-HUD launches described in manufacturers' own announcements.
| Year | Vehicle | Details |
|---|---|---|
| 2020 | Mercedes-Benz S-Class | 10 x 5 degree field of view; image at about 10 m, equal to a 77-inch monitor; animated turn arrows ("fishbones") and Active Distance Assist information[4] |
| 2020 | Volkswagen ID.3 and ID.4 | Far-range window at about 10 m with a diagonal of around 1.8 m; close-range band at about 3 m for speed, road signs and static symbols[5] |
| 2021 | Hyundai IONIQ 5 | Hyundai's first AR-HUD, showing navigation, safety alerts and surroundings[12] |
| 2025 | Cadillac VISTIQ and LYRIQ-V | Envisics "GEN-2" holographic AR-HUD; production at GM's Spring Hill plant began in 2025[13] |
| 2025 | BMW iX3 (Neue Klasse) | Optional 3D Head-Up Display shows navigation and automated driving graphics "on the road with spatial depth"[14] |
In the S-Class, when the car approaches a turn, the navigation arrows appear to float above the road where the driver should turn, and drivers see animated red lines if the car starts to drift out of its lane.[15] In Volkswagen's system, the vehicle ahead is marked with a colored stripe when adaptive cruise control or Travel Assist is active; with the assist systems switched off, a red warning appears if the driver follows dangerously close. If the car moves toward a lane boundary without indicating, the Lane Assist display shows that line in orange.[5] Volkswagen described itself as the first volume manufacturer to introduce the technology in the compact segment.[5]
BMW took a different route in its Neue Klasse cars. BMW Panoramic Vision, which BMW calls a head-up display, projects information onto a dark-coated band at the lower edge of the windscreen, across its entire width, and is visible to all occupants. BMW announced it in March 2023 for series production in 2025.[16] The iX3 has Panoramic Vision alongside the optional 3D HUD.[14]
Startups
Several startups worked on holographic AR-HUDs. WayRay showed its aftermarket Navion unit at CES 2018 with a red and green overlay and an 8-degree field of view; TechCrunch reported 11 degrees for the built-in version WayRay was offering to carmakers.[7] In September 2023 Netzwoche reported that WayRay had run out of money and was finished; citing the company's CEO, it attributed the collapse to the international sanctions that followed Russia's invasion of Ukraine, given the founder's and some shareholders' Russian ties.[17] Envisics, headquartered in Milton Keynes, supplied the AR-HUD for the Cadillac VISTIQ and LYRIQ-V.[13] It entered administration in the United Kingdom on 22 April 2026, with Geoff Rowley and Simon Carvill-Biggs of FRP Advisory appointed as joint administrators.[18][19] Its accounts for 2024 showed revenue of about 1.9 million pounds and an EBITDA loss of 25.6 million pounds, according to Business Sale Report.[19]
Relationship to augmented reality
In a 2014 paper in Proceedings of the IEEE, Joseph Gabbard, Gregory Fitch and Hyungil Kim of Virginia Tech set out a research space for automotive AR. It separates head-mounted, head-up and center-mounted displays; video see-through from optical see-through displays; and world-fixed from screen-fixed graphics. The authors argued that optical see-through AR on the windshield had not yet been fully used, and that its visual perception and attention problems were not yet fully understood.[6] WayRay described its own products as "non-wearable augmented reality solutions for transportation and beyond".[20]
The optical problems are similar to those of AR headsets: eye box size, field of view, brightness against daylight and the distance at which virtual content appears. Zhou and colleagues write that an AR-HUD with only one image plane has to push the virtual image to around 10 m for it to fuse well with the road scene, while multi-plane or 3D image planes can show information at different depths. Research systems use two optical paths for a near field at 2 m and a far field at 8 to 24 m, liquid lenses or spatial light modulators to vary the image distance, and eye-tracked autostereoscopic 3D-HUDs. Whether the vergence-accommodation conflict in such 3D HUDs causes discomfort for drivers at high speed was, according to the review, still under investigation.[1]
