Many portable devices, for example mobile telephones, are equipped with a display such as a glass or plastic display window for providing information to the user. Furthermore such display windows are now commonly used as touch sensitive inputs. The use of a touch sensitive input with the display has the advantage over a mechanical keypad in that the display may be configured to show a range of different inputs depending on the operating mode of the device. For example, in a first mode of operation the display may be enabled to enter a phone number by displaying a simple numeric keypad arrangement and in a second mode the display may be enabled for text input by displaying an alphanumeric display configuration such as a simulated Qwerty keyboard display arrangement.
The display such as glass or plastic is typically static in that although the touch screen can provide a global haptic feedback simulating a button press by use of a vibra it does not simulate features shown on the display. In other words any tactile feedback is not really localised as the whole display or device vibrates and the display is unable to provide a different sensation other than that of glass or plastic.