INFORMATION DISPLAY LAST INCLUDED A special automotive display theme in its July/August 2020 issue. At the time, I and others from SID's Metro Detroit Chapter were organizing our 27th Annual Vehicle Displays and Interfaces Symposium (vehicledisplay.org), which, under the circumstances, of the coronavirus pandemic was reimagined as an online event. In this issue and the March/April 2021 issue, we revisit the symposium with an exploration of some of its most compelling points by Kyle Davis, a senior data analyst at IHS Markit, and two exciting articles on head-up displays (HUDs) that were selected as best papers by the symposium session chairs. The first, “Investigating Human Perception Studies for Head-Up Display Ghosting,” by Steve Pankratz, William Diepholz, and John Vanderlofske of 3M, covers a topic that is growing in importance because of the increase in vehicles with large multi-color (or full color) HUDs. SAE International most recently addressed ghosting in its automotive HUD standard SAE J1757-2, published in November 2018.1 The second article will appear in the March/April 2021 issue. “Holographic Optical Elements and Projector Design Considerations for Automotive Windshield Displays” by Sam Martin and Jason Thompson of Texas Instruments and Ian Redmond of Ceres Holographics offers a market overview of HOE automotive applications and performance and projector design considerations when illuminating holographic films. The specially designed films are inserted or attached to the windshield or combiner to allow information to be displayed. As long as vehicles are not fully automated (Level 5 of the six levels of driving automation SAE outlines in its J3016 standard), critical information needs to be legible and easy to comprehend so that the driver's attention remains fixed on the road. The windshield HUD (wHUD) or combiner HUD (cHUD), paired with advanced driver-assistance systems (ADAS), is a darling of the automotive safety world because it allows for quicker reaction times to visual information (see “Turning Automotive Windows into the Ultimate HMIs” in the July/August 2020 issue). However, that advantage comes with significant engineering disadvantages, including ghost images in the windshield, high ambient lighting and temperatures because of sun exposure, and the high cost of an HUD option. Nonetheless, because of the increase in the HUD's displayed image and, therefore, the increase in the field of view (FOV) from the evaluation points and multiple viewpoints as described in SAE J 1757-2 (see Fig. 1), ghosting and its challenges are the most important problems to solve. An overview of a computer-aided design with traditional eye boxes. Courtesy of the author The evaluation point for display performance cannot solely be the traditional centroid of the cyclopean eye ellipse. For wHUDs and some cHUDs, ghosting depends on view location and must be eliminated or rendered non-visible by the driver. (This can be even more complicated for taller or shorter drivers if the FOV variations set by automotive original equipment manufacturers [AOEMs] is not optimized for their viewing). Despite huge investments and technological improvements, Level 4 (in which an automated driving system [ADS] can do all the driving in certain circumstances) and Level 5 vehicles are still a long way off from production. Level 3 automation—conditional automation in which the driver must be ready to take over from autonomous mode at some points—is entering production,2 although many experts have safety concerns about it: Because it allows drivers to disengage, they may be slow to react if they need to resume control. For driver-in-control vehicles (SAE Levels 1 and 2 and sometimes Level 3), not only ghosting but also high ambient illumination is a significant engineering issue for any display operating outdoors. Military labs have developed standards and specifications for evaluation using costly integrated spheres and devices that are not affordable for consumers. The articles outlined here should lend some clarity to these important topics. Silviu Pala has been chairman of SID's Metro Detroit Chapter since 1998 and of the SAE Vehicle Flat Panel Display (VFPD) group since 1999. He is the co-general program chair of SID's Annual Symposium on Vehicle Displays and Interfaces. A former director of technology planning at DENSO International America, Pala holds 30 patents. He can be reached at.
Read full abstract