Human factors research
In a 1994 review in Accident Analysis and Prevention, Nicholas Ward and Andrew Parkes of Loughborough University of Technology surveyed the HUD literature, which came mainly from aviation. They listed the main human factors issues for car HUDs as interference from background scene complexity, system novelty, the user's perceptual style, cognitive disruption and perceptual tunnelling, and recommended that HUDs be introduced into vehicles carefully.[21]
Later studies focused on AR graphics. Researchers at Honda Research Institute USA built "Personal Navi", a navigation aid for a see-through 3D volumetric HUD. Participants recognized turn locations earlier than with conventional navigation aids alone and kept their eyes on the road more. A second study found that depth perception was worse with a fixed focal plane, and the authors argued that AR navigation HUDs should use a dynamically adjustable focal plane for proper registration.[22]
Hyungil Kim and Joseph Gabbard argued that standard in-vehicle display tests, which measure eyes-off-road time, cannot capture the main risk of AR-HUDs: graphics that pull attention away from road elements that are not augmented. Their simulator study with 24 drivers, published in Human Factors (online in 2019), compared two AR pedestrian collision warnings. Only one improved awareness of pedestrians without distracting drivers from other important parts of the scene, which the authors took to show that AR interfaces can be informative or distracting depending on the form of the graphics.[23]
A 2025 review in the International Journal of Human-Computer Interaction by Mark Winkler and Morteza Soleimani reached a similar conclusion: AR-HUDs can improve safety and user experience when applied well but may increase distraction and cognitive load if misused. The benefits it reported included easier navigation, less inattentional blindness and better detection of obstacles such as pedestrians. It also noted that most studies treat the AR-HUD as an addition to the main driver display rather than as the primary display.[24] A systematic review of 74 empirical studies on AR and VR for road safety, published in the journal Virtual Reality in 2026, reported that AR head-up displays can cut reaction times by up to 20 percent and suggested an optimal transparency threshold of 0.75 for AR-HUD graphics.[25]
Use of virtual reality in development
Researchers also simulate AR-HUDs, which a 2016 paper describes as a convenient way to design them and evaluate their benefit to the driver. In that study, researchers from Renault, Oktal and Valeo working at IRT SystemX in France built a virtual HUD in a stereoscopic driving simulator and tested it with 24 participants. The simulated display reproduced the perceived distance between real objects and their augmentation, and of three overlays for highlighting the car ahead, a trapezoid shape was judged more congruent than a U shape.[26] In 2019 Andreas Riegler, Andreas Riener and Clemens Holzmann presented AutoWSD, a low-cost driving simulator that uses virtual reality for user studies of windshield displays in automated cars, as an alternative to 2D monitor setups and expensive motion-platform simulators.[27]
See also
References
- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 Chen Zhou, Wen Qiao, Jianyu Hua, Linsen Chen (2024-03-26). "Automotive Augmented Reality Head-Up Displays". Micromachines, vol. 15, no. 4, article 442. MDPI. doi:10.3390/mi15040442. https://doi.org/10.3390/mi15040442. Retrieved 2026-10-06.
- ↑ 2.0 2.1 M. Weihrauch, G. G. Meloeny, T. C. Goesch (1989-02-01). "The First Head Up Display Introduced by General Motors". SAE Technical Paper 890288. SAE International. doi:10.4271/890288. https://doi.org/10.4271/890288. Retrieved 2026-10-06.
- ↑ 3.0 3.1 3.2 3.3 Michael Firth, Alison Norris, DJ Segler, Jason Thompson (2018-09). "DLP Technology: Next generation augmented reality head-up display (White Paper DLPA098)". Texas Instruments. https://www.ti.com/lit/pdf/dlpa098. Retrieved 2026-10-06.
