Keypads for electrical devices

#This invention relates to mobile communication systems and, more specifically, to keypads for mobile communication devices.

#In order for mobile telephones to be conveniently used, they are of a relatively small size. Accordingly, the keypads of such devices are also small. This is particularly the case since, not only are smaller mobile telephones being manufactured, but it is becoming desirable to have larger displays on such devices which means that there is less space available to provide a keypad.

#For such small keypads, an important factor is the ease with which they may be used by a user. A keypad should enable a user to select keys rapidly, in a way that is natural, intuitive and without involving unnecessary finger movement.

#FIG. 1 shows a prior art keypad.

#FIG. 2 shows a mobile terminal according to an embodiment of the invention.

#FIG. 3 is a cross sectional detail view of the keypad of FIG. 2.

#Referring now to FIG. 2 a mobile terminal 50 includes a body 52, a display 54, a keypad 56, an on/off button 58, an earphone 60, and a microphone 62. The display 54 has a non-unity aspect ratio. The keypad 56 can be moved relative to the body 52 by a motor drive or manually, as discussed in detail below. Additionally, the keypad 56 is removable. It may be “rotated” by being removed from the electrical device and then being replaced in an alternative configuration. In this way, both the orientation of the keys and the orientation of the display may both be changed so that they maintain a correspondence.

#The keypad 56 includes a keymat that includes a plurality of keys located above a pressure sensitive part. The pressure sensitive part has a plurality of pressure sensitive areas that detect key-presses and produce corresponding electrical signals. An individual key includes a part of the keymat and its corresponding pressure sensitive area on the pressure sensitive part.

#Individual keys are dedicated to the operation of the mobile terminal 50 and include keys to initiate and terminate calls, 64 and 66, respectively, an asterisk key 68, and a pound or hash key 70. The keypad 56 includes a set of numerical keys disposed in a circular arrangement around a centrally located navigation key 72. The navigation key 72 may be used, among other things, to control movement of a cursor in the display or to move a selection highlighter through menus in the display. The term “navigation key” refers to any suitable manually operable input receiving means and includes such things as joysticks, rollers, and the like.