International automotive supplier Continental is working on intelligent infrared technology for future control designs in affordable cars. Used in ever-more electronic entertainment devices, multi-touch controls will also be enhancing modern display and control systems in the especially price-sensitive car segment. With ‘infrared curtains’, Continental developers are opting for an economical alternative to touch-sensitive or so-called capacitive displays.
"Back in 2011, we showed that an infrared curtain can turn any surface in the car interior into a user interface," says Fook Wai Lee, display developer at Continental in Singapore. "We have now developed this technology to the point where it also recognizes typical multi-touch gestures as input, like swiping, zooming, and pinching.”
The technology even extends the recognition possibilities: capacitive touch screens, as known from modern smartphones, cannot be used with standard gloves. Especially designed types of gloves are necessary for the usage of standard touch screens with gloves. “With our infrared technology, there is no need for special gloves – our infrared curtain is able to detect touch gestures of gloved fingers," adds Fook Wai Lee.
The technology behind the curtain
Continental's infrared curtain is built from an array of infrared light sources on the sides of the display. While a single row of LEDs was sufficient for one-finger operation, multi-touch gestures require two rows of infrared lights connected together. If a multi-touch gesture is performed in front of the display, the electronics of the human machine interface (HMI) recognize the finger's positions from the blocked light. In addition to having a cheaper production format compared to capacitive displays that recognize gestures electronically, infrared curtains can also be operated with gloves on. "The challenge is in the integration: our goal is an infrared light source that is sticking out only minimally over the display surface yet still recognizes all desired multi-touch gestures," explains Fook Wai Lee.
With this technology, the HMI electronics recognise motions like swiping, zooming and pinching. This makes it easy to move around selection menus or change the chosen section on a map. The technology is ready for series production in 2017.