The Progress of Vehicle Displays
by Silviu Pala
It’s hard to believe how far the automotive display industry has come. I first became engaged in automotive display design in the mid-1990s at United Technologies Automotive. The company had an electroluminescent display and was considering expanding its instrument panel group. I started learning about ELD technology with Elliott Schlam, the lead UT consultant on ELD, who was very patient with my questions at the time. ELD was quite seductive for automotive applications because it had a native military robustness; in those days, it was the only solid-state display technology for vehicles.
The first automotive prototype that we tested in the lab at UTA looked great. It was very bright, with high-resolution pixels – much better than that of vacuum-fluorescent displays (VFDs), the lead automotive technology at the time, and it had much better contrast than LCDs, which had just started to enter the automotive market. In the midst of our euphoria, we took it outside to test its sunlight readability. This was one of the most embarrassing moments of my life. The outdoor contrast was so bad so we could not figure out if the display was powered on or not – it was. Although vehicle-display technology has come a long way since then, sunlight readability continues to be a major challenge, as you will read in the articles in this issue.
After our initial experiments with ELD, we learned that in a high-ambient-light environment, the top reflectivity of the glass is just one part of the contrast calculation. The reflectivity of the underlying structure behind the glass is critical as well. We were successful in our efforts in improving ELD, and, in 1998, it was named one of the top 15 automotive technologies of the year by SAE Automotive Engineering magazine. However, ELD’s lack of full-color capability and the progress of LCDs, with their better color and very small package for the same active area, eventually eliminated the ELD as well as the VFD from automotive applications.
The penetration of new reconfigurable displays into automotive applications by the end of the 1990s raised the need to specify optical performance in high-ambient-lighting conditions. How was it possible to measure this without using huge avionics sunlight spheres? While searching for answers, our team was asked by SAE to create a standard! With help from numerous individuals, including Ed Kelly from NIST, Adi Abileah from Planar, Mark Larry from Ford, Tom Creech from GM, Bob Donofrio from Display Consultants, Darrel Hopper and Fred Meyer from U.S. Air Force Laboratory at WPAFB, John Troxell and Drew Harbach from Delphi, Paul Weindorf from Visteon, Chris Slupek from Futaba, Douglas Sadrack from Sharp, Hector Lara and Michael Kline from Photo Research, Tim Moggridge from Instrument Systems, and others, we created the SAE Vehicular Display Group in 1999.
The resulting J1757 was the first standard metrology for high-ambient-luminance performance with requirements defined by the ISO 15008. The most recent SAE J1757 revision was done in January 2015, with ISO 15008 revision pending.
Since 2000, I’ve been working for DENSO International America, where we struggle to determine where society is headed in the next 10 years with regard to what automotive technologies we will need when we get there. The articles in this issue reflect those concerns. I’ve written a vehicle-displays overview, “Technologies and Trends for Vehicular Displays,” which takes a brief look back at the history and progress of automotive displays, then outlines the key issues and some of the key players for the future: readability, head-up displays, augmented reality, non-standard shapes (Sharp), “dead-front” displays with basically no luminance for black (Futaba), and small packages with high optical performance that use integrated touch (Kyocera).
Two additional authors contributed sidebar articles to my piece. Shannon O’Day, Core Ergonomics Research Engineer at Ford Motor Co., summarizes the key points for display legibility in her sidebar article titled “Legibility and Aging Eyes.” And Zahir Y. Alpaslan and Erhan Ercan of Ostendo Technologies describe a new technology that could hasten the progress of head-up displays in their sidebar article “QPI Benefits for HUD Designs.”
Many key trends for vehicles today are related to the autonomous drive capabilities that are predicted for tomorrow. HUDs and AR will be very important in the “robot/ driver” paradigm of the future. This is why I solicited two articles on HUD, “Emissive Projection Technology Enables a Full Windshield Head-Up Display” by Ted Sun of Sun Innovations, and “Next-Generation Head-Up Displays” by Alan Rankin of Texas Instruments, which describes how HUDs will eventually function as primary displays rather than ancillary ones. Last “Automotive Applications for Passive-Matrix OLEDs” by Futaba’s Jeff Hatfield and team describes how PMOLED technologies offer some excellent advantages for automotive designers.
I hope you enjoy these articles and they give you an idea not only of the challenges that automotive-display makers face, but of the kinds of display technology we’ll be enjoying in our vehicles very soon. •