Vantablack and OPTIS ANSYS

Vantablack® | Enhanced safety and quality in HUDs 

The ANSYS SPEOS optical simulation confirms the impact Vantablack S-VIS has on solving stray light issues in HUDs without the need for hardware redesigns.

Vantablack is an ultra black coating originally developed by Surrey NanoSystems for use in satellite-borne instruments. It achieved space heritage in 2015, eliminating the Sun’s glare in satellite positioning systems. Vantablack now incorporates a range of ultra-black coatings that are distinguished by exhibiting the lowest known reflectance in any of their target applications. This generally results in one of the Vantablack coatings being the material of choice in resolving critical stray light problems in challenging environments

According to Dr. David Wong, CEO of Surrey NanoSystems, “The ability to withstand space launch and extremes of temperature whilst maintaining virtually perfect absorption makes the Vantablack range an obvious choice for a host of automotive applications. Vantablack doesn’t contribute to fogging, is well-suited to complex geometries, readily scalable and entirely compatible with the materials widely used in the automotive sector”.

Stray light as perceived by the driver for a critical sun position

Stray light as perceived by the driver for a critical sun position - © ANSYS OPTIS

Of all of the applications in the automotive sector, head-up display (HUD) systems present a number of particular challenges. The virtual HUD image is projected at an apparent distance that prevents the driver from having to refocus; consequently, the virtual image is always in the driver’s field-of-view. To deliver the obvious safety and functional benefits this potentially offers to the driver and other road-users, the projected image must remain clearly legible under all conditions, and the Perceived Quality (PQ) of the image must be sufficiently high to prevent any unwanted distractions or eyestrain. 

Maintaining legibility and PQ is key to HUD performance and the projected growth of the technology1 as a critical enabler in the transition to Advanced Driver Assistance Systems (ADAS). Achieving the required projection distance of the virtual image requires a relatively large package mounted in the dashboard in front of the driver. This is expensive real-estate, and OEMs are understandably very keen to ensure that it is used efficiently. The downside of such a large package (quite apart from the volume it occupies) is that it provides multiple paths for unwanted light to enter the projection optics. This stray light is then scattered, causing undesirable artefacts that can seriously impair the actual functionality and PQ of the HUD’s virtual image. 

For these reasons, HUDs typically incorporate glare shields and light traps intended to reject stray light. Assessing stray light issues (and any number of proposed solutions) before committing to physical hardware is complex, and requires the use of advanced modeling tools. Fortunately,  these tools are available from ANSYS and allow problems to be rapidly identified.  However, even if a problem is identified, an immediate solution might not be obvious. 

Sébastien Abram, Product Owner HUD at ANSYS, explains: “Using ANSYS SPEOS® simulation, you will detect the issue on the virtual mock-up, but then it’s difficult to solve without reconsidering the complete design and layout of the system”. This is further complicated where small tweaks are made to internal components such as rotatable mirrors to match a given design to a particular windshield in a car. Unfortunately, small changes in the HUD’s internal geometry can have a disproportionate impact on stray light. According to Sébastien Abram, "after applying the Vantablack S-VIS to the housing of the HUD, even under the worst possible incident-light conditions, no more reflections were visible. It’s very close to the perfect conditions. Applying Vantablack appears to be a “miraculous” solution: it’s easy, quick and requires no change to the design or layout

HUD housing comparison using classic black plastic (top) and Surrey NanoSystems’ Vantablack ultrablack coating (bottom) © ANSYS OPTIS

Scanning electron microscopy micrograph of the Vantablack

Scanning electron microscopy micrograph of the Vantablack © Surrey Nanosystems

Vantablack S-VIS is an extremely low-density coating, with an open, coral-like structure that provides many millions of microscopic optical cavities to absorb light. Unlike other coatings, Vantablack maintains its ultra-low reflectance even at glancing angles, which is critical to eliminating stray light artefacts in HUDs and other optical systems. 

David Wong commented, “the use of the ANSYS SPEOS optical simulation clearly demonstrates the essential supporting role Vantablack can play in enabling the industry’s transition to ADAS”.

Vantablack material

You can experience the Vantablack effect on your own stray light or other sun reflection issues by downloading its material characteristics directly from the ANSYS OPTIS Library.

 

Vantablack® by Surrey NanoSystems.
Unparalleled performance solving stray light problems.
www.surreynanosystems.com/vantablack

1 The head-up display market was valued at USD 1.02 Billion in 2017 and is expected to reach USD 4.71 Billion by 2023, at a CAGR of 29.91% during the forecast period. The base year considered for the study is 2017, and the forecast period is 2018–2023. https://www.marketsandmarkets.com/Market-Reports/head-up-display-hud-market-684.html

Banner image credits: © Surrey Nanosystems 2017

 

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