- ↑ 4.0 4.1 4.2 "Meet the S-Class DIGITAL: "My MBUX" (Mercedes-Benz User Experience)". Mercedes-Benz USA Newsroom. Mercedes-Benz USA. 2020-07-08. http://web.archive.org/web/20250325150545/https://media.mbusa.com/releases/release-9e110a76b364c518148b9c1ade19bc23-meet-the-s-class-digital-my-mbux-mercedes-benz-user-experience. Retrieved 2026-10-06.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 "From the luxury class to the compact segment: the augmented reality head-up display". Volkswagen Newsroom. Volkswagen AG. 2020-12-17. https://www.volkswagen-newsroom.com/en/press-releases/from-the-luxury-class-to-the-compact-segment-the-augmented-reality-head-up-display-6730. Retrieved 2026-10-06.
- ↑ 6.0 6.1 Joseph L. Gabbard, Gregory M. Fitch, Hyungil Kim (2014-02). "Behind the Glass: Driver Challenges and Opportunities for AR Automotive Applications". Proceedings of the IEEE, vol. 102, no. 2. IEEE. pp. 124-136. doi:10.1109/JPROC.2013.2294642. https://doi.org/10.1109/JPROC.2013.2294642. Retrieved 2026-10-06.
- ↑ 7.0 7.1 Darrell Etherington (2018-01-09). "WayRay's AR in-car HUD convinced me HUDs can be better". TechCrunch. https://techcrunch.com/2018/01/09/wayrays-ar-in-car-hud-convinced-me-huds-can-be-better/. Retrieved 2026-10-06.
- ↑ Jana Skirnewskaja, Timothy D. Wilkinson (2022). "Automotive Holographic Head-Up Displays". Advanced Materials, vol. 34, no. 19, article e2110463. Wiley. doi:10.1002/adma.202110463. https://doi.org/10.1002/adma.202110463. Retrieved 2026-10-06.
- ↑ Lewis Kingston (2017-12-11). "PH Origins: Head-up displays". PistonHeads. https://www.pistonheads.com/news/ph-features/ph-origins-head-up-displays/37241. Retrieved 2026-10-06.
- ↑ "Heads up: Cambridge holographic technology adopted by Jaguar Land Rover". University of Cambridge. 2015-11-26. https://www.cam.ac.uk/research/features/heads-up-cambridge-holographic-technology-adopted-by-jaguar-land-rover. Retrieved 2026-10-06.
- ↑ Kirsten Korosec (2021-01-08). "Holographic startup Envisics partners with Panasonic to fast-track in-car AR tech". TechCrunch. https://techcrunch.com/2021/01/08/holographic-startup-envisics-partners-with-panasonic-to-fast-track-in-car-ar-tech. Retrieved 2026-10-06.
- ↑ "Hyundai IONIQ 5 Redefines Electric Mobility Lifestyle". Hyundai Newsroom. Hyundai Motor Company. 2021-02-23. https://www.hyundai.com/worldwide/en/newsroom/detail/hyundai-ioniq-5-redefines-electric-mobility-lifestyle-0000000551. Retrieved 2026-10-06.
- ↑ 13.0 13.1 "Envisics powering augmented reality on 2026 Cadillac VISTIQ". Envisics. 2025-06-25. https://envisics.com/wp-content/uploads/2025/06/Press-release-Envisics-Cadillac-VISTIQ-June-25-2025.pdf. Retrieved 2026-10-06.
- ↑ 14.0 14.1 "The start of a new era: the new BMW iX3". BMW Group PressClub. BMW Group. 2025-09-05. https://www.press.bmwgroup.com/global/article/detail/T0451998EN/the-start-of-a-new-era-the-new-bmw-ix3?language=en. Retrieved 2026-10-06.
- ↑ Brad Anderson (2020-07-29). "2021 Mercedes-Benz S-Class Has A Head-Up Display With Augmented Reality". Carscoops. https://www.carscoops.com/2020/07/2021-mercedes-benz-s-class-has-a-head-up-display-with-augmented-reality/. Retrieved 2026-10-06.
