Fluorescent Windshield Improves Visibility

Rebecca C. Jernigan, rebecca.jernigan@laurin.com

WARREN, Mich. – Head-up automotive displays are often touted as a great safety feature because they minimize the driver’s need to glance down for information, which helps drivers to keep their eyes on the road. Although monitoring your speed or checking your radio station without looking away from the windshield is useful, the technology is capable of much more.

Scientists at the research and development laboratories of General Motors (GM) Corp. are working on a windshield system that uses lasers and sensors to enhance important visual elements for drivers. Their goal is to assist drivers in poor visibility conditions, including those caused by weather, darkness and aging eyes.

Important information is displayed directly on the vehicle’s windshield. Here, the edges of the road are highlighted in blue, while a deer is outlined in pink.

The display system, developed by SuperImaging Inc. of Fremont, Calif., combines a small laser projector with a specially coated windshield to highlight features of the road. The transparent phosphor that coats one side of the glass fluoresces when excited at specific wavelengths, enabling the designers to use ultraviolet diode lasers to produce narrowband red, green or blue emission and to create multicolor images. The system can use the entire windshield as a display surface, letting the technology mark external objects accurately and in real time.

GM has merged this technology with head-tracking and inward-looking infrared sources, which identify the exact position of the driver, enabling the system to adjust the projection angle. This makes the display distortion free no matter how you look at it.

Researchers at the company envision many applications for the system. By coupling it with CMOS cameras, radar, and short- and long-wavelength IR sensors, the display can perform multiple functions, including surface guidance, which entails brightly lining the edge of the road to make it easy to follow; marking/navigation by landmark, which locates and highlights a specified destination to eliminate the hunt for building numbers; and road sign highlighting. The display luminance is visible in daylight as well as in low-light conditions.

Researchers use a projection screen to simulate driving conditions and external surroundings to test the enhanced vision system. Images courtesy of General Motors Corp.

The biggest challenge in the implementation of the technology is the need for the projected image to accurately match the external data, enabling safe and frustration-free use of the system. To achieve this, GM plans to couple solid engineering with rigorous human systems integration and human factors testing.

The Michigan-based company estimates that the enhanced vision system could be available in consumer vehicles within a decade.