Knobs and push buttons continue to evolve, providing innovative ways to provide simple control functions while giving stylists and engineers a broader palette of options. Touch-sensitive displays are moving to the fore as LCDs (liquid crystal displays) transform infotainment systems and capacitive switches also provide new capabilities.
The combination of touch screens and LCDs lets product developers do many things with little space, providing navigation buttons in one mode, then displaying radio buttons and data in another.
A touchpad added to the 2011 Audi A8’s MMI (MultiMedia Interface) lets drivers pick radio stations when it’s in the infotainment mode. In navigation, drivers can write addresses on the touch screen provided by Preh Inc. Visteon also employed touch input in a Genivi-based development platform that was unveiled at CES early this year.
In another CES announcement, Ford upgraded its MyFord Touch with an 8-in touch-screen LCD in the center stack. Touch input replaces knobs and switches, letting drivers slide their finger along the touch-sensitive bar to adjust settings such as volume or fan speed.
In more conventional inputs, moving buttons are disappearing as solid-state technologies evolve. One of the hottest technologies at present is the capacitive switch, which provides benefits for both technical and styling designers.
Capacitive switches can detect the presence of a human finger before they are touched, so engineers can make them light up only as the driver moves to activate them. The switches can also be laid out without any lines or barriers, simplifying assembly while giving developers a wide range of options.
“Once stylists see what they can do with seamless designs, they usually start doing more things,” said Scott Morrison, Principal Product Engineer at TRW Automotive. “One nice thing is that you can have a slider that lets you select any spot between minimum and maximum, which is something that’s hard to do with voice.”
Eliminating the gaps that come with older mechanical push buttons eliminates hard-to-clean areas and improves perceived quality. “Any time you can eliminate moving parts, there’s less opportunity for squeaks and rattles and more opportunities for the styling guys,” Morrison said.
Though there is a shift to capacitance switches, many component makers feel it will be quite some time before conventional switches are fully displaced, if that ever that occurs. Mechanical switches are inexpensive, reliable, and they work in all conditions. That’s not always a certainty with alternatives.
“Capacitive sensors won’t work if the user is wearing gloves,” said Eric Grange, Marketing Director for C&K Components. Capacitive sensors detect electrical charge, which can be blocked by gloves.