- ↑ "The BMW Panoramic Vision: new head-up display across the entire width of the windscreen will be in series production in 2025". BMW Group PressClub. BMW Group. 2023-03-15. https://www.press.bmwgroup.com/global/article/detail/T0410802EN/the-bmw-panoramic-vision:-new-head-up-display-across-the-entire-width-of-the-windscreen-will-be-in-series-production-in-2025. Retrieved 2026-10-06.
- ↑ Yannick Chavanne (2023-09-21). "Schweizer AR-Start-up Wayray ist am Ende". Netzwoche. https://www.netzwoche.ch/news/2023-09-21/schweizer-ar-start-up-wayray-ist-am-ende. Retrieved 2026-10-06.
- ↑ "Notice to creditors and interested parties: Envisics Ltd. (In Administration)". Envisics. https://envisics.com/. Retrieved 2026-10-06.
- ↑ 19.0 19.1 James Dawson (2026-05-12). "UK administrations update: May 5 - 11". Business Sale Report. https://www.business-sale.com/news/administration/uk-administrations-update-may-5-11-229184. Retrieved 2026-10-06.
- ↑ "WayRay". WayRay. https://wayray.com/. Retrieved 2026-10-06.
- ↑ Nicholas J. Ward, Andrew Parkes (1994-12). "Head-up displays and their automotive application: An overview of human factors issues affecting safety". Accident Analysis and Prevention, vol. 26, no. 6. Elsevier. pp. 703-717. doi:10.1016/0001-4575(94)90049-3. https://doi.org/10.1016/0001-4575(94)90049-3. Retrieved 2026-10-06.
- ↑ Karlin Bark, Cuong Tran, Kikuo Fujimura, Victor Ng-Thow-Hing (2014-09). "Personal Navi: Benefits of an Augmented Reality Navigational Aid Using a See-Thru 3D Volumetric HUD". Proceedings of the 6th International Conference on Automotive User Interfaces and Interactive Vehicular Applications (AutomotiveUI '14). ACM. pp. 1-8. doi:10.1145/2667317.2667329. https://doi.org/10.1145/2667317.2667329. Retrieved 2026-10-06.
- ↑ Hyungil Kim, Joseph L. Gabbard (2022-08). "Assessing Distraction Potential of Augmented Reality Head-Up Displays for Vehicle Drivers". Human Factors, vol. 64, no. 5. SAGE. pp. 852-865. doi:10.1177/0018720819844845. https://doi.org/10.1177/0018720819844845. Retrieved 2026-10-06.
- ↑ Mark Winkler, Morteza Soleimani (2025). "A Review of Augmented Reality Heads Up Display in Vehicles: Effectiveness, Application, and Safety". International Journal of Human-Computer Interaction, vol. 41, no. 18. Taylor and Francis. pp. 11405-11420. doi:10.1080/10447318.2024.2443252. https://doi.org/10.1080/10447318.2024.2443252. Retrieved 2026-10-06.
- ↑ Peiwen He, Paul Bremner, Colin A. Booth (2026-01-14). "Immersive technology for road safety: a systematic review of empirical studies". Virtual Reality, vol. 30, no. 1. Springer. doi:10.1007/s10055-025-01295-x. https://doi.org/10.1007/s10055-025-01295-x. Retrieved 2026-10-06.
- ↑ Sabine Langlois, Thomas Nguyen That, Pierre Mermillod (2016-09). "Virtual Head-up Displays for Augmented Reality in Cars". Proceedings of the European Conference on Cognitive Ergonomics (ECCE 2016). ACM. doi:10.1145/2970930.2970946. https://doi.org/10.1145/2970930.2970946. Retrieved 2026-10-06.
- ↑ Andreas Riegler, Andreas Riener, Clemens Holzmann (2019-09). "Virtual reality driving simulator for user studies on automated driving". AutomotiveUI '19: International Conference on Automotive User Interfaces and Interactive Vehicular Applications. ACM. pp. 502-507. doi:10.1145/3349263.3349595. https://doi.org/10.1145/3349263.3349595. Retrieved 2026-10-06.