In consumer electronics devices such as smartphones, tablets and laptop computers, this problem is solved by a combination of a graphical user interface and a user input device, which enables rapid navigation through highly complex and multi-layered software menu structures which present numerous choices to the user.
The appropriate user input technology is different for different device types: in the desktop PC, the mouse continues to be the most common user input device more than 30 years since its introduction in mainstream personal computing. In laptop computers, the touchpad has come to dominate. In the recent past, the favoured user input device in small form-factor computers such as smartphones and tablets has become the finger.
Indeed, the touchscreen offers a remarkable set of advantages, since it is intuitive and responsive, occupies almost no space, and eliminates the need for a second, peripheral device such as a mouse. In the automotive use case, however, the touchscreen has a serious drawback: it requires focussed attention on the screen to place the finger in the correct place. In a car, this necessarily draws the driver’s attention away from the road.
True, display and touchscreen system manufacturers, including Synaptics, have developed touchscreen designs adapted to the car, providing large icons in an uncluttered user interface design to make it easier for the driver to operate at arm’s length (see Figure 1). But the best solution from the point of view of car manufacturers, which are governed by extremely tough safety regulations, is one that that can be operated without requiring the driver to take his or her eyes off the road or hands off the steering wheel.
This has led automotive suppliers to experiment with methods for implementing thumb-operated touchpads mounted on the front spokes of the steering wheel. The driver may operate