Vehicle Displays in the Passing Lane
by Karlheinz Blankenbach
When I was a young electronics engineer starting out in the 1990s, the only graphics display technology suitable for ground vehicles was the CRT. Our task was to develop a monochrome monitor with analog gamma correction (digital was not feasible) and a microcontroller with a serial interface to the host system. Today, color-graphics displays with millions of pixels can take up major parts of the dashboard, as is the case for the 17-in. dashboard display in the Tesla Model S. A similar story has taken place in terms of computing power – low-MHz single core to GHz multicore processors with a graphics processing unit (GPU) as the major component and display interfaces with speed increases from kbit/sec for 8 segments to Gbit/sec for full HD.
Today, the emphasis on displays has changed as well as their technology. Vehicle displays have grown to more than 100 million units in 2015. The driving experience and entire “look and feel” of today’s car are based significantly on display systems, and displays will become even more of an emphasis in the future as vehicles are equipped with new types of curved, free-form, flexible, and seamlessly integrated displays.
At the same time, environmental requirements such as temperature-range operability and quality (e.g., lifetime) continue to present challenges. Display makers must create state-of-the-art products that enable readability both at night and on sunny days. LCDs must have fast response times even in low temperatures and a high tolerance for quasi-static data displayed for long periods of time without burn-in. For example, displays in electric cars that need to show state of charge (SoC) when the vehicle is not in use are challenged because their operating times may grow from fewer than 10,000 hours to more than 30,000 hours.
Compounding the challenges is that display systems are not made by single companies; the entire value chain must be taken into account, from materials and component manufacturers (Tier 3, 4) to display manufacturers (Tier 2), automotive system integrators (Tier 1), and, last but not least, the vehicle manufacturer (OEM). It is also important to note that innovations in automotive displays begin in luxury cars and migrate years later to intermediate vehicles. Both are challenging – introducing the latest technology and then making it feasible at a moderate price.
In terms of those innovations, there are several categories of visual displays: driver information display (instrument cluster), head-up display (HUD), infotainment display (center stack), and rear-seat entertainment. Due to advanced driver-assistance systems (ADAs) and connected cars, more and more information will be available to the driver and passengers. This functionality will require larger and more numerous displays, as well as advanced HMI concepts such as haptic touch, gesture, and voice control in order to reduce driver distraction and workload for safety reasons. As automated operation changes the way we drive, it will be less essential to view display parameters such as speed and RPM on the instrument cluster, which will convert to more of an infotainment center. However. in the case of actual dangerous situations, augmented-reality (AR) HUDs with a large field of view should pinpoint their locations directly and not just show warnings.
We are pleased to have articles from two companies that are working in these areas in this issue of Information Display, which spotlights selected topics of vehicle displays. These include “Understanding the Requirements for Automotive Displays in Ambient Light Conditions” by Daimler and “Haptics Help Drivers Keep Their Eyes on the Road” from Continental. We also have a short overview of an award-winning paper from student researchers at Bosch about their efforts to develop a 3D head-up simulator that can be used in future vehicle display research. Enjoy reading these articles, and you can find out even more in the special automotive display sessions at SID’s Display Week 2016 in San Francisco. Vehicle displays will definitively keep setting the pace for innovation. •